Unraveling the Secrets of Cold Adaptation and Hybridization in Primates with Evolutionary Anthropologist Dr. Laura Buck

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For this episode, I sat down in the studio with evolutionary anthropologist Dr. Laura Buck in the Research Centre for Evolutionary Anthropology and Palaeoecology of Liverpool John Moores University.

Dr. Susumu Tomiya of CICASP also joined the conversation.

After waxing on the plausibility that some ancient hominins in cold climates might have hibernated - spoiler alert! Not very - Laura describes the evolutionary and developmental processes that lead to adaptations and behavioral responses to the cold.

We talk about human cold adaptation and how they relate to those of Neanderthals, and how patterns emerge to help species thrive in thermally-inhospitable places.

Laura describes her current research, and how scientists might have overlooked a potentially critical evolutionary force among mammals: hybridisation.

We touch on the idea of genetic rescue for conservation, and whether the "grolar bear", a hybrid between grizzlies and polar bears, might - and that’s a controversial might! -  might allow polar bear genes to survive climate warming in the arctic.

Laura’s work on hybridisation has focused on macaques, but she argues that what we learn from studying hybrid macaque bones can help us understand many of the mysteries of evolution.

She touches on the modern techniques used in geometric morphometrics - simply put, measuring bones in cool ways to understand evolutionary processes - including the future role of AI in the process. 

Laura closes with the idea of niche construction, where it’s not only how we and other species adapt to the environments around us, but also how we change those environments ourselves, leading to the conclusion that in many ways we are responsible for our own environments of evolutionary adaptedness.

Other topics covered in the interview:

• Non-adaptationist explanations and just-so stories in human evolution
• Fieldwork fails with technology in scanning and measuring bones
• Nasal air conditioning
• climate adaptations comparing prehistoric humans in Japan with Japanese macaques
• Hybridization and evolution of the primate pelvis

As the Northern hemisphere gears up for the winter, remember that we all have some physical and many behavioral adapt

The PrimateCast is hosted and produced by Andrew MacIntosh. Artwork by Chris Martin. Music by Andre Goncalves.

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Episode Transcript

Andrew MacIntosh (00:00):
You're listening to the primate cast.
After the tune, an interviewwith evolutionary anthropologist
Dr Laura Buck on human andnon-human primate cold
adaptations, the process andoutcomes of hybridization and
modern tools that make meaningof the shape of bones.
Hey everyone, and welcome backto the primate cast.

(00:44):
I'm your host, andrew McIntoshof Kyo T University's Wildlife
Research Center, and the podcastis brought to you by the Center
for International Collaborationand Advanced Studies in
Primatology at Kyo TUniversity's Center for the
Evolutionary Origins of HumanBehavior.
Now for this episode.
I sat down in the studio withevolutionary anthropologist Dr
Laura Buck of Liverpool JohnMorris University.

(01:05):
Laura was visiting theinstitute to do some
collaborative work on the postcranial skeletons of Japanese
macaque and Taiwanese macaquehybrids.
We were also joined in thestudio by Dr Susumu Tomia, my
good colleague here in PsyCASP,who dropped some great follow-up
questions and color commentary.
That really brings to the foreLaura's breadth and depth of
knowledge about primateevolution.

(01:27):
After waxing on theplausibility that some ancient
hominins and cold climates werehibernators spoiler alert not
very Laura describes theevolutionary and developmental
processes that lead toadaptations and real-time
responses to life in the colderclimates of the world.
We talk about human coldadaptations and how they relate
to those of Neanderthals, butalso how general patterns emerge

(01:50):
to help species thrive in thesethermally inhospitable places.
Laura then describes hercurrent research and how
scientists might be overlookinga potentially critical
evolutionary force, that beinghybridization.
We touch on the idea of geneticrescue for conservation,
passing over whether the grillerbear hybrid between grizzlies
and polar bears that might, eventhough it's an extremely

(02:12):
controversial idea that mightallow polar bear genes to
survive the pendingenvironmental crisis facing the
north in climate warming.
But Laura's work onhybridization is mostly focused
on macaques and she argues thatthe things we learn from
studying hybrid macaque bonescan help us understand many of
the mysteries of evolution.
After touching on the moderntechniques used in evolutionary

(02:34):
morphometrics simply put,measuring bones and cool ways to
understand evolutionaryprocesses, including the future
role of AI, laura closes withthe idea of niche construction,
where it's not only how we andother species adapt to the
environments around us, but alsohow we change those
environments ourselves, leadingto the conclusion that in many

(02:55):
ways we, and especially humans,are responsible for our own
environments of evolutionaryadaptedness.
So I learned a lot through thisconversation and I'm happy to
share it with you all here.
On the primate cast as thenorthern hemisphere gears up for
the winter.
Remember that we all do havesome physical and many
behavioral adaptations to thecold.
But if you're unsure, hey,maybe you can just hibernate.

(03:17):
Either way, here's ourconversation with Dr Laura Buck
to help get you prepared.
Recently I've come to theconclusion that it's kind of fun
to start each of theseinterviews with like a kind of
off the wall question.
So maybe the closest off thewall question I could think of
when I was templating out thisinterview, laura, is do humans

(03:38):
hibernate?

Laura Buck (03:42):
I would say probably not well currently, although
teenagers sometimes might seemas though they do we don't?
I think the reason for thisquestion comes from an article
which came out a few years agofrom a team who studies an
amazing site called Atapueca.
There's several different timeperiods at Atapueca which are
important.
The one which is in question isthe Cimidolus huisos, so in

(04:05):
this it's called the pit ofbones in Spanish, and at this
site there's hundreds of fossilswhich belong to just to quite a
large group of people which isquite rare in the fossil record.
So it's a very well studied,very famous site and some work
came out a few years ago fromone author who working with one

(04:26):
of the Atapueca team, whosuggested that the pattern of
damage in the bones made it looklike these hominins had been
hibernating.
They were alive about excuse me400,000 years ago, so it's
quite cold period andhibernation can be beneficial in
that kind of situation.
You know other animals do do it.
Bears is the one that getsreferred to a lot and the

(04:47):
authors said that it looked likein the adolescence in
particular there had been thispattern of damage to the bones,
sort of metabolic issues, andthen in the older individuals,
healing after these periods ofdamage.
So they attributed this to sortof seasonal insults to growth
and sort of seasonal cessationof puberty.
I have to say it's notsomething that seems to have

(05:08):
been picked up bypaleoarthopologists on a wider
level.
I had a quick look at it aboutsix months ago when I was
writing a popular article forthe conversation about
adaptation to the cold.
It was during a very coldperiod in the British winter.
So we're interested in howpeople adapt.
It seems like there's just thisone paper, it's a theory.
There were probably other waysof explaining that damage and

(05:31):
personally I think it's just notthe most plausible explanation.
One thing if it was such abeneficial thing to do, you'd
expect other hominins to do it.
Neanderthals are the famouslycold adapted hominin.
Not to say that Neanderthalsare exclusively cold adapted,
but they definitely inhabitedsome cold periods.
They're also this directdescendants.

(05:53):
We think of these Atapuacapeople.
The Atapuaca people are oftendescribed as early Neanderthals,
so they have a lot of thoseNeanderthal traits already.
So if it was something thatthey were doing and that was
working, you would expect to seeNeanderthals do it.
I never heard anyone describethat pattern of bone damage in a
Neanderthal assemblage and alsowe have evidence of hunting
year-round in Neanderthal sites.

(06:14):
So it doesn't seem likesomething they're doing.
It's also pretty rare inlarge-bodied animals.
I think there's a differencebetween different types of
hybridization.
Hibernation there's the onewhere you're sort of asleep for
the entire winter and then bearsand things which are
large-bodied tend to go intotorpor but they sort of wake up
a little bit.
But even then it's quite rarein large-bodied animals and it's

(06:36):
not seen in any other primatethat's a haplarine.
So in our sort of large groupof primates which might be
partly because most primatesdon't have it a cold
environment- but, it just seemslike it would be a bolt from the
blue, if you like.
It's not something we have anevolutionary history of doing.
It's not something we haveevolutionary evidence afterwards
of doing, and if they weredoing it, they were really bad

(06:56):
at it.
It seems to have done them alot of damage, so I'm not
convinced.
Basically.

Andrew MacIntosh (07:02):
Yeah, I mean super interesting story.
So what would be the otherkinds of explanations that you
could have for the observationsthat the scientific team made
that led them to believehybridation might be one of the
explanations?
So what was it specificallyabout the bones that they found?

Laura Buck (07:17):
It's sort of a seasonal pattern, so bones grow
almost like tree rings.
So you can sometimes see wherethe damage has happened in the
sort of history of the bone.
But they do remodel afterwards,which is why the main evidence
was found in adolescence.
They describe it, withoutgetting too technical, sort of

(07:38):
beyond my expertise and beyondprobably people's interest.
They describe it as lookinglike a rotten fence post.
So it's sort of bone notgrowing normally and sort of
resorption, so breaking down ofbone where there shouldn't be.
Some probably related tometabolic issues.
I don't know enough about bonepathology, but they're talking
about it in terms of a sort ofperiodic famine, which I can see

(08:01):
how that would happen.
So I don't see why seasonalscarcity in itself necessarily
would imply hibernation.
Something just not enough foodin the winter period seems quite
plausible without thatnecessarily being related to
hibernation.

