Marlene Zuk on the Truth about Paleofantasies

June 23, 2014

We evolved to eat berries rather than bagels, to live in caves rather than condos, to sprint barefoot rather than wear sneakers—or did we? These, along with many other questions about what is or is not “natural” for humans from an evolutionary perspective are the subject of the new book by biologist, Dr. Marlene Zuk, Paleofantasies: What Evolution Really Tells Us about Sex, Diet, and How We Live. The book was recently long-listed for the Royal Society’s Winton Prize, one of the most book prizes in science writing.

Dr. Zuk is an evolutionary biologist and behavioral ecologist at the University of Minnesota, where she heads the Zuk Lab. She has published many papers and books on evolution and evolutionary biology.

Lindsay interviews her about the book with a view to the “Paleo” craze in health and nutrition, asking if we really know what some claim we do about our paleolithic ancestors and what impact, if any, that knowledge should have on our lives.

This is point of inquiry for Monday, June twenty third, 2014. 

Hello and welcome to Point of Inquiry. A production of the Center for Inquiry. I’m your host, Lindsay Beyerstein. And my guest today is Dr. Marlene Zuk, a professor of evolutionary biology at the University of Minnesota. She is the author of Paleo Fantasies What Evolution Really Tells US About Sex, Diet and How We Live, which was just long listed for the Royal Society’s Winton Book Prize, one of the most prestigious awards in science writing. If you believe pop evolutionary psychologists and paleo lifestyle gurus, we’re hapless stoneage apes adrift in a world of Cheetos and iPhones. They say we’re sad, fat and sexually frustrated because evolution has not prepared us for the world we live in. They may encourage us to imitate the imagined lifestyles of our Stone Age ancestors before agriculture or of a sexual revolution or shoes or whatever newfangled perversion they blame for casting us out of Paleolithic Eden into the hell of modernity. Zook explains that we may be better adapted to so-called modern lifestyles than we think because gene frequencies in a population can change drastically over just a few generations. In the face of strong selective pressure like the emergence of a deadly plague, or when a wind farm mutation suddenly lets some people digest a rich source of food that others can’t eat. She describes how new discoveries in archeology, anthropology and molecular biology are challenging many stereotypes about what Hunter-Gatherer life was like in the first place. Marlene, welcome to the program and congratulations on making the long list. 

Thanks a lot. So tell me, what is paleo fantasy? 

The word is one that I borrowed from Leslie I. Yellow, who is a anthropologist who is at a conference talking about early human history and was frustrated by the fact that people were just kind of making up stories about the way humans were a long time ago. And she said, well, is this really based on evidence or are we are you are these just paleo fantasies? And I love the term. And she gives me permission to use it because I think it refers to the way we tend to have these assumptions that are often tested or even unexamined about the way life was like a long time ago and how that’s affecting what we do now. 

Does an idea in the book about how the paleo fantasy has something to do with a fundamental mismatch between our Stone Age genes and our high tech lifestyle? I can see a bit more about that. 

Sure. It’s. I mean, it’s easy to look around and say, you know, we are we’re in a world with, you know, cell phones and nanotechnology and highly processed food and, you know, smart machines and so forth. 

And, you know, this is just not how we started out that really, you know, a short time ago we were living, you know, an existence that was much more tied to the seasons. 

It was much more tied to the foods that we could gather, you know, off the earth. You know, we didn’t have electric light and so forth. And so especially if you think about how well, you know, we’re also suffering from all these diseases. We’re pretty sure our ancestors didn’t have at least such a great extent like, you know, hypertension and obesity and diabetes and so forth. It’s it’s hard to escape this feeling that, you know, wait a minute, somewhere along the way, we kind of went wrong. 

And that indeed, there is this mismatch, as you say, between what’s happening, how our bodies evolved and how, you know, our lives of, you know, worth a number of years ago and what we’re doing now. And at its core, there’s nothing that that is an accurate assessment. There is kind of a mismatch in many ways between how we evolved or things that happened in our history and what’s happening to us now. The part that I started to question was the idea that somehow evolution was progressing and we’ve kind of gone astray like we were doing something wrong. 

