Can we evolve? Part 1

Mar. 29, 2024

Most people will associate the word evolution with changes in the heritable characteristics of biological populations over time. Even if Charles Darwin didn’t understand the genetics behind it, his theory of natural selection could, with some refinement, survive the discovery of genes and DNA. The result is something that is called the modern evolutionary synthesis: Diversity within a population emerge from random production of mutations, and the environment acts to select the most fit phenotypes. Those species capable of reproducing would transmit the genes that gave them their advantage.

There have been heroic efforts to explain all aspects of human society with genetics. To reduce human society to an expression of genes is, however, as useful as seeing the Earth System as an expression of atoms. Clearly, the genes of myself, people in the Roman empire, feudal lords, Nazis, Silicon valley tycoons or pastoralists in the Sahel are/were more or less the same, while their societies differ enormously.

Natural selection applied to human groups

In the article Multilevel cultural evolution: From new theory to practical applications, published in PNAS Brian Sloan Wilson and colleagues take a step back to Darwin’s original definition of natural selection — a process that combines variation, selection, and replication, irrespective of the mechanisms—and applies it to the evolution of culture and human society. (Wilson et at 2023).

Human exceptionalism is a treacherous path to tread, but the complexity of human society, and perhaps even more, the speed of changes, are in some way exceptional. This is also related to our ability to transmit information, behaviors, skills and norms across generations, i.e. culture. The authors identify three factors which are significant for this exceptional capacity* for cultural evolution: prosociality, social control, and symbolic thought.

Prosociality is defined by the authors as any behavior oriented toward the welfare of others or one’s group as a whole. It is a broader term than altruism or cooperation and includes everything that is required for a group to function as an adaptive unit. Some animal societies, especially insects, are so prosocial that they invite comparison to a single organism and are described with terms such as “superorganism”, “eusocial”, and “ultrasocial”. Humans are in that sense more similar to other ultrasocial species than to our closest living relatives, chimpanzees and bonobos.

Social control, in turn, is composed of behaviors geared at enforcing prosociality, e.g. by punishing individuals that fail to adhere to the social norms or rewarding virtuous behaviors: “Good behavior is rewarded with high status and the material benefits that come with it. Bad behavior is discouraged, at first in a mild fashion such as with gossip and humor, but in extreme cases escalating to exclusion from the group and execution.” as expressed by the authors.

The evolution of prosociality has been described as a process of “self-domestication” similar to the development of docile traits in our companion animals, including changes in the physiology of humans in a similar way that domestication has changed the anatomy of the animals and plants we domesticated (Benítez-Burraco 2020). The greatest group-level adaptation of all is the capacity of symbolic and abstract thought, including language, which also is the foundation of culture.

Multilevel cultural evolution

In terms of relative fitness, prosocial behaviors mostly have a disadvantage compared to more selfish behaviors expressed within the same group. Examples include cancer cells within multicellular organisms; free riders, bullies and cheats. At the scale of between-group interactions, prosocial behaviors, however, have an inherent advantage. This was noted by Darwin in The descent of man, 1871 already, “..a tribe including many members who … were always ready to give aid to each other and sacrifice themselves for the  common good, would be victorious over most other tribes; and this would be natural selection”. The authors mean that this tension between what is beneficial for individuals within a group and what is beneficial for the group as a whole exist on multiple layers, e.g. behaviors that are successful for one nation may not be of benefit for the whole of humanity: “thriving economies lead to the overheating of Earth. Nearly everything that is pathological at higher scales can be traced to behaviors that are prosocial at smaller scales”. What is good for humanity as whole may not at all be beneficial for the biosphere.

The economic metaphor of the invisible hand suggests that the lower-level pursuit of self-interest robustly benefits the higher-level common good. It should be noted that even Adam Smith, who coined the invisible hand metaphor for markets assumed that there would be some moral system in place to keep the self-interest of trade in check: “How selfish soever man may be supposed, there are evidently some principles in his nature, which interest him in the fortunes of others, and render their happiness necessary to him, though he derives nothing from it, except the pleasure of seeing it.” (Smith 1759). It would be unfair to criticize Adam Smith for failing to understand that the self-interest would become so dominating that the moral system keeping it in check gradually has eroded as a result of the same self-interest and its main expression, the market.

It seems apparent that the current norm of individualism and the worship of self-interest is bound to undermine human society. This norm is also reflected in the obsession with competitiveness for companies and countries. Deep inside, both people and policy makers seem to understand that there are not only winners in the globalization project. If it were so, it would not be so important to be competitive or more innovative than others as we would all share the benefits. In light of that, the backlash of globalization should not be seen as an expression of some kind of primitive populism, but actually as political realism. But let me come back to my main discourse.

How culture changes

Culture, moral and norms are clearly essential for human societies on many levels. As conditions change also culture will (have to) change and culture itself changes the conditions, and even the genes. Human populations have developed various traits for the digestion of specific foods depending on their food strategies, e.g. the genetic evolution of lactose tolerance came after the cultural evolution of milking domesticated animals.

