Niche Construction

In Through the Lens of Anthropology we read the second half of chapter 3, “Evolutionary Thought and Theory” for Intro to Anthro 2022. We also read the first part of “Human niche, human behaviour, human nature” by Agustin Fuentes (2017). This class concentrates on Niche Construction. The previous class was on Evolutionary Thought and Theory. The next class tackles bipedalism.

Niche Construction: Rough Transcript

We’re just going to wrap up the theoretical stuff about evolution before in the next class applying the specifics of what we’ve learned to human evolution. You’ve all been waiting for: how did humans come around? How do human beings get into the picture? In the last class we went through Darwin and got up to Darwin and Mendel. Then briefly talked about the combination of Darwin and Mendel, which is called the Modern Evolutionary Synthesis. We’ll talk more about that in today’s class. That’s basically where Muckle, González, and Camp take us to at the end of their text: the Modern Evolutionary Synthesis.

They say in their text (p.75) that there’s the Modern Evolutionary Synthesis or also called the Extended Evolutionary Synthesis, but that’s not entirely correct. The Extended Evolutionary Synthesis is “extended” and it’s slightly different, or it extends upon, adds on some stuff, through the Modern Evolutionary Synthesis, which is what we read in Agustín Fuentes, the first five pages of “Human niche, human behaviour, human nature,” which was really hard to read and difficult to understand for a couple reasons. One is that Fuentes is agreeing with the Modern Evolutionary Synthesis, but he’s trying to point out some flaws or problems or put on some extra things, which we’ll talk about what he’s trying to do there. I will also say straight up front that this is out there in terms of where the biologists are. Mostly in our biology classes we learn through the Modern Evolutionary Synthesis. So, I have this stuff as in some ways up for debate. Still our eventual goal was to do a rethinking of some of these old ideas that we may not have even known were with us. Some of them we didn’t know are with us because every time I said evolution several of you said, “aha, survival of the fittest.” I’ve been trying to convince you that that’s not actually the best way to think about evolution. The other thing that is still with us, although we may not know it, is this idea of the Great Chain of Being, and as evolution being an ascendancy or an ever-ascending ladder of progress. We may not be entirely able to say goodbye to those ideas because they’re so entrenched, but at least we can know what they are and know the influence that they have had on us. They don’t creep up on us unnecessarily. I want to finish this class on a rather more optimistic note, not just saying goodbye to things, (why does this matter?), what do we want to say hello to? I’m going to try and tell you that if we can adjust our thinking about evolution then what we’re going to say hello to is the possibilities and complexities of life and the continuation of life on this planet, which is what we would like to have happen. We don’t want to say goodbye to life, we want to keep it going. The purpose of life is to keep on living. So, that’s what we’re going to believe is our final goal here. Alright we’ve got to get there. So, first we want to go back into the genetics, the then. Now of genetics. We talked about “natural selection then and now” and how the idea of survival of the fittest, different traits can be adaptive in certain environments and maladaptive in others. Since the environment is always changing we can’t have an absolute measure of fitness. In the last class we talked about how Darwin’s idea, and the people around Darwin, they didn’t really know the mechanisms of inheritance. They saw it as a blending of traits, what is also called Pangenesis. So, that was around Darwin’s time.

The genetics of Mendel disproves the blending. That’s where those Punnett squares come in and all those things, but not all the time do they tell you why we do the Punnett squares. We learn about recessive and dominant . . . What this does, is it preserves variation through generations, even though you may not see it, even though it may not be visible, it endures. Then it can be worked on later in evolution and expands the possibilities for evolutionary processes and selection. So, that’s what we learned from Mendel . . . We now know that simple Mendelian genetics apply to some organisms. He was very fortunate to be able to work with those pea plants and get some pretty nice statistics from pea plants, but most of the time in most organisms it’s a pretty complex thing that goes on. Most human traits that we have, including ones that we used to think were Mendelian, like eye color are actually due to polygenic inheritance. When I was growing up they told me that brown eyes were dominant and blue eyes were recessive, but if that were true then brown eyes would be completely dominant all over the world. It’s actually a cascading array of genes, which give us the characteristics that we have. Muckle, González and Camp mentioned a couple complex processes that happen, which are gene flow and genetic drift. I’m not going to dwell on those. Their complexities speak to us as the randomness of a lot of the evolution that happens when different populations flow into each other or drift away from each other. We once had this idea that species came about pretty quickly, but we now know that’s a long and complicated process. We also know that genes are dynamic within the organism. They aren’t simply there. They don’t give you this blueprint that you’re going to follow for the rest of your life. They change over time, they develop. We’ve also begun to appreciate recently the importance of what is called epigenetics or the environmental switches that turn certain genes on and off. You may have a very similar genetic code to someone that is in a different environment, but different genes will be expressed by that person based on the environment that they grow up in. We know now that this is a much more complicated process than what Mendelian genetics gave us, although of course it is still important, those principles that we have from Mendel.

