We’re evolving right now: scientists see how our genome is changing in recent history

A new study from Europe has identified 755 traits that have changed in the past 2-3,000 years of human evolution. These traits are linked with things like pigmentation, nutritional intake, and several common diseases or disorders.

We sometimes tend to think of humans as the pinnacle of evolution, the tip of the biological pyramid. Not only does that show just how self-centered we humans can be, but it’s not really correct either. Even if it were to be the case, it’s not like evolution has stopped — it’s happening right as you’re reading this.

Natural selection (the process through which individuals better adapted to an environment are more likely to reproduce) isn’t just happening in the animal world, it’s happening for humans too. Granted, the pressures that drive this can be quite different, but the process is taking place nonetheless — and it’s been happening since the dawn of human history.

Understanding the patterns behind our past and present evolution isn’t just a scientific curiosity, it could have important applications in the field of medicine and human biology.

“The genetic architecture of present-day humans is shaped by selection pressures in our history. Understanding the patterns of natural selection in humans can provide valuable insights into the mechanisms of biological processes, the origin of human psychological characteristics and key anthropological events,” the researchers write in the new study.

The shells of individuals within a bivalve mollusk species showing diverse coloration and patterning in their phenotypes. Image credits: Debivort.

The team, led by Weichen Song  from Shanghai Jiao Tong University School of Medicine, sequenced modern human genetic data from the UK Biobank, along with ancient human DNA from across Europe. They analyzed 870 polygenic traits — traits whose phenotype (the set of observable characteristics or traits of an organism) is influenced by more than one gene, comparing differences between the old and the new genetic groups.

They found that 88% of these traits (755) underwent significant change in the past 2-3 thousand years. Some of these findings were linked to pigmentation, body size, and nutritional intake.

“One of our most interesting results was the finding that pigmentation, body measurement, and dietary traits were continuously under intense selection pressure across various human development timescales,” the study also reads.

However, researchers caution that their findings are limited exclusively to European data, and it’s not clear if there is a cause-effect between the associations between genetic variants and phenotype.

“In sum, we provide an overview of signals of selection on human polygenic traits and their characteristics across human evolution, based on a European subset of human genetic diversity. These findings could serve as a foundation for further populational and medical genetic studies,” the researchers write.

Nevertheless, this could serve as a foundation for larger, wider studies, aiding future research into human genetics and evolution.

The study “A selection pressure landscape for 870 human polygenic traits” was published in Nature Communications.

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