Joined: Jan. 2006
|Quote (oldmanintheskydidntdoit @ Nov. 11 2011,10:55)|
|Yes, Ring species really are worth looking into in some detail.|
|Ring species provide important evidence of evolution in that they illustrate what happens over time as populations genetically diverge, and are special because they represent in living populations what normally happens over time between long deceased ancestor populations and living populations, in which the intermediates have become extinct. Richard Dawkins observes that ring species "are only showing us in the spatial dimension something that must always happen in the time dimension."|
Ring species also present an interesting case of the species problem, for those who seek to divide the living world into discrete species. After all, all that distinguishes a ring species from two separate species is the existence of the connecting populations - if enough of the connecting populations within the ring perish to sever the breeding connection, the ring species' distal populations will be recognized as two distinct species.
I'd take this opportunity to present my own kind of ring species, which actually isn't a ring in a geographical sense, but it presents a continuum between intraspecific and interspecific differentiation:
The pea aphid complex.
(sorry for the multiple posts, I'm late to the party).