Andrew MacIntosh (08:15):
So you mentioned earlier, well, two,
things that I want to pick up onin one of the second.
One will go more into the thebroader scope of this interview
that I wanted to put together.
But the first one is you saidsomething interesting about this
process of science.
You said you were having in inBritain, I guess, a particularly
cold winter.
So people got interested inwhat people do when it's

(08:36):
particularly cold and sohibernation one.
But I wonder if you so that'skind of an interesting, I guess,
the process behind science kindof thing.
So do you have other examplesof where maybe this is an off
the wall question as well, andmaybe it's even in your own
process of how, like things thatare happening now in our own
kind of lives are kind ofdictating the kinds of science
that we're interested in doing?

Laura Buck (08:58):
The, the link between the cold winter and the
hibernation paper was sort ofthe popular paper, so it was
more that the popular website,the conversation suddenly
thought, oh, people will beinterested in that, it wasn't
that.
The research was done at thattime.
I think science takes like theactual research takes longer, so
it's harder to be sort of onyour toes and react to it like
that.

(09:18):
I think a lot of research hasbeen done in response to COVID,
like recently, for example,though like just our renewed
appreciation of the effect thatsomething like a pandemic has on
people, I think has has sort ofit's led to more funding and
more sort of visibility ofresearch on past diseases, but
also probably more peopleconsidering the effect that

(09:41):
disease has on the history ofour evolution and, more recently
, things like the Black Death,the effect on population
demographics, things like that.
So it definitely does happen,but it takes a few years to
filter through.
I think An example of I canthink of in my own sort of
research, history is notsomething that happened in the
sort of sense of somethingstochastic, but the publication

(10:05):
of the Neanderthal genome in2010, which was just not long
after I'd started my PhD,probably led to my interest in
hybridization Because in myundergraduate career up to that
point the possibility ofhybridization was generally
played down.
The main story was that therewas this replacement of homo
sapiens of other hominins out ofAfrica.

(10:28):
Possibly there was someinterbreeding, but it hadn't
been important.
It certainly wasn't expect tosee this percentage of
Neanderthal DNA in most nonSub-Saharan African people alive
today.
So that was a huge finding andI think that sort of.
I didn't start working onthings related to that
immediately, but it bubbledalong in the back of my, my
imagination to what effect wouldthis have hybridization have

(10:49):
had?
And then there's obviously alot of research coming out in
that area and it's sort ofbecome this, this growth
industry, if you like, in humanevolution since those first
papers have come out.

Andrew MacIntosh (11:00):
And also huge popular frenzy around it as well
, with people 23 and me or otherkind of genetic lineage stories
of people figuring out how muchof their DNA.
Is that Neanderthal?
So?

Laura Buck (11:12):
absolutely.

Andrew MacIntosh (11:13):
Yeah, definitely catches people's
imagination.
I definitely want to get intohybridization, but just to kind
of follow up on this, you'vementioned Neanderthals now a
couple of times and you talkedabout hibernation as maybe one
of the more farfitched ways thatpeople have adapted to living
in colder climates.
I think you mentioned in thatconversation piece that we've
kind of dominated the colderclimates around the planet

(11:36):
despite not really having anyadaptations to it, and so what
are maybe some of the other waysthat humans, or even other
species more generally, canadapt to cold climates?

Laura Buck (11:48):
I think all species do this to a certain extent, but
humans are like the apotheosisof using different methods of
adapting, in sort of layers ofarmor.
So we tend to adaptbehaviorally and culturally
first.
Then we might acclimatize, soshort term adaptation.
The next stage would besomething like developmental
plasticity, which thing stressesthat you're exposed to when

(12:08):
you're growing up, affect theway that you, your adaptation
goes, and then sort of the lastadaptation threshold, if you
like, is this change generationover time.
So humans definitely have allof those types of adaptation to
cold.
So the first thing you do ifit's cold is you probably put on
some clothes or you light afire.
You might migrate to somewherethat's warmer, if that's

(12:30):
possible with where you'reliving Then.
So those are all sort ofthey're easy because they don't
really cost you very much.
Okay, it might, depending onhow you're making your clothing,
if that might be something thattakes a lot of sort of time and
energy, but a behavioral optionis usually reversible and it's
usually less costly thanadapting biologically.
Then there are things likevasoconstriction, which is the

(12:54):
blood going away from yourextremities to avoid heat loss
and to, yeah, to keep the mostimportant parts of you war.
So that's a sort of very shortterm option.
Then there are sort of longerterm things which might be more
plastic, so things that mighthappen if you're exposed to cold
stress from an early age.
Things like the, the size andshape of your skeletons.

(13:15):
So one of the two of the mostfamous rules to do with animal
size and shape, including humansize and shape of Bergman's and
Alan's rules, and they're sortof taught at undergraduate level
all in biology and anthropologyall through the last well, 100
years or so at this point, thisis the idea that if you're in a
cold climate, you want to get asclose to possible as being a

(13:36):
sphere, because it has the leastsurface area, so you're losing
the least heat, so you want tobe bigger and you want to have
less, sort of shorter arms andlegs, shorter appendages.
And humans do obey those rulesto a certain extent.
Research done longer ago beforequite as much sort of gene flow
between different populationsand issues with obesity and

(13:59):
things like that have a strongerpattern, but they do still hold
, albeit more weekly today.
So that's that does seem to besomething that happens.
For example, if you take pigsand you raise them in a cold
environment, they, even ifthey're genetically the same.
The ones which are raised in acold environment will stick more
closely to Bergman's and Alan'srules, so they'll have shorter

(14:21):
arms and legs.
They'll be over bigger.
Ferriness is something thatalso in animals tends to go with
that.
So those are the sort of thingsthat happen during lifetime.
And then there are geneticadaptations sorry, like
adaptations to diet, perhapsadaptations to the way in which
fat is recruited to make energy,which have been found in

(14:41):
populations which have a longancestry in cold places.
People like the unit.
So there are many differentlayers of adaptations.
The cold and I think otheranimals do that to a certain
extent but the fact that humanshave more cultural adaptation,
potentially more physicalplasticity as well.
But one of the key ways that weadapt is cultural and

(15:01):
behavioral.
I think that's sort of the wayin which we've managed to
inhabit these cold environments,even though that's not our
ancestral background.

Andrew MacIntosh (15:09):
That's right.
We have this crazy ability tooutsource a lot of the kind of
things that we would need overmillions of years.
Through adaptations, we can getthem in relatively short amount
of time.
I mean even just animal furs asone example.
I think I saw recently thatsome of the furs that the Inuit
use are actually far betterinsulating than, like, canadian
military grade.
You know Arctic wear, so it'squite an incredible thing that

(15:31):
people can do.
And you mentioned also thisidea of replacing, so Homo
sapiens replacing Neanderthals,or now we know that there's a
lot more mixing.
So can you comment then?
Is there, are there examples,or what do we know about?
Maybe so assuming, and maybethis is a little bit of a lay
assumption, but Neanderthalswere generally quite well

(15:55):
adapted to colder climatesclimates maybe more so in
general than sapiens,physiologically or anatomically,
maybe not behaviorally, but soif there is considerable amount
of mixture as well, are theresome examples of like cold
adaptive traits that humansmight have generated during the
process of interbreeding withNeanderthals?

Laura Buck (16:16):
You mean things that we might have got from
Neanderthals.
Most of the information we haveabout sort of adaptive
integration is at the geneticlevel and I don't believe any.
I can't think of any traitsthat are definite the cold
adaptive that have come fromNeanderthals.
There is a huge range of thingswhich have been associated with

(16:38):
greater or greater amounts ofNeanderthal DNA.
Some are to do with diseasesusceptibility, which seem like
they could be adaptive, even ifin current people sometimes
they're sort of maladaptive.
So things like potentiallyrisks for mental health
disorders.
They might be bad for us nowbut they could have been
beneficial in the past and youcould see how, in terms of more
infectious diseases, it would bebeneficial to take something

(17:01):
from a group that's been manygenerations adapting to the
local bacterial fauna and thenuse it without having to spend
that time adapting.
But in terms of morphologywe're not at the stage where
it's easy to say this geneticbackground causes this gross
morphological feature, so it'sharder to to make that link.

(17:25):
But there's so many papers aboutnew genetic traits which are
linked to Neanderthals thatwouldn't be completely confident
that no one has said okay, thisis related to better use of
brown fat to produce energy.
Or there might be things thatare related to metabolism, but
nothing that comes to mind.