So after Darwin and Mendel had passed away, again like I said, they did not know of each other’s work while they were writing it, they had each wrote in very separate worlds. It was in the 1930s, 1940s and 1950s that people put this stuff together as what is called the Modern Evolutionary Synthesis. This is also known as the Neo-Darwinian Paradigm. It’s new, Neo meaning new, and an advanced Darwinian paradigm. Or it is known, Fuentes calls it, as the standard evolutionary approach. So, again this is what is taught and it’s a very powerful and important approach and idea, but in recent years in the last 10 or 20 years I would say, Fuentes and some others, he’s drawing on other biologists, began to make the argument that we needed to supplement or go beyond this approach. That it was necessary and important to us, but it wasn’t sufficient for all the things that we needed to describe. So, what he’s saying here when he talks about the Standard Evolutionary Approach or the Modern Evolutionary Synthesis. He’s going to sometimes be summarizing it in order to then tell us how we need to do other things or go on from there. So, what does he want to add to the Standard Evolutionary Approach? So what he wants to do is give us a little bit of what is called the Extended Evolutionary Synthesis, on page two he says it’s going to expand beyond the selection-focused standard approach. So, what he means by the selection-focused standard approach is an approach that concentrates on the classic elements of natural selection: Reproductive advantage, competition over resources, and being able to have reproductive differential. The standard selection focus has told us a lot about evolution, but it really concentrates on reproductive events and genetic change to the exclusion of some other ideas or other things that people have argued, or are starting to argue, are important. So, he wants to include the processes of niche construction, ecological inheritance, and multiple modes of inheritance in evolutionary inquiry. Now I want to talk mostly in this class about the idea of niche Construction. We’ll also be talking about multiple modes of inheritance, although that’s a very big way of saying I think we’ll be talking mostly about the idea of culture and behavioral or idea transmission across generations. Now again I want to contrast that, or I want to say that sometimes Fuentes can be confusing, because he is talking about the Standard Evolutionary Approach and the focus on reproduction and genetic change.

So one of you quoted something from page four that talks about “in a nutshell.”

Page four top right-hand corner: “In a nutshell, standard evolutionary approaches see evolutionary pressures as potential impacts on reproductive output.” So what he’s saying here is that the standard approach focuses on those things that matter for reproduction, but then at the very end of that, if you keep reading he says that it remains incomplete, especially when applied to the human niche. Now the reason I’m dwelling on this is because of the image, or the book image that I chose for talking about this for our posts and our comments, is a book by Joan Roughgarden called _Evolution’s Rainbow: Diversity, Gender and Sexuality in nature and People_. What is really super interesting about Roughgarden’s work is how they talk about the vast diversity of gender and sexuality that evolutionary biologists have often overlooked because they were only focused on the reproductive sex, the stuff that they said would make stuff for the next generation. What Roughgarden does is go through all of nature and says there’s a whole lot more stuff going on out there, if you look beyond some of the standard approaches that are only looking for things that create offspring, that all kinds of creatures are engaging in all kinds of activities, which we might consider sexual if we opened our eyes a little bit. I think what Fuentes is saying here is that human beings and other creatures are doing a whole lot of things to shape their environment and engage in a whole lot of activities that can be important in an evolutionary process. Like I said, I want to focus here, mostly for simplicity and for what is important to anthropology, on this idea of Niche Construction. Now this can be a little bit confusing because sometimes when we hear the word “niche” we mostly think about people who are trying to find their own niche in the world, but Niche Construction refers to how organisms are transforming their environments. So, if we know that genes are dynamic in an environment and (again going beyond the one-gene-one-trait Mendelian genetics model) we also know that organisms are constantly, in the process of their lives, altering the environment or altering the conditions in which they live. We can see that in various organisms, probably one of the most obvious outside of humans, is beaver dams and the way that they transform and make things, rivers go in different directions, and make lakes and stuff, all transforming things in ways which are complicated. Birds and the ways that they make nests. Rodents that make houses. Some of these are intentional, in the sense that they’re trying to do them (not saying they’re … making choices about them), but there’s a lot of things that are simply done unintentionally. In fact, we are all altering our environment every time we breathe in oxygen and breathe out CO2 and other stuff into the world. So, there are all kinds of organisms that are altering their environment. The idea of Niche Construction is that as organisms are altering their environment, those alterations can change the conditions of selection for the next generation. So, that means that evolution is potentially more than simply what happens during genetic change and reproductive change, it happens because of what organisms do during the course of their lives because they’re then altering the environment and changing the conditions of selection.

