IRA FLATOW: This is Science Friday. I’m Ira Flatow.

Later in the hour, we’re going to explore how fiber optic cables can actually count cicadas– really. And a leading AI expert shares her vision for the future of the technology.

But first, we’re all familiar with the concept of the hunter-gatherer in ancient times– men venturing out for game meat, while women largely stayed closer to home, foraging for plants, tending to the kids. Well, as with most things, it’s likely this wasn’t as black and white as it appears. New research shows that women likely hunted just as much as men did and that they were well suited to this type of long-distance hunting that occurred in ancient times.

Here to tell us more about this research and how this myth gained popularity in the first place are my guests Dr. Cara Ocobock, assistant professor in the Department of Anthropology at the University of Notre Dame, and Dr. Sarah Lacy, biological anthropologist at the University of Delaware. Their findings were published in the American Anthropologist.

Welcome to Science Friday.

SARAH LACY: Thank you.

CARA OCOBOCK: Thank you so much, Ira.

IRA FLATOW: Nice to have you both. OK. So let’s get right into this. So this Man the Hunter theory was introduced, when, in the 1960s? How did it become, Dr. Ocobock, so embedded in our culture?

CARA OCOBOCK: Yeah. So it started out as a conference in 1966 and then became an edited volume about two years later. And it was built on a lot of ethnographic evidence at the time, where folks were going out among different cultures, looking at what people were doing with their time and how they gathered their sustenance, and put forward this idea that it was men that did the hunting and that women did the gathering, and that the hunting itself is what became critically important for our human evolution trajectory; that everything that made us human today was because of skills needed to hunt, and that it was men doing the hunting. Therefore, evolution was acting mostly upon men.

And it became pervasive, I think, for a couple of reasons. One, it is this popular idea that was honestly around well before Lee and DeVore– who were the ones who put together the edited volume– actually proposed this Man the Hunter idea. It doesn’t take much to see these dramatized images of cavemen dragging cave women by the hair and men hunting and women rearing children. It’s been in the popular culture for a very long time.

IRA FLATOW: But there was no evidence to support that.

SARAH LACY: Yeah. So when you actually look at their skeletons– because everyone’s doing the same thing, right– so if you are convinced by the evidence that men were hunting, then women are clearly also hunting because their bodies show all the same activities.

IRA FLATOW: And so, Cara, why did you want to pursue this topic?

CARA OCOBOCK: Yeah. So I’m a former powerlifter, but I can no longer lift due to a pretty severe back injury. And in this particular powerlifting gym that I attended, I was faced with some incredible sexism based on these very strange stereotypes. And I was told things like, be careful not to lift too heavy, your boobs will shrink, or, you lift like a man so you might as well be a man.

IRA FLATOW: Wow.

CARA OCOBOCK: Yeah, I know, right. This was really fascinating ideas about what women’s bodies should do or, quote, unquote, are supposed to do. And that got me interested in this idea of, well, what actually are the supposed differences between females and males when it comes to athletic performance?

And then the other part of it came from my students. So in my introductory biological anthropology course, one of the fun assignments I have my students do is creating an online dating profile for the fossil hominin of their choice, which gives the most hilarious results you can imagine. And semester after semester, no matter the sex and gender breakdown of my students in that particular class, the vast majority of the dating profiles they turned in were from the male perspective. And it’s kind of stunning.

And so I kind of sat with that and wondered why– why in the world are my students identifying as hominins as male and male only? And it’s because of the depictions they’ve seen in books. And it’s the depictions and descriptions they’ve seen in the papers that they read for class, where the male view is always the prominent view.

IRA FLATOW: And you make an important distinction in your research paper between sex and gender when talking about this.

CARA OCOBOCK: So sex is what we view as the biological aspect of things and gender is more of the identity aspect. But the important thing to remember is that there are times where a strict sex binary makes sense when it comes to different topics to study within science. But a lot of times it doesn’t make sense and we assign these basic averages– like hormone levels to females versus males. But there’s a huge range of variation from individual to individual as well as within an individual across a life span.

And so when people are asking questions about sex, they’re actually often asking questions about other things that they’re correlating with sex.

IRA FLATOW: I see. Cara, we’ve heard a lot about what testosterone does in terms of physical activity, but not so much about the advantages that estrogen has related to exercise. Tell us about some of those.

CARA OCOBOCK: So this I think was my favorite part of just doing this research– was learning the real importance of estrogen to everything for life. Estrogen affects everything from your brain development, skeleton development, your cardiovascular health– all of those things. But when it comes to exercise, estrogen seems to be critically important for endurance activity.

It allows or enables the body to use more fat rather than carbohydrates during endurance activity. And fat is one of these slow-burning fuels that you want during endurance exercise, but it also packs more bang for your buck– having nine calories per gram versus just four calories per gram of carbohydrates.

And so burning fat allows you to run for longer without getting fatigued. And females– I use “female” here in particular as this is the term used in studies looking at this– females have higher estrogen, more estrogen receptors on their skeletal muscle, and they burn far more fat at every given exercise intensity level relative to males. And it has been shown a number of times that females do not fatigue as quickly as males do doing that same level of exercise intensity.