Cultural evolution is as dependent on variation, selection and replication as genetic evolution. The teenager phase of humans is like mutations in genetics. Adolescents experiment with new identities, revolt or protests against norms and are mostly rather self-centered (even if there are exception such as Greta or Malala). It is tiring for the parents and a strain on society and its norms. Most of the teenage mutations will fail in the same way as genetic mutations will, but a smaller share will prevail and perhaps be turned into new norms (selection) and those new norms will be transmitted or imposed on coming generations (replication) through traditions, religion, laws, language or other institutions.

Technology and innovations of many kinds challenge prevailing norms and society (Currie et al 2024) and thus also act as mutations.  In the world of today, technology is a more disruptive, and thus evolutionary, force than teenagers ever were, disruptive has even become a badge of honor. The speed of technological development is so rapid that culture in a wider sense can’t adjust to it and social cohesion is therefore eroding.

Parallel to this, the global human dominated biosphere is on the verge of collapse.

It has happened before

It has happened before that a species or a group of species were too successful for their own good and caused mass extinctions. Before the Great Oxidation Event, the earth had an atmosphere consisting of carbon dioxide, methane and water vapor, as opposed to the present-day atmosphere that consists primarily of nitrogen and oxygen. Around 2.7 billion years ago, cyanobacteria evolved. They introduced photosynthesis, (the ability to use the energy of sunlight). They ate water and one by-products was oxygen. This oxygen acted as a poison and wiped out much of anaerobic life, creating a massive extinction event. It almost killed the cyanobacteria as well, certainly their numbers dropped dramatically.

Another example is the rapid development of fern like trees in the period called Carboniferous 359–299 million years ago. They sucked up huge quantities of carbon dioxide from the atmosphere and the plants’ debris over time formed most of the carbon that today is used as fossil fuel. Consequently, the carbon dioxide concentration in the atmosphere sank drastically, and Earth cooled down, almost to global glaciation, leading to a massive extinction of species as well as a drastic reduction of the number of trees (Feulner 2017).** Ironically, the remains of the trees have now been combusted by a hairless ape and might well cause another mass extinction.

It seems that humans are repeating the achievements of cyanobacteria and trees: being too successful, too many, with a too big appetite for our own good, changing the climate and possibly crashing both our own population as well as the population of many other species. And of course, the longer we continue on the same path the stakes and the risks are higher and the harder the crash will be, if we fail. And we will, the question is only when and how.

A heroic retreat?

Can we use our extraordinary ability of symbolic and abstract thinking to get out of this? Well, I don’t think we can modify the path we are on to make it more green or sustainable, that is just wishful thinking. Or rather, of course we can make it a bit greener but it will not change the underlying mismatch between our demands on the rest of the living and our numbers and appetite. Perhaps we just have to accept that we are not as smart as ecosystems are, or the planet***? If so, the solution is to humbly accept that we can’t, or even shouldn’t, be in command, drop the Anthropocene narrative and just adjust to the respective ecosystems we live in. We must use our extraordinary abilities for a planned retreat, ensuring that we take care of the wounded and saving what is most valuable in our current culture. The German writer Hans Magnus Enzensberger wrote 1989 an inspiring article called Die Helden des Rückzugs (The Heroes of Retreat) where he hailed those leaders, people like Gorbatchev and Jaruselski, that recognized that the system that they were part of was not viable or good and participated in the dismantling of them. It is that kind of insight we need today, not people continuing the charge forward.

Even with a planned retreat we need to think about how human society can be organized to avoid repeating the same, again and again. The same forces that undermine nations in which humans are organized undermine efforts to steer the development towards a common good. Here we have a double challenge, we must both include all humans in our group as well as the rest of the living. That will be the topic of another article.

* The identification of this exceptional capacity should not be understood as any value statement, the exceptionalism includes both fantastic achievements and holocausts.

** There seems to be different opinions about the details in how much trees reduced carbon dioxide content in the atmosphere as well as the climate. See for instance Dahl et al 2022. I don’t think it changes the bigger story though.

*** I don’t mean to imply that ecosystems or the planet have intelligence in the normal meaning of the word, also not that they have purpose or design.

References

Benítez-Burraco A, Clay Z, Kempe V. Editorial: Self-Domestication and Human Evolution. Front Psychol. 2020 Aug 25;11:2007. doi: 10.3389/fpsyg.2020.02007.

Currie Thomas E., et al 2024, Integrating evolutionary theory and social–ecological systems research to address the sustainability challenges of the Anthropocene, Phil. Trans. R. Soc. B3792022026220220262

Feulner, Georg 2017, Formation of most of our coal brought Earth close to global glaciation, PNAS 24 oktober 2017.

Smith, A. 1759, The Theory of Moral Sentiments

Wilson, D. S., Madhavan, G., Gelfand, M. J., Hayes, S. C., Atkins, P. W. B., & Colwell, R. R. (2023). Multilevel cultural evolution: From new theory to practical applications. Proceedings of the National Academy of Sciences of the United States of America, 120(16), https://doi.org/10.1073/pnas.2218222120