Ellen Phiddian
Cosmos science journalist
Human activities have caused a type of insect to change colour in Aotearoa New Zealand, according to a new study.
The research, published in Science, shows that stoneflies have been driven to change their hue by deforestation.
“In natural forested regions, a native species has evolved ‘warning’ colours that mimic those of a poisonous forest species, to trick predators into thinking they are poisonous too,” says study co-author Professor Jon Waters, from the department of zoology at the University of Otago, Aotearoa New Zealand.
“But the removal of forests since humans arrived has removed the poisonous species. As a result, in deforested regions the mimicking species has abandoned this strategy – as there is nothing to mimic – instead evolving into a different colour.”
The finding reflects one of the most famous evolutionary observations – the evolution of peppered moths in the UK following the industrial revolution.
The common tale says that black moths suddenly became the more favourable phenotype, because they could camouflage better against smoke-stained trees.
But the actual story is more complicated. The researchers say that their finding is a neater example of human-driven rapid evolution.
“This study is important because it shows that, at least for some of our native species, there is the possibility of adapting to the environmental changes caused by humans, even when the change is rapid,” says co-author Dr Graham McCulloch, also at the University of Otago.
“It also shows that independent populations have undergone similar changes in response to deforestation – there have been similar shifts independently in different parts of the species’ range – showing that evolution can be a predictable process.”
