April 2, 2009

Evolution’s impact on ecosystems confirmed

Canadian scientists say they have conducted the first experiment that shows the evolution of new species impacts the environment.

Scientists at the University of British Columbia created mini-ecosystems in large aquatic tanks using different species of three-spine stickleback fish and saw substantial differences in the ecosystems within 11 weeks.

Stickleback fish originated in the ocean, but began populating freshwater lakes and streams following the last ice age. The researchers said that during the past 10,000 years -- a relatively short time span in evolutionary terms -- different species with distinct physical traits have emerged in some fresh water lakes.

The UBC study involved new species found in British Columbia lakes -- limnetic sticklebacks that have narrow mouths, benthic sticklebacks with a wide gape and a generalist species to represent the probable ancestor of the two species.

Simply by what they eat and how they live, even young species that have 'recently' diversified can have a major impact on their food web, says study lead author Luke Harmon, who conducted the study while a UBC post-doctoral fellow. He is now an assistant professor at the University of Idaho. This study adds to a broader body of literature showing that species diversity matters in important ways.

The research that included co-author Professor Dolph Schluter is reported in the early online edition of the journal Nature.