Susumu Tomiya (17:42):
Interesting.
That reminds me.
So I have a kind of a follow upquestion based on your very
interesting paper published inScientific Reports in 2019, in
which you compared morphologicalvariations in the scouts of
Japanese macaques versus theprehistoric German people of

(18:04):
Japan, and you found that boththe macaques and the German
people were pretty variable, butonly the macaques their skull
shapes correlated with theclimatic gradient in Japan and
not the German people.
So, listening to what you'vebeen describing about all these

(18:29):
aspects of human evolution, Iwonder if humans are somehow
less capable of morphologicallyevolving compared to other
primates within the specieslevel.

Laura Buck (18:42):
I don't think it's so much that we're not capable
of doing it, because one thingwas interesting, that was
interesting about the monkeyswas that the pattern overall of
variation was quite similar towhat's seen in humans at a
global population.
So the ways in which the coldadapted macaques differed from
the warm adapted macaques wasquite different, was quite
similar to the way in which verycold adapted human populations

(19:04):
differ from more temperate orwarmer adapted populations.
I think the level of coldstress that's needed to make
that change is just greater.
So the reason that we comparedthe Japanese macaques to the
prehistoric German people wasthat they were inhabiting pretty
much the same condition.
So we want to say for thisamount of cold stress, is the

(19:25):
effect similar?

Susumu Tomiya (19:26):
I see, so they both respond to different
degrees.

Laura Buck (19:30):
Yes, and I think there are probably other things
involved which come back to mein a minute.
But I do think culture is oneof the reasons why we don't see
the similarity between theGerman and the monkeys in the
way in which they adapt, becausethe German culture was very
rich, they had houses, they hadfire, they had clothes.
You know, they had a verysophisticated way of dealing

(19:51):
with the cold, which was notbiological, which the monkeys
don't have.
The other things that mightplay a part of things like the
fact that there's probablygreater gene flow between the
groups of humans than there werebetween the groups of monkeys.
As you know, the most of theareas where the monkeys live now
are quite separate, becauseJapan's a very developed country

(20:12):
in terms of lots of cities andagricultural land.
So the areas where the monkeyslive, the forested areas, tend
to be quite widely separated andso it's not very easy for them
to sort of for genes to passbetween the two.
Whereas the German thereprobably was regional.
There are regional differencesbetween different groups which

(20:35):
can be seen in things like thepottery and the patterns of
tooth modification and things.
But there's also trade networksthat can be shown with valuable
artifacts being passed betweendifferent groups.
So there was definitely sort oflarge-scale movements between
groups of people.
So that might have sort ofstopped this pattern of regional
variation building up as well.

Susumu Tomiya (20:54):
I see.
So it might be interesting tocompare prehistoric samples of
Japanese macaques across Japan,when there was less
fragmentation of habitats.

Laura Buck (21:05):
Yes, yeah, if there were such a sample, yeah, that
would be interesting.

Andrew MacIntosh (21:09):
Cool In general I think, this idea of
and I think, Laura, you've donea fair amount of it but this
comparison, using human past,ancient human populations and
primate populations to answerkind of big questions.
I think for you thisinterest-specific variation is
big.
Also adaptations to certain,for example, ecological or

(21:30):
climate regimes, I suppose.
But can you maybe just commenton, I think, how long have you
been studying the Japanesemacaque as a model for this or
macaques in general forcomparison with people?

Laura Buck (21:42):
Since 2015,.
I guess.

Andrew MacIntosh (21:44):
Yeah, was that around the first time that you
came to Japan?

Laura Buck (21:47):
Yes, 2016.

Andrew MacIntosh (21:48):
Yeah.
So maybe, as we kind oftransitioned in a little bit, I
can ask you and also everyonejust heard from Susumu as well,
who's sitting here in the studiowith us.
Excuse me, but I can just askyou what it is that you're doing
in Japan here these days.

Laura Buck (22:05):
I'm scanning a collection of a very special
collection of macaques that'shoused at e-hub, which is hybrid
between Japanese macaques andTaiwanese macaques, so I'm
scanning the pelvises.
When I say scanning, I'mstructured light scanning them,
so I'm Reconstructing virtualmodels of their shape, which I

(22:26):
will use to then analyze howtheir shape Relates to the fact
that they're hybrids, and alsothen the two full-breed parents
as well, the Japanese macaquesand the Taiwanese macaques.

Andrew MacIntosh (22:36):
So one question I wanted to ask that
was related to both what youjust said now and what you were
talking about earlier withadaptations, particularly
adaptations of cold, is you'rehere visiting?
Well, one of your hosts isTakeshi Nishimura.
I was a faculty member here ate-hub, has been for many years,
and he's also Been putting outsome pretty interesting research

(22:57):
in recent years and and I think, some that's relevant to this
discussion too.
So I recently discovered a paperof his that was looking at the
nasal passages of humans andcomparing them also with other
primates and Finding thatthey're not really good at air
conditioning, and so I wasthinking that I guess nasal
temperature should be some waycorrelated with it, how we can

(23:17):
kind of regulate the passage ofair at different temperatures
into our body Homostatically,which is kind of in theory
supposed to be kept at a certainlevel, and so so I know you've
also I don't know if this isrelated at all, but you've also
done some work on sinuses, Ithink, and I don't know if that
has anything to do with, butit's all connected kind of with
the craniofacial architecture,and so I kind of wanted to ask

(23:39):
you about that as a potentiallyone kind of adaptation that we
didn't make for cold climates,and then, just in general, how
you yeah, you think about thatthat definitely on nasal
adaptations to adaptations totemperature, is one of the
things.

Laura Buck (23:54):
So Most of human variation in cranial form is
drift, most of it is just chance, it's you know who you live
near, who you happen to havechildren with.
But there are a few thingswhich, on top of that Imprinted,
which have function, and one ofthose is extreme cold.
So as I was saying earlier tosumo, it's, it's not something
that has an effect at a sort ofmedium temperate environment,

(24:17):
japan level temperature, but wesee adaptation in in populations
living at very high latitudesSuch that their body shape is
different, as I said before,relating to Bergman's and
Allen's rule.
There and this is on average,you have to remember their
cranial shape tends to beBrowner, often bigger as well.
So that's again relating toAllen's rule, to getting close

(24:39):
to a sphere, to avoiding Heatloss, and the no nasal
architecture is something that'saffected.
People who live in cold, dryclimates tend to have taller,
narrower noses and the internalmorphology has changed as well
and this seems to be to do withsort of increasing the time
passage of the air within whenyou're breathing in, so it's

(25:00):
Warming it more before it goesinto your lungs and getting
close to your brain and reallydelicate tissues, so it's
increasing the turbulence of theair.
So there are differences withinhumans, and then there's the
question of how that differs toother species.
One of the areas where it's beenlooked at a lot again is with
Neanderthals, because there'sthis, this sort of trope that

(25:20):
Neanderthals are cold adapted tothe level where Every single
feature in any and a towel hasbeen pulled out and said, okay,
well, that's, that's a coldadaptation because of blah blah,
blah Golden wanting called them, just so.
Stories is this Adaptionistparadigm where you look at one
thing and you say, okay, well,what would that be useful for?
That must be what it's for.
So Neanderthals weirdly, interms of what we know about cold

(25:44):
adaptation in nasal aperturesin general and this isn't just
in terms of humans, it's alsobeen shown in Japanese macaques
and also in lab rats they shouldNeanderthals if they were
called up.
They should have tall, narrownoses, but actually they have
huge noses, they have great, big, wide, beaky noses, which
should be really bad for coldadaptation.
So this is sort of been thisparadox and there are sort of

(26:05):
two potential explanations forit.
One is that they aren'tactually that bad at Recouping
heat with their noses.
They just do it in a verydifferent ways to humans, and
when I say humans I mean homeiscipians, which is another
argument we can get into, butthey have.
So there was a recent studywhich looked it modeled the

(26:27):
airflow computationally througha Neanderthal nose, through a
Homo sapiens nose and throughcabway, which is, depending on
where you stand, homorudiesiensis, homo hadlopiensis.
At any rate it's an olderspecies which probably isn't the
ancestor of the two, but it'sabout 200 to 300,000 years old

(26:48):
and found in Africa.
And they found that actuallythe Neanderthal nose was better
at conserving heat, better atair conditioning, than the
cabway nose, not quite as goodas the Homo sapiens, but it just
did it in a different way.
So the morphology internallywas such that there was still
longer sort of passage time andit was more efficient than you

(27:09):
might expect in terms ofrecouping heat.
So it could be that the nasalaperture or the nose has to stay
wide for another reason.
That could be to do withsomething like diet, to do with
chewing, it could just be driftgave Neanderthals bigger faces
and then they had to adapt to behaving efficient nose for
breathing in cold climatesafterwards.
Or it could be thatNeanderthals actually needed to

(27:32):
dump quite a lot of heat atdifferent time periods.
They also have these reallybarrel shaped chests, which
could be a cold adaptation or itcould be to do with an active
lifestyle.
There's some argument that theyhad very sort of active hunting
practices so running afterlarge game, maybe getting quite
up close and personal with biggame stabbing them, things like

(27:53):
that.
So if they were getting andthey're very muscular, so
they're very insulated, so ifthey were producing a lot of
heat, that can be detrimentaleven in a cold environment.
So the large nose might beneeded to dump heat at certain
times but also try and balanceboth requirements.

