Rainforest Flies May Evolve to Survive Changing Climate and Drier Conditions

Evolution is a powerful force, and could allow species to adapt to changing conditions that are brought on by climate change. Now, scientists have taken a closer look at some tropical species and have found that rainforest-restricted flies may actually be able to avoid extinction by evolving.

"Whilst many believe some species have the evolutionary potential to adapt, no one really knows for sure, and there are fears that some could become extinct," said Belinda Van Heerwaarden, one of the researchers, in a news release.

In order to see whether tropical flies native to Australian rainforests could adapt to changing conditions, the researchers collected these insects and then exposed them to very dry conditions. This mimicked the effects of potential climate change.

In the original experiment, the flies died within hours and despite rescuing those that survived the longest and allowing them to breed, the flies were no more resistant to change. Then, the scientists changed the conditions from 10 percent to 35 percent humidity, which is a more realistic change.

"In our test we decreased the humidity to 35 percent, which is much more relevant to predictions of how dry the environment will become in the next 30 to 50 years," said Van Heerwaarden. "We discovered that when you change the environment, you get a totally different answer."

While most of the flies died just after 12 hours, some survived. The ones that survived were allowed to breed and after just five generations, one species evolved to survive 23 percent longer in 35 percent humidity.

"Tropical species make up the vast majority of the world's biodiversity and climactic models predict these will be most vulnerable to climate change," said Carla Sgro, one of the researchers. "However these models do not consider the extent to which evolutionary response may buffer the negative impacts of climate change."

The findings reveal that tropical species may be able to adapt to changing climate conditions. This is hopeful news for the future as tropical forests become drier and as environmental conditions continue to shift.

The findings are published in the journal Proceedings of the Royal Society B.