Has the Nature of Humanity Changed the Rules of Biological Evolution?
Things were much easier for the biological world two hundred thousand years ago, or so. That world was ruled by a relatively simple logic that caused it to become ever more complex over time. Dan Dennett called it an algorithm1. Others have called it a process. By whatever name, we have come to greatly understand the basic logic of evolution, thanks in many ways to Charles Darwin and Alfred Russell Wallace. In very recent years we have come to understand evolution as a systems phenomenon and actually a co-evolving process taking place within a complex web of competitive and cooperative interactions between species, conspecifics, and interactions with the constantly changing physical environment. The world was easier in the sense that all biological systems, at every scale of complexity (from cells to ecosystems) followed the same basic rules to produce the world as humans found it when they first developed second and a half order consciousness. Indeed, it was the simple following of those rules that led to the evolution of human-kind consciousness2. And with it, one can argue, there has been a change in the whole rule system. Once humans started using their consciousness, their intelligence and their creativity to change the world for their own benefit, evolution changed.
To understand how this might be we need to first analyze the old biological rules. We should also note that the rules of evolution (taken here to simply mean changes in structures and functions over time) of pre-life were also a bit different from those of biology. So the notion that once a new level of complexity emerges the rules change is not really that strange. I shall try to explain as I work through biological evolution.
Basically there are just three rules that constitute biological evolution. The first is that organisms compete with one another for resources, especially energy flows. At various scales in the hierarchy of complexity certain groups of organisms actually compete with other groups of organisms by cooperating with one another. Colonies of bacteria, coral polyps, and human tribes are all examples of group cooperation in an on-going effort to obtain otherwise limited resources. Many forms of symbiotic relationships may also be viewed as cooperation to obtain mutually beneficial resources. Ultimately, competition is essential since it leads to testing of competency of the organism or group at extracting and using those resources. More successful organisms (or groups) will endure while others, not so competent, will succumb to the lack of said resources. Note that one might consider maintaining one's life against predation as a kind of competition for resources. The prey and the predator are competing for the right to live. Rule one might be called the ‘fitness rule’.
The second rule is that an organism (or group) must replicate itself as much and as often as possible. Rule one ensures that rule two can be followed over longer periods of time for the more successful or fittest units within the context of competition.
Rule three is that replication be based on a quasi-stable blueprint that is, itself, replicated with the whole organism. The term ‘quasi-stable’ refers to the fact that occasional errors can creep into the blueprint replication process. Most times such errors will be detrimental to the copy but, occasionally, the error will be either neutral or even possibly beneficial in terms of affecting rule one. That is, the organism might attain a higher level of fitness as compared with its competitors as a result. I should also note that more recently biologists are discovering mechanisms for inducing errors (or changes) in the underlying blueprint as a result of environmental stresses on the organism. This is not a form of Lamarckian evolution, but rather a way to speed up the potential for the species to search for changes that are more fit in rule one. This strategy depends on rule two for its success in that a large number of copies need to be made in order to test the resulting and probabilistic modifications.
All three of these rules are followed by all biological systems within the context of a physical environment which is forever changing over time. Indeed, it is often the changes in the environment which play a major role in the outcomes of the application of rule one. In some cases even a small change in the environment can change the dynamics of competition dramatically leading to events like species extinctions.
There are actually many different mechanisms at play in biology to implement these rules. For example, rule three isn't just implemented in random genetic mutations. There are numerous transcription, developmental, and even mutation enhancing controls in the DNA that can be subject to mutations that simply change the gene readout dynamics3. Other epigenetic factors such as parental imprinting may be subject to copy errors as well. However, regardless of the details of implementation, the basic rules are followed during the play out of the lives of individuals and groups, leading to the tendency for these units toward greater fitness or expulsion from the game. Since only the fittest survive to be counted in the next round, evolution always leads to higher fitness all around. Lest you think this a tautology, recognize that it is actually a case of mutual causality, driven from the outside by physical factors that operate on all participants.
