Epigenetic Evolution

Epigenetic Evolution: A Theory of Cultural Evolution through Directed CreativityExcerpt from the Introduction:

If we observed another species evolve as dramatically as modern humans have over past many thousands of years, we would presume that the change was genetic—the natural selection of genetic variation must be involved. But this has not played a significant role in the evolution from hunters and gatherers to the modern culture. We know this because, over time, we see little or no change in human biology, including the capacities for culture. The evolution of irrigation agriculture did not require genes for irrigation agriculture. When modern hunters and gatherers emigrate to an industrial culture, they can adapt, and vice-versa.

The cause of the evolution from stone to bronze to iron and beyond—and thus the trajectory towards more, more and more—must therefore rest in the capacities for culture, as they evolved in our pre-cultural ancestors. Hence, if we can identify what has caused our capacities for culture to be put towards these ends, and understand the process by which culture evolves, we might also be able to ascertain whether we are able to control our future evolutionary trajectory.

That is the object of this book: to elaborate a theory of human cultural evolution. This theory builds on certain key concepts of anthropology and sociobiology, rejects others, and fills in gaps.

A theory of cultural evolution must carefully delineate the relationship among culture, human biology and natural selection. Criteria for such a theory include:

  • Explain the general direction of cultural evolution, the long arc.
  • Account for diversity among cultures.
  • Describe the process by which culture evolves.
  • These must be done while holding human biology constant.
  • Explain how natural selection of genetic variation could give rise to the biological capacities for culture, yet does not appear to be significantly implicated in cultural evolution for the past many thousands of years.

I will add one additional criterion. A previous book, Dynastic Theory: The Evolution of Altruism in Animal Societies, set forth a theory of the biological evolution of group adaptations in all other species—including our pre-cultural, hominid ancestors. A key component of this theory is that animal societies are structured through natal philopatry—what I call dynastic structure. Members of an animal society are related by descent to a common founder of the society. Human societies are not structured dynastically. Although families are central to social structures in all societies, group bonds in large modern societies extend far beyond kinship. A theory of cultural evolution must explain why human societies are an exception to the rule in other animal societies.

The theory is called epigenetic evolution: a theory of cultural evolution through directed creativity. In brief, the theory holds that human minds create, select and build the “library” of culture, which exists above the level of individual humans. Because culture is communicated from minds to minds through language, culture evolves separate from the pathway of biological reproduction and inheritance—and, thus, is decoupled from natural selection. But as minds create, select and build culture, they are biased in a Darwinian direction. This is because, as the human brain evolved through natural selection in our pre-cultural ancestors, the psychology that motivates the brain to action co-evolved with it.

Check out the Table of Contents.

Take a look at the Bibliography.

Get the entire book:

Download the PDF (free) Get it for Kindle ($7)

About the Author & Project

Britt W. Hanson
Britt W. Hanson

Each of these three books aims to solve a significant scientific puzzle: the evolution of group altruism; the evolution of culture and its relationship to natural selection; and the function of sex. Along the way, these books present theories of human nature, creativity, free will, and goal-directed causation, while also unloosening biology and the social sciences from the shackles of mechanical determinism.

I did not set out to do any of this. In the mid-1990s, I had asked a simple question: why, over the millennia, has the human species put its ingenuity towards extracting more and more resources and generating more and more people? And this follow-up question: do we have any control over this trajectory, or is it somehow ingrained in us?

When I couldn’t find an answer to these in the social sciences, I turned to evolution, expecting that what modern humans do should have some connection with what our ancestors evolved to do. Eventually I stumbled onto sociobiology. I became persuaded that a fundamental thesis of sociobiology must be correct: human culture must derive from human biology, as evolved through natural selection. The alternative is a blank slate hypothesis. But the more I examined sociobiology, the more I also became persuaded that most of the rest of its propositions were wrong.

My skepticism began with kin selection. In On Human Nature, E.O. Wilson stated that kin selection accounted for cooperation among close relatives, implying that kin selection could explain tribalism in our ancestors. This led me to wonder how modern human societies could have expanded so far beyond tribes of close kin. I searched for sources that would provide a rationale for how kin selection works. In The Selfish Gene, Richard Dawkins emphasized again and again that kin selection does not predict tribalism at all. It is not a group theory. It is a theory of selfish individualism. Dawkins argued that group altruism is impossible, even theoretically. Although Dawkins is a persuasive writer, this did not seem right. Human groups, including tribes, are real. And the more I examined Dawkins’ selfish gene rationale for kin selection, the more I questioned its plausibility.

