Do you think humans can play a role in driving their own evolution through sheer will?
We thought it only fitting to open this column with the question that created the spark that was to grow into the collaboration that cool anthropology is today. In 2004, a few days after the end of the introductory anthropology class I (your cool anthropologist) had taught and she had attended, Victoria (your cool idea transmission specialist) wrote me an email with an anthropological question. The answer I gave at the time was a pretty standard scientific response and has never really satisfied her. As it turns out, nine years and two degrees later, I find myself reading an increasing number of scientific studies that fly in the face of my standard response and support her intuitive ideas about what the answer might be.
In most introductory anthropology courses, like most biology courses, we teach that the primary mechanism of evolution, including human evolution, is mutation. Mutation, in a general sense, is random: genes alter through replication and these changes are inherited by offspring.
The beneficial mutations are usually kept around as the offspring live to have their own, while the detrimental mutations usually die out with the offspring who were unlucky enough to get randomly saddled with them.
While there is certainly truth to this answer, there have always been suspicions how it could be so, well, random. Now, claims of an “intelligent designer” never presented enough scientific evidence for consideration and so I stuck with the random mutation explanation. Over the past decade, as discussions of genetics moved more and more into popular conversation, it seemed that the gene became more and more immutable and a greater determinant of all sorts of behaviors from alcoholism to depression- even cancer. As an anthropologist, and a student of culture, I’ve always been a little uneasy about attributing too much to the gene.
There is so much that happens to us after we are born, potential random mutations in tow- so much stuff of culture that determines who we are and what we do.
Now, being a student of culture and the effects of our environments on our behavior, until recently, has had almost nothing to do with genetics. Having control over what happens to us at a genetic level was the stuff of fringe movements and something like will or focus- the stuff of emotion- couldn’t have a place in biology. Or could it?
A few years ago, I read a study that intrigued me. It was conducted by a medical anthropologist interested in the role of culture in why certain people are at higher disease risk. Dressler (2004) found that many cultural issues played a role in measurable differences in the risk for high blood pressure, including sociocultural stresses generated within the process of social change and modernization and individual differences in an individual’s behavior compared to the guiding awareness of his or her culture.
In other words, what people talked about as genetic risk factors for certain diseases seemed to be related to cultural factors.
This study resonated with me for a while and then I read another, which had similar conclusions to make. Gravlee (2009) specifically studied a hot topic for both social and biological anthropologists- as well as the world at large: race. He noted that racial basis, albeit social, has real biological outcomes. He and his colleagues continue to argue against race as a biologically-salient tool for classifying humans into genetic risk categories. The increased risk of cardiovascular disease, diabetes, stroke, certain cancers, low birth weight and preterm delivery among certain disadvantaged populations, he argues, has to do with the effects of the stressors associated with living with racism on the epigenetic processes. In this sense, a social process, racism, creates a biological category, African-American risk for metabolic disorders. Importantly, these biological risks can be inherited. Suffering through daily racism can change us on the genetic level.
This blew me away. Our social system, and our place in it, can change our genes? The implications of this research, to me, was vast.
I don’t remember when I first heard the term epigenetics but it was nice to finally put a “science word” to these ideas. How does this actually work- this changing of the genes and then passing on these changed genes to the next generation?
It has to do with the process of methylation, which can be affected by all sorts of factors, including environmental stress. That the pattern of methylation is heritable, a decades-old suggestion, has just recently been discussed at length. It is understood that DNA methylation and histone modification lead to changes in chromatin structure that may affect gene expression in a way that is inheritable.
You can read lots of cool studies involving mice that address how the process works. These studies were likely less cool for the mice but, regardless of how you feel about the ethics of animal studies, they really have helped us figure out the mechanisms involved in epigenetic processes.
Here’s one that I like: Epigenetic transmission of the impact of early stress across generations.
Epigenetics research has shown us that the gene can and does change during the lifecourse. There are many factors that can cause the change: stress, environmental pollutants, etc. It wasn’t until one recent study, however, that I seriously considered the affect of sheer will, or desire, on the alteration of genes. The study focused on pain and how people who consciously think differently about pain can actually change their physiology.