One of the most important physical factors in the drive of evolution is the availability of usable energy. One of the reasons that evolution has generally driven toward higher complexity, in what could be called progress if you were brave enough to risk the wrath of teleologic-fearing evolutionists, is that over the course of biological evolution the amount of available energy from the sun has always exceeded the actually used energy to form biomass. Evolution's best accomplishment in achieving light-to-biomass conversion has been photosynthesis in plants, the primary producers. But photosynthesis is inherently inefficient in producing biomass, between 1 and 5%. Over the course of the evolution of land plants there have been some improvements, the occasional adding of a new pigment to the mix, along with chlorophyll. But this is still a long way off from the total amount of energy that might be usable if nature just discovered a better conversion approach. Nevertheless, the evolution of plants, particularly land plants, shows how the increase of complexity, enabled by the flow of energy, leads to an increase in the capture of available energy, and that, in turn leads to the enabling of evolution toward even more complexity. Then, of course, the evolution of animals, perhaps mostly as a way to recycle CO2 and nutrients as well as spread seeds, increased this complexity even more so, thus increasing the potential for capturing more solar energy still.
Chemical evolution, and to a large measure pre-biotic evolution of organic molecules, operates with rules that are similar but not completely the same. For example, rule number two (replication) is not generally seen in chemical evolution. Chemical species (say for example in an aqueous solution) come into existence based strictly on the laws of chemical combination, the formation of bonds between atoms and energetic considerations. The only thing that resembles replication in pre-biological (chemical) evolution is the autocatalysts. Autocatalysis means that a catalytic molecule promotes its own formation resulting in a positive feedback that drives the reaction in the forward direction until it exhausts its resource constituents or there is no more binding energy left to exploit. It is believed that the development of more complex mutual catalysis among certain RNAs (ribozymes) or proteins (enzymes) led to more stable patterns of copying that were the precursors of actual replication. When one looks at the machinery involved in biological replication (say mitosis) it becomes clear that it is a long way from mere chemical reactions.
Much the same holds for rule one. There isn't actually competition between individual atoms or molecules each with slightly different competencies. Rather, it operates on a first come first served basis as to which specific atoms/molecules get to enter a chemical reaction. At the atomic level all entities of the same kind are the same in terms of their combinational competencies, so there is nothing akin to variable fitness within the population, except in the sense of variable kinetic energy distributions. When proteins had emerged with highly complex folding patterns and topological properties the story gets more interesting. Competency becomes a matter of which folding pattern does a better job of, say, catalyzing a reaction that turns out to create a more favorable condition for the continuation of that particular protein. However, it is most likely that this occurred in the context of already formed primitive cells and so counts more as the result of biological evolution than of pre-biotic evolution. A great deal more needs to be learned about the conditions and properties of pre-biotic systems that led to real life that then followed the rules above. Happily we seem to be making a fair amount of progress in this direction4.
Enter the Human Mind
Biological evolution led eventually to the modern human species. Not that long ago, in evolutionary time, animals went from being merely aware and, perhaps, vaguely aware of themselves as actors, to becoming fully conscious of the world, themselves, and other actors who were like themselves in various ways (the theory of mind). The transition included the development of a fully symbolic representation capability in words (language) and pictures. It also included the capacity to imagine the future (or construct memories of the future). And one crucial element in this transition was the tremendous expansion of the capacity for recognizing affordances in naturally occurring objects (e.g. seeing the potential for a sharp blade in a piece of rock). All of these massively expanded (or newly emergent) capacities along with the heightened intrasocial bonds involved in tribal maintenance gave human beings an incredible expansion of the ability to construct cultures. Many species have now been documented as having tool making or food gathering practices that are unique to a specific group and that are passed on through generations. This is accomplished not by symbolic communications, but through learning by demonstration and observation. Man is the first species to develop culture through language and significant invention.
