January 11, 2024 • 36 mins
Catherine interviews Dan on one of his areas of expertise, human evolution. Not only is a Dan a professor of Biology at Franciscan University of Stubenville, but he is also the author of several articles and books on evolution. His newest book on evolution will be released in 2025 by Word On Fire Press. Dan and Catherine's discussion unearths the complex mosaic of human evolution where our shared ancestry with chimps is just the beginning.
Have your call in questions be featured on the podcast:
Leave a voicemail at 949-257-2436
Learn more and read articles:
https://www.magiscenter.com/purposeful-lab
Mark as Played
Transcript
Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
Speaker 1 (00:00):
Welcome to Purposeful Lab, a Magistenter podcast.
I'm Catherine Hadrow with DrDan Kebler.
So here we are, season three.
Again We've been looking atbiological evolution and this
episode we're going to dive moreinto human evolution and better
understanding all theenvironmental factors at play,
which is important to betterunderstand us and humans.
Speaker 2 (00:22):
Right yeah, If we want to understand humans who
they are, who we are, ourpurpose and so forth,
understanding the context inwhich humans emerge is important
.
Speaker 1 (00:30):
For this topic.
I have the privilege tointerview you.
So thanks, for what are youforward to?
Yes, for diving into this,because you've written on this
topic again about humanevolution.
You've written the book theEvolution Controversy a survey
of competing theories.
You have a new book coming outearly 2025 with Word on Fire
press about the church's view onevolution.
(00:52):
So again, and, of course,biology professor at Franciscan,
where you've been for over 20years.
So grateful to speak with youon this.
Speaker 2 (00:59):
Yeah, it's going to be good to talk about this.
Speaker 1 (01:02):
So I know we're going to start talking about the
hominin fossils, but can youfirst just set us up what is a
hominin?
Speaker 2 (01:11):
Yeah, so what we're going to talk about today is
what's happened in recenthominin evolution, so about 7
million years ago.
There's a common ancestor thaton one branch led to modern
humans and on another branch ledto modern chimps, our closest
living relatives.
Hominid evolution is looking atthe fossil form, if you find
that are more closely related tomodern humans than to modern
(01:33):
chimps.
So we're going to be looking atwhat happened in that lineage
and what you see.
What factors played a role inthe diversity you see in hominin
fossils?
Speaker 1 (01:44):
So to get us started on that and looking at the
patterns found in these fossilrecords over the past 7 million
years and really discussing whatthat reveals and, again, all
the environmental changes thatinfluenced it, so can you give
us a quick summary of thispattern that we see in these
fossil records?
Speaker 2 (02:01):
Yeah, you know it.
Just you know this field is alot of active research.
So the little details you know,they're finding new details all
the time, but sort of the youknow the 30,000 foot, you know
overview of what you see andwhat you don't see is you know
those neat bumper stickers wesee in A, so they're gradually
standing up like this the A goto B, go to C.
It's like neat linearprogression.
(02:23):
That's not what you see in thehominin fossil record.
What you see is more of a mosaicpattern.
What I mean by that is youstart to see a variety of
different fossil forms.
Some look more modern, moremodern in like their brain,
others might look more modern intheir jaw right, and so you get
these sort of.
It's hard to put them alltogether like which one is more
(02:47):
modern, which one is moreancient and so forth in terms of
their features, because you seethis sort of almost a
experimentation going on withAll simultaneous.
Yeah, so, particularly if youlook in Africa between two and
four million years ago, there'sa lot of different hominin forms
in Africa that it's hard to howexactly are they all related?
But what you do see is adiversity and they are changing
(03:10):
in ways that are getting on thepath towards sort of the modern
human form.
Speaker 1 (03:18):
So is it fair to say, if all that was going on
simultaneously, was there trulya progression?
Speaker 2 (03:23):
You see, on average you know, an increase in brain
size over time.
But say, if you go back to fourmillion years ago and look at
the, the hominin fossil has thebiggest brain size.
There's going to be a largerbrain than if you go back six
million years.
And if you look at the homininfossils from, you know, half a
(03:44):
million years ago, the largestbrain is going to be bigger than
the largest brain two millionyears ago.
But at the same time there'sthis mosaic.
So there was a hominin fossilfound that dates to about 20,000
years ago, was found inIndonesia and has a relatively
small brain size.
So it's not like every homininfossil is going in one direction
.
In a sense it's exploring thedifferent possible ways that you
(04:06):
can make a hominin and out ofthat sort of exploration one
emerges and takes over.
You know that's modern humans.
Speaker 1 (04:15):
You mentioned and I can totally picture it right now
, that popular bumper stickerthat people see of again like
it's like a chimp and it'sgradually, you know, it's
hunched over and then it'sslightly less hunched over and
then it's an upright man.
But you said again, it's notnecessarily that clear
progression like that.
But what are the factors thatwould have led to again a more
(04:38):
upright, big brained human?
Speaker 2 (04:40):
Yeah, so if you look at, you know, the hominin fossil
record up until about twomillion years ago, all the
hominins are found in Africa.
So this is the factors that aregoing to drive the first stages
are all going to be changes thatare occurring in Africa at that
time, and one of the thingsthat major factors is changes in
(05:01):
the climate.
Okay, so two major things arehappening, particularly from
five million years ago till thepresent.
You see two things.
One, you see sort of a globalcooling going on and you also
see more fluctuations in sort ofglobal temperatures, right, so
you're getting more variabilityof the temperatures and you're
getting a global cooling.
(05:22):
Now what that does in Africa inparticular, as the, the earth
cools, you get more watertrapped in the at the poles and
the ice caps and you have sortof a drying out of the climate
in Africa.
And so what is that going to do?
So you know, if you think of,like, where chimps are in sort
of a river forest, you know alot of vegetation and so forth.
(05:44):
If you start to dry out areasof Africa, you have these
savannas, these plains, whereyou have, you know, a different
way of possibly making a living,having upright posture to
travel through these savannas,having the ability to, you know,
use your arms to throw thingsand hunt and so forth are going
(06:06):
to help you survive in thisdrier, savanna-type climate,
whereas, you know, the primatesthat remain in sort of the river
areas are going to do well andthen develop into, say, modern
chimps.
So there's sort of twodifferent ways of in a sense
it's more complicated than that,but sort of two different.
You can see in these twodifferent paths, the hominid
(06:28):
path is exploring this new drierclimate in Africa and there has
to be some, you know, a numberof changes to be able to, you
know, know where food might beat different times of the year.
You should migrate from onearea to the other in this new
environment.
So having a larger brain canhelp you remember, divide up,
you know this labor, you knowsocial group and so forth, and
(06:50):
having that upright postureallows you to move more
efficiently.
Yeah, so one of the things youknow, upright posture, you know
as you move across the savanna,it, you know, you're gonna have
a couple benefits.
One, humans are very good atlong distance, running right, as
opposed to other species, yeah,and particularly like ungulates
(07:16):
, you know, they like zebras andthings like that, the game that
they would have in Africa.
And so, having the ability tobe upright and to run, they can,
they can actually outrun, evenif they go at a moderate pace,
can outrun these ungulates, andthen they get really overheated
and fall over, whereas humanswith this upright posture
they're not, but they have aneasier time dissipating heat and
(07:37):
they can run better they can.
They can hunt better in thesavanna environment.
Speaker 1 (07:42):
So you mentioned this .
You know cooling period thathappened.
So is that the ice age thatyou're referring to?
Speaker 2 (07:48):
Yeah, Well, so the cooling period, you know it
started about 50 million yearsago and particularly accelerated
maybe the last two and a halfmillion years ago.
But what you see is not just acooling of the temperature.
You see these big fluctuations,right, and so you see these
glacial periods and then theinterglacial periods.
So you would have say the iceage and then you'd have the
inter ice age and there was acycle roughly about every
(08:11):
100,000 years that you would gothrough this, right, and right
now we're in this interglacialperiod for the last 11,000 years
or so.
