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(upbeat music)

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- So I'm Sara Mana,

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a professor in the Geological
Sciences Department,

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and it is a great pleasure to
introduce my friend Cat Beck.

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Cat and I were PhD students
together at Rutgers University.

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She is originally from New Hampshire,

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got her bachelor at Tufts,

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and then went to Rutgers for
her master in science and PhD.

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She is currently an
associate professor and chair

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at Hamilton College and the recipient

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of a couple of big research grants,

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including a multimillion
dollar project studying

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the Miocene in Turkana from the
National Science Foundation.

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And today, she's going to talk to us

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about reconstructing past environments.

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In what conditions did our
ancestors survive and thrive,

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I guess I should have read

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the title before to be more prepared.

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This talk is sponsored

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by the Geological Sciences Department.

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Cat, thank you for being here.

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- Thank you so much.

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Thank you so much for
having me here today.

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It's a pleasure to be back

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in the Northeast and in New England.

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And so, oops, sorry,

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I'm just gonna go ahead
and share my screen.

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All right, so as Sara mentioned,

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I'm really fascinated by the ways

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in which the fields of paleoanthropology

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and geologic science has come together.

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And so, that work has taken
me all over the globe,

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but right now I'm really,

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I'm doing a lot of work in Eastern Africa

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where I'm looking at the interplay

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between the ways in
which climate, tectonics

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and volcanism all come together
to shape human ancestors.

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And so, I'm going to kind of highlight

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one particular case study.

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And, I wanted to kind
of start it things off

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with a bit of a challenge, right?

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Like, why is this work so important?

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Why am I doing what I'm doing?

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And particularly, you know,

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since this is the Darwin Festival,

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thinking back to Darwin as
one of these first people

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who kind of posited the hypothesis

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that maybe there's some connection

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between environmental change

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and the way we are as organisms,

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whether that's looking at other animals

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or also looking at ourselves.

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There we go.

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And, let me see if I can move this around.

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Does this move?

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Yeah, there we go. Okay.

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So, one of the big challenges

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that we face as a scientific community is

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the fact that oftentimes when

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we think about paleoclimate,

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when we think about past climate,

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the folks who are really
leading the charge

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in that field are focused
on the marine realm.

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They're focused on
records from the oceans.

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And so, on this map here,
you see in these red circles,

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you see these are some of
the key paleoclimate records

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that we use to contextualize and think

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about climate change in tropical latitudes

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around the continent of Africa.

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In the yellow diamonds,

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you see a lot of famous
paleoanthropological sites spanning

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a whole range of time,

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a whole host of different
evolutionary milestones

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that are recorded in a
sedimentary and a rock record.

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Now, it looks like, say
record, you know, 231

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and the site of Hadar,

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which is where the famous
fossil Lucy comes from,

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are quite close together.

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But, in reality, when we look at a map,

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and we actually measure those distances,

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they're quite far apart.

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And so then, the question
is, you know, is using

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all of this data,

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this really rich data

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from all around the continent
of Africa sufficient

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for understanding what's
happening on the continent

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in terms of climate?

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And, when you look at a map like this,

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it becomes pretty apparent

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that the continent is
extremely heterogeneous, right?

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There are areas that
are dry, extremely dry,

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like the Sahara up in the north,

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and then there's this transitional Sahel,

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and then we get into areas
that are extremely wet,

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like the tropical rainforest
right on the equator.

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And, I'm gonna be specifically speaking

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about this location in the box here,

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which is the Turkana Basin.

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And you're seeing modern Lake
Turkana highlighted here.

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But, when we think about
how much variability occurs

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in a transect from say,

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the Atlantic Ocean across
to a place like Turkana,

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we realize that no,

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this is not enough to
have simply ocean records

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and apply what we're seeing in the oceans

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to the environment in which
ancestors are evolving

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in the past.

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And so, with that kind of resolve in mind,

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a group of people came together and formed

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the Hominin Sites and
Paleolakes Drilling Project.

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And, this was an
international collaboration

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of geoscientists and paleoanthropologists,

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paleoclimatologists, ecologists

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who all kind of shared this
goal of trying to derive

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climate records from locations

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much closer to where
the fossils were found.

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Ideally, right, we'd have, you know,

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a beautiful complete skeleton of a hominid

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and then a beautiful, complete,

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multimillion year old record of climate

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right in the same place.

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Now, we're never gonna get that perfectly,

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but what this project
sought to do was take

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a series of different time slices

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or little windows in time and couple them

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with key archeological

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and paleoanthropological
sites to better understand

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the climate.

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So again, this is gonna
be the focus of my talk,

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this particular project.

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But then, I also wanna kind of give

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a little bit more context

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because this will be this one data point,

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specifically this West
Turkana Plio-Pleistocene site,

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which spans from about
two million years ago

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to about 1.5 million years.

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And, this is a really
important interval of time,

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because we see the
appearance of genus homo.

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So, things that that look like us,

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things that we are directly derived from.

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So, before I really get rolling,

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I just wanted to make
some acknowledgements.

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This is part of a huge team
that I actually became involved

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in as a graduate student.

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So, I had the chance to really grow

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in my scientific community due to

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many of the individuals here
and listed in this slide.

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So, to give you the roadmap,
here's where we're headed.

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I wanna start with the why, right?

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I've given you a little bit of a taste

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for why we need a terrestrial record,

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but I wanna talk about
Turkana specifically.

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And then, how?

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How did we get this
record? What did we do?

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What were the archives
that we were working with?

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That will lead us to the what.

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What did we find?

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And, ultimately my
favorite part, the so what,

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why does all this matter?

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Why did we sink all this time

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and energy into doing this science?

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How does it benefit us
as humans, as people,

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as people who wanna know about the origins

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of who we are and where we came from?

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All right, so here again,

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I wanna zoom into this Turkana Basin.

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You see the outline of
modern Lake Turkana here,

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and then it's expanded here.

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And, these areas in yellow are showing

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you some kind of key locations

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where fossils have been found.

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Those are the really
fossiliferous sediments

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in this location.

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And, this purple dot is showing you

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the site of our drill core.

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So in 2013, this is kind of where we went,

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and there are a couple of
reasons why we went here.

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As I mentioned, I mentioned
this hominid story,

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but the Turkana Basin is
a really unique location,

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because it records evolutions
on multiple scales.

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Now, oftentimes,
especially for those of you

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who are biology inclined,

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when you think of evolution,

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you're thinking of

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kind of like modification through descent.

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But, as a geoscientist,
I think of evolution

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as change through time.

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So, I'm trying to document
things that are changing.

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And, that thing that could
be changing could be climate.

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It could be environment,

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and it could be the biota as well.

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All of those are coming
together here in Turkana.

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The first thing that's
changing through time is

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we have actually rifting,
plate tectonic activity,

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tearing a continent apart and creating

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what's known as the East
African Rift System.

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It's one of the only active
continental rifts in the world.

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So, if you wanna know about
how continents split apart,

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how oceans are formed,

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this is a great place
to study that evolution.

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The next thing is kind of
thinking about faunal ecosystems.

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And, this is actually one of the places

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where we see the advent of
the modern faunal community.

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Now, this is gonna occur
in the Miocene times.

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So, before kind of this story

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that I'm going to tell takes place,

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but we see all the things you think of,

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the lions, the giraffes, the
wildebeests, the crocodiles,

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all of those things have their ancestry

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and the fossils are preserved in Turkana.

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And then, finally bringing
it closest to home, right?

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We see the origins of
ourselves as a species,

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the origins of homo as a genus.

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And, we see the earliest stone tools.

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These are not a picture
of those stone tools.

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They're much less charismatic than these.

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They look kind of just like big rocks

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with some edges chipped off.

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But, we see the origin of stone tools.

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The oldest dated tools
are 3.3 million years old,

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and they're from the Turkana Basin.

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This is a great example of

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a more modern stone tool technology.

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But, what's really cool
is we have all of these

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different technologies
changing through time preserved

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in this record.

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And then, finally, we come
to this character right here

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who's known as Nariokotome
Boy or Turkana Boy.

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And, this is one of

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the most complete homo
erectus fossils ever found.

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You can see that we can see

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a lot of details about this individual

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because of the number
of bones that we have.

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And, we've learned fascinating things

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about this individual's life.

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There were probably, it's a young boy,

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it's somewhere in the age
of seven to 11 years old

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who actually had some
physical deformities.

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So, there's then a suggestion

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that this individual might
have been receiving care,

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and there may have been

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some kind of connections
here helping to support

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this individual.

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And Turkana Boy is located
less than three kilometers,

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so less than two miles from
where we drilled this core.

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So, we had the opportunity
to, again, as promised,

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directly tie into that fossil record.

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We also had the opportunity
to look at outcrops,

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so exposures of rocks and
sediments at the surface,

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which are a great way to kind of take

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what had previously been done

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and integrate it into this new work

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that we were developing

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through scientific drilling and coring.

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So, here's an example of
one of these outcrops.

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And, outcrops are fantastic.

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Those of you who are studying geology,

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you've probably had the experience
of being able to walk up

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00:11:28,440 --> 00:11:30,360
to an outcrop, put your hands on the rock,

260
00:11:30,360 --> 00:11:32,040
trace things along laterally,

261
00:11:32,040 --> 00:11:34,080
so we can see where things change.

262
00:11:34,080 --> 00:11:36,240
Maybe we can see the transition from, oh,

263
00:11:36,240 --> 00:11:37,440
here's a river channel.

264
00:11:37,440 --> 00:11:39,360
And then, suddenly, that sand disappears,

265
00:11:39,360 --> 00:11:41,367
and now I'm in a soil of the floodplain.

266
00:11:41,367 --> 00:11:44,760
So, we can trace things
laterally through space.

267
00:11:44,760 --> 00:11:46,740
And, obviously this is oftentimes

268
00:11:46,740 --> 00:11:48,150
where those archeological

269
00:11:48,150 --> 00:11:52,380
and paleoanthropological
investigations are taking place.

270
00:11:52,380 --> 00:11:54,026
But, the thing we're lacking here is

271
00:11:54,026 --> 00:11:56,085
that's one meter high, right?

272
00:11:56,085 --> 00:12:01,085
So, in terms of time, we have
very little preserved here,

273
00:12:01,380 --> 00:12:03,645
maybe only a couple thousand years

274
00:12:03,645 --> 00:12:05,507
in this particular location.

275
00:12:05,507 --> 00:12:07,830
And, we know that evolution occurs

276
00:12:07,830 --> 00:12:09,780
on really long time scales.

277
00:12:09,780 --> 00:12:11,280
So, there's a disconnect, then.

278
00:12:11,280 --> 00:12:12,750
If we wanna study evolution,

279
00:12:12,750 --> 00:12:14,250
we can't study evolution

280
00:12:14,250 --> 00:12:17,220
just from this narrow time slice alone.

281
00:12:17,220 --> 00:12:20,340
We need temporal resolution.

282
00:12:20,340 --> 00:12:21,870
And, that's where cores come in.

283
00:12:21,870 --> 00:12:24,240
And, the final thing I wanted to point out

284
00:12:24,240 --> 00:12:27,360
in this outcrop is you can see
some kind of changes, right?

285
00:12:27,360 --> 00:12:29,319
Like, there's a little
bit of a rusty color here,

286
00:12:29,319 --> 00:12:32,040
and there's some greenish colors there,

287
00:12:32,040 --> 00:12:34,830
but we often, when we work in outcrops,

288
00:12:34,830 --> 00:12:36,510
because they're at the modern surface,

289
00:12:36,510 --> 00:12:38,550
we have to contend with modern weathering.

290
00:12:38,550 --> 00:12:40,260
And so, we're facing the challenge of

291
00:12:40,260 --> 00:12:42,570
what is an old soil structure,

292
00:12:42,570 --> 00:12:45,900
and what is a kind of
a modern soil structure

293
00:12:45,900 --> 00:12:48,270
and how do we tease those apart?

294
00:12:48,270 --> 00:12:50,370
So, in come scientific drill cores,

295
00:12:50,370 --> 00:12:52,380
and these are cores of essentially

296
00:12:52,380 --> 00:12:55,710
that exact same interval
that you just saw in outcrop.

297
00:12:55,710 --> 00:12:59,220
But now, notice we have
an unprecedented scale

298
00:12:59,220 --> 00:13:02,820
of resolution in terms of what we can see.