And the only way to make that better was to, you know, go back to some imagined really cast of the way things were. 

Do you feel like it’s a kind of nostalgia that draws people to these stories? 

Oh, sure. You know, and also, you know, one can argue that that, you know, it’s whatever. That’s right. 

I mean, ancient Romans complained about how, you know, kids these days, you know, didn’t do the things that, you know, their parents had taught them and and so forth. So know. Yeah, I mean, you can talk about nostalgia or, you know, some people think it would be great if we had the whole world more like, I don’t know, sort of this 1950s sitcom, at least in terms of family life. You know, some people think, you know, would be great if we went back to what it was like before the Industrial Revolution. And then there’s the idea that, you know, but but it’s all about the first page. 

And I got interested in the Stone Age part of it, because as someone who studies evolution, I’ve become increasingly aware of how rapidly evolution can happen in people as well as other kinds of living things, and that there’s kind of a formality about this idea that, oh, we’re evolving towards something until we got to this perfect, perfect world where we were in harmony with our environment. 

And now we’ve kind of fallen from grace. That’s just not how evolution work. 

What’s fallacious about the idea that we had so many tens of thousands of years in a Hunter-Gatherer environment and then switch that we haven’t had time to evolve? 

Well, in one sense, nothing. I mean, that there’s nothing wrong with that. 

That is absolutely true. We spent a long time being hunter gatherers and we spent a lot less time with, you know, cell phones and cheeseburgers. I mean, yeah, that’s that’s absolutely true. But it’s also true that evolution is a continuous process. And it’s not like you kind of evolve, evolves, evolve, and then you get to a point and then you can go through. Now we’re done evolving and we can go often, you know, like learn to knit or something. It’s just that’s just not how it works. Evolution is happening all the time and it always happens with a lot of trade offs and compromises so that, you know, the analogy I sometimes use with people as well. It is true that some things are not, you know, have had lots of costs and benefits. So think about walking by Teeley, which is something that, you know, human beings evolved to do a long time ago. Well, there’s actually some real drawbacks to walking on two legs. It means that you have a constraint on how large a child you can give birth to because of the size of the pelvic region. You know, there’s some back issues that arise, although sometimes that’s thought to be tied, more sitting than necessarily with how we’re walking. But. But it certainly has to do with our where skeletons work. There’s, you know, different kinds of strains on the joint. We certainly can’t run as fast. And so you can come up with this litany of things that are terrible about walking on. But that ship has sailed. I mean, you just can’t. You know, we’re people when when when we were coming down from the trees, you know, we should anyone have been sitting there saying, wait, hold on. Maybe we should stay up here? You know, it’s nice up here and we should work, you know, or we should be on four legs or something like that. I mean, it’s evolution just goes the way it goes. And it’s always accompanied by trade offs and compromises. And so this idea that we should go back to a particular point in time is just not very well supported. 

In the book, you talk about how they’re uneasy compromises that are still left over from when our ancient ancestors were fishlike creatures, even short or actually more recently. 

So my new favorite example of these compromises that are leftover is from actually from actually book that came out after my book called The Story The Human Body by Daniel Lieberman from an anthropologist at Harvard. And he’s got this fantastic example that I wish I’d known about when I wrote the book, talking about how so are are a throat and jaw contains all these specializations so that we can speak, so that we can do what you and I are doing right now. And what that means is that our vocal tract is located really close to our esophagus. And so we’ve all had the experience of, you know, food going down the wrong pipe. Right. Goes into the place where you’re supposed to be speaking from. And our trachea and our esophagus are located close to each other and we don’t have a hard separation between them. If you look both at our closest primate ancestors currently and at ancient human remains, they don’t have that problem because they just don’t have this juxtaposition of where you talk and where you eat. Having that juxtaposition is because of the length of the different parts involves. And you know what what needs to what apparently needed to happen for us to be able to talk? Well, the drawback is more than just a nuisance. I was really blown away to find out that choking on your food is the fourth leading cause of accidental death in the United States, which I thought was just wild. 

