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Maybe it’s Habiline?: Human Evolution with Vincent Battista - Ep 148
2.5k Plays3 years ago
In this episode, David chats with his good friend, Vincent Battista about species, Neanderthals, human evolution, and his new job as a PhD in the Private Sector for a pharmaceutical company. David and Vincent have a conversation regarding how to determine what a “species” is, and whether it is just a construct. They then get into a deep discussion about human origins, and where we fit on the family tree.
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For rough transcripts of this episode go to https://www.archpodnet.com/ruins/148
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- Coyote America by Dan Flores
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Transcript
Introduction and Guest Introduction
00:00:00
Speaker
You're listening to the Archaeology Podcast Network. Welcome to episode 148 of Life Endurance podcast. I'm here with my friend Vincent Batista. He's a recent PhD from the University of Michigan, what I like to call my genetics guy. Today we're talking about mainly stuff I find interesting, but probably human evolution, paleo-anthanism, human genetics. You might remember Vincent from episode 114.
00:00:27
Speaker
Did I read that wrong? Did I say 114 before? Probably. No. I didn't. Okay. 148.
Free-form Discussion and Personal Interests
00:00:34
Speaker
Connor and Carlton aren't here today. So we're free balling it. Yeah. So any episode 148, you might've seen Vinny on episode 114, but you know, here we are 148 now. So we're gonna talk Vincent. How are you doing?
00:00:48
Speaker
Good. How are you doing? All right. I'm enjoying Freeball, and it's Tom Petty's famous song. You're a classic rock guy, aren't you? Big, classic rock guy. Okay. You like fishing, you like dogs, and you like classic rock. You know, I'm a man with very simple hobbies, beer, canons, and fly fishing.
Coyotes in New England and Wildlife Stories
00:01:12
Speaker
I appreciate the canons and not canons, bro.
00:01:15
Speaker
Yeah. Yeah. Like coyotes were big coyote guys. You're a big coyote guy. Big coyote guy. You do send me a lot of stuff. I referenced to your dog looking at coyotes. You want to dive into that? Sure. Yeah. I mean, I have a, a livestock guardian dog rescue named Mack. He was a runt of his litter and he's a 120 pounds when he's lean. He's a brick chair house. Yeah. He, uh,
00:01:42
Speaker
He's great. You know, I take him with me when I go fishing and everything. And obviously New England has a really wild coyote problem right now. It's all over New England. It's wild. Yeah. Yeah. Like they brought in sharpshooters a couple of towns over and it like didn't help with the coyote problem. It's like, guys, get some wildlife biologists over here. Like talk to them about how like, you know, the landscape is contributing to this. But yeah, Mac is a big fella.
00:02:11
Speaker
These livestock guardian dogs are bred to not really have a prey drive. They are very gentle with livestock and stuff. We think he was raised on a chicken farm because we have pictures of him as a puppy on a chicken farm. He really loves ducks. He's like Tony Soprano.
00:02:29
Speaker
for a hue neutron. Yeah. He just loves ducks and birds. But he can distinguish between predatory birds and non-predatory birds. So he sees a hawk, like a red-tailed hawk, he bugs out at it, but he sees a mallard and he's perfectly fine. That's like a scent thing or a chemical thing? No, I genuinely think it's an animal that's circling above your head. You know what I mean?
00:02:53
Speaker
These dogs are great because they can sense all dogs can smell way better than we can, hear way better than we can. And so they detect things in the landscape more easily than we do.
00:03:05
Speaker
I took him fishing up in the Green Mountain National Forest, and he sits next to me when we fish. He's usually off leash or, you know, I had the leash dropped next to me or whatever, but he just booked it up this riverbank and he'd treat a black bear. He did not care. And this is pretty common. I can call them off. It's fine, but here in Massachusetts, the coyotes are to the point where I take him with me on purpose because they come up to you. They just do not care.
00:03:31
Speaker
they'll just approach you and they've like been people on the beach. Black bears? No, no coyotes. Can you imagine a black bear? I was like, I feel like I heard about that. Yeah. Nah, yeah. I mean, there's definitely black bears over here, but the coyotes are really what's the.
00:03:49
Speaker
What's the big thing? If you ever read the book, Coyote America, that's a really good book if you're interested in that stuff. I haven't. It's by Dan Flores, is the name of the author. Basically, the whole thesis is like, coyotes are a good model for humans. Okay. It's funny to bring that up too, because one of the things I wanted to ask you about when I get into species later is about coyotes.
00:04:10
Speaker
But also you said that they're a big issue in New England. I see my aunt sends me pictures sometimes of coyotes on Long Island all the time. And I've seen several pictures on like Long Island Wiseguy on Instagram of like just coyotes like roaming suburbs now. And that wasn't usually a thing when I was a kid in the nineties. So it's like they're populating a lot now.
00:04:31
Speaker
They're all over the place, man. They're everywhere. The only place in Massachusetts where they aren't is like Martha's Vineyard or Nantucket. They're everywhere now. Yeah, in Connecticut growing up, you know, you'd see one every once in a while, but like I see one.
