The study of evolution has a deeply fascinating and complex history. A notable example is the debate between French zoologist Jean-Baptiste de Monet Lamarck, who came up with the theory of Lamarckism in 1809, against that August Weismann, who developed the Germ Plasm theory in 1883. Lamarckism was centered around the “use and disuse” of organs – Lamarck believed that giraffes had long necks because they kept stretching their necks to reach foliage on higher branches of tall trees when vegetation on lower levels had run out. However, Weismann conclusively disproved Lamarck with an experiment where Weismann cut off the tails of more than sixty rats at birth, yet on breeding the rats for up to five generations, no “tail-less” rats were born. Weismann, therefore, claimed that evolution was not about external characteristics, but about the “germ plasm” within, which dictated heredity and evolution.

It was right at this juncture that Charles Darwin, in his famous work On the Origin of Species published in 1859, propounded the theory of natural selection. Darwin has attributed the title of ‘Father of Evolution’ and Darwinism is now the most accepted theory that explains our evolutionary process as that which “selects” the “fittest” population, which has the most reproductive potential to continue generations of life on earth. However, even now, there are many evolutionary questions that remain unanswered. Recent theories indicate that evolution is not as linear as evolutionary biologists believed for so long. In fact, anthropologists are now advocating that cultural processes also play a crucial role in the evolutionary process.

It is here that the concept of “social learning” gained importance. It is believed that acts of learning and cooperation picked up by our early human ancestors when they transitioned from an isolated, nomadic life to living in groups, spawned important innovations which could effectively deal with external constraints such as disease, or extreme climate. Therefore, humans no longer needed to evolve against such difficult externalities. Instead, they could focus on more effective strategies such as building tools and weapons, hence the name Homo habilis translating to “handy man”. This is correlated to the timeline of humans evolving to become bipedal from quadripedal – from Homo habilis to Homo erectus (“upright man”) – in order to use said tools and weapons more effectively. As the movement became facilitated, and more protection from predators was afforded, the human species began to push their territorial boundaries. The Homo habilis moved to colder regions. Old evolutionary theories would have us believe that our ancestors would have to develop a layer of thick fur to adapt to a colder climate. But anthropologists now believe that social learning resulted in Homo habilis building fires and making clothes, making survival possible in a non-tropical climate. These skills were even more refined by the Homo neanderthalensis, as sophisticated tools made of bones and stone have been discovered in Neanderthal excavation sites. Moreover, evolutionary anthropologists also link the growing size of the human brain to the cultural processes followed by Homo neanderthalensis, who have been proven to have developed rituals involving elaborate paintings, and systematic burials of their dead, which indicate advanced cognitive development and the birth of a complex thought process.

Another important example of cultural processes influencing evolution can be seen in the development of language. This is also linked to the formation of complex cognitive thought. Starting from mere vocal sounds to the creation of a complex system of conveying thoughts in order to effectively communicate with other members of a species is perhaps the biggest indicator of how cultural processes aided in the sharing of information which changed the trajectory of evolution as it ensured the passing down of social learning to subsequent generations. In fact, Darwin himself seemed to be aware of this link between evolution and the cultural process of language, as he wrote: “The formation of different languages and of distinct species, and the proofs that both have been developed through a gradual process, are curiously parallel.” 

Evidently, it is not without reason that the latest advances in the field of evolutionary biology show that it is important to rethink the theories of Darwin. The evolutionary process cannot be reduced to a binary of whether the outside environment or the genes within determine how we evolve. Clearly, the bigger ideas of Lamarck and Weismann are not to be completely discarded, as anthropologists are opening up the idea of a link between the idea of “use and disuse” to the theories of inheritance explained by geneticists. Newer ideas in the field of molecular anthropology, which advocate for “gene-culture coevolution” are surely the latest developments to watch out for.