They were essentially willing their bodies to be different- and it was working! These changes are heritable.
The scientists concluded both that the brain is a very plastic organ and “having fun and friends is really good for you.” We knew this, of course, but did we really believe that we could alter our genes this way? That we could pass on the positive attitude to our kids through our genes? It’s looking that way, and it’s pretty exciting if you ask me.
I can’t look at Facebook these days without seeing an article about this process: pain, nutrition, pregnancy, metabolic disorder- all from the perspective of the epigene. Follow us if you would like to see more of these articles in your feed. Epigenetics is exciting in that is gives us a certain amount of control back. What’s interesting to me, as an anthropologist, is if we are going to take the control. If we are willing our evolutionary path, which one are we going to choose?
I wrote about these choices as they relate more specifically to mental health on Recycled Minds, a website run by another cool anthropologist and his cool sister.
So, to answer your question, Victoria, while the science is new and the studies are still flooding in, more and more anthropologists do believe that our place in our environment, and how we think about it, can affect us on a genetic level. Sheer will? Not so sure. But we, as a species, are likely in far greater control of the evolutionary process than we ever thought we were.
Kristina Baines is our resident cool anthropologist. She’s been formally trained in applied, sociocultural, ecological and medical anthropology at Florida Atlantic University (BA, MA), the University of Oxford (MSc) and the University of South Florida (PhD). She has a strong interest in corn, how what we do in our environment makes us well, and using innovative methods to make anthropology relevant and accessible to a wide audience. You can find out more about how these interests translate into projects and pursuits by perusing the rest of our site, or you can contact her directly at kristina@coolanthropology.com.
Hey Kristina, I would also like to add that not only anthropology is moving in a new direction because of epigenetics and the biobehavioral research, but so is evolutionary science. Jablonka argues that evolution happens in four dimensions (i.e. genetics, epigenetics, behavior and symbolic variation). And talking about evolution, for those that remember evolutionary history Lamarck was not wrong. He was as right as Darwin in many cases; he just didn’t know the right mechanism not unlike Darwin. We realized the importance of these “epigenetic” mechanisms about 60 or so years ago in nonhumans. However not until the last 10 years have we begun to understand the significance of the epigenome on human development and health. Well that’s enough for my blurb. Cheers!
Here are some of the journal DOIs:
Jablonka & Lamb’s Précis [doi: 10.1017/S0140525X07002221]
Costa’s Non-coding RNAs, epigenetics and complexity [doi: 10.1016/j.gene.2007.12.008]
If more are needed, more can be given. I have around 50 or so. Cheers!
thank you for this interesting, well written article. fascinating stuff and also, well, paradigm-breaking, for sure. it’s time that we realize the tremendous impact of the environment on our bodies — and the fact that this impact extends to GENES is really mind-blowing.
as you know, i’m interested in queerness. it is really interesting to me to think that in-utero and even post-birth environments may play with a genetic predisposition to same-sex loving. i wonder what the implications for the “i’m born like that” approach to queer-acceptance are (not that that was ever a good argument!). certainly something to ponder. as these ideas gain a foothold in public discourse, are parents going to freak out that they are “causing” their kids to be gay?
on another note, i’m not a bit fan of the idea of willpower in relation to changing our fate (biological, psychological, etc.). there are so many other variables, and willpower is definitely, it seems to me, the weakest link. also, insisting on willpower puts a tremendous burden on the individual. no one should have to shoulder this burden. this is often used against people with cancer. the way it goes is that “you have the wrong attitude.” this seems pretty pernicious to me. we are not THAT powerful. it’s not THAT easy. and we don’t even know WHAT causes cancer!
so many issues. i’m dumping thoughts here, just thinking out loud. thank you very much for writing this, and for being cool, and a cool anthropologist!
thanks for finding these articles and thoroughly considering our 9 year old- and running- conversation and, of course, for putting it out there for the world of scholars and thinkers to casually, but credibly discuss. one of the most wonderful things about science, and scientists, is their adaptability to the “new” truths.
my original question was about evolution and whether or not “mutations” were random- Kristina summarizes it nicely at the beginning of this article. what she didn’t mention, and I supposed, was that if they weren’t random, and could be willed, then groups of people over generations could wipe out “undesirable” traits or, even cooler still, do something like grow wings. it was something I always wondered about since the day my father told me that his job as my parent was to make me less prejudiced than he was, and that my job was to make my kid less prejudiced than me, and that if everybody did that, eventually there would be no more prejudice.
