On the expansion threshold of a species` range
(PHYSorg.com Biology)

What stops a species adapting to an ever-wider range of conditions, continuously expanding its geographic range? The biomathematician Jitka Polechová, an Elise Richter Fellow at the University of Vienna, has published a paper in PLoS Biology which explains the formation of species` range margins. The theory shows that just two compound parameters, important for both ecology and evolution of species, are fundamental to the stability of their range: the environmental heterogeneity and the size of the local population.