Humans are not a patient species, and we often sacrifice our future fitness for present success. Natural selection is a process that takes place over many generations, but our egocentric nature warrants that we think only in the short term, to the detriment of both our descendants and the species in general.
Not content with evolving a thicker layer of subcutaneous fat to combat cold, or paler skin to improve Vitamin D biosynthesis, we have begun to control our environment to solve these problems in the short term. We have developed clothes to reduce heat loss by convection and radiation, and have developed artificial means of Vitamin D synthesis.
In a sense we are ignoring selective agents on an evolutionary scale, and thus natural selection no longer ‘rewards’ favourable genes. It rewards our ability to look after ourselves and adapt in a short term, cultural manner.
By tracing the origins of humanity, we should be able to determine the chapter in our history where the primary method of adaptation changed from biological to cultural evolution. From fossil records, we can ascertain that our ancestors 40,000 years ago would be virtually inseparable in appearance to contemporary humans.
These ‘Cro-Magnon people’ lived primarily in Europe, and although the human species has now filled most niche’s on Earth, the basic appearance remains constant. This lends evidence to the fact that we have pinpointed the moment in our history where we began to evolve culturally to our environment, rather than evolving biologically as a product of natural selection.
In this epoch prehumans began to control the necessities of life. They hunted game to provide food, used the skins to form shelter and clothing and used ivory to form tools. They had solved the problem of food and had developed ways to minimise the impact of their environment using shelter. Importantly, the permanency of dwellings and the improvement in tool efficiency shifted the focus from food collection to cultural pursuits (Newton and Joyce: 1979). We no longer had as great a need for selection of favourable biological traits. Natural selection now acted on our ability to make tools and extract more from the environment than our competitors.
“This does not mean that biological evolution ended. On the contrary, it remained as important as ever. It simply altered direction. The emerging human body evolved to fit its ecological niche, to survive as a living creature. The emerging human mind now evolved to fit its cultural niche, to survive as a social creature.” (Leakey, 1978).