I mean, if I did, I didn’t know. All right. And so the moral from that is. Oh, my God. Like talking. Bad idea. But wait a minute. No, it’s not. It’s just the moral of that. Is that stuff happens when the costs are outweighed by the benefits. 

And that’s been true for evolution all the way. So you can’t just point and say, oh, no, we were perfect when we were doing thing X because, well, not talking means that, you know, or having a body that’s unable to produce sound or throat structure, it’s able to produce sound is certainly going to keep you from choking more. But clearly, there are other costs to it. So there you go. And that’s that was really the focus that I think is more interesting is the where do these mismatches occur? What can you know, maybe what we can do to ameliorate them, but not this idea that, oh, no, we’re all going to hell in a handbasket because we’re not living like we were in the Stone Age. 

Can you talk a bit about your own research on crickets and what that shows about how fast evolution can happen in real life? 

Sure. I got a lot of people who didn’t surprise me. And why did you want to write a book that talked a lot about human evolution? Because, you know, you mostly be entirely studying on humans. But to me, it was a really natural connection because we work on a species of cricket that it’s subtropical and it occurs in Australia and some Pacific islands, like some land, Tahiti and so forth. It’s been introduced to Hawaii in Hawaii, but only in Hawaii. It gets a parasitic fly that homed in on the calls that the crickets produce. So the fly is able to hear the mating call of the crickets, which means that the fly comes in, deposits these larvae like maggots that burrow inside the cricket body, feed off of the crickets tissue while the cricket is still alive. It’s all very gory and like alien, you know, in the movie. And then eventually, after about a week, they burst out kill the cricket and gone to make an adult fly. And so I got interested in this a long time ago because as an egg in someone’s day’s evolution, it’s a really interesting conflict between on the one hand, evolution is saying call more, because the more you call, the more likely you are to attract a mate, which is obviously good for perpetuating your genes. But at the exact same time, evolution is saying call less, because the more you call it, you know, you don’t want to trap the fly because that’s going to kill you until he sees a fly that’s not present on other islands. 

Is kind of a unique place. Right. 

Well, the fly also Karen Stollznow crickets in other places that both of them have been introduced to Hawaii. And why and how that happened is an interesting and then sort of tangential story. But but is so, so clearly, we had we had kind of a natural experiment to say, well, alright, what happened under these circumstances when you have these conflicts between natural and sexual selection? We’ve studied this for some time. And most recently, what happened was that over an extraordinarily short period, about 20 generations of, you know, crickets, which is about five years time we started. We saw a mutation that makes the males unable to call spread on two of the three Hawaiian islands where to fly in the cricket co occur. 

So these males are their wings or modified cricket called by roving their wings together. And these crickets can’t produce the call that allows them to attract females. This protects them completely from the fly, but poses some problems in terms of main attraction. And so that’s a lot of what we’re looking at. For our purposes here, what it made me think a lot about as well. So how much does evolution happen that quickly in the wild? And so I started, you know. I mean, I read some about it before and I started getting more interested in it. And that just led me to an increased interest in how much scientists now understand about the speed at which evolution can happen. And also that it’s it happens quickly in humans. So, I mean, it’s very easy to figure, oh, yes, evolution, something that always takes millions of years. And it had to do with, like the rise of the dinosaurs and and stuff that happened, you know, age and ages ago. But it’s certainly not something was going on today. And increasingly, we’re realizing that now it is something that’s going on today and it affects us today. And so that, again, points to the fallacy of thinking that if we could just go back to one hundred gatherer lifestyle that, you know, we’d all be OK. 

Let’s talk about the two big bugbears of the paleo diet. Milkin Grain, what is the story of the evolution of lactose tolerance? Tell us about human evolution. 