00:04:45
Speaker
all the time. One of them killed a buck behind my in-laws place last year. One coyote? I was probably a pack, but they took down a buck that had recently shed its antlers. They took it down right behind the house.
00:05:01
Speaker
It happened first thing in the morning. We heard it. I went and walked my dog back there. He was going nuts, man. He was freaking out. He found the carcass. He peed all over it. He disappeared in the woods, came back with its heart in his mouth. I'm like, Mac, drop that. What the hell are you doing? It was nuts, man. Sounds like something I would do. Yeah, exactly. Yeah.
00:05:23
Speaker
That's cool, though. One thing I find fascinating is coyotes, for sure.
Complexity of Species Classification in Genetics
00:05:29
Speaker
They are canis as their species, canis or canis latrins as their species, canis as a genus. But dogs are canis lupus, familiaris, wolves are canis lupus.
00:05:39
Speaker
You're the guy who always comments on our Instagram posts, like, what even is a species, man? And like you and I, I think vibe pretty well on this idea. So I had a friend, it might even be from that book. My friend had told me, it was from a book she read that coyotes are just natural dogs. Like they're a wolf species that just exist as natural dogs.
00:06:01
Speaker
whether you want to go with that behaviorally or genetically. I would say they're different, but her point was like, they just fulfill a niche that they scavenge, right? And they do little things like that. They're not exactly like apex hunters like wolves are, but they're not dogs entirely. But my question to you is like, it's all just one species to me that does different specialized niches. And niches, I don't know, like how you would define species in that way.
00:06:27
Speaker
here's the thing is that they mix with wolves so the coyotes in the east are actually an admixed group of coyotes from further west and wolves so i mean even to call them a species would be you know
00:06:43
Speaker
Well, I mean, like, yeah, like, I mean, if they mix, they don't, you know, they're ecologically, they're their own thing, for sure. I mean, but also they have so many different ecologies. This is why they're like, canons are a good model to talk about humans, because like, people say, Oh, Neanderthals, like, well, which Neanderthal, you know, they probably live in North Africa, they lived in England, and survived for, you know, as we knew them for, you know, 100,000 years or longer.
00:07:07
Speaker
Which ecology are you talking about? You know what I mean? Like, that's the same thing with coyotes. You have coyotes out west. You have coyotes in New York City. You know what I mean? So, depending on which ecology you want to talk about. Yeah, I know they're interesting critters for sure. So, species to you. I know it's kind of a hard ask, but, and guys, everyone listening here, like what we were going to talk about today was human evolution and paleoanthropology.
00:07:32
Speaker
This applies to any zoological creature. What would you define as species? And I know that's a loaded question. That's tough. I can tell you what a species isn't. Probably a little bit more easily. So a species isn't something that somebody invents so they can get tenure. It's the first way of talking about it. So taking a step back from that, I understand and appreciate the value of calling something a species for conservation reasons.
00:08:02
Speaker
If you can call a local population of orangutan its own species in order to save that local population of orangutans, I will be the first person to call it species with you. Whether or not it meets a genetic definition of species is
Paleoanthropology and Species Differentiation
00:08:16
Speaker
a different story. So there's different sorts of species definitions from an ecological species to a biological species, whatever. But I think if you ask 20 biologists, set a defined species, you'll get 20 different answers.
00:08:31
Speaker
probably equally good reasons. I mean, as it applies to humans, human fossils specifically, people will describe a new species in the genus Homo, right? And they'll say, oh, this species of Homo xyz falls in between Homo xyz minus one and xyz plus one. You know what I mean? And it's like, well,
00:08:53
Speaker
First of all, one, how do you know that? Second of all, the radiometric dating isn't that high enough resolution. You don't have a good age range for it. You also can't tell me if this is a male or a female or a juvenile. A lot of the times, especially in the past, people called species was basically following what we do with dinosaurs. Basically, every fossil gets a species name, you know what I mean? Sure. Which isn't to say that there aren't species of humans. If somebody were to say to me that Homo naledi was a species,
00:09:21
Speaker
I'd say that's okay. Yeah. If you want to call it a species, you can call it a species. But if somebody were to say that Homo habilis, Homo arghast, or Homo rudolfensis, Homo erectus were four different species of human, I'd be like, I don't really know if I'd buy that. You know what I mean? You have a huge spectrum of variation of humans.
00:09:43
Speaker
that we can call Homo, and especially if they're living around the same period of time and in the same places, you have to prove that they were not able to breathe with one another. I don't think you can really do that. You know what I mean? You could probably say that maybe the paranthropus lineage was
00:10:02
Speaker
distinct from the stuff that turned into us. Like that's probably a fair argument, but I wouldn't say that they were, you know, that they couldn't interbreed with any other human population. And that's like a very strict biological species definition. Would you agree with the idea then that species is like any organism that can interbreed and have viable offspring? Well, you know, because then coming out as a geneticist, like
00:10:29
Speaker
There are things that I would call species that produce five blobs for you, you know what I mean? So, I mean, I don't know. And it's like, it's really difficult. So I think you need to just have, especially when it comes to ancient humans, the null hypothesis is that groups are the same and you have to prove that they're different. It takes fewer assumptions to say they're the same and puts the onus on the actual science and makes you actually have to do the work to prove that species are different.
