Ker Than (formerly of 3QD) in LiveScience.com:
Plants and animals living in warm, tropical climates evolve faster than those living in more temperate zones, a new study suggests.
The finding, detailed in the May 2 issue of the journal for the Proceedings of the National Academy of Sciences, could help explain why rainforests have such rich biodiversity compared to other parts of the planet.
A census of all the plants and animals around the world would reveal that species richness is uneven: it is highest in the tropics, the regions of Earth near the equator, and lower the closer one goes toward the planet’s poles.
To investigate the reasons for this trend, Shane Wright of the University of Auckland, New Zealand, and colleagues looked at the rate of molecular evolution for 45 tropical plants and compared it to that of related species living at more temperate latitudes.
More here.