University College London scientists say they've found why so many species of butterflies live in Central and South America, as compared with other places.
Tropical areas of south and central America, such as the Amazon rainforest, are home to some 7,500 species of butterfly, compared with only around 65 species in Britain.
The UCL scientists say they ruled out the common theory that attributes the difference to climate. Instead, they believe biology played a far greater role than external factors.
"Different types of rainforest butterflies in the Amazon basin are evolving at very different rates, not at all the pattern expected if forest refuges during the ice ages were causing the origin of new species," said UCL Biology Professor Jim Mallet, who led the research. "Instead, we think idiosyncratic features of the biology of each species, such as competition for food and their individual reactions to the environment, dictate the pattern of evolution in each group."
The research is detailed in the Dec. 7 issue of the Proceedings of the Royal Society B.
Copyright 2005 by United Press International