00:10:54
Speaker
And also not everything needs to have a biological species definition. I think we put a lot of emphasis on nomenclature. And I understand the importance of that, and I value that. But I also think at the same time, we really split hairs a lot.
00:11:11
Speaker
Like, somebody tried telling me that the reason why Neanderthals and us were the different species was because we have chins. I'm like, come on. That's really what you're going to reduce the argument to, is that we have chins? Really? Like, come on, man. Like, I cannot buy that. Like, that one phenotype is like, come on. Also, Neanderthals had chins. You know what I mean? They weren't the crimson chin, but they had chins. Sure. Shout out for the other parents. Yeah, and I see...
00:11:40
Speaker
those differentiations all the time, it's like they had, they were shorter in stockier or versus like, you know, they hunted with thrusting spears and things like that versus atlatls. But that to me boils down to, I mean, obviously the phenotypical stuff is, what I'm trying to say is it's a cultural difference to me usually, like through stone tools more so than there's a genetic difference.
00:12:03
Speaker
So, yeah, I mean, especially because they all mixed. They all mixed with us and that, you know what I mean? They mixed with what we would call the Denisovans, even though the Denisovans probably never called themselves Denisovans. The Anatols never called themselves the Anatols, you know what I mean? These people were more concerned with just surviving the winter than anything else, right? They didn't care about population labels and stuff. But yeah, no, I mean, I would agree with you. I mean,
00:12:28
Speaker
I would not say that Neanderthals went extinct. They changed, right? But Neanderthalism is probably more of a starting to think of it. Like, yeah, when you say Neanderthal, everybody knows your meat. That's also a whole different sets of assumptions, but like that lifestyle changed, evolved as these groups were absorbed by other people.
00:12:50
Speaker
groups migrating in and out of Africa and the Near East and things like that. So yeah, I mean, like, then you could say they went extinct in the same way that, that Mycenaean Greeks went extinct or the Vikings went extinct, you know, like the lifestyle went extinct. The gene pool changed. Yeah. It was still, I mean, we still descend from then, but you know, they didn't, didn't disappear like that. You know what I mean? Long story short is
00:13:16
Speaker
in the past and in the present. And it's really difficult to say, without having boots on the ground of the time machine, what population dynamics were like. And that's why the genomics exists. So we're trying to reconstruct that stuff. But yeah,
Translational Epidemiology and Daily Work
00:13:24
Speaker
that's it. What is genomics, by the way? Genomics of the past. So, yeah, it's not just humans either. So, like, failure of genomics can be woolly rhino, Neanderthal, LeBron, yeah.
00:13:34
Speaker
Sure. What's the difference between genomics and genetics? Genetics is like, when I think of genetics as a field, I'm specifically speaking about the study of genes, right? Okay. That could be whatever you want. Genomics is the study of the structure, the function, the mapping of genomes, how the genomes evolve, and all that other stuff. So they overlap, obviously, but, you know, when we talk about genomics, we're talking about the genome. When we talk about genetics, we're talking about genes, which is, you know, people use them interchangeably. I don't use them interchangeably all the time, but I don't mean the same thing. Yeah, yeah. Okay. So I think that's a good spot to end the first segment, and then we'll pick back up afterwards. I've got a few questions about what you're doing.
00:14:02
Speaker
Okay, welcome back to episode 148 of the Life Hormones Podcast. I'm here with my friend, Vincent Batista. We're talking paleogenomics, paleogenetics. We just discussed what genomics and genetics are. I don't think I got to ask you last segment, but what is it you're currently doing for work?
00:14:17
Speaker
The last time we spoke was at Massachusetts General Hospital. That's right. And I was in the Center for Translational Epidemiology, which was in GI. And I since finished just kind of like a non-traditional postdoc. And I finished that and got a job in industry where I do translational epidemiology for a company called Bristol Myers, which is a pharmaceutical company.
00:14:46
Speaker
Okay. So we're allowed to call that big pharma. You can call whatever you want. Yeah. It's a very, very small, very, very small group. And we do a lot of really cool stuff. I personally did do some cool things.
00:15:00
Speaker
Yeah. How do you feel doing that, having gone through three degrees of anthropology and not teaching like anthropology? I do anthropology every day. Yeah. I get to use my degree in my training every single day. Every single day. And you're not doing musical chairs of training students and giving degrees and stuff? No, I still get to mentor young scientists.
