Saturday, April 23, 2005
Fly Sheds Light on Birth of New Species
A unique fly from the Canary Islands has helped shed light on one driving force behind the birth of new species, Nature magazine reports this week.
"Imagine you have an island colonised by 100 species and a similar island colonised by 10 species," explained Dr Emerson. "If you leave that for a period of evolutionary time, the percentage of entirely new forms will be higher on the island with 100 species on it."
This research could help explain why islands in warm areas have a lot of unique speciesThe researchers can think of three reasons why this might be the case. First, species that are forced to share a space with a lot of other species usually have smaller population sizes. That means they are more susceptible to genetic drift, which can speed up speciation.
Secondly, islands with a rich biodiversity have more habitat complexity. In other words, instead of just one habitat - say, grass - there is, for example, grass, shrubs and trees. That means species are more likely to evolve new adaptations and, eventually, become different species.
Thirdly and, the researchers believe, most importantly, competition between species can encourage speciation.
