Darwin and natural selection: are we still evolving?

“A good definition of culture could be: anything that curbs natural selection.” This is according to Jaume Bertranpetit, researcher at the Institute for Evolutionary Biology (CISC-UPF) in Barcelona and co-leader of this B·Debate session with Elena Bosch. If natural selection is the basic mechanism behind evolution as proposed by Darwin, and if human beings are deeply immersed in what we call culture, the question is: are we still evolving?

The short answer is yes, at least if we take into account the past thousands of years. Examples of genetic adaptations after the first humans left Africa can be seen in lighter skin tone to improve vitamin D production, ability to digest milk throughout our lives and certain populations’ adaptation to higher elevations. New genetic tools are making it possible to explore other changes not by observing traits but through the marks natural selection leaves on the genome.

To discuss the latest advances in this field, several top international experts met for the debate entitled ‘Natural Selection in Humans: Understanding our adaptations’, organized by B·Debate –an initiative of Biocat and the “la Caixa” Foundation to promote scientific debate– and the Institute for Evolutionary Biology (CSIC-UPF) and Pompeu Fabra University (UPF).


  1. Genetic tools are allowing us to disentangle the marks left by natural selection in humans over the past thousands of years.

  2. Some of the more recent changes include lighter skin tone to take advantage of sunlight and adapting to life at higher elevations or specific diets.

  3. The immune system is one of the parts of the body that shows the most variation among populations, and could explain differences in response to infectious diseases, which varies widely in time and space, and in the frequency of autoimmune diseases.

  4. There are traits that seem to be changing, like a tendency to be taller. However, scientists doubt this is a mechanism of natural selection.