00:15:22
Speaker
I get to mentor people from a bunch of different backgrounds from all over the world. I get to work with people from all over the world. And I get to use my training as an anthropologist. I also want to say like, you know, I was an archeologist as an undergrad, but then I got a bio-enteric degree from a four-field school. And that meant that I had to
00:15:43
Speaker
take everything from a genetics course to an osteology course to, which I did both of those for my dissertation, to doing computational methods to take medical anthropology. And I use that stuff all the time. I even use linguistics all the time, linguistic anthropology all the time, like talking about power dynamics, talking about the language of consent, talking about these things. I use that all the time. And I don't know many
00:16:10
Speaker
I don't have a whole lot of colleagues that are at this stage in their career where they get to do that all like every day. And I do it literally every day. That is so cool, man. Yeah. And when you say consent, you mean like for like research purposes, genetics. Yeah. And like, you know, we have, we might, for example, on a given day, be speaking with stakeholders about
00:16:30
Speaker
I can't really go into too much detail because a lot of it is proprietary. Say we were hypothetically getting a project off the ground with the community, making sure that the research questions that are directly relevant to their specific health outcomes are being met and that they're informed and knowing that this is done in a sustainable way.
00:16:52
Speaker
You know, like I haven't been there that long, but people that I work with, there's actually like several people who have an anthropology background in my department. Really? Yeah. Who are biometricians. Yeah. So yeah. What's your day to day look like there? Like as say, like for someone who's anthropologically interested? I do a lot of writing computer programs.
00:17:17
Speaker
So my dissertation, my PhD research was on, it was computational biology. I mean, I did genetics and I did physiology and anatomy. And so I was pretty light on the physiology stuff because I was looking at genes implicated in non-physiological processes. So I didn't do a lot of hands-on physiology stuff. But in my postdoc training, I did a lot of proteomics. So for my day-to-day, I might do some proteomic stuff, some population genetic stuff, which is what I'm really familiar with.
00:17:44
Speaker
to writing machine learning programs to help refine stuff or, you know, doing code reviews, things like that. I do a lot of writing also, like writing up white papers for new disease areas that we might be interested in, things like that. Yeah. Yeah. That's pretty cool.
Role of AI and Machine Learning in Science
00:18:00
Speaker
How do you feel about machine learning and AI going into the future? If you don't mind me asking.
00:18:05
Speaker
I do machine learning all the time, and it's a really powerful tool. The problem with powerful tools in science is that people think they will save the world. And people who do machine learning and AI know that it's an important tool, but also know the limitations. But people who want to fund a lot of the research, I'm not saying my company, but I'm saying like NSF things that I've seen, NIH things that I've seen.
00:18:29
Speaker
are promising you the moon and stars when you can get to the moon and stars with conventional statistics. You can do things from your stat 101, stat 201 classes. You don't need machine learning. So that's one thing.
00:18:44
Speaker
On the other hand, machine learning is going to really help us to be able to identify possibly new therapies. It could help us to learn things from orphan drugs, like drugs that were developed and never brought to market, for example. It's going to help us identify new things from diagnostic imaging. These are all things that are being published right now in high-impact journals that people are using this to make a positive influence on human health. And I think I'd suffer from being an optimist, but
00:19:13
Speaker
This could, you know, AI could be something that leads us to a four day work week, you know, or a three day work week. You know, if we, if we get our stuff together, you know, we can spend more time, you know, doing the other important things in our day to day. But, you know, again, I'm a futurist optimist person. So, but I got a real, that's nice to dream. Yeah. Yeah. I see it every day and I want to get back to genetics here in a minute, but
00:19:41
Speaker
Like my friend's an engineer. He loves AI because it can like, he can type in stuff and he'll let the program run for like 24 hours and he'll have this like really cool computer thing that he designed or like a product he designed. Uh, and it comes out looking super cool, but then there's also the, like, I would love to use artwork for AI, but like, or AI for artwork, but I don't want to plagiarize people's art that it's taking from and things like that, which is a bummer.
00:20:09
Speaker
A big thing too is like any kid now can use chat GPT and type in like, make me a YouTube video about the history of dogs. And like, I did it and it took some straight up quotes from my Instagram, um, some of Angela's work and just like put it right there and then they can make it, which is great. I want kids to be able to be creative, but like, it's just scary to me that you can just do that, but it's also a cool tool. Like you said, so I'm glad that it wasn't a big thing when I was teaching.
00:20:36
Speaker
Oh, the cheating and tests and classes. Also like I think, but also like an anthropology. At least what I was teaching, there was so much in-class stuff, like lab practicals and stuff that you can't chat GBT your way out of. Right. The other thing is like having students be like write personal reflections, things like that.
00:20:57
Speaker
in person, you can't really chat GPT that either, right? So like having introspection, like that sort of stuff is really important. And I think, you know, it's definitely a windfall in what we do, but I think, you know, we'll find a way, we'll find a way. AI is cool though. AI is super cool. Like I think we're going to be able to use AI to build like better, safer automobiles and, you know, things like that. So that'll be sweet.
00:21:23
Speaker
I'm glad you're optimistic about it. I see a lot of people who aren't, but I also think it's, it's got more positive than negative. I think currently anyway, getting back to genetics that I would love to chat to you about that forever, but in genetics, I understand.
Human Origins and Evolutionary Models
00:21:40
Speaker
Well, actually, I think we might've mentioned this on our last episode.