299
00:13:02,820 --> 00:13:06,750
So, we have a relatively a tool

300
00:13:06,750 --> 00:13:08,430
that hadn't really been applied

301
00:13:08,430 --> 00:13:10,890
in continental African records,

302
00:13:10,890 --> 00:13:15,450
particularly on land that
optimizes this idea of temporal,

303
00:13:15,450 --> 00:13:17,610
gives us a long time record

304
00:13:17,610 --> 00:13:20,250
and yields records that are less weathered

305
00:13:20,250 --> 00:13:23,010
and allowing us to see
things on a whole new scale

306
00:13:23,010 --> 00:13:25,923
that were previously completely
inaccessible from outcrop.

307
00:13:27,390 --> 00:13:30,690
All right, so to summarize
then to kind of this,

308
00:13:30,690 --> 00:13:32,254
what we went in to do is

309
00:13:32,254 --> 00:13:37,230
we wanted this window of time
into this particular location,

310
00:13:37,230 --> 00:13:38,340
which is, okay,

311
00:13:38,340 --> 00:13:40,293
so this is modern Lake Turkana.

312
00:13:41,615 --> 00:13:42,990
And, during the time period
that we were targeting,

313
00:13:42,990 --> 00:13:44,857
we actually had another
lake in this basin,

314
00:13:44,857 --> 00:13:46,710
Paleolake Lorenyang,

315
00:13:46,710 --> 00:13:48,660
which is significantly larger

316
00:13:48,660 --> 00:13:51,084
than the modern outline of the lake

317
00:13:51,084 --> 00:13:52,470
that you see here in black.

318
00:13:52,470 --> 00:13:55,710
And so, we employed all of these tools,

319
00:13:55,710 --> 00:13:58,723
dating stratigraphy and sedimentology,

320
00:13:58,723 --> 00:14:02,430
accessing paleoecological records

321
00:14:02,430 --> 00:14:04,891
through different proxies
and extracting paleoclimate

322
00:14:04,891 --> 00:14:06,390
from a lot of that,

323
00:14:06,390 --> 00:14:10,230
and then ultimately applying
that to paleoanthropology.

324
00:14:10,230 --> 00:14:11,820
So now, I'm gonna take
you through the how.

325
00:14:11,820 --> 00:14:13,620
How did we do all these things?

326
00:14:13,620 --> 00:14:14,760
Oh, there's Kaitio.

327
00:14:14,760 --> 00:14:15,870
So, that's our drill core.

328
00:14:15,870 --> 00:14:17,820
So again, notice based on what we know

329
00:14:17,820 --> 00:14:21,180
about the reconstruction
of the lake itself,

330
00:14:21,180 --> 00:14:23,430
we can see that this
record's right on the edge

331
00:14:23,430 --> 00:14:25,560
of this very large lake system.

332
00:14:25,560 --> 00:14:26,393
And, lakes are great,

333
00:14:26,393 --> 00:14:28,530
because they're kind of just big.

334
00:14:28,530 --> 00:14:30,750
I always talk about the
cereal bowl analogy.

335
00:14:30,750 --> 00:14:32,550
It's like a big cereal bowl, right?

336
00:14:32,550 --> 00:14:35,040
You go to the to a dining hall,

337
00:14:35,040 --> 00:14:37,350
or you stumble outta bed in the morning,

338
00:14:37,350 --> 00:14:39,150
and if you wanna accumulate things,

339
00:14:39,150 --> 00:14:40,350
you're gonna take a bowl,

340
00:14:40,350 --> 00:14:43,470
because you can just pour
sediment or cereal in this case

341
00:14:43,470 --> 00:14:45,420
into it and it's going to accumulate.

342
00:14:45,420 --> 00:14:47,220
It's gonna stay in that bowl.

343
00:14:47,220 --> 00:14:49,200
And so, lakes do just that.

344
00:14:49,200 --> 00:14:50,670
Now, you would never take that bowl

345
00:14:50,670 --> 00:14:53,430
and flip it upside down and
pour cereal onto it, right?

346
00:14:53,430 --> 00:14:54,263
That's your mountain.

347
00:14:54,263 --> 00:14:56,460
That cereal's just gonna
shed off to the side,

348
00:14:56,460 --> 00:15:00,154
and we're never gonna see what
cereals you chose that day.

349
00:15:00,154 --> 00:15:02,670
And so, by targeting a lake,

350
00:15:02,670 --> 00:15:05,040
we have this continuous sedimentation,

351
00:15:05,040 --> 00:15:06,390
and we hope to have a record

352
00:15:06,390 --> 00:15:09,303
that has minimal
interruption due to erosion.

353
00:15:11,250 --> 00:15:14,820
So again, in 2013, we took
this big drill rig out here,

354
00:15:14,820 --> 00:15:17,760
contended with some very sandy roads,

355
00:15:17,760 --> 00:15:19,522
which you can see right here.

356
00:15:19,522 --> 00:15:22,260
And, we began coring.

357
00:15:22,260 --> 00:15:25,080
And, ultimately after about
a month of coring time,

358
00:15:25,080 --> 00:15:28,800
we came away with 216 meters.

359
00:15:28,800 --> 00:15:31,620
So, half the lap of a track of sediment

360
00:15:31,620 --> 00:15:35,580
with about 95% recovery,
which is really high recovery.

361
00:15:35,580 --> 00:15:38,193
We were very excited about
this record that we got.

362
00:15:39,150 --> 00:15:42,060
And, we took this record back to the lab

363
00:15:42,060 --> 00:15:43,290
at the University of Minnesota,

364
00:15:43,290 --> 00:15:46,560
which is the National Lacustrine
or Lake Core Repository.

365
00:15:46,560 --> 00:15:49,160
And, we split these cores
and began to analyze them.

366
00:15:50,310 --> 00:15:53,035
Some of the thing, like
one of the first parts,

367
00:15:53,035 --> 00:15:56,310
if you wanna understand faunal change is

368
00:15:56,310 --> 00:15:57,690
we need some dates.

369
00:15:57,690 --> 00:15:59,487
We need to know where we are in time.

370
00:15:59,487 --> 00:16:00,570
And so, we employed

371
00:16:00,570 --> 00:16:03,577
a number of geo chronological techniques.

372
00:16:03,577 --> 00:16:07,980
Here, I'm highlighting
the paleomagnetism record.

373
00:16:07,980 --> 00:16:09,840
So, this is recording changes

374
00:16:09,840 --> 00:16:12,360
in the direction of the
earth's magnetic field.

375
00:16:12,360 --> 00:16:13,380
And, we have a record,

376
00:16:13,380 --> 00:16:15,772
almost like a barcode of
when those changes occurred.

377
00:16:15,772 --> 00:16:18,510
So, when we see a flip
in that magnetic field,

378
00:16:18,510 --> 00:16:20,340
we can tie it to certain events

379
00:16:20,340 --> 00:16:22,740
if we know more or less
where we should be coming

380
00:16:22,740 --> 00:16:23,910
in on this record.

381
00:16:23,910 --> 00:16:27,840
And, in this case we did
and we recovered this switch

382
00:16:27,840 --> 00:16:29,970
here in the magnetic field,

383
00:16:29,970 --> 00:16:32,520
which marks the top of
the Olduvai Subchron

384
00:16:32,520 --> 00:16:35,820
at about 1.78 million years.

385
00:16:35,820 --> 00:16:38,340
We also used glass shards.

386
00:16:38,340 --> 00:16:41,010
So, this area was very
volcanically active due to

387
00:16:41,010 --> 00:16:42,150
that active rifting,

388
00:16:42,150 --> 00:16:44,850
that ripping apart of the
continent that I mentioned.

389
00:16:44,850 --> 00:16:47,310
And, all these volcanoes,
when they would erupt,

390
00:16:47,310 --> 00:16:49,380
they would blow glass fragments

391
00:16:49,380 --> 00:16:51,240
with a geochemical fingerprint.

392
00:16:51,240 --> 00:16:52,920
Each of these glass shards has

393
00:16:52,920 --> 00:16:55,410
a very unique geochemical signature.

394
00:16:55,410 --> 00:16:59,160
And by analyzing individual
shards for their geochemistry,

395
00:16:59,160 --> 00:17:02,670
we can correlate them to
areas where they are dated.

396
00:17:02,670 --> 00:17:05,580
So even if we don't have
directly dateable material,

397
00:17:05,580 --> 00:17:07,200
we can use stratigraphy,

398
00:17:07,200 --> 00:17:10,740
we can use correlation in
order to connect the dots

399
00:17:10,740 --> 00:17:14,280
and to create a
tephrachronological record.

400
00:17:14,280 --> 00:17:17,070
And so, when we combined all
of these data points together,

401
00:17:17,070 --> 00:17:18,030
including one place

402
00:17:18,030 --> 00:17:20,280
where we actually could date the sediments

403
00:17:20,280 --> 00:17:23,670
or date the the ash layer directly,

404
00:17:23,670 --> 00:17:27,210
we came away with a
number of really nice ties

405
00:17:27,210 --> 00:17:29,673
that help us figure out where we are.

406
00:17:31,110 --> 00:17:34,140
From oldest to youngest,
we're kind of interpreting

407
00:17:34,140 --> 00:17:36,626
the base of this core based
on something we didn't record,

408
00:17:36,626 --> 00:17:38,160
which isn't necessarily

409
00:17:38,160 --> 00:17:41,378
the best chronological technique to use.

410
00:17:41,378 --> 00:17:43,671
But, we know the top of the Olduvai here

411
00:17:43,671 --> 00:17:45,360
from paleomagnetism.

412
00:17:45,360 --> 00:17:47,730
We had a new date for a new Tephra

413
00:17:47,730 --> 00:17:49,989
that had never been seen before here.

414
00:17:49,989 --> 00:17:53,460
And then, we have a number of
other ages up near the top.

415
00:17:53,460 --> 00:17:58,460
And so, we see this plotted
here in this time depth plot

416
00:17:58,800 --> 00:18:01,590
where we have depth in the core here

417
00:18:01,590 --> 00:18:06,180
and age in thousands
of years on the Y-axis.

418
00:18:06,180 --> 00:18:09,337
And so, there's a kind of
famous geochronological saying,

419
00:18:09,337 --> 00:18:10,980
"No dates, no rates,"

420
00:18:10,980 --> 00:18:13,980
but basically what we're
able to do here is create

421
00:18:13,980 --> 00:18:16,470
sedimentation rates to understand, again,

422
00:18:16,470 --> 00:18:19,830
how rapidly are these
sediments being deposited,

423
00:18:19,830 --> 00:18:21,690
and where might we be?

424
00:18:21,690 --> 00:18:24,750
Say I have something at
a hundred meters depth,

425
00:18:24,750 --> 00:18:26,700
and it's not directly dated,

426
00:18:26,700 --> 00:18:29,070
where might I be based
on what I'm inferring

427
00:18:29,070 --> 00:18:30,843
from my sedimentology rates?

428
00:18:33,030 --> 00:18:35,370
The sedimentology was
one of the main roles

429
00:18:35,370 --> 00:18:37,590
that I took within this project.

430
00:18:37,590 --> 00:18:42,120
And so, here I had just
such beautiful material

431
00:18:42,120 --> 00:18:45,360
to work with, 216 meters of cores,

432
00:18:45,360 --> 00:18:47,370
many of which were super charismatic

433
00:18:47,370 --> 00:18:48,930
such as what you see here.

434
00:18:48,930 --> 00:18:50,760
And so, I went through all of these cores

435
00:18:50,760 --> 00:18:54,600
and logged them using a
technique called facies analysis.

436
00:18:54,600 --> 00:18:56,432
So I'm looking both at
the size of the grains,

437
00:18:56,432 --> 00:18:59,617
the shape of the grains, the
composition of the grains.

438
00:18:59,617 --> 00:19:02,760
And then, I'm also looking at
the sedimentary structures.

439
00:19:02,760 --> 00:19:05,610
Are these say laminated,
which might indicate

440
00:19:05,610 --> 00:19:09,090
a very low energy depositional environment

441
00:19:09,090 --> 00:19:12,870
where sediment is raining
out a suspension i.e. a lake,

442
00:19:12,870 --> 00:19:16,320
or am I seeing places where
the texture is massive?