IRA FLATOW: So this would be really useful, as you say, for long-distance hunting, for example.

CARA OCOBOCK: Absolutely. Yeah, for the persistence hunting, where you’re running an animal down to fatigue so that it’s an easy kill once it finally slows down– absolutely. And the other interesting part of it is that estrogen also seems to be beneficial for recovery after large bouts of exercise. And so females tend to recover faster from this as well.

IRA FLATOW: And Sarah, what were some of the fossil evidence that backs all of this up?

SARAH LACY: Yeah. So when you look at Neanderthal skeletons, we see that they lived rough lives. They have broken bones. They have lots of arthritis. It was hard being a Neanderthal because they’re practicing a form of hunting we call ambush hunting, where you have to get in really close proximity to large mammals. Hence, why there’s been this analogy made between Neanderthals and rodeo clowns because they have similar injury patterns in the OSHA database.

IRA FLATOW: Wow.

SARAH LACY: Yeah, the women aren’t being protected from anything.

IRA FLATOW: Wow, that’s interesting. They have injuries like rodeo clowns because they get very close to the animals in the rodeo and break their bones. What about the burial graves– very consistent evidence there?

SARAH LACY: Yeah. So once they actually start burying their dead, there is no sex difference in what is being placed into the burials. And as we get more into the Upper Paleolithic with modern humans, there, again, they’re more likely to put things into the burial and have these richer goods placed with them. But again, no differences between males and females.

CARA OCOBOCK: And women contributed a ton through gathering and men also likely did. And as for mothering, lactation, child rearing, and child birth, yeah, we know those are biological realities and are the key to our species’ survival. I think where there’s a point of contention is this idea that being pregnant and breastfeeding makes somebody incapable of doing any other day-to-day activities. And that’s just not the case.

IRA FLATOW: Right.

CARA OCOBOCK: If somebody has a normal healthy pregnancy, they can continue on their exercise routine up until the day that they give birth, and quickly bounce back after giving birth to take part in very vigorous physical activity. The wonderful example of that is Sophie Power, the ultramarathon runner, who competed in an ultramarathon three months after giving birth to her son. And that means she was training all through that pregnancy and then still breastfeeding while doing that ultramarathon.

It is highly unlikely that women in our evolutionary past were even able to take steps away from daily activities because life depended on those activities being done. And we see this in the wild as well. You don’t see a pregnant lion just giving up and not hunting. She’s going to go hunt and she’s going to get those calories.

IRA FLATOW: So when do you see the separation occurring in men’s work and women’s work spheres? When does that emerge?

SARAH LACY: That’s really a reflection of agriculture.

IRA FLATOW: Really?

SARAH LACY: When you start to have a fixation with land as opposed to people. As your group– your group is now tied to a specific plot of land– people become more interested in paternity certainty, inheritance– all of these things end up being actually pretty terrible for women. And we can actually see in their teeth, for instance, increased levels of stress, more disease, all coming about with agriculture. Which hit men as well, but not as badly as it did women.

IRA FLATOW: Now, I understand that after this research was published that you both got some online pushback on that. Cara, what happened here?

CARA OCOBOCK: Oh, yeah. There’s a part of me that fully understands the pushback– this idea of Man the Hunter, that’s been persistent for a really long time. It’s really hard for people to shift their ideas of what our past looked like when they’ve been fed the same story this whole time.

And we get these interesting ideas proposed to us to try to refute our evidence of, like, oh, well, Neanderthal injuries are the same between females and males because males are doing the hunting and females are running away from the animals for which, of course, there’s zero evidence, or this idea that they were getting these injuries from warfare, when we have absolutely no evidence for warfare until what– like 10,000, 11,000 years ago.

And then it’s just these same ideas that people think we are trying to do a woke revisionist history, when all we’re really doing is taking evidence that has been around for decades and shining the light back onto it so it can no longer be ignored because it should be included in our reconstructions of the past.

IRA FLATOW: Interesting. So where do you hope this research goes from here, Sarah?

SARAH LACY: Well, I hope that this makes this the default in the discipline. For a long time it was viewed as the feminist critique of some of the paradigms for human evolution. And I hope that we put that final nail in the coffin so that people recognize, no, this is the default hypothesis. And if you see evidence of the contrary, cool, but you shouldn’t assume that it exists.

IRA FLATOW: And you, Cara?

CARA OCOBOCK: Yeah. So basically all of the research we know about training, nutrition, and recovery in terms of exercise has been performed on males, and then you basically shrink the quote, unquote, dosage for females, when there really are differences. And so I am desperately hoping for a lot more research on estrogen and female exercise and athletic performance.

IRA FLATOW: Well, I hope your back is better and I hope to see all that come true. Thank you both for taking time to be with us today.

SARAH LACY: Absolutely.

CARA OCOBOCK: Thank you so much, Ira.

IRA FLATOW: Dr. Cara Ocobock, assistant professor in the Department of Anthropology. That’s at the famous University of Notre Dame. And Dr. Sarah Lacy, biological anthropologist at the University of Delaware.

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