(28:14):
So relating back to sinuses isthe fact that all these
structures in Neanderthals havebeen pulled out as being called
adapted structures, and that'ssomething that happened with
sinuses as well.
Since the first Neanderthalskulls were found, people have
said that they had very largesinuses and that those must be
called adapted, becauseNeanderthals were called adapted
, so it's sort of a circularreason.
In fact they don't.

(28:36):
So this is some of the workthat my PhD was doing, and also
Todd Ray, my supervisor, chrisStringer, did some of this
previously.
But Neanderthal sinuses aren'tactually large when you look at
their overall cranial size andalso there's no evidence for
sinuses large sinuses being acold adaptation.
It doesn't work.
When you look at humans overall,the airflow between the sinus

(29:00):
and the nasal passage is tooslow really for it to be
efficient at cooling anyway.
So I think that's important interms of thinking about not
trying to pick out every singletrait and trying to think of a
purpose for it.
Traits are integrated, so thesinuses might be related to
something else going on in theface, and drift, I think, is a

(29:20):
really like neutral processesare something we tend to forget
in human evolutionary studies, Ithink, and they're probably
what leads to most of what wesee in terms of physical
variation between individualsand even at the species level.
Tim Weaver and some of hiscolleagues did a really
interesting paper that showedthat most of the differences
between humans and Neanderthalscranial could be a portion to
drift.
So I think it's a reallyimportant sort of process to

(29:42):
think about.

Andrew MacIntosh (29:43):
Yeah, really interesting.
I mean, I've noticed thatnon-adaptationist hypotheses
have started to kind of grow alittle bit in popularity, but we
still maybe it's the scientifictraining, but we still have
this bent on trying to figureout what the function of
everything is.

Laura Buck (29:57):
I think it's a problem in fossils because we
have such small sample sizes sowe rarely get to look at
variation, and that's one of thereasons I like using non-human
primates, using an extantspecies, because you can
actually start looking atintraspecific variation.
How does that compare tobetween species variation?
It's a problem in hybrids aswell, because hybrid populations
are thought to be more variable, but if you've only got one or

(30:19):
two individuals, they might befrom different times, different
places.
It's very difficult to say howmuch variation there is in a
population.

Andrew MacIntosh (30:25):
So Taiwanese macaques and Japanese macaques.
So there is a place withinJapan where I don't remember the
full backstory behind this, buthow did Taiwanese macaques end
up in?

Laura Buck (30:35):
They were a captive population and they escaped and
they'd bread with local Japanesemacaques.

Andrew MacIntosh (30:40):
Yeah, and it's been some decades.

Laura Buck (30:42):
I guess that they've been interpreting yeah, yeah
since the 70s they were culled,so it hasn't it stopped, I think
in the early 2000s so sort of25, 30 years.

Andrew MacIntosh (30:53):
Yeah, I'm not interested in the hybridization
process, but so what are themajor, then similarities and
differences that you'd beinterested in when you look at
hybridization between Taiwaneseand Japanese macaques?

Laura Buck (31:03):
One of the big differences is size.
Japanese macaques are largerand Japanese macaques are a
really nice analogy for humansand Neanderthals homo sapiens
and Neanderthals becauserelative to the Taiwanese
macaques they're sort of coldadapted, so they're stockier,
they have shorter limbs, theirfaces tend to be broader and
flatter, so some of thoseadaptations that are obeying

(31:24):
Bergman's and Allen's rules.
So those are the sort ofdifferences that we might expect
to see, sort of intermediates,maybe in hybrids.
One of the interesting thingsabout this sample is it's a wild
sample and the hybrids weregrowing up in a Japanese
environment, so it might havebeen beneficial to be more like
a Japanese macaque than aTaiwanese macaque, although
they're from Wakayama, which isrelatively far south.

(31:45):
So ideally it would be nice tocompare them to a sample of the
same hybrids that lived inShimokita or somewhere like
right in the far north.
But you have to work with whatyou can get.

Andrew MacIntosh (31:55):
Yeah, and probably not the best idea.

Laura Buck (31:57):
then, transport no no, I'm not going to intervene.
I don't.
Yeah, definitely not ethical.

Andrew MacIntosh (32:04):
But so you just mentioned that it might be
better than for the hybridsthemselves to have more, or you
indicated to have more Japanesemacaque like traits in order to
be successful in thatenvironment.
But obviously the hybridizationprocess itself, at least in the
beginning, is just total randomassortment, and so it isn't.

Laura Buck (32:23):
It's not totally random because there's mate
choice.
So that's another nice thingabout a wild population they get
to choose who they're matingwith.
The other hybrid populationI've worked with was captive
bred so they had less choice.
But in this case we seeexclusively male Japanese
macaques hybridizing withoriginally with the Taiwanese

(32:43):
female macaques, and then moremale Japanese macaques going
into that hybrid population.
And I think there's two reasonsfor that.
One is that males are the sexthat moves in macaques and the
other probably is that becausethe Japanese macaques are larger
, the males are sort of moreprized by the females than they

(33:06):
would be if they were theTaiwanese macaques.
So to a Japanese macaque female, a Taiwanese macaque male looks
a bit wimpy, whereas a Japanesemacaque male looks like a
really primate to a Taiwanesemacaque.

Andrew MacIntosh (33:17):
I assume that the male's dominance
interactions would probably comein there too.
So if the Japanese macaquemales are much larger than the
Taiwanese macaque males, theymay exclude mating opportunities
.

Laura Buck (33:26):
I would imagine.
So yeah.

Andrew MacIntosh (33:28):
Okay, so that's interesting.
So I'll take back what I saidabout total random assortment of
genes, but the process of beingmore like a Japanese macaque,
if you're thinking of it on anadaptationist's side, that would
then require generations.
So do you think that, apartfrom the sexual selection, do
you think that there wouldpotentially be any natural

(33:50):
selection happening against themore Taiwanese macaque-like
hybrid?

Laura Buck (33:55):
I think we have to remember the epigenetic
potential.
So it could happen on a sort oflifetime basis, not just
generationally.
So the expression of genescould be prioritized.
That may do more Japanesemacaque-like, but yes, over the
course of several generations.
I don't see why that questioncouldn't be sort of selection.
Whether enough generations havepassed for that to have

(34:19):
occurred is another matter.
My colleague, Ito Sanzuyoshi Ito, has recently published at the
moment as a pre-print but it'savailable at the moment and the
final paper will be out soon apaper looking at the
entrogenetic trajectories of theJapanese, the Japanese, the
Taiwanese and the hybrids, andhis results are interesting and

(34:42):
they're sort of they're a spoken.
My suggestion that there mightbe this adaptive integration,
that it might be beneficial tobe more like a Japanese macaque,
because he sees the sort ofpath of development being
different in Japanese macaquesand Taiwanese macaques, with
more or less intermediatebetween them, as the in the

(35:05):
hybrids.
But these differences areestablished before birth.
So what I thought might happenwould be that plasticity and
epigenetic effects might lead tothe hybrids being more like the
Japanese macaques.
But if the these differencesare established prenatally, that
suggests that that's not thecase and you would need
something of a sort of longerscale generational change to

(35:26):
achieve that which, if youimagine I don't know about
Japanese macaques, I'd have tolook it up, but in the Rhesus
macaque the generation time isabout five to six years.
You're looking at maybe fivegenerations.
I don't know if that would belong enough to see a real
difference.
There are studies which haveshown relatively quick changes

(35:49):
in macaque morphology.
There's a famous one whereJapanese macaques were taken
from a Rashiama and they weresort of honshu middle of Japan,
and then half of them were takento Oregon in Northwest United
States and half of them weretaken to Texas in the south, and
over a relatively short periodof time I can't remember how
many generations, but two orthree generations, I think their

(36:11):
body shapes were measurablydifferent.
I would imagine that wasplasticity rather than
generational change, but it'ssomething that would need to be
investigated in more detail.
I think things can happen morequickly than we expect.
The famous studies of Boazeswhere he looked at the children
of immigrants to America.

(36:32):
People often emigrate becausethey don't have particularly
good life circumstances wherethey are, so in their new
country their nutrition wasbetter and their children were
larger.
For example, Some had differentcranial shapes which were
associated with growth.
So things can happen veryquickly, but again the mechanism
may not be what we're expectingto see in the Japanese macaques
Super interesting.

Andrew MacIntosh (36:52):
I also we've talked a little bit about the.
I interviewed Devin Shohe.
He's a campaigns manager atBorn for USA.
They managed that Texaspopulation now of Japanese
macaques from Arashiyama thatwas moved there and some of my
previous professors in theUniversity of Calgary also had
studied that population as welland they had a book published
Arashiyama Monkeys East and Westor something.

