Animals could be evolving much faster than we thought. This is the conclusion reached by a team of scientists who have analyzed for years how the genes of a series of wild animals have varied.
What happens at the genetic level is that the more genetic differences there are within the same species, the faster its evolution will be . Certain traits will disappear and stronger ones will remain. Researchers call this phenomenon “the fuel of evolution.” Well, the analysis of the data has revealed that this fuel is more abundant than previously estimated and, consequently, the speed with which animals evolve should be reconsidered, something of great importance in the context of climate change in which we are immersed.
“The method allows us to measure the potential speed of current evolution in response to natural selection across all traits in a population,” says evolutionary ecologist Timothée Bonnet of the Australian National University, who was involved in the study. “This is something we haven’t been able to do with previous methods, so to be able to see so much potential change was a surprise to the team.”
The superb wrasse ( Malurus cyaneus ), a small bird endemic to southeastern Australia and Tasmania; the spotted hyena ( Crocuta crocuta ) from Tanzania; the song sparrow ( Melospiza melodia ) from Canada and the red deer ( Cervus elaphus ) from Scotland are some of the wild animals studied.
On average each field study has lasted 30 years. Details of births, deaths, mating and offspring have been recorded. The shortest field study lasted 11 years and the longest 63 years. The researchers obtained a total of 2.6 million hours of field data to combine with the genetic information of each animal. It took three years to quantify the changes that occurred in the species and that were caused by genetics and natural selection. If Charles Darwin initially pointed out that evolution was a very slow process, the truth is that, according to previous research, there are species that can evolve in a matter of a few years .
“A common example of rapid evolution is the pepper moth , which before the industrial revolution in the UK was predominantly white,” says Bonnet. “With pollution leaving black soot on trees and buildings, black moths had a survival advantage because they were harder for birds to detect […] As the color of the moths determined the probability of survival and was due to genetic differences , the populations of England were quickly dominated by black moths”.
Scientists point out in their study that there is more “evolutionary fuel” than previously believed, but there is still not enough evidence to show that species are evolving at a faster rate than in the past.
Knowing more about how quickly animals adapt to existing climatic conditions is important to get an idea of which species will survive and which will disappear . There is concern that as changes in climate accelerate, animals may not be able to adapt in time.
“This research has shown us that evolution cannot be dismissed as a process that allows species to persist in response to environmental change,” says Bonnet. “What we can say is that evolution is a much more important driver than we thought in the adaptability of populations to current environmental changes.”
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Reference:
Bonnet, T. et al. Genetic variance in fitness indicates rapid contemporary adaptive evolution in wild animals. 2022. Science. DOI: 10.1126/science.abk0853