So, what this means is that creatures are actively involved in their own evolution. It doesn’t always mean we get the things that we want. There’s a lot of unintended consequences, but when creatures do things like migrate, go to a different place, raft (we saw those rafting monkeys), when creatures alter the environment or even when we and other creatures are practicing something called sexual selection, selecting mates, who we’re going to mate with, it can reshape the evolutionary process. So, now let’s bring in a couple people here . . .

In fact, not just the human animal, but non-human animals as well can learn from their parents. We saw some of that with the non-human primates and their use of tools and different kinds of behaviors and different environments. So, many different species have transmitted behavior, but it’s perhaps super-pronounced when it comes to human culture. I mean obviously that’s developed among other creatures, but when it comes to human culture the patterns become particularly complex and humans transform their environment in ways that have feedback loops into our biology and our developing genome. One very interesting example of this (to go back into Muckle, González, and Camp) is lactose tolerance. This was at the beginning of chapter three. This box on people developing lactose tolerance and how “Food Matters: Evolution in Action.” In the United States we probably didn’t think much about lactose tolerance for a long time. We only had those “drink milk” commercials with the milk mustaches. (You remember those? Maybe they’re still around.) It was assumed that everybody could do that. It’s unusual, or I would say the majority of human beings are not lactose tolerant. In fact, only one third of people produce the lactase enzyme during adulthood. We all can do this as we’re kids, which enables us to drink milk later. So, who has lactose tolerance? It’s people who grew up, it turns out, or whose ancestors were very dependent on cattle and milk. This arose in several different areas, one of them being of course northern Europe, but also in western Africa in southeastern Africa among animal herders, in Saudi Arabia and in parts of India. Again, this is a percentage of the adult population, even in those places where it’s very prevalent that doesn’t mean you get to 100%, although some places get close, and some are more like 50%. So, even some people in southern Europe are not, as a percentage, lactose tolerant as those who were much more dependent on milks and cheeses . . . in the north. I would first point out to you that (we’ll be talking about this when it comes to ideas about human race and human groupings) lactose tolerance occurs among people of very light-skinned, very dark skinned, and a lot of different skin tones in between. It’s not something that corresponds to our ideas about who lines up on the racial continuum. We’ll talk about this as something that is a biological variation that does not correspond to our ideas about human races. For now, what I want to talk about is the fact that this is an evolutionary change to the human organism that results in variability, that has arisen because of human culture and human cultural transformation of the environment. Different people who domesticated cattle and were able to extract or rely upon their milk, cheese. and other products that they had. This brings us again into ideas that have changed about evolution, which is the way in which the time scale of evolution occurs. So, back in Darwin’s time, most everybody around Darwin thought about evolution as this very gradual process that happened over long periods of time, in which traits were slowly accumulated. In the last 50 or 60 years we’ve talked about other kinds of evolutionary processes in addition to gradualism.