443
00:19:16,320 --> 00:19:18,690
And, in this particular core here,

444
00:19:18,690 --> 00:19:20,790
you're seeing these little white blobs.

445
00:19:20,790 --> 00:19:22,920
Those are actually what we call pedogenic

446
00:19:22,920 --> 00:19:24,750
or soil carbonate nodules.

447
00:19:24,750 --> 00:19:27,960
And so, this is telling me
this lack of fabric plus

448
00:19:27,960 --> 00:19:29,433
the presence of carbonate is telling me

449
00:19:29,433 --> 00:19:31,064
that this was actually a soil,

450
00:19:31,064 --> 00:19:33,660
much like a soil that
you might walk across

451
00:19:33,660 --> 00:19:36,000
the next time you walk across the field.

452
00:19:36,000 --> 00:19:38,850
And sometimes, we had
units full of fossils.

453
00:19:38,850 --> 00:19:41,880
So, here you see a whole
bunch of little gastropods

454
00:19:41,880 --> 00:19:42,960
and bivalves.

455
00:19:42,960 --> 00:19:45,390
So we're seeing, oh, okay,
this is an environment

456
00:19:45,390 --> 00:19:47,850
where these organisms
maybe weren't living,

457
00:19:47,850 --> 00:19:51,810
but are being concentrated
after death into some kind

458
00:19:51,810 --> 00:19:54,150
of assemblage that that represents

459
00:19:54,150 --> 00:19:56,100
probably high energy reworking,

460
00:19:56,100 --> 00:19:58,620
such as on a beach where
you might wander around

461
00:19:58,620 --> 00:20:02,640
and find like a zone of shells
that are all piled together.

462
00:20:02,640 --> 00:20:04,110
And then finally, we had some things

463
00:20:04,110 --> 00:20:05,790
that were definitely sand.

464
00:20:05,790 --> 00:20:07,470
And, in these particular intervals

465
00:20:07,470 --> 00:20:09,060
we're oftentimes interpreting, okay,

466
00:20:09,060 --> 00:20:10,890
this is probably a river.

467
00:20:10,890 --> 00:20:12,480
So, we're seeing an interplay then

468
00:20:12,480 --> 00:20:15,068
between lakes and the floodplains

469
00:20:15,068 --> 00:20:18,480
that might be associated
with either lakes or rivers

470
00:20:18,480 --> 00:20:20,370
and sometimes beaches.

471
00:20:20,370 --> 00:20:22,170
So, these were the types of environments

472
00:20:22,170 --> 00:20:24,028
and sort of representative examples

473
00:20:24,028 --> 00:20:27,120
of some of what these cores look like.

474
00:20:27,120 --> 00:20:30,000
Unfortunately, because of
the length of the core,

475
00:20:30,000 --> 00:20:32,250
it becomes very hard
to actually image this

476
00:20:32,250 --> 00:20:33,480
in any kind of meaningful way,

477
00:20:33,480 --> 00:20:35,670
because it's just a little smooshy thing.

478
00:20:35,670 --> 00:20:37,770
But, I'll make a couple
of attempts at that

479
00:20:37,770 --> 00:20:39,450
as we continue through,

480
00:20:39,450 --> 00:20:41,160
because basically understanding

481
00:20:41,160 --> 00:20:43,529
that fundamental environmental signal is

482
00:20:43,529 --> 00:20:46,350
really important for every other kind of

483
00:20:46,350 --> 00:20:49,200
fancy geochemical and environmental proxy

484
00:20:49,200 --> 00:20:52,350
that you might lay on top of this record.

485
00:20:52,350 --> 00:20:55,920
So, here in this first
column on your left,

486
00:20:55,920 --> 00:20:58,770
you're seeing a stratigraphic column.

487
00:20:58,770 --> 00:21:01,800
So this is showing the core,

488
00:21:01,800 --> 00:21:05,340
the depth in the core with
the white spots being gaps,

489
00:21:05,340 --> 00:21:06,960
some of that five percent of the core,

490
00:21:06,960 --> 00:21:08,820
that record that we didn't recover.

491
00:21:08,820 --> 00:21:11,940
And, the X-axis is actually
showing you grain size.

492
00:21:11,940 --> 00:21:13,500
So, areas that are bumped out

493
00:21:13,500 --> 00:21:16,920
just a little bit are slightly
coarser, silts to sands.

494
00:21:16,920 --> 00:21:20,430
And, overall, you can see that
this core is characterized

495
00:21:20,430 --> 00:21:23,790
by a very consistent size of sediment.

496
00:21:23,790 --> 00:21:26,943
It's pretty much all silt to silty clay.

497
00:21:27,900 --> 00:21:31,650
In this next column over what
you're seeing is the aggregate

498
00:21:31,650 --> 00:21:34,644
of all of those detailed
facies associations

499
00:21:34,644 --> 00:21:38,910
that I kind of assigned to
each interval in the core.

500
00:21:38,910 --> 00:21:41,280
And, what you'll notice here
is that suddenly intervals

501
00:21:41,280 --> 00:21:44,280
that looked kind of just like
it's just a lot of silts,

502
00:21:44,280 --> 00:21:47,790
just some boring like this is true color,

503
00:21:47,790 --> 00:21:51,250
so just some boring
green silts actually are

504
00:21:52,290 --> 00:21:55,380
lakes and soils and lakes and soils

505
00:21:55,380 --> 00:21:58,230
and lakes and soils back and
forth and back and forth.

506
00:21:58,230 --> 00:22:01,920
So, what used to be
just like a lot of silt,

507
00:22:01,920 --> 00:22:05,105
big pile, all lake actually
is far more complicated

508
00:22:05,105 --> 00:22:08,193
in terms of what the
environment it represents.

509
00:22:09,510 --> 00:22:11,430
And, one of the things that emerged

510
00:22:11,430 --> 00:22:15,060
from this analysis were
consistent patterns

511
00:22:15,060 --> 00:22:16,740
that we saw over and over again.

512
00:22:16,740 --> 00:22:19,620
And, this one was
probably the dominant one.

513
00:22:19,620 --> 00:22:23,970
And, I termed it Lam-Scram,
laminated to scrambled,

514
00:22:23,970 --> 00:22:27,120
which is this association here

515
00:22:27,120 --> 00:22:30,930
where you have kind of this
scrambled unit down here.

516
00:22:30,930 --> 00:22:34,800
Again, pretty massive, but
the way it's breaking apart is

517
00:22:34,800 --> 00:22:38,490
analogous to what we see in
modern and ancient soils,

518
00:22:38,490 --> 00:22:40,380
which are the ped structures.

519
00:22:40,380 --> 00:22:43,470
So, these little surfaces
in these particular soils,

520
00:22:43,470 --> 00:22:46,170
we're in an area where it's
seasonally wet and dry,

521
00:22:46,170 --> 00:22:49,410
because we're in this Savannah
ecosystem with monsoons.

522
00:22:49,410 --> 00:22:51,450
And so, when the soils become wet,

523
00:22:51,450 --> 00:22:54,540
they swell, and then when they dry,

524
00:22:54,540 --> 00:22:56,580
they contract making mud cracks.

525
00:22:56,580 --> 00:22:58,590
And, that wet drying creates

526
00:22:58,590 --> 00:23:02,880
these really strong ped
surfaces, which you see here.

527
00:23:02,880 --> 00:23:05,010
Then we have a little sand interval,

528
00:23:05,010 --> 00:23:06,960
which is actually full of micro fossils.

529
00:23:06,960 --> 00:23:08,520
It's full of ostracods, which are

530
00:23:08,520 --> 00:23:12,189
these kind of sand grain size crustaceans.

531
00:23:12,189 --> 00:23:15,180
It's kind of like a little shrimp

532
00:23:15,180 --> 00:23:17,190
inside a little clamshell.

533
00:23:17,190 --> 00:23:18,390
And, I love ostracods.

534
00:23:18,390 --> 00:23:21,030
They're some of my favorite organisms.

535
00:23:21,030 --> 00:23:22,170
And then, on top of that,

536
00:23:22,170 --> 00:23:24,232
suddenly now it's laminated,

537
00:23:24,232 --> 00:23:29,232
and we're gonna associate
those laminations with a lake.

538
00:23:29,670 --> 00:23:31,557
So what we've just done then is gone

539
00:23:31,557 --> 00:23:36,557
from having a soil to a
flooding surface to now a lake.

540
00:23:37,590 --> 00:23:40,770
And, I'll highlight that flooding
surface in red right here.

541
00:23:40,770 --> 00:23:44,370
So, that's this transition
between this package.

542
00:23:44,370 --> 00:23:46,770
And, as you you go up,
you start to see, whoops,

543
00:23:46,770 --> 00:23:48,369
sorry, I made it mad.

544
00:23:48,369 --> 00:23:51,600
You start to see that we
lose those laminations,

545
00:23:51,600 --> 00:23:53,435
and it becomes scrambled once again.

546
00:23:53,435 --> 00:23:58,435
So this sequence of Lam to Scram
continues on and on and on.

547
00:23:58,770 --> 00:24:02,910
And, we interpret this to
represent a low energy lake margin

548
00:24:02,910 --> 00:24:04,200
that's very dynamic.

549
00:24:04,200 --> 00:24:05,673
It's moving back and forth.

550
00:24:06,600 --> 00:24:07,950
So here's that sand,

551
00:24:07,950 --> 00:24:09,960
here's your fine grain laminated

552
00:24:09,960 --> 00:24:11,703
into maybe fine grain massive.

553
00:24:11,703 --> 00:24:14,986
And then, ultimately, if we
were to stack this on top,

554
00:24:14,986 --> 00:24:18,450
this P standing for paleosalt,

555
00:24:18,450 --> 00:24:20,580
V standing for verdict structure,

556
00:24:20,580 --> 00:24:24,003
which is that strength swell
process that I just described.

557
00:24:25,260 --> 00:24:27,900
And, we can make a a schematic
model of this, right?

558
00:24:27,900 --> 00:24:31,950
We can visualize this as a
cartoon in these time steps

559
00:24:31,950 --> 00:24:32,850
that I'll show here.

560
00:24:32,850 --> 00:24:34,650
So, here is time one.

561
00:24:34,650 --> 00:24:37,919
We have sediments
depositing being laminated

562
00:24:37,919 --> 00:24:39,450
on a lake floor.

563
00:24:39,450 --> 00:24:40,710
The water's going up,

564
00:24:40,710 --> 00:24:42,341
but the water starts to fall back down.

565
00:24:42,341 --> 00:24:45,540
And now, we're going to expose that.

566
00:24:45,540 --> 00:24:48,420
We're gonna form a soil with
all of our little plants

567
00:24:48,420 --> 00:24:50,880
and roots and burrowing organisms.

568
00:24:50,880 --> 00:24:52,410
And, it's exposed to the surface,

569
00:24:52,410 --> 00:24:55,080
so it's mud cracking and
shrinking and swelling.

570
00:24:55,080 --> 00:24:57,600
And then, ultimately that
lake comes right back,

571
00:24:57,600 --> 00:24:59,340
depositing that layer of sand

572
00:24:59,340 --> 00:25:02,763
and then continuing on
with a laminated sequence.

573
00:25:04,770 --> 00:25:08,130
So, get this, when we
looked at the outcrop,

574
00:25:08,130 --> 00:25:12,720
we saw about 30, 33 examples
of flooding surfaces,

575
00:25:12,720 --> 00:25:15,840
and we were like, whoa, that's
like 400 meters of sediment.

576
00:25:15,840 --> 00:25:18,544
Like we've got a bunch of these,

577
00:25:18,544 --> 00:25:20,073
like 30 of them.

578
00:25:20,940 --> 00:25:23,938
When we looked at the core,
and I did that facies analysis,

579
00:25:23,938 --> 00:25:28,320
we realized, oh shoot, we like
missed a hundred of those.

580
00:25:28,320 --> 00:25:31,980
There's actually about
130 of these transitions,

581
00:25:31,980 --> 00:25:33,180
which is fascinating,

582
00:25:33,180 --> 00:25:36,843
because if we take that age
model, if we take that rate,

583
00:25:36,843 --> 00:25:38,880
then we realize that these are occurring

584
00:25:38,880 --> 00:25:41,190
about every 5,000 years.

585
00:25:41,190 --> 00:25:42,720
They're super rapid.

