Flies change color in New Zealand due to human action

Oct. 25 () –

New Zealand native stoneflies have changed color in response to human-caused environmental changes, new research shows.

The study from the University of Otago, published in the journal Scienceoffers possibly the world’s clearest example of animal evolution in response to changes made by humans.

Professor Jon Waters, from the Department of Zoology and co-author of the study, says in a statement that the stonefly has changed 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 fool predators into believing it is also poisonous.

“But the elimination of forests since the arrival of humans has eliminated poisonous species. “As a result, in deforested regions, mimicking species have abandoned this strategy (since there is nothing to imitate) and have evolved toward a different color.”

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

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

But Professor Waters says even that case has been considered controversial. This new study shows how humans have changed the way native species interact.

Co-author Dr Graham McCulloch says humans have altered ecological interactions between species that 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, at least for some of our native species, there is the potential to adapt to environmental changes caused by humans, even when the change is rapid,” says Dr McCulloch.

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