But you know, having to survivethese, these, that changes in
climate, having, you know, moredeveloped social structure, a
bigger brain allowed to adapt tothese, these, these changes in
(08:32):
the environment could help drive, you know, hominid evolution
towards a large brain, socialhominid.
Speaker 1 (08:38):
Would you, you know, with something like humans have
evolved without this cyclical,dramatic change in the
environment like you'redescribing?
Or, again, are humans just achance product of a chance
environmental happening?
Speaker 2 (08:54):
Yeah, so clearly in the way evolution has played out
in the last seven million years, there's certain environmental
factors that have triggered andhelped shape the human form over
hominid evolution time.
Had the environment changeddifferently, maybe the form
would have been slightlydifferent.
But there's something about, Ithink, a large brain hominid
(09:17):
like you and I that has anadvantage over other ways of
making a living.
And so had the environmentchanged slightly differently, I
think eventually there's lots ofenvironmental change going on
over time that you would emergesome large brain primate.
That's upright.
It might have been a differentpattern, different timing and so
(09:39):
forth, but I think it'ssomething like that would have
emerged.
That's something that we've hadSimon Conway-Morrison before
and he talks about that in hisbook Life Solutions that there's
this convergent evolution.
So this is the factors thatdrove human evolution this time.
Had it been slightly different,well the pathway might have
been different, but we probablywould have, through this mosaic
(10:00):
experimentation, come up with aform that's very similar not
identical, but similar.
Speaker 1 (10:04):
You mentioned Africa and how hominids were present in
Africa and they were only foundin Africa until about 2 million
years ago.
Why did hominids leave Africa?
Can you speak about that?
Speaker 2 (10:15):
Yeah, so up until 2 million years ago the hominids
were in school.
They leave in Africa.
Now some of them start to leaveAfrica and some hominids
obviously are still in Africaduring that time.
But whatever reason, about 2million years ago the first wave
, this is Homo erectus, which isAfrica, and heads into Asia.
(10:37):
So they don't go into Europe,which is probably too cold at
the time.
But why?
It's a great question.
I think there's something aboutas they can migrate.
The long-distance migrationbecame part and parcel of the
sort of hominid forms and yousee this wave of hominids leave
(10:57):
Africa 2 million years ago.
You see another wave thatleaves and gives rise to
Neanderthals about a halfmillion years ago.
And then finally, you see awave leaving Africa of modern
humans about 50,000 years ago.
That then colonizes basicallythe whole globe other than
Antarctica.
So there's something in our DNA.
It was this wonderlust ofwanting to go explore, and it's
(11:20):
something that we find in ourhominin ancestors too.
Speaker 1 (11:24):
You mentioned Neanderthals already and they're
fascinating for a number ofreasons.
Can you first explain what youmean by Neanderthals exactly,
and how are they related tohumans and where did they end up
?
Speaker 2 (11:38):
Yeah, so Neanderthals , the lineage leading to them
and humans separated about500,000 years, like half a
million years ago, and theyleave Africa into the Middle
East and they eventually maketheir way into Europe, and so
they were able to colonizeEurope as, while like the
(11:58):
earlier, like homorectis, whenthey left they didn't, and they
seem to have a larger, morerobust form that they were
better suited and adapted forthe colder climate in Europe,
most likely.
And they're really fascinatingbecause when humans modern
humans leave Africa, theyencounter Neanderthals, and
(12:19):
Neanderthals were still therethey don't disappear until
roughly 30,000 years ago.
So when modern humans leaveAfrica, there's a number of
hominid forms that they mighthave encountered.
They weren't the only hominidform on the planet, and so
there's a lot of interestingthings about the interactions
between Neanderthals and modernhumans.
Speaker 1 (12:39):
Remember I had asked you in a previous episode how my
DNA test showed up.
I have Neanderthal DNA and I'mlike what is this about?
So why did they end up the waythat they did?
Eventually Neanderthals.
Speaker 2 (12:53):
And why did they end up in Europe?
Yeah, so again, the idea isthat there's a niche there in
Europe, so there is no hominids,and so they were able to take
over and make a living there.
Maybe they have a larger brainthan, say, homorectis, and so
maybe that allowed them, and alarger body that allowed them to
(13:16):
adapt to this climate that, say, other hominids weren't able to
successfully adapt.
Speaker 1 (13:23):
So, as we're looking through this process of human
biological evolution and gettinga little bit closer to modern
human culture, the modern humanform, my understanding is it
seemed to emerge, and Africa,200,000 to 300,000 years ago.
Is that right?
So what do we know about thosefirst modern humans?
Speaker 2 (13:44):
Yeah, we don't know that much about those first
modern humans, but if you lookat the fossil record, it's in
Africa that you see theemergence of fossils that look
relatively similar to UNI right,and so the oldest of.
There's some fossils that areabout 300,000 years old that are
found in Morocco, so likeNorthwest Africa.
(14:05):
And then there's some that areabout 200,000 years old that are
found in Ethiopia and they looksimilar, the ones that are
300,000 years old.
They have about the same brainsize as modern humans, but the
shape of the brain is a littlebit different, a little flatter
and more elongated, and soexactly what their behavior
(14:27):
differences were versus the onethat the fossils you find
200,000 years ago, it's notclear.
But there is this the formstarted in Africa.
So you don't see like earlymodern humans in Asia first
right, so the earliest ones arein Africa.
So it's the idea that modernhumans emerged in Africa
somewhere between 300 and200,000 years ago.
(14:49):
And we say that we're talkingabout biological humans, the
humans that biologically looklike UNI right.
Speaker 1 (14:55):
I'm thinking about signs of human culture.
So thinking of pictures.
I've seen in old historytextbooks of jewelry that humans
had made years ago, or againcave paintings.
When did we first start to seethat emerge, and can you speak
to that aspect of our humanevolution?
Speaker 2 (15:14):
So we talk about, like you mentioned, about,
biological humans, humans thatphysically okay, they're similar
enough to UNI.
We'll call them homo sapiensbiologically.
The other question this is oneI think it's more interesting so
is when do you see humans thatare like us in terms of their
behaviors, right, and, I think,have this, particularly the
(15:39):
symbolic thought and languageand so forth that?
How do you know when thatemerges?
Speaker 1 (15:44):
Okay, so we've talked about modern.
Humans emerged 200 to 300,000years ago.
When did we first start to seesigns of culture though?
I'm thinking of old history,textbook photos of cave art when
did that start emerging?
Speaker 2 (15:57):
Yeah, interestingly, there's a lot of debate in the
archaeological record becauseyou have to interpret these
things, but most people tend toagree that you see sort of clear
signs of sort of human culture,these artifacts that you say,
well, whoever made that is gotthe same sort of rational
conceptual thought that you andI do, right, you start to see
(16:18):
that maybe 100,000 to 50,000years ago you start to see signs
of that.
You know, one of the bestexamples is Blameless Cave in
South Africa, where you see acouple things.
You see these shells that haveholes drilled into them at the
exact same point that it'sthought to have been used for
shell jewelry, right?
You see ochre, which is an ironsort of plate pigment that has
(16:43):
regular sort of markings on itthat seem to be very intentional
, have maybe meaning behind them, and you see this elsewhere as
well, sort of sporadicallyduring that time period, right?
So it's somewhere in that now,just because you don't see it
doesn't mean it wasn't therebefore.
(17:05):
You know, absence of evidence isnot evidence of absence, right?
So maybe we just haven't foundin the archeological record
signs of this earlier, and thereare some signs of it earlier.
It just depends on how youinterpret them.
Some people over interpretcertain things, some people
under interpret and we don'thave them there to interrogate.
We can't ask these people whatthis thing was for, you know,
(17:26):
and so forth.
Speaker 1 (17:27):
So what was going on with the human evolution process
that now culture is showingitself?
About 150,000 years ago?
Speaker 2 (17:35):
Yeah, yeah.
So around 100,000 to 50,000years ago you start to see this
and then, from 50,000 on, youstart to see.
You know, all of these cavepaintings, in particular the
things that you're talking aboutin your textbooks, you know,
you see those, and you see thoseall over the globe.