So lactose, the evolution of lactose tolerance is probably the poster child for rapid human evolution. And I mean and I let let me preface this by saying that I and people have lots of reasons why they don’t want to consume dairy or think it’s not, you know, something that’s good for them or whatnot. And I’m not going to get involved in that. And I think people should eat whatever they want. And they’ve all had to say in interviews, I did not write a diet book and I don’t want to write a diet book. I think people really should eat what it’s like. Having said that. So one of the great things about the story about lactose persists are lactase persistence is that humans, like other mammals, drink milk, their mother’s milk when they’re infants, and then all other mammals lose the ability to break down lactose, which is the sugar in milk at weaning. 

And so then they just can’t digested anymore and they go on these other things. In some populations of humans, depending on where your ancestors are from, that’s no, that’s not true. And the ability to break down lactose persists because we have an enzyme called lactase. So the way we think this happened is that five to seven thousand years ago, which is hugely, you know, like Tinh, which is really tiny in an evolutionary perspective. So this is really recent. People were herding cattle and cattle like animals, and they were doing that not for the milk because they couldn’t digest it. But for the meat and hides. Well, imagine that you’re in one of those populations and you happen to have a genetic variant, just your chance. It’s not directed. There’s no you know, it’s just it just happened that allowed the lactose to be broken down longer into your life. If you could continue to use if you could use the milk that was being produced by those cattle, then you had a food source that other people in your population didn’t have. And especially if you’re from a part of the world that where there’s common drought or where it’s hard to get uncontaminated water, you had a source of unpolluted fluid. So both of those things would put you in an advantage and make it more likely that you would pass your genes, including that variant, onto your kids. That then means that herding cattle becomes more advantageous and that then, of course, selects for more people who have the gene variant, which then makes them more likely to herd cattle. And so you end up with this feedback that’s called gene culture coevolution between the practice of herding cattle, the culture and the gene that enables you to digest the milk. And so we’ve seen a genetic change in human populations from some parts of the world in literally just, you know, all of a handful of generations. And so it’s it’s a really remarkable evolutionary change that. Sure are. Absolutely. Our ancestors for many, many years ago could not digest dairy because they lacked the gene. Some people in the world and not all people, but some people in the world, especially your ancestors, are from northern Europe or from some parts of Africa. Some people do have it and they can break down lactose. So humans have evolved quickly to be able to utilize this new food and to say, well, that it’s not natural for us. Well, again, it’s really not natural for us to have come out of the water, I guess. But again, ship sailed, already happened. 

What about the evolution of blue eyes? You mentioned in the book that that’s also a very recent human trait. 

Yeah, it’s just something that has to increase. One of the cool things about having written this book is that I realize how much. Our new tools that allow us to look very closely at the genome can tell how much that can tell us. And so what people can do is look at the distribution of genes that are associated with things like blue eyes and how those have arisen. And the story on that one is not completely out yet. But people have speculated that Blue Eyes became selected for because they were attractive and that, you know, those people might have gotten more made. 

And again, it happened fairly recently with the lactose thing. 

I mean, that’s one g one gene that changed that enabled people to have liked his persistence. 

So what’s fun about that is that. Well, there’s there’s genes associated with it. But the main thing that does it, yes, it’s one gene. And yet it’s it has the same effect. But the gene that does it, that that enables breaking down lactose is a different gene in both in, say, African peoples. And people from the people from northern Europe. So there’s been what’s called convergent evolution, where things happened rapidly when subject selection. But it’s another illustration of how selection just uses whatever tools are to hand. And it doesn’t have to be the same change. 

How about grain? The paleo people insist that, you know, grain is introduced into our diets far too recently for us to be possibly evolved mechanisms for coping with all its supposedly nefarious effect. What’s wrong with that view? 

You know, again, you know, caveat, I know lot of people are finding that not eating a lot of starches is good for them. I really think that’s what they should do. At the same time, it’s high. 