… [One alternative is] punctuated equilibrium, which is the idea that you have these long stretches of not much evolutionary change. Then you have what are called sudden bursts of change, where a lot of stuff begins to change. Now there’s been some debate about whether some people got very excited about punctuated equilibrium and said that was the way that evolution occurred, and other people are like, “No, it’s gradualism.” I think that hopefully by now we have come to realize that both processes can be at work in evolution. We should also realize that when the geologists and the biologists talk about punctuated equilibrium and bursts of change, they might be talking about a hundred thousand years or 200,000 years, which is a very short period of time on an evolutionary scale, but in terms of our lifetimes, what we think of as generations it is still a very long time. We have realized that evolution can occur more quickly than we thought, and lactose tolerance is one of those examples of something that has happened relatively recently in human life. This leads Fuentes and others to propose something that he calls the “Human Niche,” which is the title of this article. The idea here is that humans are some of the best niche constructors around. In fact, if you look around right now, you’ll realize that we’ve done some amazing niche construction here. Nothing we see, (trying to think of anything that’s natural around here, that would have been around here 200 years ago). No. There’s no nature here. We don’t even have a window to look out on nature. We can’t see it at all. Everything we see around us in this room has been constructed in order that we have a whole different environment. So, what is the human niche? “The increased use of extra-somatic materials” (2). By “extra-somatic” that just means outside of the human body, the things you’re using: pens, clothes, shoes, desks, tools, and “a dynamic feedback between action, perception and neural structures” (2). Whoa that’s what you’re doing right now. You’ve been using these tools, you’ve been trained in a way or sitting at desks, and you’re having a feedback, hopefully a dynamic feedback, between action, the things that you’re doing, perception and your neural structures, “which in turn altered the potentials for information acquisition and problem solving” (2). Now you’re able to acquire information, solve problems, and pass that on to the next generation, which is going to change the conditions of selection in the next generation, the kinds of traits that we’re hoping to promote, the kinds of activities that we’re hoping to help people do.

I would say that probably not many of your parents encouraged you to be iron workers, develop your ironworking skills. Probably should, but it’s faded out as this thing that we need to have as a trait. Hunting: we weren’t encouraged to do much persistence hunting of non-human animals. So, our selection processes are changing. What Fuentes argues that this enables us to do is to rethink the idea that we have that human nature is one fixed thing that has been present with us for forever and is the same for all the members of our species. So, instead what he argues is that what this enables us to do is think about human nature as a “suite of potentials” (1). Suite, a big room full of different things that we can draw on, different potentials that we have, which we get from our evolutionary history, which has for a long time been flexible and diverse and vibrant. Our present and our flexible capacity to create and sustain human cultures and to be shaped by them. So, think again about lactose tolerance and growing up in a society in which cattle herding is important as opposed to a society in which planting things is important or a society in which hunting and gathering are important. These are all different kinds of human cultural activities, which then reshape our evolution. So, describing and assessing the actions of evolutionary processes and patterns in the human niche, which again is to say that by participating actively in our environment we then change our own conditions during evolution.

Note: For an extended version of this argument, see the lecture on Tim Ingold’s “People Like Us” or check out the YouTube lecture:

That brings us to what we wanted to say “goodbye” to, which is goodbye to these ideas of the Great Chain of Being and survival of the fittest. So, first, evolution doesn’t result in some automatic marching ahead to better and better and better. As we’ve seen, the environment is going to be always changing. We’re in interaction with other organisms, which are themselves reshaping the environment.

As we’ve seen, traits that are adaptive in one environment might become maladaptive or bad in other environments. So, if you are a lactose-tolerant individual who then goes into a whole different place, that might not be the best trait. It might not work out so well for you. Or if you’re a lactose intolerant individual who has been pushed milk and cheese all the time it might not be the best thing to have. Fortunately, now we have those little pills and lactase things that you can buy. You can be a milk drinker if you want to be. The idea that we had in the old days that humans were these perfect creatures at the pinnacle of evolution with all the best traits: we have to realize that all of our traits involve trade-offs. So, there’s something that Muckle, González, and Camp told us at the beginning of the chapter: “We are far from the perfect creation, biologically speaking. Humans are more like an accumulation of quick fixes that serve a purpose. The biology that enables people to walk upright, for example, works well for a long time, but not necessarily into middle or old age–just ask an older person how their feet, knees, hips, and back are doing” (58). Not as well as they used to be! I’ll just tell you right now, you can deteriorate over time. So, these things (and that’ll be what we’ll be talking about in the next class), the emergence of bipedalism and walking. People get all excited about that because it seems so cool, but over time maybe it hasn’t been so cool. There are trade-offs. The other thing is that evolution just doesn’t always “work.” I put work in quotes because it _works_, but it works in ways that we might not like so much.

What happens if the environment is changing and you’re a species that is well adapted to that environment, but the environment is changing?

A lot of times, most of the time, as the environment changes you would go extinct. In fact, it’s estimated that in evolutionary terms over 99 percent of the species that have ever lived are gone. They’re not here anymore. In fact, as the environment changes most of the time–this is the reason I say that evolution doesn’t always work–it’s not like there’s going to be that adaptation present. You don’t know if it’s there. Sometimes it’s there and you get lucky, you’re able to adapt, but most of the time it’s not and you just die. So, then you’re extinct. By the way, this isn’t just right now, it is like over millions of years. . . .