You see them in Indonesia, yousee them in Europe.
So it's not like, oh, they allstart here and spread out.
They just seem to show up allover the place.
(17:58):
And I think you know what mostlikely occurred is that you have
different human populationsliving in different places and
they're developing cultures, andthen they're interacting with
different human groups.
So there's, you know, exchangeof cultures and information and
so forth, and then out of thisstarts to emerge what we would
(18:20):
recognize as sort of humanculture, art and artifacts, and
it sort of explodes over time.
Eventually you hit a criticalmass where this is a sort of
human artifacts that explodeeverywhere.
Speaker 1 (18:34):
So would you say that's an explanation why there
is this delay between theemergence of modern humans and
then the emergence of thisculture?
Speaker 2 (18:42):
Yeah, I think that it's indication that they've
gotten to that point where Imean, just because you have the
potential, say, to do calculusright, doesn't mean the humans
that lived 10,000 years ago hadthe potential to do calculus.
They just didn't have theculture and the learning to get
that right and so it's the samething, like the humans that
existed 100,000 years ago mayhave had the ability to do art,
(19:05):
but hadn't had the culture wherethat became part of their
culture.
Right, the potential was there,right.
So you have a human form thatlive in Africa, that have maybe
the potential to do this, butit's not actualized until human
culture starts to develop overtime, and that can be a slow
process, and then it starts toemerge more recently than, say,
(19:30):
the biological form that werecognize as humans.
Speaker 1 (19:34):
So these are modern humans we're talking about, but
what do we know about otherhominids?
It's said that Neanderthalseven had burial practice.
Speaker 2 (19:44):
Yeah, yeah, neanderthals are really
interesting the hominid speciesbecause we interacted.
Modern humans interacted withthem.
There was great, good evidencethat we interbred with
Neanderthals and in addition tothat, there is some evidence
that Neanderthals had burialpractices.
(20:04):
Now whether that means they hadsymbolic thought, maybe they're
just taking a corpse and buryit because it smells bad For
practical reasons, the reasonsright is that they have a belief
in the afterlife it's not clear, but there is cave paintings in
Europe that date to beforemodern humans got there that are
thought to have been made byNeanderthals.
(20:24):
Now they're not as robust aspaintings that are known to have
been made by earlier humans,but there's a question there
what type of abilities didNeanderthals have?
And obviously modern humans,when they left Africa, interbred
with Neanderthals, and so we'vetalked about before, we have
(20:46):
picked up some genes fromNeanderthals, genes that might
help us survive in colderclimates or and survive certain
pathogens that they were exposedto in Europe before modern
humans get there.
So they're a very interestingspecies because of their
(21:06):
interaction with us and becauseof sort of a lot of they're
almost doing the same thing, butnot that you don't see the full
flourishing that you see inmodern humans in the last 50,000
years.
Speaker 1 (21:17):
Just from my context.
When did they die out?
When was the end ofNeanderthals?
Speaker 2 (21:21):
Neanderthals by 30,000 years ago.
So modern humans leave Africa.
Well, modern humans left Africaback and forth over the last
200,000 years, but the last wavethat left Africa about 50,000
years ago, that's the wave thatseemed to displace all the other
hominid species on the planet.
That's the one that ended upgetting to Australia, getting to
(21:42):
the new world that one goesinto Europe and the Neanderthals
disappear about 30,000 yearsago.
So there was this overlap withthat last wave.
Exactly what drove theNeanderthals to extinction?
Did they just get assimilated?
Did they get outcompeted?
Were there diseases that modernhumans brought?
There's a lot of differentideas and theories.
What drove the Neanderthals toextinction?
Speaker 1 (22:04):
So we've talked about this relationship between
modern humans and Neanderthalsand how we carry some of their
DNA.
Still this relationship.
What connection is there?
Okay, both biologically, butalso spiritually.
Can you speak about thatdynamic?
Speaker 2 (22:18):
Yeah.
So when you think about whatmakes modern humans distinct
from other forms, it's ourrationale.
What makes us different is thatwe can have language and
conceptual thought.
We can think about things thatare not material.
We're not stuck in the material, where we think about concepts,
justice or fairness or aperfect circle which doesn't
(22:41):
exist in the world.
So we have this ability tothink about and judge our own
actions and so forth.
So the question is didNeanderthals have that same
ability?
And it's not clear whether theydid or not.
If they did, then they would bein a sense, human, in the same
way we are human, meaning thatthey have rational, conceptual
(23:03):
thought.
And it may be the Neanderthalsthat we interbred with are
similar enough to us to beconsidered humans in the sense
that they're made in the imageof the likeness of God, which is
really.
What does that mean?
It's that you have thisrational, conceptual thought of
a spiritual soul that allows youto be a communion with God.
(23:25):
That's a question that sciencecan't answer, but it does give
clues about what Neanderthalswere able to do.
They were able to do some, itseems like some significant
things, but what were theyexactly?
Like us?
It doesn't seem that way, butit's very much a gray area, I
think.
Speaker 1 (23:46):
Well, to that point.
I mean, how does that all meshwith the Christian understanding
of the creation of man?
You said there's a limit towhat science can explain.
Speaker 2 (23:58):
Yeah, yeah.
So science, you look at whatmakes us human right.
We are more than just amaterial being.
We have a material body, but weare a unity of body and soul.
So the question is, where isthe human soul?
Where does that enter theprocess?
How does that come into being?
And I would say theevolutionary process, the
(24:20):
process of how man, evolution,produces the form at some point
that's fitting, to receive arational soul, to be the human
that can be in relation with God.
Exactly when that happened.
I can't say, oh, that happened60,000 years ago, that happened
100,000 years ago.
I think it certainly would havehappened before you see cave
(24:42):
paintings and so forth, 50,000years ago.
So I would argue that had tohappen somewhere before that.
And exactly when it probablyhappened in Africa, because
that's where you see the oldestmodern humans.
So sometime in Africa the formemerges that's fitting, to
receive a rational soul, right,and with that you have the
(25:03):
abilities, right, they might notbe manifest immediately, but
you have the abilities to do allthe things that we associate
with humans and modern humanculture.
Speaker 1 (25:12):
You cite Pope Benedict XVI pretty frequently
on this topic, because he wouldwrite and speak about the topic
of evolution.
But Pope Benedict XVI, he talksabout creation and evolution
when looking at the origin ofman.
So for many people, though,there's that juxtaposition that
seems incoherent again bothevolution and creation.
(25:34):
What did Pope Benedict XVI meanby this, and does that fit in
with what you just talked about,with human evolution?
Speaker 2 (25:44):
Yeah, no, what he uses that and is that, you know,
understanding of humanevolution is going to give us
some information about what itmeans to be human, the human
body, our relationship to otherhominins and other primates and
the way that we make a livingand our physiology and so forth
and when that might emerge.
But that alone can't explainall there is about the human
(26:07):
person and that's where thecreation aspect that we are made
in the image of the likeness ofGod.
So, whatever the evolutionaryprocess that got produced, the
form, there was a creation eventin the sense that God directly
creates the human soul and thefirst humans that come into
(26:27):
being.
That form has evolved.
But once it's there, it's nowin soul that there's a creation
event.
So it's creation and evolutionto understand how you get that
first human form.
Speaker 1 (26:40):
As we're talking about human evolution, you know,
a question kind of comes tomind are we still evolving, and
if so, are we continuing toevolve into a different species?
Speaker 2 (26:50):
Yeah, yeah, that's a great question and I get that
question a lot when.
I talk to my students, yeah, andit's clearly we're still
evolving in the sense that wehave, you know, like changes in
populations that occur.
So you have, you know, changesin our lactose tolerance, so you
have changes in immuneresistance and disease
(27:10):
susceptibility genes and soforth.
So clearly, there is that, youknow.
I think the question thatpeople are getting at are we
evolving into uberman, somethingelse?
Right, what is there?
And you know, from myperspective, right again, this
is to realize what are thelimits of evolution.
I don't think, like our abilityto have rational conceptual
thought.