I believe there is plenty of evidence that supports the human ability to “overcome” environmental challenges- take polio, for instance. assuming “sheer will” means magic or hope is just as silly to me as a “random mutation” explanation- maybe that should be made more explicit. by my mind, lots and lots of “intervention” “would be” required to change our genome. what is important about this article, and the perspective it hopes to inspire, is that the scientific truthiness- the paradigm shift that is occurring right now across anthropology and evolutionary biology and psychology and beyond- the one that talks about environmental changes having a direct connection to genetic changes- changes that are heritable- gives us more power than we’ve ever known.
there is remarkable research linked in the article that discusses racism and its genetic response- it shows that our social construct affects the fragments of data that just might get passed along to the next generation/s. and while this knowledge that what we do to ourselves and each other and the environment affects our children’s children, and our species at large, might seem like a burden to some, I hope the rest of us see it as a grand opportunity.
Well one of the things that we must keep in mind is that mutation is random, and there are different types. Also there are various mechanism that cause and influence mutation (e.g. pollution). Mutation is generally, and I hesitate to use this but I will for simplicity, a “mistake” in genetic coding. These mistakes can be deleterious, neutral or beneficial. However more to the point, mutations are “permanent” changes that occur in an individual’s genes. If it’s there, it’s there and there is nothing that can be done about it. Yet, just because it’s there it doesn’t mean that the individual will have it expressed, as no one gene is 100% “penetrant.”
Now with epigenetics, the “changes” that occur are NOT “permanent” like those of genetic mutation. The simplest way to envision this is origami. The sheet of paper is your DNA, so any changes, such as adding or cutting we’ll say, will be permanent on that piece of paper. Epigenetics then are the “outside” forces (i.e. environment whether natural or constructed and everything therein) that fold and purpose the piece of paper. This is where it get interesting, as an individual’s life becomes imprinted, so do their choices and those choices made for them. This is to prepare future progeny for the environment they are to be born in.
So, epigenetics is generational, but not inherited; as inheritance is on the burden of genes. And like mutation, these changes can be adaptive, neutral or maladaptive. The reason why epigenetics is so important to humans is because it allows us to adapt very quickly because we are a long lived species with few progeny i.e. we evolve very slowly compared to many animals. This way we can adapt and be more “plastic” in any situation, which gives us an advantage in the animal kingdom to certain regards. Our genes just haven’t had the time to catch up with us, so epigenetic mechanisms help us along the way.
The take home message is that the choices we make and the environment we are exposed to, affects not only us but our possible offspring. Choice and perception then become very real and biological as well. So, we need to change our mindset to better help not only ourselves, but the world. Again this is a very simple and cursory gloss over of evolution and epigenetics. I need to also give the disclosure that there are various other forces and mechanisms that go into this.
Cheers!
P.S. Think of a butterfly when you think of epigenetics: a butterfly will lay its eggs, which are minute packets of genetic material that will create a little caterpillar that will then grow to an enormous size; its only purpose is to feed. Once it reaches a certain size, something will click in its genetic material to let it know that its time to pupate, where it will become into a genetic soup. It will then reconstitute itself into a butterfly that can take many forms and shapes and sizes and colors. At that point, it’s only purpose is to reproduce, and lay it’s eggs to start the cycle anew. This insect undergoes some drastic and dramatic transformations throughout its life cycle and it has the same DNA throughout. The only thing that changes are the factors that turn the epigenome “on/off” that then express certain parts of the DNA. These factors both influence the behavior and the “look.”
thank you for clearing up epigenetics vs mutations- there was some confusion about that on our facebook meme! and thanks, also, for clarifying generational vs heritable- that seems like a pretty important distinction 😉
I am excited to see the cultural implications of this “new” scientific trajectory play out and sincerely appreciate your contribution to this discussion.
