By Victoria Gill
Science reporter, BBC News
The results could help explain why the warm tropics are so species-rich
Climate could have a direct effect on the speed of “molecular evolution” in mammals, according to a study.
Researchers have found that, among pairs of mammals of the same species, the DNA of those living in warmer climates changes at a faster rate.
These mutations – where one letter of the DNA code is substituted for another – are a first step in evolution.
The study, reported in Proceedings of the Royal Society B, could help explain why the tropics are so species-rich.
DNA can mutate and change imperceptibly every time a cell divides and makes a copy of itself.
But when one of these mutations causes a change that is advantageous for the animal – for example, rendering it resistant to a particular disease – it is often “selected for”, or passed down to the next few generations of that same species.
Such changes, which create differences within a population but do not give rise to new species, are known as “microevolution”.
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