What makes us different from isnot fully a material thing,
(27:34):
right, so it is.
You know, there's a materialaspect to our person that is the
type of thing that is fittingto receive a rational soul and
then allows us to have rationalconceptual thought.
And so, you know, I don't thinkwe can evolve beyond that
because it's not a physicalthing.
It's certainly dependent uponour brain size and so forth and
(27:55):
things like that, but it goesbeyond that.
So I don't see us.
You know, we might evolve tohave more intelligence and so
forth, but we're still arational creature.
That's in relation with God.
I don't think that that'ssomething that evolution is
going to move us beyond.
Speaker 1 (28:11):
For example, Sometimes I wonder I mean just
with technology and how much ourface is in front of screens all
the time.
I sometimes wonder if that'sgoing to affect just human
evolution and how we continue toevolve.
For someone who wants to learnmore about this topic in
particular, are there anysources you'd want to point them
towards to delve even moredeeply?
Speaker 2 (28:30):
Yeah, I think if you're just interested in trying
to get your mind wrapped aroundwhat we know about human
evolution and maybe the originsof humans from a scientific
perspective.
Ian Tattersall has a number ofbooks.
Masters of the Planet is one ofthose.
I don't agree with everythinghe has in there, but I think he
does a good job of explainingwhat might have occurred.
(28:50):
And this, and Yuval Harari alsohas a book as well called
Sapiens, and it does sort of thesame thing.
It's got, I think, a briefhistory of humankind and that
book also, I think, just setsthe context of what we've been
talking about.
They don't get into thespiritual aspect, but just from
the biologic perspective.
This is sort of how people havethought about how humans emerge
(29:14):
in the context within themodern human form emerges.
Speaker 1 (29:18):
But just kind of last question, as we're thinking
about and this has beenfascinating just to learn about
how I as a human would haveevolved Any final thoughts,
especially from your perspectiveas a Catholic biologist?
Speaker 2 (29:33):
Yeah, I think one of the things.
I mean it's a very fascinatingfield but with a lot of sort of
evolutionary history, there's alot of inferences that people
have to make, and so we want todo that cautiously, with
humility, and realize okay, thedata we find a year from now,
okay, that's going to reshapehow we view human evolution in
(29:54):
the process.
So the science is going tochange and evolve and develop as
we get more archaeologicalevidence, more genetic evidence
and so forth.
But no matter what evidence weget, I think that from a
Catholic tradition, however thatprocess unfolded and where
modern humans emerge, they aremore than just an evolutionary
(30:16):
adaptation.
We're more than that andthere's nothing in so the
evolution process that'sinconsistent with that notion
that man is made in the image ofthe likeness of God.
However that form comes to be,and all its messiness and all
the different ways and processesthat might be involved, that
emerging out of that is the typeof thing that can be in
(30:38):
relationship with God.
Speaker 1 (30:40):
You use this term of the biological form.
Speaking philosophically nowand bringing that aspect in,
would you say the soul is thebiological form of the body.
What are your thoughts on that?
Speaker 2 (30:53):
So people will say that the soul is the form of the
body.
From a philosophicalperspective.
I'm not using form in that term.
I'm talking about a biologicalform or the biological structure
, if we want to distinguish that.
So once you get the biologicalstructure, the biological being
that is suitable for a rationalsoul, then that gives the form
(31:16):
of the person.
But it's two different things,right.
The soul being the form of thebody is one thing.
I'm talking about the physicalstructure.
Speaker 1 (31:28):
Got it Well.
Thanks for being in the hotseat for this topic, but moving
on now to the office hourssegment of the podcast, and,
again, this is where people cansubmit questions.
You tackle other questions.
The theme for this office hours, though, happens to still be on
this topic of the environment,so I'll just start throwing them
your way.
This has to do Pope Francis.
(31:50):
He recently released a newwhat's called an apostolic
exhortation, which is a letterfancy word for a letter and it
was to build on and be a followup to his 2015 encyclical on the
environment called Lodalto C.
So this new letter he releasedcalled Lodalto deum, which
translates to praise God, and init he's very critical of people
(32:11):
who deny climate change, and hesays it is verifiable that
specific climate changesprovoked by humanity are notably
heightening the probability ofextreme phenomena that are
increasingly frequent andintense.
So he really didn't, you know,mince his words on this topic of
climate change.
What was your read of thisletter, lodalto deum?
(32:34):
And, as a Catholic biologist,what do you think the Catholic
approach to climate change andthe environment should be?
Speaker 2 (32:41):
Pete Sautner.
Yeah, no, I think you know froma Catholic perspective, I think
you would find, you know, broadagreement amongst Catholics
that we have a duty to stewardour environment, that nobody
really wants to just spoil theenvironment right.
And you know it's relativelyclear that human behaviorist
changed the amount of CO2 in theatmosphere and that's having
(33:03):
effects on the climate.
And you know some people say,well, look like we talked about
here, though climate changes allthe time, it changed during
human evolution and there'snothing we can do about that.
And I don't think that's ahealthy perspective.
But this is a bigger question,you know.
So I think the church can pointout.
You know we have to steward theenvironment Exactly how is
extremely complex, you know, andjust you know, one decision
(33:25):
that we think is going to begood might have some adverse
consequences over here.
So it's a really, you know,difficult issue to show.
You know, if you think aboutelectric vehicles, okay, well,
that can reduce CO2 emissions,but then that creates, you know,
all the mining for the cobalt,nickel that is needed for those
batteries can create otherenvironmental problems.
So there's, it's a very, youknow, multi-layered thing that
(33:48):
we have to get through.
But I do think you know fromthe Catholic variable, all
Catholics, I think, would agreethat you know we have a duty to
steward the environment and toensure that we protect the
environment.
And a lot of prudential judgmentinto what that looks like for
every person.
Speaker 1 (34:05):
Similar topic.
So, ahead of Pope Francisreleasing this letter on the
environment, pew Research Centerthey released new data
specifically about US Catholicviews on climate change and,
broadly speaking, the viewsvaried by political affiliation,
by race, by ethnicity, by age.
82% of Catholics who areDemocrat or lean Democrat at
(34:25):
least, say that global climatechange is extremely or very
serious, and that's compared toa quarter of Republicans or
Republican-leaning Catholics.
Were you surprised by thesefindings?
Or, you know, did it just kindof fall into predictability?
Speaker 2 (34:42):
That's not too surprising, given you know our
divided culture.
You know there are, you know,mischaracterizations.
I think on the one side youthink, well, the Republicans are
these?
Young people, older peopledon't care about the environment
?
And that they do?
And then on the other side, youthink, oh, these Democrats?
(35:04):
What all they want to do iskill the economy and take
control of it.
And I don't think that's thecase.
I think both you know you'retrying to reach a very difficult
decisions about how to approachthese things.
And again you get back to allthese potential judgments and I
think there's a lot that peoplehave in common, but we tend to
scream these slogans.
Speaker 1 (35:23):
Elabel and assume but .
Speaker 2 (35:25):
I think, at the end of the day, people, all people,
want, I think, a planet that'shealthier, and they want people
to be thriving and have athriving economy.
And then you know it comes downto how do you do that best?
Speaker 1 (35:36):
Yeah Well, thanks for tackling these tough topics and
I want to remind our listenersand viewers that if you have a
question, you can submit themfor Dr Dan Kebler to answer here
at the Office Hour segment ofthe podcast.
You can email info atModjaCentercom.
You can also go ahead and giveus a call, leave a voicemail.
You might hear your own voiceright on this podcast.
You can call 949-257-2436.
(36:02):
But until next time, make sureto subscribe to Purposeful Lab
on your favorite podcastplatform and find out the latest
of what's happening at thepodcast at ModjaCentercom.
That does it for now.
We'll see you next week.
Welcome to Purposeful Lab, a Magistenter podcast.
I'm Catherine Hadrow with DrDan Kebler.
So here we are, season three.
Again We've been looking atbiological evolution and this
episode we're going to dive moreinto human evolution and better
understanding all theenvironmental factors at play,
which is important to betterunderstand us and humans.
