Humans just as vulnerable to climate change as other animals, study finds

Humans may be just as vulnerable to changes in the environment – including those caused by the climate crisis – as other animals, according to a new study that assessed genetic data from the past 45,000 years.

The research, published on Monday in the journal Nature Ecology & Evolution, suggests that the ability of humans to use tools and technology to adapt has not been enough to survive when environmental conditions changed drastically in the past.

In the study, scientists, including Yassine Souilmi from the University of Adelaide in Australia, looked for traces of “hard sweeps” in ancient and modern human genomes.

Hard sweeps are rare genetic variants that rapidly spread through a population most likely after environmental condition changes that wipe out those lacking the variant.

These environmental changes are drastic events in which a set of genes harbouring selectively advantageous traits rise in frequency.

While genomes of ancient humans have played a major role in the adaptation of various populations to different environmental conditions such as the frigid regions of the Arctic to humid tropical rainforests, humans have also relied on cultural innovations such as fire and clothing to survive in different environments.

However, the new study – which considered the genomes of over a thousand humans spanning 45 millennia – suggests these cultural innovations may not have always helped people cope with new environments.

While previous research has found hard sweeps and adaption in many animals, researchers say little evidence of such events has been discovered in human genomes.

Previous research has speculated that such genetic adaptations could be rare in humans because cultural innovations rendered them largely unnecessary.

The latest research applied DNA analysis techniques to scan over a thousand ancient human genomes from across Eurasia and found that hard sweeps were indeed part of human genetic adaptation.

This finding suggests humans may not be very different from other animal species in how we adapt to the changing environment.

Based on the results of the study, scientists say hard sweeps may be more common across human populations than currently thought.

“Overall, we may have a biased view of how species have genetically adapted to environmental pressures,” the scientists write in The Conversation.

The researchers called for the development of new methods to analyse signals of hard sweeps and other selection events in ancient and modern humans.