On the Relevance of Natural Selection in Humans


Over recent centuries, it would seem that humans have overcome many of the limitations imposed by the slow process of natural selection. By conquering many diseases and improving the safety of our living environments, the average life expectancy of humans across the world is at an all time high1:

I believe that natural selection in humans will become increasing irrelevant as time passes. Many of the improvements in our living conditions over the past few millennia have been brought about via applications of the human mind to solving problems. It is almost as if designing a sophisticated brain was natural selection’s last triumph: a means to surpass itself! Since then, humans have developed a form of intelligence hitherto unseen in any other creatures. While some creatures may display a certain degree of ingenuity(such as ants domesticating aphids), it is nowhere close to human levels of creativity.

Consider the wheel, and how it could result from evolution. While this is a concept that has been explored in fiction(the Mulefa from the His Dark Materials trilogy), no animal has actually evolved a wheel. This is because evolution is inherently an incremental process. The evolution of a certain trait or body part proceeds only if most of the intermediate steps of the evolution also benefit the organism. An incomplete wheel, however, is completely useless. The entire wheel must be constructed: smooth, round and with an axle to rotate about. Natural selection cannot give rise to such a structure2.

An artist's depiction of the Mulefa

An artist's depiction of the Mulefa ©2008-2018 JamesMargerum

Going back a couple of decades, the internet was invented. This has grown today to encompass almost the entire world: billions of interconnected computers! People have access to the ideas and creations of people on the other side of the world. In effect, the internet is a giant nervous system that spans the entire globe! Would natural selection have evolved such a contraption? Possibly, but it would be very slow: considering the billions of years it took to construct a nervous system for single organisms. The closest analogue in the animal kingdom is animals communicating using subsonic audio signals across huge distances. This has been observed in elephants and blue whales(blue whales had an acoustic range of 1600km in 1940!3).

Some diseases, like smallpox, have been completely eradicated. Others, such as malaria, are in the process of being eliminated. In 2015, there were around 212,000,000 cases of malaria, and 429,000 deaths from the same4. And since 2015, the number of malaria cases have, unfortunately, been rising5, giving rise to notions that the parasite may be becoming more resistance to medication. Malaria is spread by certain types of mosquitoes. There are organizations in the world that are dedicated to engineering genetically modified insects to weaken the species as a whole. In the case of mosquitoes, Oxitec is creating genetic variant of mosquitoes that will breed with the existing mosquitoes, passing on a gene that will prevent offspring from living until adulthood. This is a very recent example of humans using their technological prowess to rise above the limitations of nature. CRISPR-Cas9 is a tool used by geneticists to modify DNA. In the future, we can imagine entire swaths of genetic diseases in humans being eliminated!

My point is not to look down upon natural selection. Natural selection has created many wonderful ecosystems that thrive even in harsh environments. A notable example is the bacteria that can survive on volcanoes6. Natural selection has bestowed upon us a complex arrangement of specialized organs: we possess an elegant circulatory system that pumps blood to all our extremities, a strong skeletal system that helps us locomote and survive various levels of shock, and a wonderful brain to manage the other systems as well as partake in creative endeavours, among other things. My point is, that in the recent past and in the future, it will be ideas, and the subsequent materialization of these ideas that drive forward progress and aid the survival of the species.