Speaker 2 (00:22):
Right yeah, If we want to understand humans who
they are, who we are, ourpurpose and so forth,
understanding the context inwhich humans emerge is important
.
Speaker 1 (00:30):
For this topic.
I have the privilege tointerview you.
So thanks, for what are youforward to?
Yes, for diving into this,because you've written on this
topic again about humanevolution.
You've written the book theEvolution Controversy a survey
of competing theories.
You have a new book coming outearly 2025 with Word on Fire
press about the church's view onevolution.
(00:52):
So again, and, of course,biology professor at Franciscan,
where you've been for over 20years.
So grateful to speak with youon this.
Speaker 2 (00:59):
Yeah, it's going to be good to talk about this.
Speaker 1 (01:02):
So I know we're going to start talking about the
hominin fossils, but can youfirst just set us up what is a
hominin?
Speaker 2 (01:11):
Yeah, so what we're going to talk about today is
what's happened in recenthominin evolution, so about 7
million years ago.
There's a common ancestor thaton one branch led to modern
humans and on another branch ledto modern chimps, our closest
living relatives.
Hominid evolution is looking atthe fossil form, if you find
that are more closely related tomodern humans than to modern
(01:33):
chimps.
So we're going to be looking atwhat happened in that lineage
and what you see.
What factors played a role inthe diversity you see in hominin
fossils?
Speaker 1 (01:44):
So to get us started on that and looking at the
patterns found in these fossilrecords over the past 7 million
years and really discussing whatthat reveals and, again, all
the environmental changes thatinfluenced it, so can you give
us a quick summary of thispattern that we see in these
fossil records?
Speaker 2 (02:01):
Yeah, you know it.
Just you know this field is alot of active research.
So the little details you know,they're finding new details all
the time, but sort of the youknow the 30,000 foot, you know
overview of what you see andwhat you don't see is you know
those neat bumper stickers wesee in A, so they're gradually
standing up like this the A goto B, go to C.
It's like neat linearprogression.
(02:23):
That's not what you see in thehominin fossil record.
What you see is more of a mosaicpattern.
What I mean by that is youstart to see a variety of
different fossil forms.
Some look more modern, moremodern in like their brain,
others might look more modern intheir jaw right, and so you get
these sort of.
It's hard to put them alltogether like which one is more
(02:47):
modern, which one is moreancient and so forth in terms of
their features, because you seethis sort of almost a
experimentation going on withAll simultaneous.
Yeah, so, particularly if youlook in Africa between two and
four million years ago, there'sa lot of different hominin forms
in Africa that it's hard to howexactly are they all related?
But what you do see is adiversity and they are changing
(03:10):
in ways that are getting on thepath towards sort of the modern
human form.
Speaker 1 (03:18):
So is it fair to say, if all that was going on
simultaneously, was there trulya progression?
Speaker 2 (03:23):
You see, on average you know, an increase in brain
size over time.
But say, if you go back to fourmillion years ago and look at
the, the hominin fossil has thebiggest brain size.
There's going to be a largerbrain than if you go back six
million years.
And if you look at the homininfossils from, you know, half a
(03:44):
million years ago, the largestbrain is going to be bigger than
the largest brain two millionyears ago.
But at the same time there'sthis mosaic.
So there was a hominin fossilfound that dates to about 20,000
years ago, was found inIndonesia and has a relatively
small brain size.
So it's not like every homininfossil is going in one direction
.
In a sense it's exploring thedifferent possible ways that you
(04:06):
can make a hominin and out ofthat sort of exploration one
emerges and takes over.
You know that's modern humans.
Speaker 1 (04:15):
You mentioned and I can totally picture it right now
, that popular bumper stickerthat people see of again like
it's like a chimp and it'sgradually, you know, it's
hunched over and then it'sslightly less hunched over and
then it's an upright man.
But you said again, it's notnecessarily that clear
progression like that.
But what are the factors thatwould have led to again a more
(04:38):
upright, big brained human?
Speaker 2 (04:40):
Yeah, so if you look at, you know, the hominin fossil
record up until about twomillion years ago, all the
hominins are found in Africa.
So this is the factors that aregoing to drive the first stages
are all going to be changes thatare occurring in Africa at that
time, and one of the thingsthat major factors is changes in
(05:01):
the climate.
Okay, so two major things arehappening, particularly from
five million years ago till thepresent.
You see two things.
One, you see sort of a globalcooling going on and you also
see more fluctuations in sort ofglobal temperatures, right, so
you're getting more variabilityof the temperatures and you're
getting a global cooling.
(05:22):
Now what that does in Africa inparticular, as the, the earth
cools, you get more watertrapped in the at the poles and
the ice caps and you have sortof a drying out of the climate
in Africa.
And so what is that going to do?
So you know, if you think of,like, where chimps are in sort
of a river forest, you know alot of vegetation and so forth.
(05:44):
If you start to dry out areasof Africa, you have these
savannas, these plains, whereyou have, you know, a different
way of possibly making a living,having upright posture to
travel through these savannas,having the ability to, you know,
use your arms to throw thingsand hunt and so forth are going
(06:06):
to help you survive in thisdrier, savanna-type climate,
whereas, you know, the primatesthat remain in sort of the river
areas are going to do well andthen develop into, say, modern
chimps.
So there's sort of twodifferent ways of in a sense
it's more complicated than that,but sort of two different.
You can see in these twodifferent paths, the hominid
(06:28):
path is exploring this new drierclimate in Africa and there has
to be some, you know, a numberof changes to be able to, you
know, know where food might beat different times of the year.
You should migrate from onearea to the other in this new
environment.
So having a larger brain canhelp you remember, divide up,
you know this labor, you knowsocial group and so forth, and
(06:50):
having that upright postureallows you to move more
efficiently.
Yeah, so one of the things youknow, upright posture, you know
as you move across the savanna,it, you know, you're gonna have
a couple benefits.
One, humans are very good atlong distance, running right, as
opposed to other species, yeah,and particularly like ungulates
(07:16):
, you know, they like zebras andthings like that, the game that
they would have in Africa.
And so, having the ability tobe upright and to run, they can,
they can actually outrun, evenif they go at a moderate pace,
can outrun these ungulates, andthen they get really overheated
and fall over, whereas humanswith this upright posture
they're not, but they have aneasier time dissipating heat and
(07:37):
they can run better they can.
They can hunt better in thesavanna environment.
Speaker 1 (07:42):
So you mentioned this .
You know cooling period thathappened.
So is that the ice age thatyou're referring to?
Speaker 2 (07:48):
Yeah, Well, so the cooling period, you know it
started about 50 million yearsago and particularly accelerated
maybe the last two and a halfmillion years ago.
But what you see is not just acooling of the temperature.
You see these big fluctuations,right, and so you see these
glacial periods and then theinterglacial periods.
So you would have say the iceage and then you'd have the
inter ice age and there was acycle roughly about every
(08:11):
100,000 years that you would gothrough this, right, and right
now we're in this interglacialperiod for the last 11,000 years
or so.
But you know, having to survivethese, these, that changes in
climate, having, you know, moredeveloped social structure, a
bigger brain allowed to adapt tothese, these, these changes in
(08:32):
the environment could help drive, you know, hominid evolution
towards a large brain, socialhominid.
Speaker 1 (08:38):
Would you, you know, with something like humans have
evolved without this cyclical,dramatic change in the
environment like you'redescribing?
Or, again, are humans just achance product of a chance
environmental happening?
Speaker 2 (08:54):
Yeah, so clearly in the way evolution has played out
in the last seven million years, there's certain environmental
factors that have triggered andhelped shape the human form over
hominid evolution time.
Had the environment changeddifferently, maybe the form
would have been slightlydifferent.
But there's something about, Ithink, a large brain hominid
(09:17):
like you and I that has anadvantage over other ways of
making a living.
And so had the environmentchanged slightly differently, I
think eventually there's lots ofenvironmental change going on
over time that you would emergesome large brain primate.
That's upright.