00:21:43
Speaker
I got in contact with you because you reached out to me about a Neanderthal post that I had and you had said something to me on the, like, Hey, you're not entirely accurate about this. And instead of like getting pissed, I was like, Oh wait, this guy's right. Who are you? And then I realized you were my teacher's teacher's student. Uh, and I'll, okay.
00:22:00
Speaker
We are kids so like I immediately listen to you more So that being said we have the same background of information on out of Africa versus multi-regional But would you be able to explain what out of Africa is? Yeah, so those terms so
00:22:16
Speaker
So out of Africa and multi-regionalism are two contrasting models of human origins. So out of Africa says modern humans, the way we are today, appeared in Africa and we replaced populations that were outside of Africa. So multi-regionalism, if you want to contrast the two, says that
00:22:38
Speaker
humans, the earliest humans on record, earliest hominids on record appear in Africa. There were primates outside of Africa, but the first things that we know were things that led to us appear in Africa, and they disperse outside of Africa. And even within and without Africa, you have
00:22:57
Speaker
core and peripheral populations, your population centers and population edges. And these populations are connected through migration and gene flow between them. And something that's advantageous in one place will become higher in frequency until fixation in that specific region. And if it's even beneficial to other regions, it'll, because of migration, spread throughout the planet.
00:23:22
Speaker
Essentially, it says that populations like Neanderthals or the hominids that you find in East Asia, they didn't go extinct in the way that we replace them.
00:23:34
Speaker
But in actuality, we mix with them. And the evidence for that is that traits that we see in ancient human populations in specific parts of the world can be found in their descendants who live in those parts of the world today. Now, the support for the out of Africa is that if you look at mitochondrial DNA and YSTR, so like the Y-chromosomal DNA, these things coalesce in Africa.
00:23:59
Speaker
And none of the ancient DNA that we've gotten from Neanderthals or other humans that are, you know, the Nisibans, whatever you want to call them, none of those uni-parentally inherited markers from antiquity are found in humans today, right? So like both arguments have their merits, but I come from an academic tradition that tends towards this multi-regional braided stream idea of human evolution. And the evidence of that
00:24:29
Speaker
since we started sequencing Neanderthal genomes, and not just the mitochondrial DNA, is that we find a pretty alarming amount of Neanderthal and Denisovan ancestry in living human populations. And as was predicted by this multi-regional model, traits that were advantageous to certain places in the world in antiquity, where there was a geographic center of humans, let's say Denisovans, can be found in descendant populations today.
00:24:55
Speaker
For example, genes that allow people who live in high altitude regions to survive a high altitude in the Himalayas, those haplotypes can be actually traced back to Denisovans who lived in those same areas. So we see other things like a certain Neanderthal related traits that we believe contribute to body proportionality and things like that. So essentially the big difference between the two.
00:25:21
Speaker
which these competing camps in the back in the past thought was like, either all humans were replaced, or all humans mixed, and the reality is somewhere between the two of those. And oftentimes,
00:25:34
Speaker
There is this argument about multi-regionalism that says that it's this model of actually the candelabra, which was a model put forward by guys like Carlton Coon, I believe it was Carlton Coon, basically said that you have distinct human species
00:25:52
Speaker
And these species never mixed and people from East Asia are the same species as people from East Asia from a million years ago. People from Africa are the same as people from Africa a million years ago. People from Europe are the same as people from Europe a million years ago when they don't mix. And that's often what people think of because they are given this incorrect model of multi-regionalism.
00:26:14
Speaker
when in reality the underlying assumption of multi-regionalism, the thing that makes the model work, is that humans mix, and they mix in the past, similar to how they mix today. And I believe the second that we found any Neanderthal DNA in living populations today, it showed that multi-regionalism has merit, and it's true. I mean, we see
00:26:37
Speaker
genes from Neanderthals in North African populations that isn't from like post bronze age population expansion into North Africa from people from Eurasia. Like they were probably Neanderthals in the Middle East and North Africa. You know, they were Neanderthals in the Levant. They were, you know, they probably moved around. They probably, why would they stop? Yeah, they were in Spain too. Why would they stop when they got to, you know, Mount Sinai, you know what I mean?
00:27:07
Speaker
Too nice over here. Yeah. Damn. Okay. So you think it's a, it's a mix of the two then like out of Africa and I guess you can't have one with that. I, I, I am, I adhere to the braided stream multi-regional idea. Insofar as humans mix, they have always mixed and they will always continue to mix. Mm-hmm.
00:27:29
Speaker
Out of Africa happened. It's a matter of if you think it happened 50,000 years ago or 2 million years ago. Whoa. Right. So we have demonisi, right? Demonisi is in Georgia. It's an archeological site that has five individuals that are attributed to Homo erectus. Right. And these, I think it's 1.75 million years, something like it's pretty, it's older.
00:27:56
Speaker
than 1.6 million years old. I don't remember the exact date. But long story short, these are five individuals who have males and females, you have younger folks and older folks. And there's so much variation in this one population from this one cave site that it almost completely encompasses the variation that you see within Homo in Africa at that exact same period of time. So it's like, as soon as they show up in Africa, they're in Europe and Asia.