So if you talk to anthropologists about what people were eating a long time ago, they’re pretty cautious about people’s diets. It’s clear that human diets varied a lot in different parts of the world. Increasingly, we’re finding that there were actually more starches and grains consumed than we had thought previously. So there was this huge headlines. I think it’s 2010 when somebody discovered that a population in Europe had been there was evidence, evidence of people from 10 to pretend, often years ago, grinding up the seeds of a cattail like plant to make a sort of flour and then mixing of water and then baking it into what every single news release said that it was a kind of pita bread. I think they just couldn’t figure it. They were like, Grampy, like, what should we call this? Is this crackers? It is like what you said, it’s gone. I don’t know. Anyway, so they all called it pizza. I don’t know if it was really like it or not. And so this made huge news because it was like, oh, no, our ancestors maybe really were eating starches and grains. And so, sure, they were probably eating whatever they could. So this idea that they were consuming solely, you know, meat and the occasional tuber or vegetable. Well, you know, it depends what part of the world you were in. It depends what time period you’re talking about. It depends on cultural pressures. And you know, what people could get their hands on. So it’s not even the case that they were eating, you know, the same thing or that we could even come up with that. And then the other issue, of course, is that all of our foods now are heavily modder, even the meeting. And most of the vegetables are still modified from what their ancestors were that we couldn’t even go back to that if we wanted to. 

So you’re thinking about things like the ancestral corn cob that was the size of a farm and science science and the early apple. 

You know, Michael Pollan’s got this great statement about how, you know, like their ancestry. He tried one of the ancestors of modern apples. And it was like this incredibly bitter thing. What he said was like a Brazil not covered and, you know, bitter tasting leather or something like that. It’s like now that’s appealing. 

So what are their alternatives for eating closer to what? Stone Age people? What would you actually eat if you were to be maximally attempting to replicate a Stone Age diet? 

Oh, I don’t know. I mean, the thing is, you don’t need you don’t need to be, you know, a paleoanthropologists to have someone point out that eating a lot of calorie dense but nutrient poor food is not good for you. I mean, people you know, pretty much any, you know, dietitian will be able to tell you the same thing. And so I think tagging stuff, too. But what were we eating X thousand years ago? I don’t think it’s necessarily a helpful way to proceed. I mean, we can figure out what kinds of diets are are reasonable for for people without that. And people are also able to eat a lot of different things. It’s not like there’s only one thing that works for every single person. 

Can you talk a bit about how digesting starch has worked its way into the human genome and people from places that habitually had a fair amount of starch in the diet? 

This is the idea of us being able to adapt. And starch is another place where you can look at recent and modern human evolution. Sometimes genes don’t change themselves so much as they duplicate. There’s more copies of them in the genome. And when that happens, the functions that gene has is often enhanced. And we think that’s happened with the ability to digest starch. There’s some genes that, again, allow you to break down starch. And if you look at the genomes of people from parts of the world where a lot of starch was consumed, and then compare that to the genomes of people in parts of the world where relatively little starch was consumed. The people from the starch eating places turn out to have more copies of this analyze genes than than the other groups do. Suggesting, again, that, you know, selection can actually do this. Pretty quickly, and it’s happening at a very fine scale. This is one of the fun things about being an evolutionary biologist now is that there are these tools available that people would not have dreamed of even like 10 years ago. And in a way, it was a very hard book for me to let go of, because every time I finished the chapter, there would be another paper that came out like right then born. Oh, but then there’s this that people have found out and then there’s that that we’ve discovered. It’s a really exciting time to be looking at human evolution. I think I mean, that isn’t to say that sometimes, you know, people conclusions don’t outstrip the data. But but by and large, there’s some really fun stuff being discovered. 

There was really interesting discussion in the book about how you can now survey chunks of the genome to see suspiciously large bits that have moved. And that’s that’s a signal that there has been some kind of natural selection on something within that some gene within that chunk. Can you explain how that works? 

Yeah, so so we can look for what are called selective sweeps. And I should add, let me preface this by saying that there’s something that human geneticists who are cautious about the degree to which these have been important in human evolution. So there’s a lot of kind of inside baseball arguing about all of that. 