It might have been a differentpattern, different timing and so
(09:39):
forth, but I think it'ssomething like that would have
emerged.
That's something that we've hadSimon Conway-Morrison before
and he talks about that in hisbook Life Solutions that there's
this convergent evolution.
So this is the factors thatdrove human evolution this time.
Had it been slightly different,well the pathway might have
been different, but we probablywould have, through this mosaic
(10:00):
experimentation, come up with aform that's very similar not
identical, but similar.
Speaker 1 (10:04):
You mentioned Africa and how hominids were present in
Africa and they were only foundin Africa until about 2 million
years ago.
Why did hominids leave Africa?
Can you speak about that?
Speaker 2 (10:15):
Yeah, so up until 2 million years ago the hominids
were in school.
They leave in Africa.
Now some of them start to leaveAfrica and some hominids
obviously are still in Africaduring that time.
But whatever reason, about 2million years ago the first wave
, this is Homo erectus, which isAfrica, and heads into Asia.
(10:37):
So they don't go into Europe,which is probably too cold at
the time.
But why?
It's a great question.
I think there's something aboutas they can migrate.
The long-distance migrationbecame part and parcel of the
sort of hominid forms and yousee this wave of hominids leave
(10:57):
Africa 2 million years ago.
You see another wave thatleaves and gives rise to
Neanderthals about a halfmillion years ago.
And then finally, you see awave leaving Africa of modern
humans about 50,000 years ago.
That then colonizes basicallythe whole globe other than
Antarctica.
So there's something in our DNA.
It was this wonderlust ofwanting to go explore, and it's
(11:20):
something that we find in ourhominin ancestors too.
Speaker 1 (11:24):
You mentioned Neanderthals already and they're
fascinating for a number ofreasons.
Can you first explain what youmean by Neanderthals exactly,
and how are they related tohumans and where did they end up
?
Speaker 2 (11:38):
Yeah, so Neanderthals , the lineage leading to them
and humans separated about500,000 years, like half a
million years ago, and theyleave Africa into the Middle
East and they eventually maketheir way into Europe, and so
they were able to colonizeEurope as, while like the
(11:58):
earlier, like homorectis, whenthey left they didn't, and they
seem to have a larger, morerobust form that they were
better suited and adapted forthe colder climate in Europe,
most likely.
And they're really fascinatingbecause when humans modern
humans leave Africa, theyencounter Neanderthals, and
(12:19):
Neanderthals were still therethey don't disappear until
roughly 30,000 years ago.
So when modern humans leaveAfrica, there's a number of
hominid forms that they mighthave encountered.
They weren't the only hominidform on the planet, and so
there's a lot of interestingthings about the interactions
between Neanderthals and modernhumans.
Speaker 1 (12:39):
Remember I had asked you in a previous episode how my
DNA test showed up.
I have Neanderthal DNA and I'mlike what is this about?
So why did they end up the waythat they did?
Eventually Neanderthals.
Speaker 2 (12:53):
And why did they end up in Europe?
Yeah, so again, the idea isthat there's a niche there in
Europe, so there is no hominids,and so they were able to take
over and make a living there.
Maybe they have a larger brainthan, say, homorectis, and so
maybe that allowed them, and alarger body that allowed them to
(13:16):
adapt to this climate that, say, other hominids weren't able to
successfully adapt.
Speaker 1 (13:23):
So, as we're looking through this process of human
biological evolution and gettinga little bit closer to modern
human culture, the modern humanform, my understanding is it
seemed to emerge, and Africa,200,000 to 300,000 years ago.
Is that right?
So what do we know about thosefirst modern humans?
Speaker 2 (13:44):
Yeah, we don't know that much about those first
modern humans, but if you lookat the fossil record, it's in
Africa that you see theemergence of fossils that look
relatively similar to UNI right,and so the oldest of.
There's some fossils that areabout 300,000 years old that are
found in Morocco, so likeNorthwest Africa.
(14:05):
And then there's some that areabout 200,000 years old that are
found in Ethiopia and they looksimilar, the ones that are
300,000 years old.
They have about the same brainsize as modern humans, but the
shape of the brain is a littlebit different, a little flatter
and more elongated, and soexactly what their behavior
(14:27):
differences were versus the onethat the fossils you find
200,000 years ago, it's notclear.
But there is this the formstarted in Africa.
So you don't see like earlymodern humans in Asia first
right, so the earliest ones arein Africa.
So it's the idea that modernhumans emerged in Africa
somewhere between 300 and200,000 years ago.
(14:49):
And we say that we're talkingabout biological humans, the
humans that biologically looklike UNI right.
Speaker 1 (14:55):
I'm thinking about signs of human culture.
So thinking of pictures.
I've seen in old historytextbooks of jewelry that humans
had made years ago, or againcave paintings.
When did we first start to seethat emerge, and can you speak
to that aspect of our humanevolution?
Speaker 2 (15:14):
So we talk about, like you mentioned, about,
biological humans, humans thatphysically okay, they're similar
enough to UNI.
We'll call them homo sapiensbiologically.
The other question this is oneI think it's more interesting so
is when do you see humans thatare like us in terms of their
behaviors, right, and, I think,have this, particularly the
(15:39):
symbolic thought and languageand so forth that?
How do you know when thatemerges?
Speaker 1 (15:44):
Okay, so we've talked about modern.
Humans emerged 200 to 300,000years ago.
When did we first start to seesigns of culture though?
I'm thinking of old history,textbook photos of cave art when
did that start emerging?
Speaker 2 (15:57):
Yeah, interestingly, there's a lot of debate in the
archaeological record becauseyou have to interpret these
things, but most people tend toagree that you see sort of clear
signs of sort of human culture,these artifacts that you say,
well, whoever made that is gotthe same sort of rational
conceptual thought that you andI do, right, you start to see
(16:18):
that maybe 100,000 to 50,000years ago you start to see signs
of that.
You know, one of the bestexamples is Blameless Cave in
South Africa, where you see acouple things.
You see these shells that haveholes drilled into them at the
exact same point that it'sthought to have been used for
shell jewelry, right?
You see ochre, which is an ironsort of plate pigment that has
(16:43):
regular sort of markings on itthat seem to be very intentional
, have maybe meaning behind them, and you see this elsewhere as
well, sort of sporadicallyduring that time period, right?
So it's somewhere in that now,just because you don't see it
doesn't mean it wasn't therebefore.
(17:05):
You know, absence of evidence isnot evidence of absence, right?
So maybe we just haven't foundin the archeological record
signs of this earlier, and thereare some signs of it earlier.
It just depends on how youinterpret them.
Some people over interpretcertain things, some people
under interpret and we don'thave them there to interrogate.
We can't ask these people whatthis thing was for, you know,
(17:26):
and so forth.
Speaker 1 (17:27):
So what was going on with the human evolution process
that now culture is showingitself?
About 150,000 years ago?
Speaker 2 (17:35):
Yeah, yeah.
So around 100,000 to 50,000years ago you start to see this
and then, from 50,000 on, youstart to see.
You know, all of these cavepaintings, in particular the
things that you're talking aboutin your textbooks, you know,
you see those, and you see thoseall over the globe.
You see them in Indonesia, yousee them in Europe.
So it's not like, oh, they allstart here and spread out.
They just seem to show up allover the place.
(17:58):
And I think you know what mostlikely occurred is that you have
different human populationsliving in different places and
they're developing cultures, andthen they're interacting with
different human groups.
So there's, you know, exchangeof cultures and information and
so forth, and then out of thisstarts to emerge what we would
(18:20):
recognize as sort of humanculture, art and artifacts, and
it sort of explodes over time.
Eventually you hit a criticalmass where this is a sort of
human artifacts that explodeeverywhere.
Speaker 1 (18:34):
So would you say that's an explanation why there
is this delay between theemergence of modern humans and
then the emergence of thisculture?
Speaker 2 (18:42):
Yeah, I think that it's indication that they've
gotten to that point where Imean, just because you have the
potential, say, to do calculusright, doesn't mean the humans
that lived 10,000 years ago hadthe potential to do calculus.