00:28:31
Speaker
You know, they're, they show up and then they disperse, right? Born to run thing, right? It's like Forrest Gump, you know? All right. Uh, let's, uh, let's cut that there. And then in the next segment, I want to ask you more about that. And just for the record, we're talking about Georgia, Hezbollah, Asia. We're not talking about Georgia, Tennessee, Florida. No, Georgia, America. That's the word. There we go. All right. We'll be right back.
00:28:46
Speaker
You know what I mean? They show up, and then they're all over the place. I'm all right with this? Yeah, if that's what you want.
00:29:00
Speaker
All right. Welcome back to episode 148 of a life nurse podcast. I just want to clear one thing up last segment. I mentioned a hospital is from Georgia. Hozballa is actually from Dagestan, which is not Georgia. Very different former satellite states of the Soviet union. Anyway.
00:29:16
Speaker
We're talking with Vincent's about why I want to get into Homo erectus. Now that area you're talking about in Georgia, I need to think about this, but I, I often tell people that humans are, we're just mutant Homo erectus. Like once we reached Homo erectus and made actually in hand axes and that tool industry, we've kind of just interbred with other various variants of humans and we are what we are today. Would you agree with that? Yeah. Yeah.
00:29:44
Speaker
That's basically, I mean, so that site in Georgia, Diminisi, it's interesting because when the first archaeological finds, well, the first human remains were found there, there was, I think, four individuals.
00:30:01
Speaker
They tried to call it Homo georgicus. They wanted it to be its own species. And then a couple of years later, they found a fifth individual. And that fifth individual was interesting because the variation that you have in these five individuals almost completely encompasses all the variation you see for contemporaneous members of the genus Homo in Africa. And it's about 1.8 million years old, this site. So to me, to say that we are all different versions of
00:30:32
Speaker
Homo erectus is fine. I don't know if you would take a two million year old Homo erectus and drop them off in New York City today. Some people would be like, oh, okay. This guy looks a little bit different, right? Or this person looks a little bit different. That could be the case. But especially for later Homo erectus, they're really not that different from us.
00:30:54
Speaker
I don't think it was the case that there was a speciation event. I don't think there was ever a clean break in the human lineage from the last Australopiths to the earliest members of the genus Homo up into us. Remember, it's a long and slow process evolution is. Some people are in favor of things like a model where there's cladogenesis where you have this branch that goes off and makes their own thing.
00:31:22
Speaker
It doesn't really seem to have been the case for us. Now there are some unique
00:31:29
Speaker
populations of human like Naledi. Naledi looks pretty different. It doesn't look like us necessarily. It doesn't look like Homo erectus necessarily either. It's its own population. And there's a remarkable amount of similarity between the individuals there. And what's weird is that they're only known from like, you know, a small geographical area, a cave site, right? So now if you compare Naledi, which is more recent, with Diminisi,
00:31:57
Speaker
I can get the variation in the c is incredible you have males and females younger folks you older folks you people that are healthy folks with a lot of bone resorption in their teeth are missing from the manual. You have one individual a male who is the biggest skull out of all them and he has a small spring the smallest in the cranial volume out of all them so you know it's pretty interesting but yeah i mean.
00:32:22
Speaker
All human populations on the planet today, even though we have regional variation in the amount of ancestry derived from archaic human populations like Neanderthals, Denisovans, et cetera, the first tomorectis that moved to East Asia met
00:32:37
Speaker
some really unique evolutionary selective pressures. The same with the first Homo erectus that went to Northwest Africa or ones that went to Iberia, right? Each one of these places would have had their own sets of pressures ranging from UV radiation to possibly high altitude to maybe even heat, maybe even hotter places in what they were like living in sort of a tropical environment, maybe in East Africa or South Africa or whatever you want to talk about.
00:33:04
Speaker
Yeah, it's pretty interesting. There's no clear break, no line in the sand that separates us from really any of our ancestors because that's not really how evolution works.
Human Evolution Complexity and Interconnectedness
00:33:14
Speaker
Sure. Why do you think people are so hellbent on like getting a line in the sand or like
00:33:23
Speaker
Yeah, there you go. Yeah, no, it's because we humans are weird because we like really simple explanations. And for some evolution is a simple explanation, right? Like things that are fit for an environment are going to have a greater likelihood of being passed on to subsequent generations. We delay public
00:33:46
Speaker
On the other hand, this is like, you know, this is everybody. This isn't just people who are interested in science or not, whatever. We latch onto certain ideas from the past and sometimes it takes a long time to unlearn these things. So you see like, you know, the ascent of man or something like that, the cartoon of the chimp and then an early human and then some human and then us. We have this idea that there's a missing link, but every time you find a missing link and you stick it into that,
00:34:11
Speaker
lineage, a new gap opens up on either end. So there's something that will come before it and something that will come after it. And if you populate all those gaps with all the variation of humans, it's a big bushy tree with vines interconnecting them. And it's a really tangled bank, as Darwin called it. And if you follow the braided stream analogy of human evolution,
00:34:34
Speaker
It says that, you know, our genes that were, we have parts of our genome that evolved in places that are not where we live today. Right. Like there are, there are parts of our genome that evolved to selective pressures in East Africa. There are parts of our genome that evolved in maybe in the near East or, you know, but as far as like a missing link goes, you know, it's, I think it's, it's a catch all term. Cause we expect there to be one thing that we can point to that can answer all our questions. And that's never going to be the case.