Also, there’s nothing inherent in the evolutionary mechanism, even of natural selection, which says that the next adaptation is going to be more complicated than the previous. We see the emergence of more complex organisms over time, but that’s not because of anything in-built into the evolutionary mechanism. That’s simply because of chance. Sometimes being a simpler organism is going to make you more adaptable to changes over time.

Perhaps the most successful evolutionary organism is the single-celled organism, the bacteria. They’re the winners of the evolutionary scheme. In fact, they’re the winners of us. We have more bacteria growing in, on, and around our bodies than we have actual human cells. We need them to digest things, the gut bacteria, we need them to live, and our actual bodies have more bacteria than there are human cells. They are the winners. They’ll be here long after us. We have to be careful about that, about the idea that everything automatically gets more complicated.

Some people like to look at this as less of an ascendancy model and more using the metaphor, that nice little picture that shows up on Muckle, González, and Camp on page 74, the braided stream model of human evolution. The idea that there’s one interconnected species at all times, but there are different things going on and they flow apart. Then they flow together. In this model we have some feet somewhere, some bipedalism, and some language and some hands, but it all flows together over time. We’ll be talking about some of the characteristics of human evolution in the next class, but this is perhaps a better analogy if you want to think in naturalistic terms the ways in which evolution occurs.

Now the question is, “who cares?” What difference does it make if you have good metaphors and ideas about evolution or if you’re all caught up in Great Chain of Being and survival of the fittest? I think that if we only have our ideas of evolution as this progressive ascendancy fantasy, that everything’s getting better and better, or the opposite, it’s only fatalism. We’re not going to see the complexities of life. We’re going to reduce our appreciation for the whole of the human and the natural experience, and how different organisms interact with each other, and how we do a whole lot more than just reproduce and have genetic change. We’re going to miss out on being able to see different kinds of possibilities. I know I keep wondering if I’m making you too sad because of what’s happening these days, that we’re worried about everything, in this chapter climate and the possibility that those 99% of extinctions are going to be us, and like everything else because of climate change and those kinds of things. . . . It’s something that we should be concerned about, it’s good for us to be concerned about, but we want to not despair. Despair is not what we want. We want to be able to see different kinds of possibilities.

In fact, something that was weird when the environment is changing, and different species are being pushed together . . .

Hybrids. Mew creatures coming together and making new hybrid things. It’s an interesting thing that’s going on, that different creatures are coming together. We’ve done this, tigers and lions and making ligers and stuff like that, but this also occurs in the natural world. In fact, hybridization as we’ll see is very important in human evolution as well, different kinds of hybrids that occur along species lines, which are not as well defined as we once thought. I put the title of this book up Eben Kirksey is an anthropologist who gets discussed for a different book in Muckle, González, and Camp, but in this book, called _Emergent Ecologies_. As you can see from the picture we have an oil rig or something in the forest, and he’s talking about here how although there’s a bunch of doomsday scenarios for environmental change he’s trying to, as he puts it “reject such apocalyptic thinking and instead find possibilities in the wreckage of ongoing disasters, as symbiotic associations of opportunistic plants, animals, and microbes are flourishing in unexpected places.” So things that are coming together and doing different things, and the human beings who are in fact, helping some of these plants, animals, and things go along. So, Kirksey is an anthropologist who has been involved in what is called multi-species ethnography or multi-species research to figure out how things work together and cooperate. So, apparently in this book he talks about “frogs, fungal pathogens, ants, monkeys, people, and plants.” People who are caring for them and putting them in different environments. In fact, just today my wife turned on NPR and they were talking about releasing sparrows in an endangered sparrow population in Florida and all of a sudden, it’s gone from down to 80 poor little sparrows, but now they’re up to 100s and the sparrows are, at least these sparrows, are making a little bit of a comeback… I think that changing our ideas from the incorrect ideas about “ah, it’s just a survival of the fittest race,” will hopefully open our minds to the possibilities out there that we might be able to do new and different things and avoid the end of everything. That is still avoidable.

In Through the Lens of Anthropology we read the second half of chapter 3, “Evolutionary Thought and Theory” for Intro to Anthro 2022. We also read the first part of “Human niche, human behaviour, human nature” by Agustin Fuentes (2017). This class concentrates on Niche Construction. The previous class was on Evolutionary Thought and Theory. The next class tackles bipedalism.