Human Evolution Is Not Only Driven by Climate Change, Competition Plays a Part Too [Study]

Several factors affect human evolution. It was previously thought that climate change pushed humans to evolve, but researchers learned that competition was another factor.

Competition Is Also Part of Human Evolution

A new study from the University of Cambridge looked into human evolution. The researchers discovered that competition also played a part in why humans evolved.

"We have been ignoring the way competition between species has shaped our own evolutionary tree," said lead author Dr. Laura van Holstein, a University of Cambridge biological anthropologist from Clare College. "The effect of climate on hominin species is only part of the story."

Most other vertebrates have the trait of interspecies competition, which causes an evolution of species as each species adapts to occupy a new niche in the environment. But when every niche is taken, competition sets in, and this rapid evolution comes to an end.

Van Holstein says that the pattern we witness in many early hominins is the same as in all other mammals. Extinction rates begin to rise when speciation rates rise and subsequently plateau. This implies that a significant evolutionary element was interspecies rivalry.

But things became considerably more strange when van Holstein looked into the evolution of our own genus, Homo. The pace of speciation increased with the number of Homo species. Thus, something prompted the emergence of additional species after those niches were filled. According to the expert, this is nearly unheard of in evolutionary science.

Put another way; it seems that competition between distinct Homo species actually fueled the emergence of further Homo specie -- a total inversion of what one would anticipate from the history of the majority of other vertebrates.

Van Holstein, however, believes that it most likely has to do with the way we utilize technology.

"Adoption of stone tools or fire, or intensive hunting techniques, are extremely flexible behaviors," van Holstein said. "A species that can harness them can quickly carve out new niches, and doesn't have to survive vast tracts of time while evolving new body plans."

The capacity to employ technology enabled our predecessors to contend for resources and space in various markets, which probably fueled their rapid expansion. The development of Homo sapiens and the eventual extinction of all other Homo species may have been influenced by this greater tool use.

"These results show that, although it has been conventionally ignored, competition played an important role in human evolution overall," van Holstein concluded. "Perhaps most interestingly, in our own genus it played a role unlike that across any other vertebrate lineage known so far."

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Natural Selection Is Still at Play in Human Evolution

There's a widespread misperception that modern humans are not evolving. Nonetheless, the majority of experts nowadays concur that evolution still affects our species. This process is occurring "more rapidly" than it has in the past, according to one scientist.

Despite the fact that technological and cultural developments appear to be the main drivers of adaptation for modern people, scientists maintain that biological adaptation has not been surpassed by them.

According to evolutionary biologist and anthropologist Jason Hodgson of Anglia Ruskin University in the United Kingdom, humans are "undoubtedly" still evolving since genetic drift and natural selection are still affecting our species. Genetic drift influences the frequency of alleles, or unique variations, of a given gene, just like it does in all biological groups.

Over 8 billion people have been counted in the human census. There should be relatively minimal genetic drift in a population this large. However, Hodgson contends that humans are more likely to choose their companions because they are grouped into much smaller groups. This indicates that, in reality, genetic drift still happens and evolution takes place in considerably smaller groups, he added.

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