00:35:03
Speaker
Yeah. What's the braided stream? Remember that in human origins. Yeah. Yeah. So it's like, it's multi-regionalism. It's basically that, I don't know who came up with the term braided stream. I think maybe Hawks may have.
00:35:17
Speaker
But essentially, it's just like a glacial stream that has these little rivulets that break off and reconnect. And when they diverge, some of these divergent streams may disappear and evaporate, but other ones could pick up more steam and collect more meltwater and they become bigger and they become a main stem of a stream. You will have this process of divergence and reticulation. And that seems to be the case for human evolution.
00:35:42
Speaker
For example, we have a population movement out of Africa into the Near East, and that population separated into Western Neanderthals, then Eastern Neanderthals, and Denisovans. And these different populations traded genes with each other.
00:35:58
Speaker
And you have things like local lineage loss, like there was a population turnover in Neanderthals that happened at one point in time where you have Neanderthals in the East basically moving back into Western Europe. You know, Western Europe is where genes go to die. It's a cul-de-sac. And when you have things like glacial events happening,
00:36:16
Speaker
populations get stuck. You know, the gene pool gets smaller, populations become more inbred, and that's happened a billion zillion times in human evolution. But then, you know, if these populations survive, new populations will move in and mix with them and bring with them advantageous genetic variants. And we see that with early humans that look like us,
00:36:38
Speaker
who go to Europe, they mix with Neanderthals and Denisovans. We see the same thing when they go into Central Eurasia, probably East Asia, Southeast Asia. It happens every time humans in the past move somewhere, they mix with whoever was there. And that kind of defies this.
00:36:53
Speaker
model of a single dispersal with complete population replacement. It didn't happen like that. Population's mixed and it seems like they always mix. It seems to be the rule more than anything else. Every ancient genome that we get has some level of admixture in it with archaic humans with very few exceptions. Is it possible that some of those gene sequences that are more archaic are just still in the DNA or is it pretty evident that it's admixture?
00:37:20
Speaker
You can tell that there's admixture, yeah. So even though ancient DNA can be very degraded, because of this population, basically bifurcation that you get, you have these things evolving on their own and they evolve kind of unique ancestry informative markers, right? So mutations that are unique to a place in a time that are then passed down to offspring.
00:37:43
Speaker
There's this, I guess you can call it a mathematical modeling process using these admixture algorithms where you can detect amounts of these ancestry components being crossed into populations. There's also a really simple test called ABBA-BABA, where it's basically you have ABBA-BABA. It's also called the B-statistic.
00:38:08
Speaker
But basically, you have a test for deviation from a very strict bifurcation event or a splitting event in evolutionary time. And long story short, if you have an excess of these mutations that are found in this archaic human population, inside your non-archaic population, chances are they were crossed in. So that's oversimplification of it. But it's an interesting test.
00:38:38
Speaker
So Neanderthals, just like kind of as you put it, like they were existing populations in Eurasia. How did they? Probably North Africa. And probably North Africa too, yeah. Okay. You know, they're a human group and these humans left. There was a population dispersal from Africa sometime after 2 million years ago.
Early Human Dispersal and Technological Advancements
00:38:58
Speaker
We found the earliest evidence of this at demon EC. And there's some archeological sites in China that are around the same age. So it looks like as soon as they
00:39:06
Speaker
got out of africa they probably went back into africa probably went into maybe what is today that you know saudi arabia that area probably went into India and east Asia probably went all over the place but we do find archaeological signatures in Georgia we find early human remains in Iberia over a million years ago
00:39:26
Speaker
So, you know, they move into these places and they put down roots and then they evolve to local selective pressures. And so, like, we have the Atapuerca hominids, who are over a million years old. I think the earliest evidence of a human there, like, osteologically is a tooth. Yeah, I think the oldest individual there is a tooth at SEMA. I'm not 100% sure you have to fact check that. But, you know, we have ancient DNA from those individuals too, and we see that
00:39:53
Speaker
Like, I think their mitochondrial genome was more closely related to Denisovans than it is to the Neanderthals who lived in Spain after them. But I think their Y lineage is more closely related to the Neanderthals. It might be backwards. It's been, you know.
00:40:09
Speaker
six or seven years, maybe longer than that since I last read these papers. But yeah, no, it's interesting. But what you do see is that you have the formations of basically a population structure of these Western hominids and these Eastern hominids and probably multiple Eastern hominids. The ones that are in Southeast Asia might look a little bit different. But realistically, like East Asia in China was probably a population center, like
00:40:36
Speaker
the proper pronunciation is like you have a whole lot of individuals living there and like the last ones of them are called the late homo erectus and they could have been around.