I am looking forward, too, for the random-carbon-copy-error-explanation to get off the table (the feeling of which is attributed as the impetus to this column). I’d rather scientists just say, “I don’t know [yet]” because that agrees more with my sensibilities.
Thanks, all, for the great comments here and over on the various postings and reposting of the link. I am truly heartened at the sheer numbers of folks that have found their way here and championed both our mission to send cool research into the world and for thinking and discussing and life-changing in response to this first answer to what I think was a very important question.
I wanted to speak to some of this discussion and clarify my role as the anthropologist here. Honestly, what interests me the most about this discussion is the role our social system plays in determining our health. It seems like every day, since I can remember being aware of these things, I read popular writing about how individuals, and the fixed biology they were born with, was the reason they were not well. “Good genes”, “bad genes”- I heard these things so many times. Now, I agree, Giovanna, that this argument has been helpful to gay folks when gayness is cast as either “healthy” or “unhealthy”- but it seems to me that gayness is something altogether different than hypertension or cancer, which we can all agree are undesirable. Most of us in the world have various shades of brown skin (determined by many different melanin genes)- we can change it a little but not too much and it exists on a gradient. It always made sense to me that sexuality was similar- a gradient with a root in biology (with all kinds of social stuff on top). Maybe I’ve taught that bonobo article too many times in intro to anthro classes to think otherwise (Meredith Small- a classic- look it up!)
I’m glad that Victoria brought up the issue of race that was highlighted in the first two articles in the column post because I think that this issue really demonstrates what I feel is the critical point to take away from this discussion: our biology is changed by our environment- in the relatively short term. Now, I could have been clearer in my response to Victoria’s question and said that this doesn’t mean that we don’t still have random gene mutations occurring and perpetuating for various reasons. Willing away detrimental mutations is not something that anyone I’ve read is suggesting. What these studies I’ve looked at above seem to be suggesting is that we think twice about attributing certain illnesses to certain populations based on “bad genes” and think about social factors that seem to be contributing to this ill health- especially in light that we have an ethical responsibility to do what we can to alleviate human suffering.
To me, this kind of work does not target individuals and tell them they are responsible for their illness (I actually think immutable gene discussions do this in a far more pernicious way), but instead it turns the mirror onto all of us and asks us to reconsider what we do collectively- the environments we build for ourselves and others. Do individuals have a part in this? Absolutely. But is the take home message here that one strong thought=one change that stays around forever. No. That said, the research really does show that both YOU and WE have much more power than we might have thought.
This sparked a really cool, ahem, chat with a friend of mine over the weekend. She’s a certified nurse midwife. She clarified for me a bit on the nuts & bolts of how epigenetics work and how the genes are only “turned on” — so to speak– in utero. some really fascinating studies about the levels of stress or conditions during pregnancy and its possible effects on babies’ genetic make-up. Our other friend has done a ton of research into infanticide from a feminist perspective and was explaining the apparant higher levels of cortisol in women who suffer from post-partum depression & the resulting increased levels of cortisol in their babies.
In epigenetics, there are multiple “switches” in all living things occurring at the pre-, peri- and post-natal stages. In humans the gene-environment mechanisms are more complex and not permanent, so these switches can be turned “on/off” at any stage in development in utero and after, but imprinting is not kept on throughout an individuals lifetime. In utero development for humans its seems from ongoing research is very important because it “primes” the individual for the environment they are going to be born in to. As such, the environment is crucial. However it varies among gender. If a woman is pregnant with a female child in utero, the environment imprints the mother, the child and the future offspring of the female child in utero. This is because women in utero are undergoing oogenesis (that is they are already creating their “eggs” that they will use in later life to reproduce). So there are various implications and environmental factors for epigenetics. Stress being one of the most important ones in biobehavioral research and its deleterious impacts on people.
