Just three years after crayfish were introduced to a B.C. lake, two species of fish that had existed in the lake for thousands of years were suddenly extinct. But it’s what took their place that has scientists fascinated.

New research from UBC shows that when humans speed up the usually slow process of evolution by introducing new species, it can result in a lasting impact on the ecosystem. The phenomenon is known as reverse speciation and researchers witnessed it in Enos Lake on Vancouver Island where two similar species of threespine stickleback fish disappeared within three years.

“When two similar species are in one environment, they often perform different ecological roles,” said Seth Rudman, a PhD student in zoology at UBC. “When they go extinct, it has strong consequences for the ecosystem.”

More at Source: Humans speeding up evolution by causing extinction of ‘younger’ species | LifeSciencesWorld