Human Evolution: Natural Selection Is Still at Play, Evolutionary Biomechanist Says

Are humans still evolving? Some believe that evolution has already stopped, but experts suggest otherwise.

Human Evolution Is Still Affecting Species

It's a common misconception that humans nowadays are not progressing. Still, most scientists today agree that evolution continues to impact our species. One expert said this process is happening "more rapidly" than it has in the past.

Scientists believe biological adaptation has not been superseded by technological and cultural advancements, even though these innovations currently seem to be the primary forces behind adaptation for modern humans.

"I don't think [the question of whether humans are still evolving is fully appreciated by the general public," said Michael Granatosky, an evolutionary biomechanist at the New York Institute of Technology. "Perceptions of evolution tout the phrase 'survival of the fittest,' which automatically recalls epic battles between fighting individuals vying for a mate, or a ragtag bunch of animals surviving a cataclysmic event beyond all odds."

It is easy to presume that selection pressures are no longer present in current populations. But evolution is only the modification of a population's gene pool across multiple generations, the expert added. Given this more expansive interpretation, he doesn't think there is much disagreement among evolutionary biologists over the fact that humans are still evolving, Granatosky said.

Nick Longrich, a paleontologist and evolutionary biologist at the University of Bath in the United Kingdom, agreed that humans still evolve. He said evolution was a thing from 2020- to 2023, but its effects would not be that noticeable until after 50 years.

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How Natural Selection Is At Play Today?

Humans are "undoubtedly" still developing since natural selection and genetic drift are still impacting our species, according to evolutionary scientist and anthropologist Jason Hodgson of Anglia Ruskin University in the United Kingdom. As in all biological groups, genetic drift affects the frequency of alleles, or distinct variations, of a particular gene.

The number of persons counted in the human census has topped 8 billion. This population size should have very little genetic drift. But, according to Hodgson, humans are organized into much smaller groups, where individuals are more likely to select their partners.

"This means that in practice, evolution occurs in much smaller groups, and genetic drift does still operate," he said.

As for natural selection, it reportedly causes gene frequencies that are not random. However, some versions become less frequent as the preferred form increases.

"The ultimate fate of a variant evolving through natural selection is to replace all other variants in the population," Hodgson said. "Perhaps counterintuitively, natural selection is a stronger force in larger populations. This is because in large populations, selection is not countered by genetic drift."

Natural selection is observed in humans with resistance to vivax malaria in Madagascar. The COVID-19 pandemic also showed how natural selection was at play depending on how individuals respond to the virus.

Granatosky added that the variation was the "basis for evolution." However, COVID-19 stood out because it was a global pandemic, and such an event rarely affected the entire species.