586
00:25:42,720 --> 00:25:45,330
This lake is rising and
falling and constantly

587
00:25:45,330 --> 00:25:46,920
in a state of flux.

588
00:25:46,920 --> 00:25:50,610
And, we never would've had
that opportunity to see that

589
00:25:50,610 --> 00:25:52,590
without the scientific drill cores.

590
00:25:52,590 --> 00:25:54,215
What we now realize is a lot of that,

591
00:25:54,215 --> 00:25:57,030
those kind of rusty
layers that I pointed to

592
00:25:57,030 --> 00:25:58,620
in that outcrop photo,

593
00:25:58,620 --> 00:26:01,350
those are actually those
little ostracod sands.

594
00:26:01,350 --> 00:26:03,930
And so, those are actually
those transgressive sands

595
00:26:03,930 --> 00:26:06,810
or lake level rising,
flooding surface sands.

596
00:26:06,810 --> 00:26:10,050
And, we previously just hadn't recognized

597
00:26:10,050 --> 00:26:11,160
what we were looking at.

598
00:26:11,160 --> 00:26:12,120
But, now that we know that,

599
00:26:12,120 --> 00:26:13,620
we can apply it to other outcrops

600
00:26:13,620 --> 00:26:15,393
where we might have similar things.

601
00:26:17,040 --> 00:26:17,873
And, the other thing

602
00:26:17,873 --> 00:26:20,160
that's really cool about this record is,

603
00:26:20,160 --> 00:26:23,220
again, here's that core plot
just kind of showing you

604
00:26:23,220 --> 00:26:25,864
the true colors and general grain size.

605
00:26:25,864 --> 00:26:29,700
And, you notice that at the
top third of this record,

606
00:26:29,700 --> 00:26:31,740
it goes from something
that's very characterized

607
00:26:31,740 --> 00:26:34,830
by green sediments, lots of silt

608
00:26:34,830 --> 00:26:36,000
to something that's characterized

609
00:26:36,000 --> 00:26:38,670
by these kind of like reddish brown.

610
00:26:38,670 --> 00:26:41,850
And, what we're interpreting here is that

611
00:26:41,850 --> 00:26:45,300
we have a change from
something that's more lakey

612
00:26:45,300 --> 00:26:46,980
to lake margin, right?

613
00:26:46,980 --> 00:26:49,380
So, something that's
that's much more dominated

614
00:26:49,380 --> 00:26:52,860
by reduced processes,
low oxygen processes,

615
00:26:52,860 --> 00:26:55,710
hence that that green color to something

616
00:26:55,710 --> 00:26:58,080
that's more oxygenated,

617
00:26:58,080 --> 00:27:00,780
that's kind of characterized probably

618
00:27:00,780 --> 00:27:02,970
by something like a delta plane.

619
00:27:02,970 --> 00:27:06,240
And so, we can actually map
the types of environments

620
00:27:06,240 --> 00:27:08,100
that we're seeing in the paleo record

621
00:27:08,100 --> 00:27:11,130
2 million years ago from
this Paleolake Lorenyang

622
00:27:11,130 --> 00:27:12,990
onto Modern Lake Turkana.

623
00:27:12,990 --> 00:27:15,780
And, there are direct analogs for that.

624
00:27:15,780 --> 00:27:19,380
So, here at the bottom, these
kind of laminated intervals,

625
00:27:19,380 --> 00:27:21,180
these are the types of
things we would expect to see

626
00:27:21,180 --> 00:27:22,323
in the open lake.

627
00:27:23,610 --> 00:27:26,100
Now, the lake margin, which is over here,

628
00:27:26,100 --> 00:27:29,130
so that back and forth,
sometimes wet, sometimes dry,

629
00:27:29,130 --> 00:27:32,100
we see in areas such as
this depression right here,

630
00:27:32,100 --> 00:27:34,020
which is known as Sanderson's Gulf,

631
00:27:34,020 --> 00:27:37,043
that oftentimes seasonally
will be connected to the lake,

632
00:27:37,043 --> 00:27:39,141
but during the time that
this photo was taken,

633
00:27:39,141 --> 00:27:42,240
it's just, it's kind
of an isolated wetland.

634
00:27:42,240 --> 00:27:43,410
So, it's somewhat wet,

635
00:27:43,410 --> 00:27:46,620
but it will completely
dry out at other times.

636
00:27:46,620 --> 00:27:48,480
And then, the top of this core looks

637
00:27:48,480 --> 00:27:50,280
a lot like what we would expect to see

638
00:27:50,280 --> 00:27:51,860
in kind of a deltaic plane.

639
00:27:51,860 --> 00:27:54,172
So, similar to the delta here

640
00:27:54,172 --> 00:27:56,944
with the modern Omo River that flows

641
00:27:56,944 --> 00:28:01,890
from the north into the
south and enters Lake Turkana

642
00:28:01,890 --> 00:28:04,563
and actually sustains
the lake as it is today.

643
00:28:05,970 --> 00:28:09,450
So, we have this first
order, big scale transition

644
00:28:09,450 --> 00:28:13,170
in environment from lake to floodplain.

645
00:28:13,170 --> 00:28:17,280
So, it appears to be a
contraction of that lake.

646
00:28:17,280 --> 00:28:19,050
So, the next question then becomes,

647
00:28:19,050 --> 00:28:22,410
is this an environmental signal

648
00:28:22,410 --> 00:28:24,480
or is this a climatic signal,

649
00:28:24,480 --> 00:28:27,000
i.e. did the climate
get drier through time?

650
00:28:27,000 --> 00:28:28,600
And, that's what we're tracking.

651
00:28:29,730 --> 00:28:31,050
Oh, and there you go,

652
00:28:31,050 --> 00:28:33,750
there's the boundary
right there highlighted.

653
00:28:33,750 --> 00:28:36,030
So again, just to to emphasize,

654
00:28:36,030 --> 00:28:37,763
we've got this first order transition

655
00:28:37,763 --> 00:28:41,125
of at about 60 meters depth,

656
00:28:41,125 --> 00:28:44,730
which we see in green size and color.

657
00:28:44,730 --> 00:28:47,520
And, overall we have something

658
00:28:47,520 --> 00:28:49,650
that's a very dynamic system

659
00:28:49,650 --> 00:28:53,160
with this sub-Milakovitch scale cyclicity,

660
00:28:53,160 --> 00:28:54,810
which also will emphasize,

661
00:28:54,810 --> 00:28:57,600
it's something that we can't
get from the marine record.

662
00:28:57,600 --> 00:28:59,250
Those ocean cores, they're beautiful,

663
00:28:59,250 --> 00:29:00,990
and they're consistent through time,

664
00:29:00,990 --> 00:29:03,102
but generally those
sedimentation rates are so slow

665
00:29:03,102 --> 00:29:06,681
that something like
5,000 years is contained

666
00:29:06,681 --> 00:29:08,640
in like a millimeter.

667
00:29:08,640 --> 00:29:09,990
You can't see it.

668
00:29:09,990 --> 00:29:11,820
So, by drilling on the continent,

669
00:29:11,820 --> 00:29:15,390
we now not only can tie more
directly to our fossil sites,

670
00:29:15,390 --> 00:29:18,720
but we can see things at a
different scale of resolution

671
00:29:18,720 --> 00:29:20,343
than previously we were able to,

672
00:29:21,300 --> 00:29:22,590
which begs the question,

673
00:29:22,590 --> 00:29:25,170
climate change or environmental change?

674
00:29:25,170 --> 00:29:27,570
Maybe something changed
about the tectonics.

675
00:29:27,570 --> 00:29:29,340
And again, coming back to my cereal bowl,

676
00:29:29,340 --> 00:29:31,530
maybe that cereal bowl
was bigger or smaller

677
00:29:31,530 --> 00:29:32,490
than we thought.

678
00:29:32,490 --> 00:29:35,190
Maybe it was one of those
camping bowls that's collapsible,

679
00:29:35,190 --> 00:29:37,920
and it suddenly kind of
collapsed a little bit.

680
00:29:37,920 --> 00:29:38,910
We dunno.

681
00:29:38,910 --> 00:29:41,850
And that's what we needed
to, to address next.

682
00:29:41,850 --> 00:29:44,492
So, integrating the sedimentology
and the stratigraphy

683
00:29:44,492 --> 00:29:49,290
and the chronology with other
proxy records allowed us

684
00:29:49,290 --> 00:29:51,300
to address this question.

685
00:29:51,300 --> 00:29:52,530
Here I'm showing some data

686
00:29:52,530 --> 00:29:54,600
from my collaborator Chad Yost

687
00:29:54,600 --> 00:29:56,210
and his colleague Stephen Rucina

688
00:29:56,210 --> 00:29:58,230
at the National Museum of Kenya.

689
00:29:58,230 --> 00:30:02,040
And okay, paleoclimatologists
love wiggles.

690
00:30:02,040 --> 00:30:03,768
They love squiggly wiggly curves.

691
00:30:03,768 --> 00:30:06,851
And that is, they're all
about the wiggle curve.

692
00:30:06,851 --> 00:30:10,440
So, bear with me and let me
break this down a little bit.

693
00:30:10,440 --> 00:30:12,973
On, this X-axis, you're gonna see time,

694
00:30:12,973 --> 00:30:14,724
and again they're transitioning,

695
00:30:14,724 --> 00:30:17,700
using that age model that
I showed you earlier,

696
00:30:17,700 --> 00:30:19,770
they're taking every
single depth in the core

697
00:30:19,770 --> 00:30:21,540
and giving it an age.

698
00:30:21,540 --> 00:30:23,430
And then, they're modeling
what they would expect

699
00:30:23,430 --> 00:30:25,661
between the different
samples that they have.

700
00:30:25,661 --> 00:30:28,200
On the Y-axis of the next two slides,

701
00:30:28,200 --> 00:30:31,770
you're gonna see a whole
host of different axes,

702
00:30:31,770 --> 00:30:33,810
but what I want you to kind of look at are

703
00:30:33,810 --> 00:30:36,960
the kind of relationships between them.

704
00:30:36,960 --> 00:30:37,950
So, up at the top here,

705
00:30:37,950 --> 00:30:39,540
this is solar insulation,

706
00:30:39,540 --> 00:30:43,290
and this is showing a very
strong processional signal.

707
00:30:43,290 --> 00:30:46,500
And, solar insulation's really
important for this study,

708
00:30:46,500 --> 00:30:49,075
because the strength of
the solar insulation,

709
00:30:49,075 --> 00:30:53,580
i.e. stronger solar insulation
leads to a stronger monsoon,

710
00:30:53,580 --> 00:30:57,930
so a stronger wet period
in Eastern Africa.

711
00:30:57,930 --> 00:31:00,630
And, we see this at kind of
the most recent peak of this,

712
00:31:00,630 --> 00:31:03,390
we had a monsoon that was 17% stronger

713
00:31:03,390 --> 00:31:04,290
than what we see today.

714
00:31:04,290 --> 00:31:06,210
So, the wet times get wetter.

715
00:31:06,210 --> 00:31:09,030
The dry times though often will stay dry,

716
00:31:09,030 --> 00:31:11,520
and that does not change.

717
00:31:11,520 --> 00:31:13,950
So, here again, you're
seeing processional cycles.

718
00:31:13,950 --> 00:31:16,260
These are these 20,000 year cycles,

719
00:31:16,260 --> 00:31:19,590
which again points to
kind of the disconnect

720
00:31:19,590 --> 00:31:22,075
between the high resolution
that we can get in this record

721
00:31:22,075 --> 00:31:24,510
and what previously was really the focus

722
00:31:24,510 --> 00:31:26,760
of paleoclimatic records.

723
00:31:26,760 --> 00:31:31,710
This next plot down is
showing you pollen data.

724
00:31:31,710 --> 00:31:33,600
And, one thing that was
really interesting is

725
00:31:33,600 --> 00:31:35,220
the bottom of the core pollen.

726
00:31:35,220 --> 00:31:37,350
In that lakey part pollen was great,

727
00:31:37,350 --> 00:31:39,600
but right where we hit that transition,

728
00:31:39,600 --> 00:31:42,979
where we went into this
more deltaic location,

729
00:31:42,979 --> 00:31:44,670
pollen drops off,

730
00:31:44,670 --> 00:31:47,790
and we see almost nothing in
the upper part of the core.