Human cultures, rich as they are in invention and semantic communications, evolve. And there is much similarity to the way cultures appear to change over time, especially those that become more complex over time, and the way biological evolution has produced ever more complex species, even while ancient forms (think alligator) persist almost unchanged. There have been many sociological theories of cultural evolution (see the previous link) that relate it to the biological, or Darwinist form. One of the more thought provoking of modern theories was due to Richard Dawkins of ‘Selfish Gene’ fame5. Dawkins was convinced that the gene was the main (only?) unit of selection in biological evolution since it is involved in all three rules to one extent or another. He had thought about what the unit of selection might be for cultural evolution. He hit on the notion that many of our ideas come as fully-formed, if fuzzy-bounded, concepts that can be transmitted from one person to another, as genes are transmitted from the mother to daughter cells. Here brains took the place of cells, and the ideas he called ‘memes’ or memory genes. Today there is a vigorous field of social evolution study called ‘memetics’ that attempts to explain cultural evolution in terms of the memes following similar rules to biological evolution. It is a stimulating notion, to be sure. But see the critiques that point out how memes are not similar to biological systems (i.e. they are not like genes after all).
Culture: The New Environment for Evolution
Cultures are more like ecosystems than like species or populations as units upon which evolution works. Ecosystems evolve in the sense that they have changing complements of species over long enough scales of time. When a major change to the local climate or geography takes place, an ecosystem is disrupted. The loss of a keystone species (through local extinction) is also disruptive to the ecosystem. In general such disrupted systems experience a kind of dissolution or simplification in terms of the biodiversity and biomass. After hitting the bottom, so to speak, the geography covered by the original system is subject to invasion by opportunists species that start the process of evolution by succession of species mixes as the system essentially learns to capture and redistribute the available energy flows among the extant species. Eventually, if left undisturbed, the system will settle into a climax community, which may remain stable until the next (inevitable) disruption changes the dynamics of the system again.
Cultures have a very similar kind of dynamic where humans are the main vectors for change, though the ultimate causes are likely to be climate and geographic alterations just as with ecosystems. A culture evolves by the process of inventions leading to the capture and redistribution of energy flows working toward a maximum organization and energy usage (maximum power principle6). As I have written about frequently, humans are incredibly good at discovering and exploiting energy stocks (fossil fuels) and flows (solar, hydro) to power the work that converts raw natural resources into human artifacts and biomass (food, more children, and larger bodies). Step far enough back and observe all cultures and you will see this pattern of evolution. Generally it goes from the simple to the complex. If no other forces were to disturb a fully developed culture (that is one in which all available energies were being put to work), presumably it would enter a steady-state condition similar to a climax community ecosystem7. However, humans, as the intentional driving force inside a culture, have never been particularly content with the status quo. In societies blessed with a sufficient abundance of energies, a level of complexity evolves such that hierarchies of governance and political ambitions, exercised through militaries, causes such cultures to expand into other geographical regions, displacing or absorbing the local, presumably weaker, cultures. This strategy, however, seems not to pay off in the long run8!
Today we would seem to be in the throes of a globalization of culture, a wild amalgamation of various previously local cultures into a broad-based one. The lead is being taken by American pop culture. The US has been seen as the innovator of technology and arts for the past several decades and the spread of television, movies, music, etc. have been instrumental in morphing other cultures into variations on those themes. All the while, American culture has undergone adoption of many aspects of those other cultures, my personal favorite being ethnic foods.
Given enough time and continuation of energy flows it is entirely possible that the entire planet would come to share common features of cultures (e.g. neoliberal capitalism) even while some local flavors kept life interesting. However, that is not likely to happen. As we now know the flow of oil and after it the other fossil fuels, is coming to a peak after which it will decline and the energy needed to fuel our complex global culture will decline. Long-distance movement of mass will likely begin to diminish first, followed by diminishment in the long-distance movement of people. It could be that long-distance communications will be maintained for a while, but even that is dependent on sufficient energy flow. Those computers don't run on air you know. There are net energy export regions and all the rest are net importers. The latter group are going to suffer much more as the former start to lower their exports to conserve and use for their own populations. An end is in sight for this globalization as we have come to see it. Even now the signs of a process of relocalization can be seen everywhere, from people starting to do more home food gardening, to attempts to tackle energy security on the home front (or at least start to worry about it).