(37:14):
But it's quite interesting tothink about those animals now
encountering completelydifferent environments in a
place like Texas, includingdifferent set of species that
they can interact with likerattlesnakes or so, even
behaviorally they must have beenin for a rude awakening there,
maybe they're more about it thanme, but what sort of?

Laura Buck (37:34):
it's been a while since I read the paper.
They're captive, but are theyfree ranging?
How much sort of interaction dothey get to have?

Andrew MacIntosh (37:41):
Yes, free ranging in confined space?
For sure I don't.
I've never seen them, I haven'tbeen there, I don't know how
big their areas were, but theywere basically out out of doors
in a kind of naturalisticenvironment, and I believe that
there was a story about themdeveloping new kinds of alarm
calls, for the rattlesnakes forexample.
But yeah, kind of aninteresting story.

Laura Buck (38:02):
That's the whole other angle.
The behavioral adaptations,right, and how?
So this is really relevant whenyou think about hominins,
because we are such behavioralcreatures.
How ready were Neanderthals andhomo sapiens to recognize each
other as mates?
And that might have beendetermined by by behavioral
patterns.
So it'd be really interestingto know if there are any sort of
ways in which the macaquemating behaviors differ the

(38:25):
Japanese and Taiwanese macaques,whether they it's easy for them
to see each other as mates, orif it's only sort of if you
don't have any other options orthing.
Yeah, I'd love to know moreabout that.
Yeah, fascinating I thinkthere's a little bit of work on
hybrid baboons from Mozambiquethat touches on sort of male
mating behaviors, but I thinkit's an area that's sort of
really ripe for investigation.

Andrew MacIntosh (38:48):
Cool.
So I want to ask maybe veryspecific questions about the
kinds of analyses that you'redoing here.
And you gave a seminar a coupleof weeks ago and you talked
about mainly about previous workyou did at the University of
California Davis, the primatecenter there, or sorry, the
California primate NationalPrimate Research Center looking

(39:08):
at hybrids of Rhesus macaques sothese were Chinese and Indian
Rhesus macaques and then thegradient of hybrids between them
, and you were specificallylooking, in the data you showed,
at the pelvic morphology and so, before transitioning to that
with the Japanese and Taiwanesemacaques, what is the kind of
focus then of the analyses thatyou're doing here?

Laura Buck (39:29):
At the moment I'm scanning the palvases, but
that's partly because Ytosana'salready scanned the crania.
So I'm hoping we can comparewhat's happening in the Japanese
and Taiwanese macaque hybridsto what's happening in the
Rhesus macaque hybrids in boththe cranium and the pelvis.
That's partly because I'minterested in applying this to
the fossil record.
Most sort of fossil studies aredone on the cranium, partly

(39:53):
because of preservation reasons,partly because it's sort of
most informative about taxonomyand how where things fit.
So it makes sense to look atthe cranium.
But the pelvis is alsointeresting because it's one of
the areas where we see mostdifference between humans and
the andatals and also becauseit's sort of crucial to survival
.
If you can't successfully passa fetus through its mother's
pelvis then both of them willdie.

(40:15):
So it's a really sharpselective pressure and how that
works in a hybrid affectswhether you can have a viable
sort of hybrid, whether there'llbe more than one generation
effectively of hybrids.
So both of those areinteresting, but also they might
be constrained in differentways.
So I think it's important toknow whether there's certain
parts of the skeleton which aremore or less affected by
hybridization.

(40:35):
So that's the first step iscomparing what happens in the
hybrids in the two differentspecies and in the two different
areas.
The reason that I want to sortof get a better handle on sort
of the the different variablesthat affect the outcome of
hybrid morphology, is because,ultimately, I want to be able to

(40:56):
build a model that we can applyto the fossil record that will
probably be with crania, becausethere aren't enough palvases in
the fossil record to be able tobuild anything of interest.
So I want to know things like ifthe parents are more or less
related to one another in termsof sort of evolutionary history,
in terms of split time, howdoes that affect what happens to

(41:17):
the hybrid offspring?
If they're morphologically orphenotypically more or less
similar, how does that affectwhat happens to the hybrid
offspring?
And the sort of part of thebody we're talking about is also
interesting in that context.
So if we're looking at whathappens in the cranium, it might
be good to be able to say butyeah, but there's a lot less
variation in, there's a lot lesseffect in the cranium than

(41:39):
there is in other parts of thebody, for example.
Then if further down the linewe want to say something about
femora or something, we mightknow that there would be
probably more or less effectthan there would be in the
cranium.

Andrew MacIntosh (41:51):
Yeah, it's really interesting.
I mean, I think, when peoplethink about hybridization, the
idea of the chimera comes intomind.
Right, you can have thesecompletely, you know, lion body,
eagle, head kind of, which isobviously, in naturalistic terms
, an impossibility based oncontingency and how things have
to work and what you just said.
I mean it just, you can't justcompletely reconstruct a

(42:12):
skeleton like a mashup ofdifferent species.

Susumu Tomiya (42:15):
I think it's important to remember that until
fairly recently, hybridizationwas thought to be a pretty rare
thing, at least rarelysuccessful phenomenon, among,
I'd say, mammals at least, andso it's relatively recent.
Development in populationgenetics and ancient DNA

(42:40):
techniques and so on have givenus a much different picture of
the importance of hybridizationas an evolution of the human
force, even among mammals, andso for that reason I think what
Laura's studying is reallyinteresting, even beyond the
realm of human evolution.

Laura Buck (43:01):
I think one of the things I'd like to do is to put
humans back a bit more into thecontext of other primates.
I think often anthropologists.
As anthropologists, we don'tthink about humans as being part
of the natural world enough.
Obviously, humans are distinctin many ways, but some of the

(43:22):
lessons that we can learn fromother species are very
applicable to hominins, andpresumably the other way as well
.
So I think it's important toremember the sort of zoological
context, if you like.

Susumu Tomiya (43:34):
Sure, there are major differences between, let's
say, macargot hybrids versusbaboon hybrids in terms of
skeletal morphology and how thehybridization produces
morphological traits.

Laura Buck (43:56):
Some of the sort of foundational work looking at
non-human primates, particularlylooking at non-human primates
in the context of humanevolution, was done with baboons
.
Becky Yakerman was sort of theperson who popularized this,
although James Chevrode also wasimportant at the beginning
looking at tamarins.
So some of the very classicstudies are done in baboons and

(44:17):
they sort of lay a foundationfor sort of what we have come to
expect in non-human primatesand what Becky and her
colleagues found in,particularly this one sample of
baboons which was a captivepopulation that's housed in
Texas, and these individualsshow what she characterized as a
hybrid signature, so that theyhave sort of a lot of variation

(44:41):
in the hybrid population.
They have extremes of size andthey have sort of weird traits,
so what are called non-metrictraits, things like the sutures
in their skull might go in weirdways or they might have extra
teeth or rotated teeth, thingsthat probably weren't functional
.
You can imagine that having theextra teeth might be
problematic, but it doesn't seemlike it affected their lives

(45:02):
too much.
They weren't seeming to die ofthese conditions or anything.
But definitely the hybrids weredistinctive, because what we
have seen more recently in otherpopulations is that this sort
of level of strangeness inhybrids is less apparent.
There have been several studieson wild populations of

(45:24):
platterines, of new worldmonkeys, things like howler
monkeys and I'll see the otherone Colortricids, tamarins and
marmosets, and it's difficult tocompare them in several ways
because they're working withlive monkeys, so they're not
looking at their skeletons, sothey're measuring size in a

(45:44):
different way and, unlike thecaptive populations where
there's a pedigree, so you knowexactly who's given birth to
whom, which gives you the amountof hybridity in each individual
.
These are often estimatedhybridity, so they are known to
be hybrids from their coatcolour, for example.

(46:06):
But it seems like there's morevariation in the hybrid
population but there are fewerextremes and in my own work I
found even less of this pattern.
So in my research macaques fromCalifornia, which are also a
captive population, so they knowfrom pedigree, the hybridity

(46:28):
there was very little effect.
It was a very subtle effect andsome of the things which
previous researchers havesuggested affect the amount of
sort of hybrid signature ofthings, like how closely related
the parents are in terms ofsort of genetic distance, split
time between those two taxa, andalso how physically different
or phonetically different theyare and the baboons which form

(46:50):
those classic studies have beenseparated for a much longer
evolutionary history than themacaques which I'm studying and
some of the platterines are sortof intermediate.
It's not a simple relationshipand a lot of the work
determining the effect of thesethings have been done on plants
or fish so it's not always clearthe effect that it would have
on non-human primates.

(47:11):
But it certainly seems, andit's sort of intuitive, that the
less related the parents are,sort of weirder the offspring
are.
Interesting yeah.

Susumu Tomiya (47:20):
Well, if I remember right, in the case of
baboons hybridisation is knownto have occurred not just among
congenital species but acrossdifferent genera.
So the depth of that phenomenonis probably much deeper than in
the case of macaques.