731
00:31:47,790 --> 00:31:49,080
However, there were other ways

732
00:31:49,080 --> 00:31:50,785
we could get at plant communities.

733
00:31:50,785 --> 00:31:53,724
And, one of the great ones
that we can use are phytoliths,

734
00:31:53,724 --> 00:31:55,950
which are these little silica components

735
00:31:55,950 --> 00:31:58,951
that plants build in their structures

736
00:31:58,951 --> 00:32:00,840
for stability and strength.

737
00:32:00,840 --> 00:32:03,930
And, so coupling the pollen record here

738
00:32:03,930 --> 00:32:05,550
with the Phytolith record,

739
00:32:05,550 --> 00:32:09,630
we have kind of one larger
molar holistic picture

740
00:32:09,630 --> 00:32:13,470
of change in vegetation or
lack thereof through time.

741
00:32:13,470 --> 00:32:15,177
And, in this case it's a lack thereof.

742
00:32:15,177 --> 00:32:18,750
Both the pollen and the phytoliths showed

743
00:32:18,750 --> 00:32:21,420
that we had Mesic to Xeric,

744
00:32:21,420 --> 00:32:24,780
so kind of moderate to
dry adapted vegetation,

745
00:32:24,780 --> 00:32:27,870
grasses in particular, so much grass.

746
00:32:27,870 --> 00:32:30,510
So, just grass through time,

747
00:32:30,510 --> 00:32:34,350
very little change in that
grass, which was interesting.

748
00:32:34,350 --> 00:32:36,150
But, we always like multi proxies, right?

749
00:32:36,150 --> 00:32:37,980
So we look to some other things too.

750
00:32:37,980 --> 00:32:39,510
And now, I'm showing a data set

751
00:32:39,510 --> 00:32:41,190
from my colleague Rachel Lupien.

752
00:32:41,190 --> 00:32:44,433
And again, we're seeing
time on this X-axis,

753
00:32:44,433 --> 00:32:48,921
and now we're looking at
compound specific isotope records

754
00:32:48,921 --> 00:32:50,910
from leaf waxes.

755
00:32:50,910 --> 00:32:53,580
So, the lipids that that coat every leaf

756
00:32:53,580 --> 00:32:57,000
of every plant are what's
being analyzed here.

757
00:32:57,000 --> 00:32:59,580
And, you're seeing another solar curve.

758
00:32:59,580 --> 00:33:01,113
This time we're looking at eccentricity

759
00:33:01,113 --> 00:33:03,333
at this 40,000 year cycle.

760
00:33:04,320 --> 00:33:09,240
And, when my colleague
Rachel looked at these data,

761
00:33:09,240 --> 00:33:10,950
and you can look at these data too, right?

762
00:33:10,950 --> 00:33:12,570
There's some wiggles.

763
00:33:12,570 --> 00:33:14,070
There's some back and forth.

764
00:33:14,070 --> 00:33:16,410
There's actually a lot of variability.

765
00:33:16,410 --> 00:33:20,250
This record's characterized
by a highly variable record.

766
00:33:20,250 --> 00:33:23,160
However, there's no
statistically significant trend

767
00:33:23,160 --> 00:33:25,140
in terms of directionality.

768
00:33:25,140 --> 00:33:26,370
And, in particular,

769
00:33:26,370 --> 00:33:28,560
this deuterium record's really important,

770
00:33:28,560 --> 00:33:30,810
because this tracks rainfall

771
00:33:30,810 --> 00:33:33,390
and amount of rainfall in particular.

772
00:33:33,390 --> 00:33:36,142
And, what you're seeing is
that throughout this record,

773
00:33:36,142 --> 00:33:39,543
the amount of rainfall does
not appear to be changing.

774
00:33:40,590 --> 00:33:45,060
So, when we combine the kind
of plant functional types

775
00:33:45,060 --> 00:33:50,060
with the records from rainfall,
paleo precipitation records,

776
00:33:51,690 --> 00:33:54,720
we can as we can now test this hypothesis.

777
00:33:54,720 --> 00:33:57,360
So, if we started out with
the hypothesis of, okay,

778
00:33:57,360 --> 00:33:58,800
the bottom of this looks like a lake,

779
00:33:58,800 --> 00:34:02,070
the top of this looks like
a floodplain, that or delta,

780
00:34:02,070 --> 00:34:03,840
then we must have gone from something

781
00:34:03,840 --> 00:34:06,330
that was very wet to
something that was very dry,

782
00:34:06,330 --> 00:34:08,496
which was often kind of
what was always interpreted.

783
00:34:08,496 --> 00:34:11,280
When we see lakes, it must be wet.

784
00:34:11,280 --> 00:34:12,840
When we look at the pollen and phytoliths,

785
00:34:12,840 --> 00:34:15,690
we see consistent grasses throughout.

786
00:34:15,690 --> 00:34:18,087
When we look at the biomarker record,

787
00:34:18,087 --> 00:34:21,810
we see no trend in terms
of amount of rainfall.

788
00:34:21,810 --> 00:34:23,010
So, what that means then is

789
00:34:23,010 --> 00:34:25,290
that we have to revisit this assumption

790
00:34:25,290 --> 00:34:28,350
that every time we see a lake
in the geological record,

791
00:34:28,350 --> 00:34:30,840
it means that things were
wet and thus, you know,

792
00:34:30,840 --> 00:34:33,480
Genus Homo was living at a very wet time.

793
00:34:33,480 --> 00:34:36,270
And, instead what we're seeing
is an environmental change,

794
00:34:36,270 --> 00:34:38,100
one from lake to river

795
00:34:38,100 --> 00:34:41,460
that probably is related
more towards tectonics

796
00:34:41,460 --> 00:34:43,710
that change in the size of the bowl

797
00:34:43,710 --> 00:34:46,623
as opposed to climate per se.

798
00:34:49,680 --> 00:34:54,390
Now, tying back, coming back
to this kind of, so what story,

799
00:34:54,390 --> 00:34:55,950
why does that matter

800
00:34:55,950 --> 00:34:58,721
that Genus Homo is not necessarily living

801
00:34:58,721 --> 00:35:02,610
in a increasingly dry environment?

802
00:35:02,610 --> 00:35:04,560
This actually does tie to to Darwin

803
00:35:04,560 --> 00:35:08,670
and kind of as one of the first
people to kind of toss out

804
00:35:08,670 --> 00:35:10,920
this idea of the Savannah hypothesis,

805
00:35:10,920 --> 00:35:12,423
this idea that we became bipedal,

806
00:35:12,423 --> 00:35:16,743
because we suddenly the
woodlands were drying up

807
00:35:16,743 --> 00:35:19,290
and they were being
replaced by grasslands.

808
00:35:19,290 --> 00:35:21,120
And, we were more vulnerable
in the grasslands,

809
00:35:21,120 --> 00:35:22,590
so we needed to have our hands

810
00:35:22,590 --> 00:35:25,050
in order to carry things between trees

811
00:35:25,050 --> 00:35:29,010
to then escape predation
on these grasslands.

812
00:35:29,010 --> 00:35:32,385
And, what we're coming to
realize more and more is that

813
00:35:32,385 --> 00:35:36,930
it seems less like large
scale directional changes are

814
00:35:36,930 --> 00:35:39,120
what we as humans are contending with.

815
00:35:39,120 --> 00:35:41,080
And rather, it's this variability.

816
00:35:41,080 --> 00:35:45,270
It's this Milakovitch to
sub-Milakovitch variability,

817
00:35:45,270 --> 00:35:47,580
and the fact that we're really adaptable.

818
00:35:47,580 --> 00:35:50,430
We handle changes very well.

819
00:35:50,430 --> 00:35:52,287
We've all handled a lot
of changes recently,

820
00:35:52,287 --> 00:35:54,150
thinking about, you know,

821
00:35:54,150 --> 00:35:56,180
the 2020 and what it looked like to go

822
00:35:56,180 --> 00:35:58,230
from one day sitting in class

823
00:35:58,230 --> 00:35:59,490
with everybody around you

824
00:35:59,490 --> 00:36:00,801
to the next day being at home

825
00:36:00,801 --> 00:36:03,420
on a computer all the time, right?

826
00:36:03,420 --> 00:36:07,383
We are very good as a species
at handling variability.

827
00:36:08,490 --> 00:36:12,540
And, Turkana Boy then is living at a time

828
00:36:12,540 --> 00:36:14,130
that is very variable.

829
00:36:14,130 --> 00:36:17,367
We were actually able
to find the ash layer

830
00:36:17,367 --> 00:36:20,268
that Turkana Boy is directly
associated with in our core.

831
00:36:20,268 --> 00:36:22,290
It comes in right around here.

832
00:36:22,290 --> 00:36:25,890
So, in that upper kind of
deltaic part of the record.

833
00:36:25,890 --> 00:36:29,520
And, underneath it is
a soil and, actually,

834
00:36:29,520 --> 00:36:31,860
or sorry, is a sand and
on top of it as a soil.

835
00:36:31,860 --> 00:36:33,060
And, we found this soil.

836
00:36:33,060 --> 00:36:36,300
We can get those pedogenic carbonates.

837
00:36:36,300 --> 00:36:39,424
We can analyze the kind of signature

838
00:36:39,424 --> 00:36:42,330
of what this landscape looked like.

839
00:36:42,330 --> 00:36:44,280
And actually, this irregular surface

840
00:36:44,280 --> 00:36:45,113
that you're seeing here,

841
00:36:45,113 --> 00:36:46,980
these were little hippo footprints.

842
00:36:46,980 --> 00:36:49,260
So, the teeth of Turkana Boy were pooled

843
00:36:49,260 --> 00:36:50,547
in these hippo footprints.

844
00:36:50,547 --> 00:36:55,500
And so, because we are able
to tie right into this record,

845
00:36:55,500 --> 00:36:58,881
we can now say we can
sample this interval,

846
00:36:58,881 --> 00:37:01,380
and we can look at seven year intervals,

847
00:37:01,380 --> 00:37:03,330
about the life of Turkana Boy,

848
00:37:03,330 --> 00:37:05,040
and we can actually map

849
00:37:05,040 --> 00:37:07,830
a record of environmental change

850
00:37:07,830 --> 00:37:11,970
directly onto this Hominid fossil

851
00:37:11,970 --> 00:37:13,970
and the community that it was living in.

852
00:37:17,430 --> 00:37:20,705
Okay, so having a
beautiful record like this

853
00:37:20,705 --> 00:37:24,690
of the plio-pleistocene
is really exciting.

854
00:37:24,690 --> 00:37:28,323
But, that record alone is
you know, maybe a little,

855
00:37:29,550 --> 00:37:32,970
it's like a little window
into a larger time.

856
00:37:32,970 --> 00:37:34,560
And, some of the things that are

857
00:37:34,560 --> 00:37:37,494
currently really captivating
my interest is expanding this

858
00:37:37,494 --> 00:37:39,900
and looking back further in the past.

859
00:37:39,900 --> 00:37:41,910
As Sara mentioned, we're both involved

860
00:37:41,910 --> 00:37:44,670
in this Turkana Miocene project

861
00:37:44,670 --> 00:37:47,100
where we're now stepping back in time,

862
00:37:47,100 --> 00:37:51,120
and we're trying to look
at the very first primates

863
00:37:51,120 --> 00:37:53,700
that occupy this region.

864
00:37:53,700 --> 00:37:55,350
And, here you see a diagram,

865
00:37:55,350 --> 00:37:57,065
and there's a lot going on here,

866
00:37:57,065 --> 00:38:00,750
which points to just the size of this team

867
00:38:00,750 --> 00:38:03,270
that we've assembled through
the Turkana Miocene project

868
00:38:03,270 --> 00:38:05,100
and the complexity of
the types of questions

869
00:38:05,100 --> 00:38:06,840
that we're seeking to answer.

870
00:38:06,840 --> 00:38:09,720
Here again, we have kind of
three components of this,

871
00:38:09,720 --> 00:38:11,762
which are also represented
in our project logo.

872
00:38:11,762 --> 00:38:15,243
The idea that we have a
record of earth change,

873
00:38:15,243 --> 00:38:19,307
geologic change, a
record of climate change,

874
00:38:19,307 --> 00:38:24,307
and then ultimately that's
influencing the change in life.