But but having said that, the basic idea is pretty simple, that once you’re able to look at the sequences, that the way that the arrangement of DNA on a chromosome, you can say, all right, give as much as genetic material has changed over the generations, if there’s been selection for a particular bit of DNA to stay, you know, in that to be produced more and more because individuals that have that bit of DNA are at an advantage, we should be able to detect that even if we don’t have you know, it’s not like we have this little magic machine that can say, OK, it’s going to locate this particular gene. But what you can do is look for places where it seems like there have been chunks of DNA that have been recurring over and over again through generations. And the neighboring parts have stayed associated with that particular piece of DNA. And so you can do it at a different at a different scale. And notice that there have been places where you would expect things to have been recombine and recombine and recombine. And they haven’t been. So they’ve stayed together. And that shows you that there are these hotspots where you can then look further to see whether there are specific genes associated with, say, resistance to a disease or some other characteristic that would have been important. Resistance disease is probably a place where our genes have changed more than almost anything else, because you can end up with a very strong selection and you can end up with situations where it’s literally a life or death matter, whether you have a particular gene variant or not. So disease is a great place. Again, to say, hold on, we’re not the same as our ancestors and our ancestors were less well equipped to deal with some of the pathogens that have arisen more recently. 

So you’re saying that a plague could sweep through and literally wipe out everybody who doesn’t have a particular mutation and then none of them pass their genes on and the only people that survive to reproduce are the people that have the resistance now. 

And so you get the. Yeah, exactly. And so you get this really what’s called a really hard selection. 

Then after that, what happens is that because you’ve selected for that gene to resist the disease, the genes that surrounded that area are also being sort of drawn along with it. And you can detect what are called signatures of selection by looking for those. 

Are there any particular diseases that people are looking at as being. There’s been candidates in this kind of sweep based evolution. 

Oh, tons of them. And, you know, this is part of the problem is that it’s kind of the Wild West out there because, you know, admittedly, you know, I’m making it sound like, oh, yes, we have this technology. We can do all this really cool stuff and we can. 

But it’s almost a case of, you know, this fire hose of DNA sequences being produced. And it can be really, really challenging to sort through all the data. 

Having said that, you know, people are starting to look at the evolution of resistance to smallpox as the evolution of resistance to to plague the evolution of resistance potentially to HIV and how that might be associated with other diseases, not not necessarily HIV itself, but other diseases that we had in our history. 

And so it’s really a whole new world out there that that we’re able to do to examine that we just didn’t have the tools to examine before. 

It’s really fascinating. Another really interesting part of the book is your discussion of primatology and what kinds of lessons people are fantasy’s people are drawing from the study of our closest primate relatives. Sort of think of it as team bonobo versus team chimpanzee. How does that work? 

Yeah, I, I, I’ve actually been interested in that for a long time because, you know, working in animal behavior and I do a lot of stuff on secondary production and and so you know, there’s. 

No place where people are more committed to what’s natural. What do we know about, you know what? Let things have happened in our ancestors and when it comes to sex and gender and. Yeah. OK, so where are you going to get information about what’s natural about your sex life? Well, one place is to look at our closest relatives, the great apes, and to see what their sex lives are like or their social lives or life. And that’s a really cool thing to do, except that, again, it’s not like evolution sort of produces this kind of version of, OK, we’re now going to make an ape sexual system and then we’re going to see a bunch of variations on it. And then we’re gonna look at, you know, which one is closest to humans. Well, you don’t inherit a gene for your sexual behavior. That’s just not how it works. And so if people look at chimpanzees and you start concluding that, oh, you know, humans early on maybe were had a lot of aggression and violence, whereas if they look at bonobos, they often conclude that humans had a lot of sharing and a lot of use of sexual relationships to defuze tension in society. And, you know, you end up with, you know, kind of teen, chimpanzee and teen bonobo. And I think the real message is that evolution can act in a lot of ways to solve the same problem, but with different solutions. So everybody’s, you know, leaving genes in the next generation. And in primates, everybody’s having to figure out how to take care of an infant. That requires an enormous amount of effort to rear. But the way that happens is going to be different under different circumstances. 

So what are some of the circumstances that would give rise to a more cooperative breeding type type of strategies to humans evolutionarily? 

