The limits of evolution

The theory of evolution by natural selection as initially formulated in 1858 by the British naturalists Charles Darwin and Alfred Russell Wallace has been able to explain with a great level of accuracy how species change over time, split, disappear, get replaced by others or migrate into new habitats. In a sense one could argue that evolution is an emergent property of life: mixing the scarcity of resources (space, food, water), mechanisms of adaptability (both sexual reproduction and mutation) and sufficient time there are only two possible outcomes: either life manages to adapt itself  to a somewhat sustainable equilibrium and thereby survives, or it fails to find a suitable solution and it starves itself to death. And of course, the adaptation is only valid for a given ecosystem as long as the conditions are stable: if the ecosystem changes in size, climate or by the introduction or removal of one species, the equilibrium is broken and a different one has to be found.

The fact that evolution is an emergent property of living systems can be confirmed in the processes of cultural evolution: similar to a biological species, a culture is a group of individuals (normally we apply this to humans, but there are other animals who also have cultures) who share a series of customs, knowledge and narratives. Cultures grow, like species, by the reproduction of their members, but they can also assimilate members of other cultures. This means that the spread of the culture can happen within a generation, because it does not require the replacement of the individuals as in the case of the spread of species. This assimilation process defines, in fact, a competition among cultures: in the border between two cultures, individuals will have an incentive to embrace one or the other depending on how well they suit their goals. This is the measure for the evolutionary success of a culture.

Photo: David Wilson

But cultures thrive or dwindle in our society and as the society evolves through political or technological advances, so change the cultures as well. They can adapt by adopting new beliefs or leaving behind old ones to stay in tune with the zeitgeist. Cultures who insist on traditionalism are very often subject of fractious fights between the members who want to stay and those who are attracted by outside cultures, like the cases of the Amish or the Hasidic Jews in the US, or the Taliban in Afghanistan just to name a couple. When life under these cultures is significantly harder than in the surrounding culture many members are faced with the decision of enduring the culture and staying with their families or renounce the culture and leave their family behind. The fact that all these cultures still survive means that they are efficient enough at counteracting these defections to keep their numbers. Of course, this does not say anything about their resiliency (or even their ability to spread) if the environment changes.

One remarkable feature is the clash between biological and cultural evolution: because biological evolution is basically a biochemical process, it has no goals, no moral and no ability to plan for the future. Cultures, on the other hand, being formed by the share beliefs of all its members, do have all of these. One of the most emblematic examples of this class is the One-child policy introduced in China following the Cultural Revolution to avoid straining the productive resources of the country. Left to the mindless forces of biological evolution the people of China would have kept having several children per family, most of which would have been destined to starvation. Instead, the political decision makers established a culture where the natural forces were overpowered to ensure the survival of the culture. It is not entirely unthinkable that, given sufficient time, humans could have evolved so that women had a significantly shorter fertile life, thus limiting our ability to increase our numbers. However, this would have probably taken hundreds of thousands of years and cost great sufferings to billions of people who would have lived miserable and unusually short lives, so in a sense it is a great advantage to have cultures that help guide our destinies in a more fruitful way.

The big question now is if we will be able to adapt our cultures to the challenges of globalization and climate change. If we hide inside our shell like a tortoise and fail to find a solution, biological evolution will eventually kick in and force us to adapt or die, but the path will undoubtedly be very painful for many. Hopefully, we will be able to define joint goals, morals and plans so that we do not get to that. Have a nice weekend.