Evidence for speciation via mutation?

[bumab]

For what it's worth, the ring needs to be broken to truely create two distinct, genetically isolated species, however, since gene flow is still possible around the long way of the ring.

The biological species concept is difficult to define- interbreeding is convenient, but doesn't cover all the bases.

[Biochemist]

Originally Posted by TeleMad

Here’s a page that indicates DNA analysis confirms the above hypothesis, and also gives another example of a ring species: greenish warblers. http://www.actionbioscience.org/evolution/irwin.html

This is a great link, TM. It does not detail the genetics of the situation, but it does reference the journal article in Evolution that dug into it.

[Biochemist]

I pulled this link out of one of the trails off of TeleMad's link above.

http://www.pnas.org/cgi/content/full/94/15/7761#SEC3

These ensatina salamanders are really ineteresting, in that their home turf is surprisingly small (as small as 5 meters) and it looks like it seldom exceeds 60 meters for a entire individual's life. These guys are the new poster children for the couch potatos of the animal kingdom.

It certainly explains why the big salamander in my backyard was there for years. He was certainly a pleasant critter.

This makes allopatric speciation significantly more likely, since a short walk is the functional equivalent of a population boundary. The same is apparently true of the Ensatina in Costa Rica as in California, altough there is no ring-oriented geography in Cost Rica.

I think this is a really good example of allopatric speciaiton, but I still can't find any credible evidence of a mutative mechanism. This appears to be a cleaner example of speciation through genetic drift (i.e.,allele fixation and loss).