Why are there so many species in the world? Even Charles Darwin had difficulty answering that question. Now a University of Ottawa researcher has taken a step towards solving the mystery.
Rees Kassen, a professor in the Department of Biology and a member of the Centre for Advanced Research in Environmental Genomics, along with colleagues from Oxford University, have been studying adaptive radiation – the process by which new species arise from a common ancestor to fill novel ecological roles.
Working with a bacterium – Pseudomonas fluorescens – Kassen's team challenged the theory that more species would evolve when there are plenty of resources in the environment and the population is left relatively undisturbed. Instead the researchers found that diversity peaked when the rate of population disturbance and the amount of resources were both at an intermediate level.
The results, which were published in the October 21, 2004 issue of Nature, are important because they represent a first attempt at understanding what ultimately governs the number of new species that arise out of an adaptive radiation.