My interest was in humans, but it occurred to me that animal societies could not function if each individual member calculated altruism by degrees of relatedness, as predicted by kin selection. Poring over studies of animal societies, I quickly came to see that animals bestow altruism according to group membership, not degree of relatedness. In Ants and The Social Insects, E.O. Wilson made clear that this is true of ants and other social insects. So why then were evolutionary biologists, including Wilson, so enthusiastically proclaiming that kin selection was correct? Where were the skeptics?

In 1998, I came across two articles by Mary Jane West-Eberhard, which cast doubt upon kin selection. These articles contained what to me was a surprising, extraordinary fact: the division between queens and worker castes is epigenetic. This was directly at odds with the way that kin selection modeled the existence of “selfish” queens and “altruistic” workers as due to rival alleles for selfishness and altruism. Epigenesis didn’t solve the problem of altruism—some genetic selection must occur for worker altruism to evolve—but it did lead me from simple skepticism to a conviction that kin selection was just plain wrong. Evolutionary biology needed a theory that explained altruism at the level of the group. The theories of group selection, however, used the same gene-centered approach as did kin selection, and they were thus not persuasive, either. So I set out to devise a theory of group altruism. The outline of what I eventually called “dynastic theory” came about in short order.

Dynastic theory explains why animal societies are structured around lines of descent—what I call “dynastic structure”—and, hence, are groups of kin. I could project this structure to bands and tribes of human pre-cultural ancestors. But this still didn’t account for the fact that modern human societies have bonds that extend far beyond kinship.

I set myself to the task of figuring this out. I guessed that the solution had something to do with the distinctive way in which humans evolve, through culture. This was something else that sociobiology did not seem to get right. In places, sociobiologists were suggesting that human culture evolves just like natural selection, or maybe even through natural selection. At other times, sociobiologists pointed out that human biology has hardly changed over the past tens of thousands of years and that biological differences do not account for cultural differences. If so, natural selection of genetic variation could have nothing to do with the evolution of culture. Moreover, when I thought through specific examples of the evolution of cultural traits, it became clear that culture evolves independently of natural selection. The trick was to explain how this could happen. What emerged, in the year 2000, was a theory of cultural evolution: the theory of directed creativity.

This theory—and in particular, the very concept of creativity—conflicted with determinism, which is a premise of science. I was reluctant to open this can of worms, but it seemed too important not to do so. What emerged was a theory of guided free will and a theory of teleological causation—which is not to be confused with cosmic purpose or theology.

Meanwhile, during my reviews of kin selection, I became aware that biologists regard the function of sex as an unsolved evolutionary puzzle. This was striking. Biologists were heralding the neo-Darwinian synthesis as completing Darwin’s theory, yet the synthesis couldn’t account for a trait as apparently fundamental and as (nearly) ubiquitous as sex? Adding to the puzzle, to be consistent with kin selection, sociobiologists were asserting that sex must hurdle two-for-one leaps of benefits in order to evolve from asexual reproduction.

By this time, I had become thoroughly skeptical of almost every aspect of the neo-Darwinian framework. And since dynastic theory solved the problem of altruism without the need for leaps, I thought I might also easily solve the puzzle of sex. This quest, however, turned out to be far more difficult and time-consuming than solving altruism and cultural evolution. A sketch of the theory of sex and conjugation was completed by the end of 2002, but by then I was exhausted and needed to make a living. I took up these projects again several years later, attempting to put the several theories into comprehensible, readable forms. Given the scope and magnitude of the subject matter, this has taken several years. I hope that I have succeeded.

I realize that what these three books purport to accomplish appears to be all quite grand. I also realize that it is possible that they are simply grandiose.

The reader will rightly be skeptical, all the more so since I am not a trained evolutionary biologist, an anthropologist, or a philosopher. I am a lawyer. One of the questions that I asked myself early on in developing dynastic theory, and kept asking throughout the project, was how someone like me could possibly perceive flaws in evolutionary theory and put together improved theories. I think that my outside perspective proved to be essential. When a puzzle remains unsolved, it is usually because errors are embedded in orthodox assumptions that are so ingrained that no one questions them. In this case, the ingrained assumptions are embodied in the neo-Darwinian synthesis—a synthesis that became orthodoxy, became identified with Darwin, and then hardened into a phalanx of concepts and doctrines that is extremely difficult to breach. That is why outstanding scientists keep mulling over the same ideas and falling short of solutions. As science historian Thomas Kuhn observed, “normal science” occurs inside a scientific discipline; significant change arrives from the outside, from those who challenge ingrained assumptions. I didn’t begin with a priori assumptions. I began with the empirical patterns, then worked backwards until the puzzles were solved. The reader will judge whether I have solved them successfully.

Most of all, though, the end hope is that these books might contribute to the understanding of the questions that prompted them: why has our species evolved in the direction of more, more, and more? And do we have a choice?

–Britt Hanson