But the point of this interest in culture is less about its possible future (there will always be some culture as long as there are groups of humans on the planet) and more about how the mere existence of culture shows the impact of human evolution as it breaks out of the conventional rules of biological evolution and the impact of culture on human evolution. There is a co-evolution of humans and culture that is changing the way in which humans were subject only to biological evolution and are now subject to something more expansive.
The concept of emergence and hierarchical levels of complexity introduce some new considerations in terms of causal relations. It might be said that the interactions of components in a less complex system but one that is far from equilibrium, plus some luck, give rise to emergent structures that can interact among themselves as if they are a new kind of component set operating under new rules. For example, enzymes emerge from protein chemistry when they obtain sufficiently complex shapes and those shapes provide conformational energies to other molecules causing them to interact. In a sense, protein chemistry gave rise to enzymes. One may argue there is an upward sort of causality that produced the emergence under the right circumstances (do not confuse this with the notion of reductionist explanations for enzyme behavior, however). But there is an interesting sense in which the emergence of the higher level structures change the behavior of the lower levels ones, create a new dynamic and alter the ways in which the lower level components interact. Enzymes, for example, begin to cause certain favored reactions that drive the whole system in new directions.
The emergence of minds, and subsequently of cultures added new levels of complexity to the Earth. And the new layer of cultures added a new set of selection forces downward onto the minds and bodies of humans. Human minds, interacting with each other, both cooperatively and competitively, generated novelty in culture, driving cultural evolution. But that, in turn shaped minds and the whole of the human species. Humans migrated to environments that were hostile to their mere biology. But they wrapped themselves in ever increasing technologies that extracted or conserved energy as they spread out over the Earth. In doing so, however, they also began a process of changing their own biology. Lighter skin for those who migrated to the north. Adult persistence of lactase in those who raised dairy animals. The list is getting longer of various ways in which the evolution of culture feeds back on the evolution of the human genome. And that, in turn feeds back on the biology of the Earth.
An obvious way in which the presence of humans with their unimpeded expansive nature has changed the basic rules for the rest of biology is the way in which they are wiping out habitat and driving the sixth great extinction event9. It isn't that the basic rules of biological evolution have changed so much as the rules regarding natural selection. The comet that struck the Earth some 65 million years ago also changed the selection criteria in a wink of an eye. It created a world that didn't so much favor small, nocturnal, burrowing animals as it did simply devastating larger, diurnal beasts. The dinosaurs couldn't compete. End of story.
Nevertheless, the subsequent evolution of species after the demise of dinosaurs was still based on the three basic rules of biological evolution. Presumably after the sixth extinction, assuming humans also go extinct, the Earth would revert to the same pattern. Biological evolution would grind out a whole new set of species fit to survive in whatever environment (read climate, sea level, and ocean acidity) develops. But what if mankind manages to survive? Indeed, what if mankind manages to preserve its knowledge of genetics and genetic engineering? We already have started engineering crops and bacteria genomes? This isn't, strictly speaking, biological evolution. It is some combination of biological and cultural evolution explicitly captured in human artifacture. And, moreover, there is the possibility that we humans could begin to engineer our own genome; the preliminary attempts have already begun.
The rules have changed. Fitness will not be left to chance but defined by intentions. Full out reproduction may be set aside in order to maintain a steady turnover of individuals and we will still have introduced modifications, not as copy errors, but as intentional modifications to the DNA. No one can say that there is wisdom in this strategy. I suspect, if it is realized, there will be mistakes made along the way and those will be selected against just has happens now when someone designs a faulty artifact that proves non-utilitarian. But recognize that in the really long-term scheme of things, this new set of rules for evolution were the result of evolution in biology itself. You would have to call neo-Darwinian evolution foolish if you think that the whole idea sounds foolish. We humans are simply doing what our biology and culture have shaped us to do. We should not be afraid of these new rules. But we should adopt a proper attitude of humility in thinking about how they should be actualized in some future world.