In my research I focus on the impact of chronic stress and pesticide exposure in medically underrepresented populations. I am looking at how the “switching on” of a certain gene varies from population to population in order to cope with the environmental stressors and toxins. So what I am trying to say is that it is a complex and exciting research area as there is still more to do on the subject and there is so much more that is continuously being discovered (i.e. “epigenetic counseling” for cancer patients to silence cancer promoting genes; why there is differentiation among “identical twins” when they have the same exact DNA; and so on.)
So this is what is confusing to me: ive always thought that changes in gene expression that are induced by outside factors like environment are just part of gene regulation but that epigenetic changes are only those long-term changes in genes that are potentially inheritable. And the bulk of epigenetic changes that might happen never get passed on. P.s The work on in utero experience is pretty fascinating to me.
Hello Babs,
Well yes and no about gene regulation. To clarify, I think you might be getting epigenetics confused with mutation, which is understandable as this stuff can get a bit topsy-turvy. That being said, regulation is also very complicated coupled with various mechanisms. Epigentics is now one of mechanisms which regulates genes by “turning them off/on” by a process called methylation (i.e. when a section of DNA is methylated, that area can’t be read; or if a certain area hasn’t “unspooled” from the chromosome, it can’t be read). The epigenome is by no means permanent and in many cases can dissipate in a lifetime according to some research. The epigenetic process is thought to provide a plasticity and adaptive mechanisms for a particular environment, that is to help us adapt without causing permanent “genetic” change. Any change to a gene is technically permanent, the epigenome may lead to a permanence if it is continuously selected for, according to natural selection; in itself the epigenetic process is not permanent. The epigenome provides for some wiggle room to adapt to precarious situations so we don’t have to depend on the slow process of evolution (that is for humans). This way our progeny can be better prepared for the environment that awaits them, in regards to mothers and babies.
Epigenetics is also responsible for “directing” cells to become a specific type of cell in the human body. If you think about the human body it is composed of a multitude of specialized cells and tissues. However they all have the same DNA, so how does a cell know to become a brain cell or blood cell? Well it is through epigenomic regulation telling the cell to specialize in what and differentiate how.
Hopefully this clarifies something for you! If not let me know. Cheers!
Thanks for the comments, Babs- it’s pretty cool to be sparking up conversations about these sorts of things- our number one goal! I haven’t read the original study but this is a pretty nice summary of some of the issues you mentioned- not sure if you’ve seen it- http://www.economist.com/node/18985981 I think these sorts of studies have pretty powerful implications for ways we consider a family history of stress- in the justice system as an example. Keep the conversations going!
If you like this topic, you’ll probably like the research by Elizabeth Blackburn and colleagues on the relationship between psychological stress and telomere maintenance, the latter being something like an epigenetic process. I was bowled over when I attended a talk by Blackburn on the research showing that “psychological stress – both perceived stress and chronicity of stress – is significantly associated with higher oxidative stress, lower telomerase activity, and shorter telomere length, which are known determinants of cell senescence and longevity.” (2004, PNAS 101:17312-17315, http://bit.ly/19pfeTv). Moreover, these effects can be intergenerational, as shown in research where “[p]renatal stress exposure was a significant predictor of subsequent adult telomere length in the offspring.” (2011, PNAS 108:13377–13378, http://bit.ly/17cOAzO).
By the way, I’m here today because Jon Wilkins of the Ronin Institute called my attention to this blog. I’m glad to make its acquaintance!
Not only does perceived stress affect telomere length but research by McEwen et al. (2012) [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3196296/] has found that the brain itself responds to stress by changing structurally. These changes are associated with mood disorders among other behavioral disorders and endocrine disruptions. However, these changes not only affect one generation, as the changes become passed on to the next; to prime them for the perceived environment.
However it doesn’t stop there, as epigenetic is also associated with sleep, behavior, mood, morphology, embodiment, and a host of other fascinating phenomena. Epigenetics is one of the “sexiest” and “chicest” things in science at moment. So much so that it is dangerously close to becoming a “fad.” This process has the ability to explain the gambit of neurological, immunological, etiological and physiological phenomena concerned with the environment, society, culture and health. As such, more research has to be done and the findings moved forward and onward.