Laura Buck (47:41):
Yeah, I think there are other examples in primates
of cross-generic hybridisationas well, but I don't think
they've been studied to thepoint where we can easily say
you know, if it's cross-generic,you expect to see this effect.
If it's congenital, and alsoit's not like there's a
quantitative definition of agenus or of a species.

Susumu Tomiya (48:02):
Yeah, unless there are some kind of general
species.

Laura Buck (48:09):
I feel like some species are more splittery and
some areas of non-human primatesare more split and some are
more lumped, and it might dependon you know how many different
researchers have been there, allof the history of their study,
as much as it does the actualdiversity within that group.

Andrew MacIntosh (48:30):
I want to follow up on a couple of as soon
as questions there.
One of them was.
So now we have kind of agreater appreciation for the the
degree of hybridizationactually happens in nature.
But I think when you gave yourseminar you gave some statistics
like in vascular plants youknew about 25% of the species
have hybrids, and birds, mammalsand butterflies was only about

(48:51):
10%.
And I wonder so with vascularplants, I mean, we're not
talking about cultivars here,but you're talking about
naturally hybridized species anddo you think those differences
so two and a half times moreplants than vertebrates and
butterflies having hybrids Doyou think that's a natural
process or do you think that's a?
We're missing something.

(49:11):
Is it an artifact of sampling?
Probably both.

Laura Buck (49:15):
Plants.
I'm not very familiar withplant genetics, but as I
understand it they can do allsorts of weird things, like have
multiple copies of chroma.
They can have tetraploidy orquadruploidy or whatever.
That would be where you canhave four copies of a gene, of a
chromosome, but not in every.
They seem to be much moreflexible in sort of what works
being a plant.
So it, with my incompleteness,my incomplete understanding, it

(49:37):
would make sense if theyhybridize more readily, just
also because of the mechanismsof passing on their genes, maybe
they have less choice about whothey're interbreeding with.
If you're a wind-pollinatedplant, you don't get to choose
who you're fertilizing.
But I think there's.
That's.
The paper which I cited isalready relatively old and I

(49:58):
should update it.
I think it's 2007.
So there's probably many more.
There are many more instancesof hybridization known in
invertebrates, in mammals, forexample, but we're discovering
more all the time.
And also it goes back partly towhat we find as a hybrid, what
we define as a species.
We're splitting and renamingprimate species all the time.

(50:21):
So the Tamarins which JamesChevrod studied, for example,
are a new genus now to when hewrote the paper.
So I think those are stillintergeneric hybrid examples.
But you could imagine asituation where something goes
from being intra-generichybridization to between generic

(50:44):
hybridization just becausewe've decided to rename it.
And so we might decide somethingas a hybrid one minute and
decide it's not a hybrid anotherminute.

Andrew MacIntosh (50:52):
So some of it is definition yeah, super
fascinating, I mean the wholelike the species concepts that
we have.
We have so many different waysof defining species and so I
guess maybe where you come downkind of determines too how you
think about that situation.
But the other side of it islike I think maybe this is one
of the issues that comes up withthe Japanese macaque case and

(51:12):
various other ones.
If you think of conservationactions, these days there are
some cases where creatinghybrids might actually be
positive for preservation ofcertain genotypes, although it's
very controversial.
One example is that I thinkthere was a case in Florida with

(51:32):
the Florida wildcats, somountain lions, I suppose they
have their pumas and really badsituation with the local
population.
That was just really not viable.
So you can bring in wildcatsfrom other states, for example,
to kind of hybridize with thatpopulation and it seems to be

(51:53):
kind of successful.
So the hybrids are a little bitmore successful in their
reproduction and survival and soit's a form of genetic rescue.
And I think you mentioned andsomething that fascinates me is
this Groller Bear example aswell, where if you encourage the
hybridization between grizzlyor brown bears and polar bears,

(52:13):
you may be able to kind of Idon't know if it's changed
behaviorally, but therequirements for, like the
strong arctic environments thatthey can maybe better adapt to
changing temperatures andclimates and find new foraging
habits.
So maybe this kind ofchallenges our general idea of
species purity and I wonder ifmaybe you can comment on that a

(52:38):
little bit as well.

Laura Buck (52:39):
Yeah, I think it's a complex and difficult area
because there's sort of badoptions both ways or potential
positives in both ways.
I think there's a differencebetween sort of human mediated
hybridization in the case of thewildcats and to my knowledge
the Groller Bears are sort ofdoing it by themselves.
They're not being led to dothat.

(53:01):
I think you have to be socareful to like human
intervention in species.
I am not saying it could neverbe helpful, but we just have
such a bad track record ofmessing with the balance between
species because the web ofinteractions between species is
so much greater than weappreciate.
On the other hand, if we haveled something to the brink of

(53:24):
extinction, then I canunderstand that wanting to try
and do something about that.
And is there really that muchdifference between bringing a
new species in which adds to thegene pool and replacing a
species that's gone extinct,like, for example, at the moment
there's been a beaverreintroduction in the UK?

Andrew MacIntosh (53:40):
Yes.

Laura Buck (53:41):
So far seems to be going well.
So I just think it would haveto be done so carefully to avoid
, you know, leading to moreproblems than you solve.
And then you end up sometimeswith sort of ego projects like
the potential reintroductionwhat do they call it?
De-extinction of mammoths,where some poor elephant might

(54:03):
be implanted with some sort ofhybrid offspring, which just
seems incredibly unethical.
So I can see the temptation,but human meddling seems
dangerous, yeah, when animalsare doing it themselves.
I think that's more difficult,or no, probably more
straightforward in a way, inthat you know, if that's the

(54:24):
only way that species cansurvive, then perhaps that
should be allowed.
We shouldn't try and controlthat.
On the other hand, you arepotentially losing biodiversity,
which is a problem overall.
We don't want sort of tohomogenize populations.

Andrew MacIntosh (54:41):
Right, this genetic swamping.

Laura Buck (54:43):
Yeah, because ultimately variation is
important and if we have, youknow, one population out
competing another and thensomething changes, then that's
going to be problematic or theniches which they fill will not
be the same.
So I mean it'd be good if wecould not lead to the situations
where these hybridizations arenecessary, so the, you know, the

(55:06):
habitat destruction and theanthropogenic hunting and all
that sort of thing could bebrought down, and that would be
great.
But that's probably not likely.
So I think I'm glad that Idon't have to wrestle with those
issues.
Personally, yes.

Andrew MacIntosh (55:20):
So one of the things I wanted to, while I have
you here in the studio, talkabout is the kind of methods,
the methodology and especiallyadvances in kind of doing the
kind of work that you're doing.
So I think in your presentationand maybe the reason you're
here is doing a lot of 3Dscanning of bones in the
collection you talked aboutgeometric morphometrics and I

(55:42):
wonder if you could just commenton the kinds of methods that
you're using to analyze thespecimens that you have and
what's kind of changed, say inthe last you know handful of
years or something, to what thekind of state of the art is now
and where do you think it'sgoing.

Laura Buck (55:58):
Geometric morphometrics is relatively new.
It's a way of analyzing shapequantitatively, but it keeps the
geometric part of the name isto do with keeping the geometry.
So if you take a bunch ofindependent measurements you
lose the overall shape of theobject, whereas if you look at,
compare something usinglandmarks which is what we do in

(56:19):
geometric morphometrics, whichmeans basically putting points
on the same place, like forexample between the eyebrows in
every individual, and comparingwhere that is in 3D shape, so
you can look at how thoselandmarks in an individual
relate to one another and lookat their overall shape, how that
overall shape differs betweenindividuals and how that's
related to variables of interestsuch as environmental variables

(56:40):
or admixture, hybridization,that sort of thing.
So it's a really powerful suiteof techniques and its origins
are quite old more than 100years old but they used to be
done with mathematicalcalculations on paper or early
computers and it's only reallywith the birth of more

(57:04):
sophisticated imaging that istaken off in the way that it has
.
Probably in the last 20, 30years it's become much more
prevalent and the types ofimaging techniques which have
really made it possible are CTscanning and then surface
scanning methods.
So at the moment I'm using astructured light scanner which
sort of bounces off light in astripey pattern and the way in

(57:25):
which it's reflected back to asensor is interpreted into the
shape of the object.
So it's pretty clever.
I think I talked about thisbefore, but the scanner which I
brought with me, which I plan touse, was even.
It's very clever because it'ssomething that's supposed to be
very portable.
It's a handheld thing thatlooks a bit like an iron and you

(57:47):
basically slowly move it overthe object in question and then
you can reconstruct single scansinto an object.
Unfortunately, the scannerwhich I brought all the way to
Japan and which I have usedpreviously with success turned
out to be really bad atcapturing monkey pelvises,
probably because they're verythin, they have sharp edges and

(58:09):
they're quite small, so theysort of scatter the light and
we're not enabling it to capturegood pictures.
So I was lucky to be able toborrow another scanner from
Professor Hirasagi here whichenabled me to carry on scanning
in the way that I'd planned to,but with a different model, and
this sort of shows theproliferation of different

(58:29):
scanning machines in the lastfew years.
So when I first started scanningthings with a laser scanner,
which is related to a structuredlight scanner.
There was a thing called a nextengine which was super popular,
relatively cheap.
It had a rotating platform anda sort of eye that you pointed
out which sends out the laser,but the quality was not great.
Since then, every time I'vetalked to someone about what

(58:52):
they're scanning or go to adifferent institution, it seems
like they have a different pieceof kit.
There's so many differentpieces of technology now and
they all use it slightlydifferent ways of doing things.
The scanner I'm using at themoment is the same sort of model
as the next engine in that ithas a rotating plate, which is
great because it means that Idon't have to be scanning all
the time, so I can do somethingat the same time.
And I think it helps becauseit's sort of got an internal

(59:18):
coordinate system, because theplatform is fixed rather than
moving the iron-shaped thingover it.
So I think it helps it to knowwhere it is, which helps it to
reconstruct the scans better.
There's a lot of sort ofcheaper versions than there used
to be as well now, and even tothe point where you can get
pretty good service scans withan iPhone.
This was one of my backup plans.

