November discussion - Are humans still evolving?

Are humans still evolving? It’s an important question, with our modern lifestyles, healthcare and technology there is seemingly no need to change ourselves even with the world changing around us. For many species, evolution cannot come fast enough, polar bears are losing hunting grounds, deserts are getting drier, more land is flooding and that’s before looking at trials faced by insects such as bees.

The thoughts are that humans are indeed still evolving just very slowly and in ways that are not as easily observed. For example, the brain gene Microcephalin (MCPH1) which regulates brain size has been found to still be evolving in modern humans (Patrick et al, 2005). A sure sign that as our world changes we are likely having to adapt through the use of our brain rather than physical attributes.

Originally many high latitude countries were populated by those with high levels of melanin (skin pigment) which then reduced leaving most with pale skin. As the climate changes and countries such as the UK are subject to increased levels of strong sunlight, which is a regulator of skin pigmentation (Parra, 2007) higher latitude countries may slowly shift back to darker skin.

Whilst physical changes may or may not occur in human futures it is widely thought that cultural evolution has now replaced evolution based on biological characteristics (Dyson, 2007, Ward, 2001). White (1959) describes cultural evolution as behaviour which has been learned or adaption outside of the body of a non-biological nature. As adaption is simply a mechanism which allows the individual to cope with the stresses of their environment. It is therefore, understandable that given the more sociable and cultural nature of modern society most of the modern humans’ evolution is cultural.

It can therefore be concluded that whilst human evolution in the traditional sense is limited, we are as a species still adapting and evolving to our environment. Whether this is to cultural changes or to disease (see Stock, 2008 for more information on disease evolution influence) the human form is still far from final.

What do you think? Are the changes we as a species are experiencing would/ should be considered as evolution? Or are they merely adaptations of a generation which will be lost in the next? Discuss in the comments, all opinions are welcome but remember there may be young readers so keep language clean.

References

Dyson F. 2007. The era of Darwinian evolution is over. New Perspect Q 24: 58–59

Parra, E.J., 2007. Human pigmentation variation: evolution, genetic basis, and implications for public health. American Journal of Physical Anthropology: The Official Publication of the American Association of Physical Anthropologists, 134(S45), pp.85-105.

Patrick D. Evans, Sandra L. Gilbert, Nitzan Mekel-Bobrov, Eric J. Vallender, Jeffrey R. Anderson, Leila M. Vaez-Azizi, Sarah A. Tishkoff, Richard R. Hudson, Bruce T. Lahn., 2005. Microcephalin, a Gene Regulating Brain Size, Continues to Evolve Adaptively in Humans. Science09 Sep: 1717-1720

Stock, J.T., 2008. Are humans still evolving?: Technological advances and unique biological characteristics allow us to adapt to environmental stress. Has this stopped genetic evolution?. EMBO reports, 9(1S), pp.S51-S54.

Ward P.,2001. Future Evolution. New York, NY, USA: Henry Holt

White L. A., 1959. The Evolution of Culture. New York, NY, USA: McGraw‐Hill