It's been long thought that species on islands evolve faster than on the mainland but it has never really been proven. Since it is published in PloS Biology it is an open access article so we all can read it! http://biology.plosjournals.org/perlserv?request=get-document&doi=10.1371/journal.pbio.0040321 See for instance the rate of evolution (in Darwins) compared to timescale in the figure below: Please Register or Log in to view the hidden image! Open circles are mainland species, closed circles island species. The island species all group together at one end of the figure. Faster evolutionary rates. discussion: So fast evolution in a very short time scale. The closing comment was quite interesting: Since mainland species have the intrinsic capability to evolve faster they could in theory be capabable of adapting to the current major changes in the environment. The question being of course if the changes do not occur too fast for evolution to keep up. I guess the authors assume that island evolution shows the fastest rate of evolution possible. Is that really the case? island colonizers end up in an environment they can cope with and they change to cope with it better. Could a rapidly changing environment induce more adaptive pressure even than an island environment?
I've been taught this many times and of course Darwin proved it, but as the author states: "faster evolution on islands holds over relatively short time scales." I think evolution is initially a function of density, but then once that density factor becomes saturated, you have to spread out geographically to increase diversity into different ecosystems. To me, the author seems to go off on a tangent in his concluding remarks. I don't understand how this "is relevant to our understanding of species' responses to isolation and destruction of natural habitats within the current context of rapid climate warming"? What do you conclude from this? Yes, there is a similarity between a destruction of habitat, leading to a fragmentation or isolation of the species habitat, but does this lead to faster evolution? No. In today's destruction of habitat it leads to extinction because the destruction is in the short term and the species has no time to evolve to adapt to it. Given that, I do not see how this study is of any relevance - or of any help? - to the destruction of natural habitats within the current context of rapid climate warming? Great post!