We’re we’ve got it. It’s a system where you have babies that are born ridiculously premature. See aforementioned tell the girl walking upright, big brain. Oh, dear. You know, and so the solution is giving birth to babies that essentially, you know, that guy anthropologists sometimes, you know, say, oh, well, you know, they really should have been in the womb for another four months or, you know, something like that, which I think you have to take out a grain of salt. 

But but the point being that human infants are born at a much less developed stage than any other primate. You know, we can’t hang on to our mothers. We can’t, you know, wander around. We can’t you know, we really can’t do anything. We require we require such an enormous amount of care that our whole social system evolved around basically, you know, dealing with that terrible after 30, who’s an anthropologist, now retired from UC Davis, wrote a lot about how she thinks that humans evolved essentially as co-operative breeders to help rear the offspring. And she says that human infants require the they seem to be raised most successfully if they have three adults or three other people that are helping in their care, not one. So not just the mom. Not even two. And not just the mom and dad, but three. And it doesn’t have to be the mom, the dad and someone else. It doesn’t have to be the mom at all. It can be. It can be lots of different people. But the point is that we’re we seem to have evolved in a situation where a lot of cooperation to take care of the babies is essential. 

How can we benefit by loosening our grip on the paleo fantasy? 

I think what helps us is this ability to see where the mismatches happen and then to realize that the solution is not to simply say, oh, therefore we have to go back to the way it was, but to say but to say, well, gee, you look at how this is a reason we don’t like this outcome. Is there some way we can ameliorate it other than, you know, going back and trying to get to live like like cave people? And so, you know, people are always arguing about, you know, ancestral diets and so forth. One of the things that’s absolutely obvious from what earlier people age is that they eat way more. They will and calorie dense food. They often had a lot more fiber in it. So it seems like, wow, that seems like something that we could actually pay attention to, you know, in some other pretty basic things. That part of it is. I mean, evolution is a tremendously fascinating thing to look at, but I’m really nervous about people using it as a way to. Oh, yes, this is how I should behave or I have to behave this way because my ancestors did. Or, you know, again, getting back to the sex and gender. It seems like every time there’s an article about some politician who’s dallying with an intern, we end up with someone trotting out some argument about alpha males and how male, how it’s in their genes and they can’t help it. 

And it seems to be like not a very productive way to go. 

So we can still take lessons from an informed view of our own evolutionary history without necessarily feeling like we have to replicate every little bit of what little we know about how we were back to that. 

Well, yeah, or even in replicating, you know, large bits and there’s lots of things that human beings have done over the years that don’t need to be things that that we’re doing now. I think one of the other Take-Home message for me in this is somebody said someone who studied savior is that it’s still becoming so clear that we don’t have thought of genes for this, that or the other thing. All behaviors, like all traits anyway, are the result of input from the genes and input from the environment. Our studies of gene expression differences. So it’s not just watch whether you have a gene, it’s when the effects of that gene are felt and how they’re felt are really important. And so this line between nature and nurture is just getting increasingly blurred for me. And I think that that’s one of the big messages from this as well, that the search for the gene for this or the gene for that is just really ill conceived. 

Do you think that people are reaching back to evolution for easy answers, for very complex problems? 

I don’t know, really. I think it’s an easy answer. I think if they are, they will be sorely disappointed because I don’t really think you’re going to get any easy answers that way. 

Marlene, thank you so much for coming on the program. Thanks a lot for having me. This has been a point of inquiry. You can follow us on Twitter at point of inquiry. Tune in next week. 

Lindsay Beyerstein

Lindsay Beyerstein

Lindsay Beyerstein is an award-winning investigative journalist and In These Times staff writer who writes the blog Duly Noted. Her stories have appeared in Newsweek, Salon, Slate, The NationMs. Magazine, and other publications. Her photographs have been published in the Wall Street Journal and the New York Times’ City Room. She also blogs at The Hillman Blog (, a publication of the Sidney Hillman Foundation, a non-profit that honors journalism in the public interest.