875
00:38:24,630 --> 00:38:27,270
So, these three spheres are intersecting.

876
00:38:27,270 --> 00:38:30,480
And so, here you have
the time scale right here

877
00:38:30,480 --> 00:38:33,600
and now kind of, you know where before

878
00:38:33,600 --> 00:38:36,648
we were hanging out in this
little blue box up here.

879
00:38:36,648 --> 00:38:39,060
Now, I'm really interested in this part.

880
00:38:39,060 --> 00:38:43,200
I wanna know all about
how primates came to be

881
00:38:43,200 --> 00:38:46,440
and how we get these
organisms on this landscape

882
00:38:46,440 --> 00:38:48,838
and how they're adapted and evolving

883
00:38:48,838 --> 00:38:52,470
to this world around them.

884
00:38:52,470 --> 00:38:54,180
And, the Miocene's really interesting,

885
00:38:54,180 --> 00:38:57,813
because we actually see a large
scale global cooling trend

886
00:38:57,813 --> 00:38:59,583
throughout the Miocene.

887
00:39:00,810 --> 00:39:03,240
And, we're getting the
development of ice sheets

888
00:39:03,240 --> 00:39:05,358
kind of closer up into
the plio-pleistocene,

889
00:39:05,358 --> 00:39:09,660
but overall we're really
changing the global climate,

890
00:39:09,660 --> 00:39:11,580
and that change is causing

891
00:39:11,580 --> 00:39:14,160
significant environmental changes.

892
00:39:14,160 --> 00:39:18,120
What you're looking at here
in this wax record is actually

893
00:39:18,120 --> 00:39:22,860
a change in the spread of C4 grasses.

894
00:39:22,860 --> 00:39:26,100
So, pretty much every grass
you see is a C4 grass.

895
00:39:26,100 --> 00:39:28,410
So, it ties to this story of the fact

896
00:39:28,410 --> 00:39:30,060
that the land around us,

897
00:39:30,060 --> 00:39:31,650
the landscape around us

898
00:39:31,650 --> 00:39:34,263
in the continent of Africa
is changing dramatically.

899
00:39:35,370 --> 00:39:38,220
And so, stay tuned for more information.

900
00:39:38,220 --> 00:39:40,560
This project's in very early stages.

901
00:39:40,560 --> 00:39:42,498
But, if you wanna follow along with us,

902
00:39:42,498 --> 00:39:44,910
we're on Twitter, we're on Instagram,

903
00:39:44,910 --> 00:39:45,965
we have a website,

904
00:39:45,965 --> 00:39:50,965
and it's a really great group
of researchers from Kenya,

905
00:39:51,000 --> 00:39:54,215
from the US and from a couple
European countries as well.

906
00:39:54,215 --> 00:39:57,333
So, stay tuned for exciting updates there.

907
00:39:58,882 --> 00:40:00,660
Here's, everybody, right.

908
00:40:00,660 --> 00:40:01,680
There are a lot of people.

909
00:40:01,680 --> 00:40:04,530
So, shout out to all of my
colleagues, including Sara

910
00:40:04,530 --> 00:40:05,363
you see here.

911
00:40:06,990 --> 00:40:08,937
Alright, so here, you know,

912
00:40:08,937 --> 00:40:11,010
the past is the key to the present.

913
00:40:11,010 --> 00:40:13,520
This principle of
uniformitarianism underpins

914
00:40:13,520 --> 00:40:15,690
all of modern geology,

915
00:40:15,690 --> 00:40:19,860
this idea that we can use
the past to understand

916
00:40:19,860 --> 00:40:20,693
the present.

917
00:40:20,693 --> 00:40:23,490
So, I'd be remiss if I
didn't also highlight

918
00:40:23,490 --> 00:40:27,780
some of the work that's been
going on in recent timescales,

919
00:40:27,780 --> 00:40:32,460
because some of how
fauna responds to changes

920
00:40:32,460 --> 00:40:35,734
in climate is really
important to understand

921
00:40:35,734 --> 00:40:39,120
as we face a world that's
shaped by climate change.

922
00:40:39,120 --> 00:40:43,650
And, in these locations
in Sub-Saharan Africa,

923
00:40:43,650 --> 00:40:44,940
a lot of times we don't have

924
00:40:44,940 --> 00:40:48,060
long-term instrument
records of temperature,

925
00:40:48,060 --> 00:40:49,950
even things like a temperature record.

926
00:40:49,950 --> 00:40:51,840
Oftentimes, they're 50 years long,

927
00:40:51,840 --> 00:40:54,000
which is not enough time
for us to really look

928
00:40:54,000 --> 00:40:55,293
at large scale trends.

929
00:40:56,670 --> 00:40:59,662
And also, when we look at
things like the IPCC report,

930
00:40:59,662 --> 00:41:01,407
we see that sub-Saharan Africa is

931
00:41:01,407 --> 00:41:06,407
one of the locations in the
world that has the most at stake

932
00:41:07,500 --> 00:41:09,150
when it comes to climate change.

933
00:41:09,150 --> 00:41:12,060
In terms of like the
economic impact of that,

934
00:41:12,060 --> 00:41:13,260
it's very high.

935
00:41:13,260 --> 00:41:15,270
And, the uncertainty of
what's going to happen

936
00:41:15,270 --> 00:41:17,520
in a changing world is pretty low.

937
00:41:17,520 --> 00:41:18,898
We don't have a lot of confidence

938
00:41:18,898 --> 00:41:22,620
about how global climate
change is going to impact

939
00:41:22,620 --> 00:41:24,750
these locations specifically.

940
00:41:24,750 --> 00:41:27,420
So then, I'm always looking
for ways to kind of connect

941
00:41:27,420 --> 00:41:30,660
lessons from the past into the present

942
00:41:30,660 --> 00:41:34,290
and hopefully, ultimately
informing the future.

943
00:41:34,290 --> 00:41:36,270
So, I'm gonna add this little red box

944
00:41:36,270 --> 00:41:38,340
and highlight some work
that I've been doing

945
00:41:38,340 --> 00:41:40,380
in and around kind of modern

946
00:41:40,380 --> 00:41:42,600
or probably what we would here refer to

947
00:41:42,600 --> 00:41:45,213
as historical time periods.

948
00:41:46,380 --> 00:41:49,324
And, what you're now seeing right here is

949
00:41:49,324 --> 00:41:52,920
a plot of lake levels through time.

950
00:41:52,920 --> 00:41:55,071
So, on the X-axis we have time

951
00:41:55,071 --> 00:41:57,750
with this end being the youngest

952
00:41:57,750 --> 00:41:59,370
and this being the oldest,

953
00:41:59,370 --> 00:42:02,520
and you're looking at lake
level changes through time.

954
00:42:02,520 --> 00:42:04,620
And, this is satellite derived data.

955
00:42:04,620 --> 00:42:06,930
So, satellites are always flying over,

956
00:42:06,930 --> 00:42:09,274
and they're measuring the
elevation of the lake.

957
00:42:09,274 --> 00:42:12,210
And, what we see is that through time

958
00:42:12,210 --> 00:42:14,130
Lake Turkana's characterized

959
00:42:14,130 --> 00:42:17,070
by very dynamic annual fluctuations.

960
00:42:17,070 --> 00:42:20,850
And, that's tied to the
annual monsoon that we see.

961
00:42:20,850 --> 00:42:22,680
Generally there's a peak and wetness

962
00:42:22,680 --> 00:42:26,917
that comes right after the
long rains in April to May.

963
00:42:29,250 --> 00:42:31,200
And then, throughout the rest of the year

964
00:42:31,200 --> 00:42:33,510
the lake is falling.

965
00:42:33,510 --> 00:42:35,010
However, when we look at kind of

966
00:42:35,010 --> 00:42:36,646
what recent trends are doing,

967
00:42:36,646 --> 00:42:39,240
we're maybe counterintuitively seeing

968
00:42:39,240 --> 00:42:41,700
a very rapid rise in lake level.

969
00:42:41,700 --> 00:42:44,010
The lake is going up
and up and up to heights

970
00:42:44,010 --> 00:42:46,980
that are kind of haven't been seen

971
00:42:46,980 --> 00:42:49,920
since the '50s and '60s in this location.

972
00:42:49,920 --> 00:42:51,000
And, this is actually something

973
00:42:51,000 --> 00:42:55,353
that we're seeing across
many sites in Eastern Africa.

974
00:42:56,970 --> 00:42:59,610
So, that in many ways,
you know, oftentimes

975
00:42:59,610 --> 00:43:02,070
I think, oh okay, higher
lakes, fresher water,

976
00:43:02,070 --> 00:43:04,140
like everything's fine and dandy,

977
00:43:04,140 --> 00:43:06,210
like ecologically we're good,

978
00:43:06,210 --> 00:43:07,320
like this is great.

979
00:43:07,320 --> 00:43:08,550
Great news.

980
00:43:08,550 --> 00:43:11,620
However, I've done a
bit of work looking at

981
00:43:11,620 --> 00:43:14,790
this location which is
known as Ferguson's Gulf.

982
00:43:14,790 --> 00:43:17,741
And, it's located again on the
western side of Turkana here.

983
00:43:17,741 --> 00:43:21,150
And, it's a really shallow embayment

984
00:43:21,150 --> 00:43:24,780
that is a key breeding ground for fish.

985
00:43:24,780 --> 00:43:27,780
And so, again, fish are a huge resource

986
00:43:27,780 --> 00:43:31,350
in this location that's
traditionally very dominated

987
00:43:31,350 --> 00:43:32,940
by pastoralism.

988
00:43:32,940 --> 00:43:35,940
Currently, it's in massive
amounts of drought though,

989
00:43:35,940 --> 00:43:38,850
so people's livestock are dying,

990
00:43:38,850 --> 00:43:42,887
potentially like 90% of livestock die off,

991
00:43:42,887 --> 00:43:46,203
really catastrophic
time for this location.

992
00:43:47,490 --> 00:43:52,470
And, unfortunately from these
cores that I took in 2011.

993
00:43:52,470 --> 00:43:53,670
So again, this is

994
00:43:53,670 --> 00:43:57,240
before that really rapid
rise really initiated.

995
00:43:57,240 --> 00:43:59,220
But, what I'm seeing in these records,

996
00:43:59,220 --> 00:44:01,620
and again, these are from
ostracods, right here.

997
00:44:01,620 --> 00:44:04,174
So, two critters in
particular highlighted here.

998
00:44:04,174 --> 00:44:07,650
But, across all ostracod taxa,

999
00:44:07,650 --> 00:44:09,480
and these ostracods are benthic.

1000
00:44:09,480 --> 00:44:11,520
They're often underpinning the food chain

1001
00:44:11,520 --> 00:44:12,600
that's on top of them.

1002
00:44:12,600 --> 00:44:15,120
And, they're good ecological indicators,

1003
00:44:15,120 --> 00:44:19,470
but we're seeing just
catastrophic loss of biodiversity

1004
00:44:19,470 --> 00:44:23,400
in this really important
fish breeding ground.

1005
00:44:23,400 --> 00:44:26,099
And so, you know, that begs
the question obviously why?

1006
00:44:26,099 --> 00:44:30,090
And, a lot of this is
probably due to overfishing

1007
00:44:30,090 --> 00:44:32,356
and human impacts in the region,

1008
00:44:32,356 --> 00:44:35,850
mismanagement of fisheries poaching

1009
00:44:35,850 --> 00:44:38,220
and then also potentially waste runoff

1010
00:44:38,220 --> 00:44:39,870
from the surrounding areas.

1011
00:44:39,870 --> 00:44:43,560
So, there's real cause for concern.

1012
00:44:43,560 --> 00:44:47,640
This basin has been in this
location accumulating sediments

1013
00:44:47,640 --> 00:44:51,178
since you know, about 17 million years.

1014
00:44:51,178 --> 00:44:53,370
And today, we're seeing things

1015
00:44:53,370 --> 00:44:55,323
that are really unprecedented.

1016
00:44:56,700 --> 00:45:01,470
And so, part of that is due
to the need for resources,

1017
00:45:01,470 --> 00:45:03,499
both hydroelectricity.

1018
00:45:03,499 --> 00:45:06,540
There are a number of
dams that are being built

1019
00:45:06,540 --> 00:45:08,280
along this Omo River,

1020
00:45:08,280 --> 00:45:11,670
which you'll notice the
border between Kenya,

1021
00:45:11,670 --> 00:45:13,860
South Sudan and Ethiopia occurs

1022
00:45:13,860 --> 00:45:15,480
right at the top of this lake.

