Stoneflies have changed color due to human activity, a new study shows

New Zealand stoneflies have changed color in response to human-caused environmental changes, new research shows. Just published in the magazine ScienceThe University of Otago study provides perhaps the world’s clearest case of animal evolution in response to human change.

Co-author Professor Jon Waters from the Department of Zoology says the stonefly has turned a different color due to recent deforestation.

“In natural forest regions, a native species has developed ‘warning colors’ that mimic those of a poisonous forest species to trick predators into thinking they are also poisonous.”

“But deforestation since humans arrived has led to the disappearance of the poisonous species. As a result, the mimicking species in deforested regions have abandoned this strategy – since there is nothing to imitate – and have instead evolved to a different color.”

Scientists have long wondered whether humans cause evolutionary changes in natural populations.

The best-known example of human-caused evolution was the population of the peppered moth in the United Kingdom, which changed color in response to industrial pollution in the 19th century.

But Professor Waters says even that case was controversial.

This new study shows how humans have changed the way native species interact.

Co-author Dr. Graham McCulloch says humans have disrupted ecological interactions between species that have evolved over millions of years, but some of our native species are resilient enough to overcome this.

“This study is important because it shows that there is an opportunity for at least some of our native species to adapt to human-induced environmental changes, even if the changes occur quickly,” says Dr. McCulloch.

“It also shows that independent populations have undergone similar changes in response to deforestation – there have been similar changes independently in different parts of the species’ range – showing that evolution can be a predictable process.”