They just didn't have theculture and the learning to get
that right and so it's the samething, like the humans that
existed 100,000 years ago mayhave had the ability to do art,
(19:05):
but hadn't had the culture wherethat became part of their
culture.
Right, the potential was there,right.
So you have a human form thatlive in Africa, that have maybe
the potential to do this, butit's not actualized until human
culture starts to develop overtime, and that can be a slow
process, and then it starts toemerge more recently than, say,
(19:30):
the biological form that werecognize as humans.
Speaker 1 (19:34):
So these are modern humans we're talking about, but
what do we know about otherhominids?
It's said that Neanderthalseven had burial practice.
Speaker 2 (19:44):
Yeah, yeah, neanderthals are really
interesting the hominid speciesbecause we interacted.
Modern humans interacted withthem.
There was great, good evidencethat we interbred with
Neanderthals and in addition tothat, there is some evidence
that Neanderthals had burialpractices.
(20:04):
Now whether that means they hadsymbolic thought, maybe they're
just taking a corpse and buryit because it smells bad For
practical reasons, the reasonsright is that they have a belief
in the afterlife it's not clear, but there is cave paintings in
Europe that date to beforemodern humans got there that are
thought to have been made byNeanderthals.
(20:24):
Now they're not as robust aspaintings that are known to have
been made by earlier humans,but there's a question there
what type of abilities didNeanderthals have?
And obviously modern humans,when they left Africa, interbred
with Neanderthals, and so we'vetalked about before, we have
(20:46):
picked up some genes fromNeanderthals, genes that might
help us survive in colderclimates or and survive certain
pathogens that they were exposedto in Europe before modern
humans get there.
So they're a very interestingspecies because of their
(21:06):
interaction with us and becauseof sort of a lot of they're
almost doing the same thing, butnot that you don't see the full
flourishing that you see inmodern humans in the last 50,000
years.
Speaker 1 (21:17):
Just from my context.
When did they die out?
When was the end ofNeanderthals?
Speaker 2 (21:21):
Neanderthals by 30,000 years ago.
So modern humans leave Africa.
Well, modern humans left Africaback and forth over the last
200,000 years, but the last wavethat left Africa about 50,000
years ago, that's the wave thatseemed to displace all the other
hominid species on the planet.
That's the one that ended upgetting to Australia, getting to
(21:42):
the new world that one goesinto Europe and the Neanderthals
disappear about 30,000 yearsago.
So there was this overlap withthat last wave.
Exactly what drove theNeanderthals to extinction?
Did they just get assimilated?
Did they get outcompeted?
Were there diseases that modernhumans brought?
There's a lot of differentideas and theories.
What drove the Neanderthals toextinction?
Speaker 1 (22:04):
So we've talked about this relationship between
modern humans and Neanderthalsand how we carry some of their
DNA.
Still this relationship.
What connection is there?
Okay, both biologically, butalso spiritually.
Can you speak about thatdynamic?
Speaker 2 (22:18):
Yeah.
So when you think about whatmakes modern humans distinct
from other forms, it's ourrationale.
What makes us different is thatwe can have language and
conceptual thought.
We can think about things thatare not material.
We're not stuck in the material, where we think about concepts,
justice or fairness or aperfect circle which doesn't
(22:41):
exist in the world.
So we have this ability tothink about and judge our own
actions and so forth.
So the question is didNeanderthals have that same
ability?
And it's not clear whether theydid or not.
If they did, then they would bein a sense, human, in the same
way we are human, meaning thatthey have rational, conceptual
(23:03):
thought.
And it may be the Neanderthalsthat we interbred with are
similar enough to us to beconsidered humans in the sense
that they're made in the imageof the likeness of God, which is
really.
What does that mean?
It's that you have thisrational, conceptual thought of
a spiritual soul that allows youto be a communion with God.
(23:25):
That's a question that sciencecan't answer, but it does give
clues about what Neanderthalswere able to do.
They were able to do some, itseems like some significant
things, but what were theyexactly?
Like us?
It doesn't seem that way, butit's very much a gray area, I
think.
Speaker 1 (23:46):
Well, to that point.
I mean, how does that all meshwith the Christian understanding
of the creation of man?
You said there's a limit towhat science can explain.
Speaker 2 (23:58):
Yeah, yeah.
So science, you look at whatmakes us human right.
We are more than just amaterial being.
We have a material body, but weare a unity of body and soul.
So the question is, where isthe human soul?
Where does that enter theprocess?
How does that come into being?
And I would say theevolutionary process, the
(24:20):
process of how man, evolution,produces the form at some point
that's fitting, to receive arational soul, to be the human
that can be in relation with God.
Exactly when that happened.
I can't say, oh, that happened60,000 years ago, that happened
100,000 years ago.
I think it certainly would havehappened before you see cave
(24:42):
paintings and so forth, 50,000years ago.
So I would argue that had tohappen somewhere before that.
And exactly when it probablyhappened in Africa, because
that's where you see the oldestmodern humans.
So sometime in Africa the formemerges that's fitting, to
receive a rational soul, right,and with that you have the
(25:03):
abilities, right, they might notbe manifest immediately, but
you have the abilities to do allthe things that we associate
with humans and modern humanculture.
Speaker 1 (25:12):
You cite Pope Benedict XVI pretty frequently
on this topic, because he wouldwrite and speak about the topic
of evolution.
But Pope Benedict XVI, he talksabout creation and evolution
when looking at the origin ofman.
So for many people, though,there's that juxtaposition that
seems incoherent again bothevolution and creation.
(25:34):
What did Pope Benedict XVI meanby this, and does that fit in
with what you just talked about,with human evolution?
Speaker 2 (25:44):
Yeah, no, what he uses that and is that, you know,
understanding of humanevolution is going to give us
some information about what itmeans to be human, the human
body, our relationship to otherhominins and other primates and
the way that we make a livingand our physiology and so forth
and when that might emerge.
But that alone can't explainall there is about the human
(26:07):
person and that's where thecreation aspect that we are made
in the image of the likeness ofGod.
So, whatever the evolutionaryprocess that got produced, the
form, there was a creation eventin the sense that God directly
creates the human soul and thefirst humans that come into
(26:27):
being.
That form has evolved.
But once it's there, it's nowin soul that there's a creation
event.
So it's creation and evolutionto understand how you get that
first human form.
Speaker 1 (26:40):
As we're talking about human evolution, you know,
a question kind of comes tomind are we still evolving, and
if so, are we continuing toevolve into a different species?
Speaker 2 (26:50):
Yeah, yeah, that's a great question and I get that
question a lot when.
I talk to my students, yeah, andit's clearly we're still
evolving in the sense that wehave, you know, like changes in
populations that occur.
So you have, you know, changesin our lactose tolerance, so you
have changes in immuneresistance and disease
(27:10):
susceptibility genes and soforth.
So clearly, there is that, youknow.
I think the question thatpeople are getting at are we
evolving into uberman, somethingelse?
Right, what is there?
And you know, from myperspective, right again, this
is to realize what are thelimits of evolution.
I don't think, like our abilityto have rational conceptual
thought.
What makes us different from isnot fully a material thing,
(27:34):
right, so it is.
You know, there's a materialaspect to our person that is the
type of thing that is fittingto receive a rational soul and
then allows us to have rationalconceptual thought.
And so, you know, I don't thinkwe can evolve beyond that
because it's not a physicalthing.
It's certainly dependent uponour brain size and so forth and
(27:55):
things like that, but it goesbeyond that.
So I don't see us.
You know, we might evolve tohave more intelligence and so
forth, but we're still arational creature.
That's in relation with God.
I don't think that that'ssomething that evolution is
going to move us beyond.
Speaker 1 (28:11):
For example, Sometimes I wonder I mean just
with technology and how much ourface is in front of screens all
the time.
I sometimes wonder if that'sgoing to affect just human
evolution and how we continue toevolve.
For someone who wants to learnmore about this topic in
particular, are there anysources you'd want to point them
towards to delve even moredeeply?
