According to the study, the genetic evidence was consistent with both scenarios, suggesting that both ice age climate changes as well as flooding of the Amazon basin could be responsible for generating diversity in leafcutter ants.
The authors rejected the idea, previously suggested by other scientists, that rivers play a role in generating diversity in the Amazon basin by separating populations that live on either side. According to the study, even the Amazon riverwhich at places is nearly 2 miles widehas not kept winged leafcutter ant queens and males from flying across it.
"It is interesting that Amazonian rivers acts as barriers to some birds, but these ants are apparently able to cross them," said Solomon.
According to the authors, the idea that refugia were responsible for generating species diversity in the Amazon has been heavily criticized. However, the new findings suggest that the refugia theory may need to be reevaluated.
"Even though we found support for the refugia hypothesis, our results suggest that climate changes had a different effect on each species, even though they are very closely related. This goes against the way people have thought about refugia in the past, and it highlights how difficult it is to generalize when it comes to making predictions about how climate change affects species," said Solomon.
|Contact: Scott E. Solomon|
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