Evolution could be taking place four times faster than previously thought

A moth well-studied for the relative abundance of light and dark forms in areas polluted by industry.
Pepper moths evolved light and dark forms in areas polluted by industry. (Getty)

The 'fuel' for evolution is much more abundant in wild animals than previously believed, according to scientists.

This could help to explain why some species – such as moths – have evolved incredibly rapidly to adapt to industrial changes.

It also offers hope that species could similarly evolve rapidly to adapt to climate change, researchers at Australian National University (ANU) said.

The fuel of evolution is the amount of genetic differences there are in a species, the scientists – who studied 19 wild animal groups around the world – said.

This allows evolution to happen faster as some traits die off and others are established.

The international research team, led by Dr Timothee Bonnet at ANU and which included staff at University of Exeter, wanted to know how much of this "fuel of evolution" exists in wild animal populations.

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The amount of fuel is two-to-four times more than previously thought.

Bonnet said that the process of evolution that Darwin described was an incredibly slow one.

"However, since Darwin, researchers have identified many examples of Darwinian evolution occurring in just a few years,” he said.

"A common example of fast evolution is the peppered moth, which prior to the industrial revolution in the UK was predominantly white.

"With pollution leaving black soot on trees and buildings, black moths had a survival advantage because it was harder for birds to spot them.

"Because moth colour determined survival probability and was due to genetic differences, the populations in England quickly became dominated by black moths."

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The study is the first time the speed of evolution has been systematically evaluated on a large scale.

The team of 40 researchers from 27 scientific institutions used studies of 19 populations of wild animals from around the world.

These included superb fairy-wrens in Australia, spotted hyenas in Tanzania, song sparrows in Canada and red deer in Scotland.

“We needed to know when each individual was born, who they mated with, how many offspring they had, and when they died," Dr Bonnet said.

"Each of these studies ran for an average of 30 years, providing the team with an incredible 2.6 million hours of field data.

"We combined this with genetic information on each animal studied to estimate the extent of genetic differences in their ability to reproduce, in each population."

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After three years of trawling through reams of data, Bonnet and the team were able to quantify how much species change due to genetic changes caused by natural selection.

Bonnet said: "The method gives us a way to measure the potential speed of current evolution in response to natural selection across all traits in a population.

"This is something we have not been able to do with previous methods, so being able to see so much potential change came as a surprise to the team."

Professor Loeske Kruuk, also from ANU and now based at University of Edinburgh, said: "This has been a remarkable team effort that was feasible because researchers from around the world were happy to share their data in a large collaboration.

"It also shows the value of long-term studies with detailed monitoring of animal life histories for helping us understand the process of evolution in the wild."

However, the researchers warned that it's too early to tell whether the actual rate of evolution is getting quicker over time.

“Whether species are adapting faster than before, we don't know, because we don't have a baseline," Bonnet said.

"We just know that the recent potential (the amount of 'fuel') has been higher than expected, but not necessarily higher than before."

According to the scientists, their findings also have implications for predictions of species' adaptability to environmental change.

"This research has shown us that evolution cannot be discounted as a process," Bonnet said, "which allows species to persist in response to environmental change."

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