(59:39):
When my scanners stoppedworking, if I couldn't borrow
another one, I thought, well,maybe I can just buy a new
iPhone but worst case scenariocome all the way to Japan and
I'm not sure.
If one thing I was worried aboutin that context was I'm not
sure the resolution is goodenough for a small enough object
.
But certainly people have usedthem very successfully for
things like archaeological digsto show what they look like, and

(01:00:02):
I believe the resolution isactually pretty good.
Photogrammetry is another bigsort of growth area, so that's
taking loads and loads ofpictures and stitching them all
together.
So these are all relativelycheap, relatively accessible.
It's all relative.
They're not cheap Ways ofcollecting the data which can
now be used for geometricmorphometrics.

(01:00:24):
I think the gold standard isstill CT scanning because, for
me at least, because the wavesgo through the object, you get
the entire structure.
You get the internal structureand the external structure and
you don't miss anything, whereaswith the scans that I'm taking
at the moment structured lightscans if I'm doing something

(01:00:44):
like a skull around the back ofthe eyes, where the bone is
quite thin and sharp, it can bevery difficult to get every
little sort of invagination ofthe skull, whereas with an X-ray
particle it just passes rightthrough the internal information
is also really great, but a CTscanner is usually not portable.
It's much more expensive.

(01:01:04):
Potentially it damages the DNAof whatever you're scanning,
which may or may not be aproblem, it seems like.
As long as you use the correctparameters, it's probably still
worth scanning things,especially before you then
sample them for DNA, becausethen that information is lost,
but it's something to beconsidered.
So there is like a whole rangeof methods now, which most of

(01:01:26):
those were available in someshape or form a few years ago,
but that they've just becomemuch more accessible to your
average researcher.

Susumu Tomiya (01:01:36):
Yeah, I just want to add that.
But when I was in graduateschool, mainstream geometric
morphometric analysis was stilltwo-dimensional, based on
pictures.
But there's only so much shapeyou can capture of, let's say, a
squirrel skull if you're onlytaking pictures in two-dimension
.
So this is another area wherethere has been a rapid

(01:02:01):
development in technology andaffordability of 3D scanners has
been greatly helpful and hasmade science much more powerful.

Laura Buck (01:02:14):
Yeah, definitely.
I remember doing things withmandibles as well as
two-dimensional, and you have tobe so careful to keep the
orientation correct and toaccount for size and things like
that.
And one of the first pieces ofkit I used I started off.
I was lucky to have CT scans,although the quality if not all
of them was great because theywere medical CT scans.
But the microscribe was a bigthing at that time, which is a

(01:02:35):
thing that looks a bit like anangle-poise light, but it has a
point on the end and every timeyou touch the place of interest,
the landmark, you push a footpedal and it records its
coordinates in 3D space.
And they were relatively cheapand relatively portable, so they
were used a lot.
But they have calibrationissues.
They can get confused aboutwhere their orientation is and,

(01:02:59):
because you don't have the scan,if you forget a landmark or
you've put it in the wrong place, you can never go back and
recapture that data, so it's alot less flexible.
I had a similar sort of problemwith the technology with the
microscribe.
When I went to the AmericanMuseum of Natural History as the
early part of my PhD, I took amicroscribe with me to collect
data on the skulls that werethere.

(01:03:19):
Happily collected data for aweek got.
I don't know, several tens ofskulls.
Got home, I re-scan, I used themicroscribe on some that I also
had CT scans for.
They were completelyincomparable.
It must have got uncalibrated,probably on the journey.
There was a way of homing it,which I did when I got there,

(01:03:40):
but probably there's internalconsistency in that sample.
I could probably use it just onits own, but I couldn't use it
as part of my PhD, so that was aweek's worth of data collection
that was unusable.
So this is the problem withtechnology.
If I was using a tape measureit wouldn't be a problem, but it
also obviously allows you to dothings that you couldn't do

(01:04:00):
with a tape measure.

Andrew MacIntosh (01:04:02):
So I another interesting thing about
geometric morphometrics is thatwe had another graduate student
recently finished who was usingit for on macaque faces as an
indicator of pain face and so away to kind of try and better
understand the welfare status ofindividuals.
But it seems like it's used ina lot of different, a lot of
different kind of areas ofscience and it also seems to be

(01:04:26):
really amenable to or fitsreally well with modern advances
in AI.
So I wonder if you have any.
So how is?
I don't know if you've alreadyexperienced any people in
colleagues using AI technologynow to do analyses of structures
, or where do you think that'sgonna have the biggest impact in
the science that you do?

Laura Buck (01:04:48):
I think it could be really great because there's so
much prep time in that sort ofdata collection and data sort of
cleaning.
Though the only place whereI've used it which I'm not sure
if it's strictly speaking AI,but programs like Checkpoint you
can build a template, so you doa landmark set on one skull and

(01:05:09):
then it will automaticallyapply it to all the others in
your sample and then you gothrough and you change it.
So there's still that.
I think the important thing isthat there's still that user
involvement.
You check they're in the rightplace.
But it saves you a lot of timeand also it takes out some of
the human error when you'relandmarking.
I don't know to some of thelandmarks with semi landmarks as

(01:05:30):
well, I might have 200landmarks, 300 landmarks on a
skull.
It's so boring, it's reallyhard to stay concentrated, so
it's really easy to put them outof order or to miss one, and
then it's very time consuming togo back and work out what your
problem is, because you findthat it's not working, so you
must have done something, sothen you have to take a really

(01:05:50):
long time to go back.
So I don't think that that's animportant part of scholarship
to spend that time doing it.
I think a computer can do thatsort of thing much better and
then the human can put theenergy into trying to work out
what the patterns are, to doingthe analyses sort of downstream.
When I was doing my PhD I did alot of measuring sinus volumes

(01:06:12):
from CT scans.
So this is virtual segmentationgoing through CT scans and
saying, okay, that area is thearea I'm interested in, and
basically coloring it invirtually with a felt tip pen to
select the region I wasinterested in and then joining
all those regions together tomake a structure and then
measuring it.
And the reason why it'sparticularly hard for sinuses is

(01:06:34):
their air.
So you can't do it by threshold.
You can't say I want everythingbelow this density threshold to
be a sinus, because it wouldtake all the air in the skull
and all the air around the skullas well.
So it had to be done more orless manually and it took so
long and I don't think evenafter doing I don't know 200
individuals I was thatproficient at it that a machine

(01:06:57):
probably couldn't have done itbetter.
And now there are sort ofsemi-automatic and automated
ways of doing that which weren'tavailable now.
And I think that's fantastic,because that is not the best use
of the student's time To behonest.

Andrew MacIntosh (01:07:08):
I mean, I know a lot of you know in my lab.
We do a lot of peristology workin the laboratory.
So you're under a microscopecounting little eggs that you
see perisa eggs and samples ofmacaque feces or whatever it's
gonna be and totally agree.
So we have some imagingtechniques that should be able
to handle that for us, but a lotof the technology is still
currently sub-human levelprobably.

(01:07:30):
That's going to changeAbsolutely.
There should be more data setsout there, training data sets,
and it's gonna get a lot betterwith accuracy.
So we're just kind of in thattransitionary period, but it's
certainly a lot of tedium thatpeople go through.

Laura Buck (01:07:43):
It's interesting to hear about those stages in other
fields.
I feel like in my field ittakes such a long time to get
the data and that's sort of that.
It takes longer than otherpeople, so it's nice to know
that other people also have tospend, you know, months, getting
to the point where they caneven start getting the numbers
to analyze.

Andrew MacIntosh (01:08:01):
Yeah, exactly Susumu.
How about you?
Any thoughts on the horizon forAI?