1023
00:45:15,480 --> 00:45:19,530
So here, you have a natural ecosystem

1024
00:45:19,530 --> 00:45:23,580
that now is spanning
two different countries,

1025
00:45:23,580 --> 00:45:24,720
three different countries,

1026
00:45:24,720 --> 00:45:26,713
but really two that are
kind of fighting over

1027
00:45:26,713 --> 00:45:28,530
who gets what water,

1028
00:45:28,530 --> 00:45:31,560
very similar to what we're
all witnessing happening

1029
00:45:31,560 --> 00:45:33,000
in the western US right now

1030
00:45:33,000 --> 00:45:35,103
with water rights in the Colorado River.

1031
00:45:36,480 --> 00:45:41,160
And so, kind of the push
for hydroelectric power,

1032
00:45:41,160 --> 00:45:44,700
the push to maintain
high qualities of life

1033
00:45:44,700 --> 00:45:49,700
for people in the large cities
is then directly juxtaposed

1034
00:45:49,860 --> 00:45:53,910
with the ecological health of places,

1035
00:45:53,910 --> 00:45:56,343
remote places such as Lake Turkana.

1036
00:45:58,020 --> 00:46:00,630
And so, if we think
about kind of, you know,

1037
00:46:00,630 --> 00:46:04,050
the impacts of climate change,
it's pretty easy to think

1038
00:46:04,050 --> 00:46:05,820
about them having just seen those data

1039
00:46:05,820 --> 00:46:09,810
and to have concern for Lake Turkana,

1040
00:46:09,810 --> 00:46:11,940
but it's much larger than that, right?

1041
00:46:11,940 --> 00:46:15,270
Climate change is going to
impact us on every level

1042
00:46:15,270 --> 00:46:18,060
from kind of the ecosystems

1043
00:46:18,060 --> 00:46:19,740
that we're used to being around,

1044
00:46:19,740 --> 00:46:24,540
and that we are so
passionate about preserving.

1045
00:46:24,540 --> 00:46:29,540
Think the charismatic megafauna
right to the agriculture,

1046
00:46:30,120 --> 00:46:32,790
what we're growing, where our
food is coming from, right.

1047
00:46:32,790 --> 00:46:35,208
All of these are impacted
by climate change,

1048
00:46:35,208 --> 00:46:37,110
to the places we live.

1049
00:46:37,110 --> 00:46:40,110
The cities that are removed
oftentimes seemingly

1050
00:46:40,110 --> 00:46:41,400
from the natural world,

1051
00:46:41,400 --> 00:46:44,490
but we know can often
be highly vulnerable.

1052
00:46:44,490 --> 00:46:47,515
And, all of these examples
I've shown are examples

1053
00:46:47,515 --> 00:46:50,550
from Kenya specifically.

1054
00:46:50,550 --> 00:46:51,960
But, we realize that, you know,

1055
00:46:51,960 --> 00:46:55,380
closer to home we also have these issues.

1056
00:46:55,380 --> 00:46:58,044
We also live in areas that are
vulnerable to climate change.

1057
00:46:58,044 --> 00:47:00,690
And so, ultimately the changes

1058
00:47:00,690 --> 00:47:03,660
that we're seeing in the
recent, in the modern are

1059
00:47:03,660 --> 00:47:06,210
at a much more rapid
rate than what we've seen

1060
00:47:06,210 --> 00:47:08,070
in terms of changes in the past.

1061
00:47:08,070 --> 00:47:09,180
And so, we've kind of come

1062
00:47:09,180 --> 00:47:10,950
to this really important juncture

1063
00:47:10,950 --> 00:47:13,590
where now physical evolution,

1064
00:47:13,590 --> 00:47:15,960
like us changing different
parts of our bodies

1065
00:47:15,960 --> 00:47:18,597
through this slow evolutionary process is

1066
00:47:18,597 --> 00:47:20,580
no longer gonna be sufficient.

1067
00:47:20,580 --> 00:47:22,800
And, we need to really take action

1068
00:47:22,800 --> 00:47:26,580
and change more rapidly
through cultural evolution

1069
00:47:26,580 --> 00:47:30,240
in order to respond to things
such as the climate crisis.

1070
00:47:30,240 --> 00:47:32,550
So, hopefully, I've
kind of come full circle

1071
00:47:32,550 --> 00:47:34,260
and made a compelling case

1072
00:47:34,260 --> 00:47:37,530
for why we're interested
in changes in the past

1073
00:47:37,530 --> 00:47:41,400
and ultimately how that
directly impacts us today.

1074
00:47:41,400 --> 00:47:44,010
So, with that, I'm happy
to take any questions

1075
00:47:44,010 --> 00:47:46,140
including how long did it take to get

1076
00:47:46,140 --> 00:47:48,630
this Land Rover out of the sand?

1077
00:47:48,630 --> 00:47:50,883
And, thank you so much for your time.

1078
00:47:55,020 --> 00:47:56,070
- [Audience Member] Yeah,
that was an excellent talk.

1079
00:47:56,070 --> 00:47:56,974
Thank you very much.

1080
00:47:56,974 --> 00:47:57,807
- Thanks for that.

1081
00:47:57,807 --> 00:47:58,988
- [Audience Member] I'm curious, are there

1082
00:47:58,988 --> 00:48:01,100
any outflows to the lake?

1083
00:48:01,100 --> 00:48:03,506
So it's not a closed space?

1084
00:48:03,506 --> 00:48:04,627
- No.

1085
00:48:04,627 --> 00:48:05,490
- [Audience Member] So it
becomes a lot more complicated.

1086
00:48:05,490 --> 00:48:06,870
- There are outflows.

1087
00:48:06,870 --> 00:48:10,631
So, the question was are
there outflows from the lake?

1088
00:48:10,631 --> 00:48:13,350
And, the answer is no.

1089
00:48:13,350 --> 00:48:14,850
It's a closed basin lake.

1090
00:48:14,850 --> 00:48:18,075
So, the only way water's
getting into that basin is

1091
00:48:18,075 --> 00:48:20,665
either through direct
rainfall, which spoiler,

1092
00:48:20,665 --> 00:48:24,240
there's only about 200
millimeters of rainfall

1093
00:48:24,240 --> 00:48:26,400
if even that in this location.

1094
00:48:26,400 --> 00:48:28,178
It's extremely dry.

1095
00:48:28,178 --> 00:48:32,370
And then, the Omo River brings in anywhere

1096
00:48:32,370 --> 00:48:36,570
from 80 to 90% of the
water that's in that lake.

1097
00:48:36,570 --> 00:48:37,980
So, cutting off the Omo,

1098
00:48:37,980 --> 00:48:39,540
changing anything in the watershed

1099
00:48:39,540 --> 00:48:41,660
of the Omo is gonna have direct impacts

1100
00:48:41,660 --> 00:48:45,250
to the health and
sustainability of Lake Turkana.

1101
00:48:46,328 --> 00:48:47,222
- [Audience Member] Thank you.

1102
00:48:47,222 --> 00:48:48,055
Yeah.

1103
00:48:48,055 --> 00:48:50,192
- [Internet Monitor] Thanks
for a great talk Dr. Beck

1104
00:48:50,192 --> 00:48:51,510
I'm monitoring the online questions,

1105
00:48:51,510 --> 00:48:54,693
and we have about 150
people watching online.

1106
00:48:54,693 --> 00:48:55,551
- Wow.

1107
00:48:55,551 --> 00:48:58,590
- [Internet Monitor] If you
could also repeat the questions,

1108
00:48:58,590 --> 00:49:01,197
'cause they actually
can only barely hear me.

1109
00:49:01,197 --> 00:49:03,818
The first question is from Canada,

1110
00:49:03,818 --> 00:49:07,807
someone who's come to the
festival quite often, and he asks,

1111
00:49:07,807 --> 00:49:11,520
"Did you find in preparing
for your expedition

1112
00:49:11,520 --> 00:49:14,760
and during it that there was
any resistance via political

1113
00:49:14,760 --> 00:49:17,460
or religious from local communities?"

1114
00:49:17,460 --> 00:49:18,293
- Yeah. Great.

1115
00:49:18,293 --> 00:49:19,830
So, the question was about kind of

1116
00:49:19,830 --> 00:49:21,451
the logistics involved

1117
00:49:21,451 --> 00:49:24,420
with conducting work in the Tukana Basin.

1118
00:49:24,420 --> 00:49:28,290
And, one of the things
that's really important to me

1119
00:49:28,290 --> 00:49:30,774
and the teams I work with is having

1120
00:49:30,774 --> 00:49:33,990
meaningful, two-way exchanges

1121
00:49:33,990 --> 00:49:35,610
in terms of our interaction

1122
00:49:35,610 --> 00:49:37,350
with the communities in this location.

1123
00:49:37,350 --> 00:49:41,299
'Cause, obviously, they're
the ones who both stand

1124
00:49:41,299 --> 00:49:44,880
to kind of gain from the finds

1125
00:49:44,880 --> 00:49:47,305
that we make in the
science that we develop,

1126
00:49:47,305 --> 00:49:50,160
but also are potentially vulnerable,

1127
00:49:50,160 --> 00:49:53,010
because if we just come
in and take drill cores

1128
00:49:53,010 --> 00:49:54,600
and then go back to the States, right?

1129
00:49:54,600 --> 00:49:56,400
Like what are they actually benefiting

1130
00:49:56,400 --> 00:49:59,850
from the resources that they provided?

1131
00:49:59,850 --> 00:50:01,980
And so, I've been working very closely

1132
00:50:01,980 --> 00:50:03,840
with the Turkana Basin Institute,

1133
00:50:03,840 --> 00:50:05,754
which is an NGO based in Kenya

1134
00:50:05,754 --> 00:50:08,370
and headquartered both in Nairobi,

1135
00:50:08,370 --> 00:50:13,050
but also with a couple of
offices in Turkana itself.

1136
00:50:13,050 --> 00:50:14,940
And, that's been a really great way,

1137
00:50:14,940 --> 00:50:18,270
because me sitting in my
office at Hamilton College,

1138
00:50:18,270 --> 00:50:21,060
I don't necessarily know
what the greatest needs are

1139
00:50:21,060 --> 00:50:22,170
for the communities.

1140
00:50:22,170 --> 00:50:24,180
So, by partnering with organizations

1141
00:50:24,180 --> 00:50:25,860
that do have that knowledge,

1142
00:50:25,860 --> 00:50:28,530
I'm able to oftentimes interface directly

1143
00:50:28,530 --> 00:50:29,700
with the local communities.

1144
00:50:29,700 --> 00:50:32,400
A lot of times jobs are really important,

1145
00:50:32,400 --> 00:50:33,270
so we're making sure that

1146
00:50:33,270 --> 00:50:35,683
we're hiring local people to
be involved in our science.

1147
00:50:35,683 --> 00:50:40,683
And then also, working with
the Turkana Basin Institute

1148
00:50:40,770 --> 00:50:43,534
and programs that they've developed,

1149
00:50:43,534 --> 00:50:46,410
including a really cool master's project

1150
00:50:46,410 --> 00:50:48,960
that's actually, or
sorry, a master's program

1151
00:50:48,960 --> 00:50:51,060
that's facilitated in Lodwar,

1152
00:50:51,060 --> 00:50:54,150
which is the capital
city of Turkana County.

1153
00:50:54,150 --> 00:50:58,350
So, enabling us to to train and to work

1154
00:50:58,350 --> 00:51:00,660
with Kenyan scientists
and to integrate them

1155
00:51:00,660 --> 00:51:04,140
into our work without
having to take people

1156
00:51:04,140 --> 00:51:07,098
out of country, to create more open access

1157
00:51:07,098 --> 00:51:10,118
and ease of access for the
next generation of scientists,

1158
00:51:10,118 --> 00:51:12,780
which hopefully will be shaped and driven

1159
00:51:12,780 --> 00:51:14,403
by a lot of Kenyan colleagues.

1160
00:51:16,057 --> 00:51:16,890
- [Internet Monitor] Dr. Beck,

1161
00:51:16,890 --> 00:51:18,334
I have another online question,

1162
00:51:18,334 --> 00:51:20,400
and also a request from
our tech team at the back.