Speaker 2 (28:30):
Yeah, I think if you're just interested in trying
to get your mind wrapped aroundwhat we know about human
evolution and maybe the originsof humans from a scientific
perspective.
Ian Tattersall has a number ofbooks.
Masters of the Planet is one ofthose.
I don't agree with everythinghe has in there, but I think he
does a good job of explainingwhat might have occurred.
(28:50):
And this, and Yuval Harari alsohas a book as well called
Sapiens, and it does sort of thesame thing.
It's got, I think, a briefhistory of humankind and that
book also, I think, just setsthe context of what we've been
talking about.
They don't get into thespiritual aspect, but just from
the biologic perspective.
This is sort of how people havethought about how humans emerge
(29:14):
in the context within themodern human form emerges.
Speaker 1 (29:18):
But just kind of last question, as we're thinking
about and this has beenfascinating just to learn about
how I as a human would haveevolved Any final thoughts,
especially from your perspectiveas a Catholic biologist?
Speaker 2 (29:33):
Yeah, I think one of the things.
I mean it's a very fascinatingfield but with a lot of sort of
evolutionary history, there's alot of inferences that people
have to make, and so we want todo that cautiously, with
humility, and realize okay, thedata we find a year from now,
okay, that's going to reshapehow we view human evolution in
(29:54):
the process.
So the science is going tochange and evolve and develop as
we get more archaeologicalevidence, more genetic evidence
and so forth.
But no matter what evidence weget, I think that from a
Catholic tradition, however thatprocess unfolded and where
modern humans emerge, they aremore than just an evolutionary
(30:16):
adaptation.
We're more than that andthere's nothing in so the
evolution process that'sinconsistent with that notion
that man is made in the image ofthe likeness of God.
However that form comes to be,and all its messiness and all
the different ways and processesthat might be involved, that
emerging out of that is the typeof thing that can be in
(30:38):
relationship with God.
Speaker 1 (30:40):
You use this term of the biological form.
Speaking philosophically nowand bringing that aspect in,
would you say the soul is thebiological form of the body.
What are your thoughts on that?
Speaker 2 (30:53):
So people will say that the soul is the form of the
body.
From a philosophicalperspective.
I'm not using form in that term.
I'm talking about a biologicalform or the biological structure
, if we want to distinguish that.
So once you get the biologicalstructure, the biological being
that is suitable for a rationalsoul, then that gives the form
(31:16):
of the person.
But it's two different things,right.
The soul being the form of thebody is one thing.
I'm talking about the physicalstructure.
Speaker 1 (31:28):
Got it Well.
Thanks for being in the hotseat for this topic, but moving
on now to the office hourssegment of the podcast, and,
again, this is where people cansubmit questions.
You tackle other questions.
The theme for this office hours, though, happens to still be on
this topic of the environment,so I'll just start throwing them
your way.
This has to do Pope Francis.
(31:50):
He recently released a newwhat's called an apostolic
exhortation, which is a letterfancy word for a letter and it
was to build on and be a followup to his 2015 encyclical on the
environment called Lodalto C.
So this new letter he releasedcalled Lodalto deum, which
translates to praise God, and init he's very critical of people
(32:11):
who deny climate change, and hesays it is verifiable that
specific climate changesprovoked by humanity are notably
heightening the probability ofextreme phenomena that are
increasingly frequent andintense.
So he really didn't, you know,mince his words on this topic of
climate change.
What was your read of thisletter, lodalto deum?
(32:34):
And, as a Catholic biologist,what do you think the Catholic
approach to climate change andthe environment should be?
Speaker 2 (32:41):
Pete Sautner.
Yeah, no, I think you know froma Catholic perspective, I think
you would find, you know, broadagreement amongst Catholics
that we have a duty to stewardour environment, that nobody
really wants to just spoil theenvironment right.
And you know it's relativelyclear that human behaviorist
changed the amount of CO2 in theatmosphere and that's having
(33:03):
effects on the climate.
And you know some people say,well, look like we talked about
here, though climate changes allthe time, it changed during
human evolution and there'snothing we can do about that.
And I don't think that's ahealthy perspective.
But this is a bigger question,you know.
So I think the church can pointout.
You know we have to steward theenvironment Exactly how is
extremely complex, you know, andjust you know, one decision
(33:25):
that we think is going to begood might have some adverse
consequences over here.
So it's a really, you know,difficult issue to show.
You know, if you think aboutelectric vehicles, okay, well,
that can reduce CO2 emissions,but then that creates, you know,
all the mining for the cobalt,nickel that is needed for those
batteries can create otherenvironmental problems.
So there's, it's a very, youknow, multi-layered thing that
(33:48):
we have to get through.
But I do think you know fromthe Catholic variable, all
Catholics, I think, would agreethat you know we have a duty to
steward the environment and toensure that we protect the
environment.
And a lot of prudential judgmentinto what that looks like for
every person.
Speaker 1 (34:05):
Similar topic.
So, ahead of Pope Francisreleasing this letter on the
environment, pew Research Centerthey released new data
specifically about US Catholicviews on climate change and,
broadly speaking, the viewsvaried by political affiliation,
by race, by ethnicity, by age.
82% of Catholics who areDemocrat or lean Democrat at
(34:25):
least, say that global climatechange is extremely or very
serious, and that's compared toa quarter of Republicans or
Republican-leaning Catholics.
Were you surprised by thesefindings?
Or, you know, did it just kindof fall into predictability?
Speaker 2 (34:42):
That's not too surprising, given you know our
divided culture.
You know there are, you know,mischaracterizations.
I think on the one side youthink, well, the Republicans are
these?
Young people, older peopledon't care about the environment
?
And that they do?
And then on the other side, youthink, oh, these Democrats?
(35:04):
What all they want to do iskill the economy and take
control of it.
And I don't think that's thecase.
I think both you know you'retrying to reach a very difficult
decisions about how to approachthese things.
And again you get back to allthese potential judgments and I
think there's a lot that peoplehave in common, but we tend to
scream these slogans.
Speaker 1 (35:23):
Elabel and assume but .
Speaker 2 (35:25):
I think, at the end of the day, people, all people,
want, I think, a planet that'shealthier, and they want people
to be thriving and have athriving economy.
And then you know it comes downto how do you do that best?
Speaker 1 (35:36):
Yeah Well, thanks for tackling these tough topics and
I want to remind our listenersand viewers that if you have a
question, you can submit themfor Dr Dan Kebler to answer here
at the Office Hour segment ofthe podcast.
You can email info atModjaCentercom.
You can also go ahead and giveus a call, leave a voicemail.
You might hear your own voiceright on this podcast.
You can call 949-257-2436.
(36:02):
But until next time, make sureto subscribe to Purposeful Lab
on your favorite podcastplatform and find out the latest
of what's happening at thepodcast at ModjaCentercom.
That does it for now.
We'll see you next week.
Popular Podcasts
On Purpose with Jay Shetty
I’m Jay Shetty host of On Purpose the worlds #1 Mental Health podcast and I’m so grateful you found us. I started this podcast 5 years ago to invite you into conversations and workshops that are designed to help make you happier, healthier and more healed. I believe that when you (yes you) feel seen, heard and understood you’re able to deal with relationship struggles, work challenges and life’s ups and downs with more ease and grace. I interview experts, celebrities, thought leaders and athletes so that we can grow our mindset, build better habits and uncover a side of them we’ve never seen before. New episodes every Monday and Friday. Your support means the world to me and I don’t take it for granted — click the follow button and leave a review to help us spread the love with On Purpose. I can’t wait for you to listen to your first or 500th episode!
Stuff You Should Know
If you've ever wanted to know about champagne, satanism, the Stonewall Uprising, chaos theory, LSD, El Nino, true crime and Rosa Parks, then look no further. Josh and Chuck have you covered.
Dateline NBC
Current and classic episodes, featuring compelling true-crime mysteries, powerful documentaries and in-depth investigations. Follow now to get the latest episodes of Dateline NBC completely free, or subscribe to Dateline Premium for ad-free listening and exclusive bonus content: DatelinePremium.com