Susumu Tomiya (01:08:06):
Yeah, so I agree with what Laura was saying.
At the same time, I think thegeometric morphometrics is a
more established method and theresults are probably more easily
interpreted than what AI speaksout.
So with the GM, you define thepoints of interest which may be

(01:08:29):
anatomically important orevolutionarily important,
Whereas if you just feed AI witha whole bunch of scanned images
, well, it may be able todistinguish among very subtle
differences, but you don'talways know what exactly the

(01:08:49):
machine is recognizing.
So I think that's one of theissues that Vanessa, one of our
graduate students, had with theapplication of neural network to
the Makak pain phaserecognition.
She ended up relying more onthe geometric morphometric
analysis in the end.
So there's definitely apotential for AI application.

(01:09:12):
But yeah, like you said, Ithink we definitely need the
transitional period and GM isstill quite valuable?

Andrew MacIntosh (01:09:19):
Yeah, it's interesting to think.
I mean, what does a computersee when it looks at these
things?
Versus what do we see?
And are they comparable in anyway?
Certainly doesn't seem to be atthe moment, but it reminds me
also, laura, in your talk whenyou were talking about the
hybrid pelvic morphology and theRhesus monkeys from California.
In the end, your results, youhave some differences, but it's

(01:09:41):
very minor and a lot of overlap,maybe no huge patterns coming
out of it.
I don't wanna get into thespecifics, but maybe related to
what Sasumi just said about theAI, it also seems like it might
make it a little bit hard toknow what the importance of
those changes might be.

(01:10:01):
So, like, how can we kind ofseparate and this is gonna kind
of transition into my lastquestion, which is more about
you've mentioned a few timesover this interview already but
how should we consider variationand how can we extract meaning
in that variation?
And then maybe you can walkthat one into the last question,

(01:10:23):
which is more about where areyou kind of going with this
science?
And you mentioned a few timesthat you're really interested in
applying what you can learnfrom more or less?
modern assemblages to kind ofhuman or hominid fossil record,
and so how can we kind of teaseout, like the meaning from the
variation in that respect andwhere do you wanna take it?

Laura Buck (01:10:45):
Okay.
To leave you with a very simplefinal question yes, it depends
what you mean by the importance.
I think that the effect ofhybridization on the variation
in that sample in particular isnot important.
I don't think it's changing thelives of those monkeys in any

(01:11:08):
way, so it's not a functionaldifference, if you like.
I do think it's interesting tounderstand how variation is
patterned overall, to understandwhat parts of it are due to
different causes, so that we canunpick the sort of neutral from
the functional and understandwhat causes the neutral
variation, because that stillleads to variation, which is

(01:11:33):
what evolution is acting on.
What I still think thevariation in those monkeys is
important in a different waythough, because it helps us to
understand what happens whenhybridization occurs, which
helps us to know what to expectin other species, particularly
in the fossil record.
So would we be expect to beable to see it in fossils that

(01:11:54):
we find, or would we expect itto be too subtle to be able to
define?
Morphologically?
Is the pattern similar, even ifthe magnitude is different?
So the monkeys that I waslooking at the two Rhesus
macaques Chinese and IndianRhesus macaques are physically
pretty similar to one another.
So it's not that surprisingthat the hybrids don't have a
huge effect.

(01:12:15):
So there's not a huge effect ofhybridization on their
offspring.
But if the pattern is the samein individuals which interbreed,
which have more differencebetween them, then we could
still use that to build therelationship between hybrids and
hominin tags.
I think I'm just trying tounderstand better the variables

(01:12:36):
which shape hybrid expression inoffspring basically.
So what effect do the parts ofthe body have?
What effect does the distancebetween the parents have?
Particularly, what effect doesphenotypic morphological
difference between the parentshave?
One of the reasons I'm sointerested in that is that
humans and Neatals, homosapiensand Neanderthals, are very

(01:12:58):
closely related but they'rereally different skeletally and
I'm interested in why that mightbe the case and the effect that
it has on their hybrids.
This sort of maybe it's a bit ofa pet subject, but I think one
of the reasons that they mightbe so different is that they do
have this layer of culturaladaptation to a greater extent
than other animals.
Neanderthals are also verycomplex in terms of cultural

(01:13:21):
behavior.
So if you are able to adaptmore culturally and behaviorally
, maybe you are free to varymore neutrally in terms of your
skeleton.
There are other reasons whythey might vary more as well.
Perhaps their environments aremore different than the macaques
are, but I feel like therelease of constraint on the

(01:13:41):
skeleton, which might be due tocultural buffering, might play a
really interesting role andmight tell us about the ways in
which humans, or hominins as awhole, are different from other
primates.
So, even though I'm interestedin putting humans back into the
primate context, I'm alsointerested in what makes us
distinctive.

Andrew MacIntosh (01:13:58):
That sounds like such an important task,
given the changes that we'reprobably about to go through in
the planet and whether we'reactually culturally able to
adapt effectively enough tohandle those.

Laura Buck (01:14:11):
I think the trouble is it's not just capacity, it's
what's the word.

Andrew MacIntosh (01:14:15):
Willingness.

Laura Buck (01:14:19):
Yeah, it's not just the ability, it's the working
together, it's the seeing beyondthe immediate it's working for
the common good rather than theindividual good.
History tells us that humansaren't very good at those things
.

Andrew MacIntosh (01:14:31):
Yeah, I wish it were different.
Well, laura, is there anythingelse that you wanted to add to
or that I've missed, or youwanna finish up with?

Laura Buck (01:14:40):
I thought we might talk about what's it called
niche construction a bit, but Iguess we sort of talked about
that a little bit.
But I just think that's aconcept that doesn't get enough.
I mean, it's not a little knownconcept but one that perhaps
doesn't get enough airtime interms of human evolution,
because it does go back to thisidea of the relationship between

(01:15:00):
culture and environment andbehavior and this link.
So I've been talking about howwe use our behavior to adapt to
the environment a lot, but ofcourse our behavior also changes
the environment, which then hasan effect on us.
So it's this real ratcheteffect, it's this we shape
ourselves and then we shape ourenvironment and our environment

(01:15:23):
shapes us.
Probably the most canonicalexample of this for humans is
agriculture.
So perhaps the start ofagriculture was due to
environmental effects, perhapsMaybe a drying and a cooling
leading to people collectingmore food sources as a sort of
protection method.
But then the way in which wechanged the environment due to

(01:15:44):
agriculture had effect on thingslike disease prevalence,
sedentism, things which are alsobehavioral, like division of
labor, specialization, leadingto differences in technology,
and then ultimately to the wayin which most of us live today
and the massive sort of climateand environmental disasters that

(01:16:04):
have come about down the lineand some of the ways in which
our bodies have changed sincethe start of agriculture are
reflected in that.
Things like less bone density,greater heights, early puberty,
all these sorts of things.
So I think it's reallyinteresting to think about the
way in which we sort ofconstruct our own evolution.

Andrew MacIntosh (01:16:23):
Absolutely.
I know that that's somethingthat's quite interesting for,
and maybe part of the storybehind the kind of renaissance
of group selection thinking,this kind of social needs
construction as an example of it, where we kind of create the
social environments and thenmaybe some versus other social
environments are actually moresuccessful.

(01:16:44):
So kind of an interesting story, but humans are definitely a
perfect example of a speciesthat creates.
Are there any other, though,examples that you can think of
apart from us?

Laura Buck (01:16:59):
Their own needs, change our environment.

Andrew MacIntosh (01:17:01):
I mean, there are some classic ecosystem
engineers, right, you think thebeaver brought up earlier is
like a great example of aspecies that has a huge
influence on its environment,and then probably there's been
some feedback mechanisms inthere.
Yeah, absolutely.

Laura Buck (01:17:13):
I think so.
I think there's bacteria thatdefinitely create the
environment in which they existwhich has probably shaped them,
sort of changing the pH and thetemperature.
Termites, for example, buildthese huge cities.
They probably couldn't existoutside them anymore.
I think lots of things do in asort of smaller way.
We're unusual in the way thatwe sort of do it in lots of

(01:17:34):
different ways.
So Robertson his co-author,whose name I can't remember off
the top of my head, have thisterm that we're specialist
generalists.
So you get your specialist likea panda who can only do one
thing.
You get your generalist like araccoon who eats anything.
Humans different.
Humans are specialists indifferent things, and so that's
one of the things that hasallowed us to sort of inhabit
all these different niches.

(01:17:54):
So we sort of we're beavers,but also bacteria, but also
termites.
You know, we do everything indifferent ways and that's sort
of how we've managed to colonizeeverything.

Andrew MacIntosh (01:18:04):
Yes, and as we continue to look beyond what
we've already colonized in thehopes of colonizing the unknown
at the moment, I hope ourability to kind of create those
niches in which we can continueto evolve doesn't slow down
anytime soon.
But I think that's a good placeto close.
So, lorbuck, thanks so much forjoining us on the primate cast.

(01:18:24):
Thank you, sussumu Tomia.
Thanks again for joining us inthe studio.