1163
00:51:20,400 --> 00:51:21,619
- Yeah.

1164
00:51:21,619 --> 00:51:23,269
- [Internet Monitor] In
your answer, could you go

1165
00:51:23,269 --> 00:51:24,373
closer to the microphone?

1166
00:51:24,373 --> 00:51:25,350
- Oh, this microphone?

1167
00:51:25,350 --> 00:51:26,187
- [Internet Monitor] I think so, yeah.

1168
00:51:26,187 --> 00:51:27,247
- Got it.

1169
00:51:27,247 --> 00:51:28,500
- [Internet Monitor] So, the question is,

1170
00:51:28,500 --> 00:51:31,320
in your view, how much,

1171
00:51:31,320 --> 00:51:32,347
let me just reread the question.

1172
00:51:32,347 --> 00:51:33,540
"How much progress do you think

1173
00:51:33,540 --> 00:51:36,597
the United States has made
in terms of climate change?"

1174
00:51:37,950 --> 00:51:42,774
- Oh, good question. Do we have all day?

1175
00:51:42,774 --> 00:51:46,950
Okay. I guess I would say

1176
00:51:46,950 --> 00:51:49,718
that I try to remain optimistic.

1177
00:51:49,718 --> 00:51:54,703
And, that any action
we take is good action.

1178
00:51:54,703 --> 00:51:57,624
I was really struck as I drove here

1179
00:51:57,624 --> 00:51:59,983
by the number of solar panels

1180
00:51:59,983 --> 00:52:03,427
along the Mass Pike, and just being like,

1181
00:52:03,427 --> 00:52:05,580
"Oh this is really different

1182
00:52:05,580 --> 00:52:08,215
than when I went to school here."

1183
00:52:08,215 --> 00:52:11,550
And so, I'm encouraged by that.

1184
00:52:11,550 --> 00:52:13,975
I think anytime the price of oil goes up,

1185
00:52:13,975 --> 00:52:18,975
we're ripe to make a push
for kind of de-carbon future.

1186
00:52:20,130 --> 00:52:22,680
I do worry about things like, you know,

1187
00:52:22,680 --> 00:52:26,547
a lot of resources that
go into your EVs, right,

1188
00:52:26,547 --> 00:52:27,900
and all your batteries.

1189
00:52:27,900 --> 00:52:31,020
They're being unsustainably
and unethically mined

1190
00:52:31,020 --> 00:52:34,435
in places like the Democratic
Republic of the Congo.

1191
00:52:34,435 --> 00:52:38,010
So, I recognize that the
issue's really complex,

1192
00:52:38,010 --> 00:52:42,420
but I think that I certainly see more will

1193
00:52:42,420 --> 00:52:44,418
and more desire to make changes

1194
00:52:44,418 --> 00:52:46,290
than I have at any other point,

1195
00:52:46,290 --> 00:52:49,410
which makes me hopeful
and makes me keep hoping

1196
00:52:49,410 --> 00:52:52,710
for a better world for myself, my kids,

1197
00:52:52,710 --> 00:52:54,060
all of us to live in.

1198
00:52:54,060 --> 00:52:57,270
So, I guess, I think
there's a lot to be done,

1199
00:52:57,270 --> 00:52:58,920
but if we think of it as like

1200
00:52:58,920 --> 00:53:01,260
here's where we need to
get to, it's so daunting

1201
00:53:01,260 --> 00:53:03,090
that we're probably all
gonna just shut down

1202
00:53:03,090 --> 00:53:05,970
and like curl up with
a book under a blanket

1203
00:53:05,970 --> 00:53:07,470
and just be like, "I'm gonna ignore it."

1204
00:53:07,470 --> 00:53:09,182
So, any little step we take is a benefit

1205
00:53:09,182 --> 00:53:11,673
and is a positive.

1206
00:53:12,930 --> 00:53:14,460
- [Internet Monitor] I don't
wanna monopolize the questions,

1207
00:53:14,460 --> 00:53:16,350
but we do have a few more online,

1208
00:53:16,350 --> 00:53:18,303
unless anyone in the audience has,

1209
00:53:20,190 --> 00:53:21,472
well the next question online is

1210
00:53:21,472 --> 00:53:24,060
you showed us right towards
the end of the talk,

1211
00:53:24,060 --> 00:53:26,370
the rising lake levels.

1212
00:53:26,370 --> 00:53:27,697
And the question is,

1213
00:53:27,697 --> 00:53:31,260
"Is this possibly due
to dams, hydropower?"

1214
00:53:31,260 --> 00:53:32,880
- It's a great question.

1215
00:53:32,880 --> 00:53:34,410
We don't know.

1216
00:53:34,410 --> 00:53:36,540
That's kind of one of the
scary parts of it is like

1217
00:53:36,540 --> 00:53:39,120
we don't really have very open access

1218
00:53:39,120 --> 00:53:40,893
to what exactly is going on.

1219
00:53:42,240 --> 00:53:45,120
Back when I took those cores in in 2011,

1220
00:53:45,120 --> 00:53:47,580
I was really worried about drawdown

1221
00:53:47,580 --> 00:53:49,920
on the lake due to
filling of the reservoirs

1222
00:53:49,920 --> 00:53:50,850
behind those dams,

1223
00:53:50,850 --> 00:53:53,070
because it's a series
of at least five dams,

1224
00:53:53,070 --> 00:53:56,730
but I think ultimately
they want seven of them.

1225
00:53:56,730 --> 00:54:00,000
So, it's a huge kind of cascade of dams.

1226
00:54:00,000 --> 00:54:01,470
And, if you have to fill each

1227
00:54:01,470 --> 00:54:03,136
and every one of those reservoirs,

1228
00:54:03,136 --> 00:54:06,155
then you're locking a ton
of water up in Ethiopia

1229
00:54:06,155 --> 00:54:08,430
and not letting it flow through to Kenya.

1230
00:54:08,430 --> 00:54:10,650
I'm also worried about
sedimentation, right?

1231
00:54:10,650 --> 00:54:13,500
If you put a dam in a water like that,

1232
00:54:13,500 --> 00:54:16,385
looks like chocolate milk, which
is what the Omo looks like.

1233
00:54:16,385 --> 00:54:17,788
I was just there in in December,

1234
00:54:17,788 --> 00:54:20,220
and it's spectacular.

1235
00:54:20,220 --> 00:54:21,840
But, if you put a dam in there,

1236
00:54:21,840 --> 00:54:23,970
then less sediment's gonna
flow down there, and it

1237
00:54:23,970 --> 00:54:25,950
dramatically changes the river.

1238
00:54:25,950 --> 00:54:27,990
And again, drawing on kind of parallels

1239
00:54:27,990 --> 00:54:29,400
with the Colorado River,

1240
00:54:29,400 --> 00:54:32,220
we see that in areas they've
actually had to go in

1241
00:54:32,220 --> 00:54:34,763
and replenish areas of
the river with sediment,

1242
00:54:34,763 --> 00:54:37,740
because when you shut off
the natural sediment that

1243
00:54:37,740 --> 00:54:39,599
should be flowing through the system,

1244
00:54:39,599 --> 00:54:44,599
you damage kind of fringe
like ecosystem habitat niches.

1245
00:54:45,780 --> 00:54:48,426
So, the short answer is we don't know if

1246
00:54:48,426 --> 00:54:51,660
that increase in water
is just due to the dams,

1247
00:54:51,660 --> 00:54:54,690
but we see it on other
rivers that are not dammed.

1248
00:54:54,690 --> 00:54:57,300
And so, it does actually seem to be

1249
00:54:57,300 --> 00:55:01,498
some kind of real signal
of increased lake levels.

1250
00:55:01,498 --> 00:55:03,870
I've also heard potentially that

1251
00:55:03,870 --> 00:55:05,433
that increase in lake level,

1252
00:55:07,121 --> 00:55:09,480
it's just kind of, we don't
have great data on this.

1253
00:55:09,480 --> 00:55:10,440
This is something that would be

1254
00:55:10,440 --> 00:55:11,940
really interesting to explore,

1255
00:55:11,940 --> 00:55:14,070
but it actually seems like areas

1256
00:55:14,070 --> 00:55:16,410
around Turkana are a little bit cloudier

1257
00:55:16,410 --> 00:55:17,460
than they've been in the past,

1258
00:55:17,460 --> 00:55:20,040
even though they're
not receiving rainfall.

1259
00:55:20,040 --> 00:55:23,790
And so, is there some
effect of clouds reducing

1260
00:55:23,790 --> 00:55:25,350
the evaporation off the lake

1261
00:55:25,350 --> 00:55:28,140
and causing the lake level to rise?

1262
00:55:28,140 --> 00:55:32,010
We don't have enough data in hand to say

1263
00:55:32,010 --> 00:55:32,843
one way or the other,

1264
00:55:32,843 --> 00:55:35,240
but that would be something
I would love to test.

1265
00:55:36,491 --> 00:55:38,490
- [Internet Monitor] I think
the last question online,

1266
00:55:38,490 --> 00:55:40,007
and then we've probably got time

1267
00:55:40,007 --> 00:55:41,900
for maybe one more in the audience is,

1268
00:55:41,900 --> 00:55:43,710
"I'm sure you prepare for this

1269
00:55:43,710 --> 00:55:47,380
when you're making the
drilling of the cores

1270
00:55:48,870 --> 00:55:52,415
in terms of damaging
or potential for damage

1271
00:55:52,415 --> 00:55:54,930
to heritage and archeological sites.

1272
00:55:54,930 --> 00:55:56,520
Can you speak to that?

1273
00:55:56,520 --> 00:55:58,050
- Yeah, that's a great question.

1274
00:55:58,050 --> 00:55:59,970
So, when we went out to do that drilling,

1275
00:55:59,970 --> 00:56:03,690
everything had been
preceded by site surveys

1276
00:56:03,690 --> 00:56:06,640
that included people from
the National Museum of Kenya

1277
00:56:06,640 --> 00:56:08,700
who is another kind of partner

1278
00:56:08,700 --> 00:56:11,550
that we work with
regularly in this location.

1279
00:56:11,550 --> 00:56:13,990
And so, we chose the sites

1280
00:56:14,880 --> 00:56:18,660
so that we were avoiding any
active archeological excavation

1281
00:56:18,660 --> 00:56:21,060
and kind of prospecting
for like, all right,

1282
00:56:21,060 --> 00:56:24,420
let's find a surface that doesn't have

1283
00:56:24,420 --> 00:56:25,846
any tools associated with it.

1284
00:56:25,846 --> 00:56:28,301
Let's use one single road,

1285
00:56:28,301 --> 00:56:32,430
so that we're not kind of
leaving tire tracks all over.

1286
00:56:32,430 --> 00:56:36,660
And then, kind of let's make sure

1287
00:56:36,660 --> 00:56:39,030
that we have the people
who have been working

1288
00:56:39,030 --> 00:56:42,150
on the archeological
and geological records

1289
00:56:42,150 --> 00:56:45,390
in this location involved
in that planning process

1290
00:56:45,390 --> 00:56:46,830
and as part of our teams,

1291
00:56:46,830 --> 00:56:48,630
which we were able to kind of recruit

1292
00:56:48,630 --> 00:56:50,820
and retain those people
within our project,

1293
00:56:50,820 --> 00:56:53,010
which really helped us feel very confident

1294
00:56:53,010 --> 00:56:57,209
that we were not having any
kind of substantial impact

1295
00:56:57,209 --> 00:56:59,884
on the archeology and paleoanthropology.

1296
00:56:59,884 --> 00:57:03,390
Although we all like were
kind of crossing fingers,

1297
00:57:03,390 --> 00:57:05,850
like maybe we'll just like
drill through a Hominid.

1298
00:57:05,850 --> 00:57:07,470
Like, maybe we'll just like bring up,

1299
00:57:07,470 --> 00:57:09,390
like split a core and
there's a Hominid in it.

1300
00:57:09,390 --> 00:57:11,040
But, we didn't find any Hominid.

1301
00:57:11,040 --> 00:57:12,397
we didn't find any tools in there.

1302
00:57:12,397 --> 00:57:14,553
We found a lot of silt.

1303
00:57:16,260 --> 00:57:18,783
Thank you all. Have a great afternoon.