Caught In the Middle
The problem is us. Homo sapiens is an unfinished piece of evolutionary work. We find ourselves biologically advanced in most respects. We have incredible cleverness and curiosity. But we are still very much driven by animal spirits. We have built-in, limbic-controlled drives and biases. And we have a dirth of sapience (and wisdom) in light of our capacity to change the world to our liking (driven by those animal spirits). We are caught in the middle between our ability to destroy our world by creating new technologies (and consuming energy stores faster than they are replenished) and our understanding of what we are doing. We are not able to muster the self restraint on our exuberance, even in light of that understanding.
In this condition we would be uncommonly dangerous were we to try to exploit the new rules of evolution that we are just now starting to learn about. We would most likely make far more mistakes than would be warranted; do far more damage to the Ecos and ourselves than could be sustained. Thus, one might view the impending impasse, the evolutionary bottleneck10 that humanity has created for itself with the burning of fossil fuels (climate change and cultural dependence on high power sources) as an opportunity to not abuse the new rules. That is, our exuberance is about to be brought to its knees. And it will hopefully come in a manner that will prevent us from doing something monumentally foolish.
In fact, we have an opportunity to use the ordinary biological evolution rules to ensure the survival of a core population of humans that could carry past the bottleneck a genome that positions future generations to be much less foolish than are we. In previous writing I have speculated on the possibility of giving sympatric speciation a nudge in producing more highly sapient individuals as a prelude to the bottleneck. Taking steps today to ensure the survival of such a core population would be our greatest gift to a future humanity if there is to be one. Greater average sapience would help induce greater wisdom in the population. And wisdom is what will be needed to curb inventive exuberance. It will be needed to manage the exploration and exploitation of the new rules of evolution.
Biological evolution is still operative for human biology. Cultural evolution and the subsequent downward causality may alter the rules, but it does not negate them. Our future lies in recognizing this and letting nature take its course. The new rules are not unnatural they are just the result of emergent organization. In our current modus operandi we could not recognize this. Hubris still rules the majority of humanity's beliefs about our place in the universe, humans as rulers of the Earth. The bottleneck event could cure us of that defect, but only if we succeed in becoming more sapient. What will we be wise enough to do now?
Footnotes & References
- Daniel C. Dennett, (1995). Darwin's Dangerous Idea, Simon & Schuster, New York. Chapter 2, sections 4 & 5.
- Two books that are must-reads for a panoramic view of the evolution of the human mind: Geary, David C. (2005). The Origin of Mind: Evolution of Brain, Cognition, and General Intelligence, American Psychological Association, Washington DC., and The Evolution of Mind: Fundamental Questions and Controversies, edited by Gangestad, Steven W. and Simpson, Jeffery A. (2007). The Guilford Press, New York. This latter book provides a wide ranging assessment of some of the open questions and critiques of several older theoretical frameworks such as sociobiology.
- Jablonka, Eva, and Lamb, Marion J., (2005). Evolution in Four Dimensions, The MIT Press, Cambridge MA.
- Those interested in the origin of life would do well to read Harold J. Morowitz's very informative Beginnings of Cellular Life: Metabolism Recapitulates Biogenesis (1992). Yale University Press, New Haven CT.
- See also: Dawkins, Richard (1987). The Blind Watchmaker, W. W. Norton & Company, New York.
- The maximum power principle is best explained in: Odum, H.T. (2007). Environment, Power and Society for the Twenty-First Century: The Hierarchy of Energy, Columbia University Press, New York.
- It is possible that pre-Columbian Native American societies had achieved a semblance of this condition. Other stable communities have been documented throughout the world and history.
- A must read on the ultimate fates for expansionary societies that suffer from declining marginal gains on increasing complexity is Joseph Tainter's (1990), The Collapse of Complex Societies, Cambridge University Press.
- Leakey, Richard and Lewin, Roger (1996). The Sixth Extinction: Patterns of Life and the Future of Humankind, Anchor.
- The preceding link is to my review of: Catton, William R. (2009). Bottleneck : Humanity's Impending Impasse, Xlibris.