00:40:48
Speaker
less than 100,000 years ago, but they were mixing with humans that are moving there all the time. They're constantly mixing. That's what they found fire too, right? Yeah. I think we were using fire at least by a million years ago, to be honest with you. Yeah. I would agree with that statement too. I don't know how we could... As a person who studied gold climate adaptation,
00:41:09
Speaker
I don't really know how we could have moved into all these places without fire. Exactly. Like even at night in the Middle East, it's still cold. Oh yeah. The desert is cold, man.
00:41:20
Speaker
Yeah, that's fascinating too. And fire too is more, that's something I always looked at as a marker of, okay, a million years ago, fire. It looks like an education or an intellectual thing, but it's not. It's literally just a technology, much like level technology or actually in technology. It might take a little more fine motor skill to make a bow drill, but like.
00:41:42
Speaker
I mean, it's assuming they were making bow drills, you know what I mean? Yeah, just hitting flint together, doing other things. Who knows? Like, even if they found naturally occurring, yeah, I mean, like, but managing that resource and protecting that resource as fire, you know what I mean? Yeah. But I mean, even in Australia, there's possibly evidence of burning, intentionally managing the landscape with fire, like, as soon as
00:42:07
Speaker
Aboriginal Australian ancestors get there. There's some evidence for that. So yeah. So I mean like even, you know, at 50,000 years ago, people are using fire in the way that we use fire today. So yeah. And especially to harness it from, let's say like a bolt of lightning or something natural, like that requires a lot of oral.
00:42:27
Speaker
and cultural transmission of like, Hey, this thing's going to strike at this point when the skies get all black. We need to run to it and get that felt like that. That's just as much intelligence to me. Yeah. Let alone like overcoming our biology to be afraid of fire. You know what I mean? Yeah. I guess that's a good point too. That's probably great. Yeah. Like, I don't know, like dogs, you know, like wolves. I mean, my dog does not like fire, but some dogs are cool with it. I'm loves fire.
00:42:54
Speaker
My dog stays about 10 feet away and stare. We also might just overheat because his coat is so thick. No, mine tries to eat the embers that fly out. Oh my God.
00:43:04
Speaker
He's got a scar on his nose from it. Yeah. Why do you think people are so, I mean, I asked you why they're hell bent on getting a missing link, but why are we so intent on classifying each other into these different little groups and species? And it's unfortunate, but like we need to, because the world is complex, we need to, we have this like need to categorize it and organize it in a way that we can understand.
00:43:29
Speaker
And also we come from an academic tradition and probably even a theological tradition in the West that says that you need to do this. Like you have this hierarchy, right? And I don't really know if that needs to be the case. Like as a scientist, like I'm interested in cladistics and phylogenetics, right? Like here's what we do. But at some point,
00:43:52
Speaker
We're going to have to have a serious recall of the way that we, the things that we call, like, I don't think or Gaster, Rudolph fences, you know, all these other, all these other early members of Homo. I don't actually think they're all their own species at all. You know what I mean? Um, lumber.
00:44:12
Speaker
sometimes, conditionally, a lumper. A lot of the times I lump, but then there's some, you know, groups of hominids where I'm like, yeah, dude, this is, I can't, like I really, it's really tough to lump this, but, but at the same time, it's like, you know.
00:44:26
Speaker
There's good reasons to split, like if it means that we can protect an endangered species and split away, you know what I mean? Yeah. You know, there's like ecological species concept, biological species concepts. I'm a big fan of the conservation species concept. It's like we can serve it, then we're going to split it. That's fine. Yeah.
00:44:44
Speaker
Yeah, that's about all I got for this time. I'd love to have you on again and talk more about this stuff because it's just endlessly fascinating. Connor and Carlton couldn't make it, but I know they have their own questions about all this stuff too. And you're a guy for that. So if anyone in the audience, if you have any questions regarding human evolution, shoot us a, I'll make a post about this. You can leave a comment or just shoot us a message so we can get it answered. But Vincent, I appreciate you coming back on, man.
00:45:07
Speaker
Don't mention it, buddy. If you've just listened to episode 148 of Life In His Podcast, you can rate and review the podcast on Apple or Spotify, and then rate and review would be great. If you give us a review and send a screenshot of it to the podcast, Carlton will send you a sticker. And Connor's not here, so I don't have a witty joke today. But we'll get back to you next week. All right, see ya.
00:45:35
Speaker
Thanks for listening to a life in ruins podcast. You can follow us on Instagram and Facebook at a life in ruins podcast. And you can also email us at a life in ruins podcast at gmail.com. And remember, make sure to bring your archaeologists in from the cold and feed them beer.
00:46:03
Speaker
This episode was produced by Chris Webster from his RV traveling the United States, Tristan Boyle in Scotland, DigTech LLC, Culturo Media, and the Archaeology Podcast Network, and was edited by Chris Webster. This has been a presentation of the Archaeology Podcast Network. Visit us on the web for show notes and other podcasts at www.archpodnet.com. Contact us at chris at archaeologypodcastnetwork.com.