Ring species as evidence for speciation

I would like to suggest the topic of ring species to be discussed. I did a search here, and only found two posts from back in 2002.Ring species are species that start at one area, with some individuals then migrating and adapting to new environments continuously, until they come full circle (around the globe, or around a mountain range or similar), and then have become a new species.In essense, it is the example of two species with all the transitional stages still living. It is a facinating issue and quite strong evidence for speciation, including the stages necessary for speciation to occur (mutations and natural selection as is the case with general evolution, and then also a form of separation while this occurs).There are several well-documented examples of this, notably a couple of Salamandar species in the US, who circled a mountain range, and also the European Herring Gull and Lesser Black-Backed Gull.

Thread moved here from the Proposed New Topics forum.

Yes, it is facinating. When a sub-species no longer produces a viable, repoductive offspring, then it is too late for a norma\you karcheologist. We are that sub-species. Forty years of desert will do that.

Its not that the subspecies no longer produces fertile offspring, it’s just that one subspecies evolves into another, with neither population going extinct. Both groups continue to produce viable offspring, but one group simply contains slightly different organisms from its parent.I'm from Fort Pierce, Florida, where a type of lizard called the Cuban anole (Anolis sagrei sagrei) is extremely common. They are an introduced species which seems to be forcing out the native species of lizards, green anoles (Anolis carolinensis) for example. Cuban anoles have been prevalent there for a few decades, according to my mother, who has lived in Fort Pierce for 50 years.Now I go college at UF, which is in Gainesville, about 200 miles north of Fort Pierce. I haven't seen many lizards around here, but all the ones I have seen are Cuban anoles with slightly different markings. They are a bit darker, and appear smaller as well. The few males I've seen lack crests, perhaps because they are not as healthy, or maybe for some other reason. There aren't nearly as many of them. Also, one morning I noticed one outside my window, and it looked much less jittery than the ones from Fort Pierce. They move much more slowly and deliberately.I think the reason for this is that the lizards here have begun to adapt to the slightly colder winters, and fewer of them can survive each year. They are not cold tolerant, and during the winter at night it sometimes gets into the 20s, while in Fort Pierce it rarely gets below 30, and I would imagine their native home of Cuba is even warmer, though I haven't looked it up. Gainesville is in a less tropical region than Fort Pierce, and it’s also farther from the coast, so the different environment appears to be having an effect on this species. I think that over time, they may be able to invade areas even farther north, where there may be more open niches for them. They eat insects, so if they can adapt to the cold, they will probably do well.My point is that they are evolving by a mechanism similar to that of ring species. Over just a few decades, Cuban anoles have spread hundreds of miles into a less favorable climate, and have begun to adapt to it through natural selection. Though they can probably still interbreed successfully with the anoles from Fort Pierce or even Cuba, they are already showing noticeable changes in their coloration and behavior, and I believe that if they are allowed to continue farther northward, they will be less able to interbreed with the parent population in Cuba.If anyone would like to see pictures of these lizards, I don't have any that would show the differences between those here and in Fort Pierce. This website has a few pictures of what the ones in Corkscrew Swamp Sanctuary look like, with information on each species. Corkscrew Swamp is far south of Fort Pierce, closer to the end of the peninsula.
Sorry, We Couldn't Find That Page | Audubon

I'm surprised you found so little, I'm sure I remember it coming up in at least a couple of threads. One was about observed speciation as I recall and another about whether artificial selection could be said to have lead to speciation in dogs. It was a wee while ago admittedly so I might be mixing up the subjects of the threads.TTFN,WKThis message has been edited by Wounded King, 06-03-2004 02:28 AM

There's a little more at http://EvC Forum: Would it be possible to recognize a transitional change at the time it was happening? -->EvC Forum: Would it be possible to recognize a transitional change at the time it was happening?.Note that the link to the recent paper has moved; now it's The herring gull complex is not a ring species

The RS paper seems to show some confusion, especially as an objection to speciation. The paper, essentially, are arguing that the variance is due more to radiating speciation than circumpolar speciation, based on mitochondrial DNA (One of the things that creationists truly hate).It states that there wasn't a steady progression accross the globe, but that there rather is variation at the fringes.And it seems to make the argument that the Herring Gull complex originated in Europe as some ancestral species that then stayed in Eurasia as Herring Gull, and also in America as Lesser Black-Backed Gull. They then claim that the LBBG has migrated West to Eurasia, but haven't quite made it accross the Atlantic to come 'home' to the US, and that the HG has migrated East to Western North America and is still a bit away from Europe again.At least that I how I read the rather cumbersome and confusing abstract. Now, I think we really need to see the article details for specifics of the Mitochondrial DNA analysis.So it seems to makes the claim that the split happened in the migration to the US, and that the variation on the fringes is where we see the speciation difference, rather than in the entire population. Seems like they are saying that the typical HG from Central Eurasia arctic is not really that different from the typical LBBG from central US Arctic, but that instead, the speciation difference occurs at the fringes.Essentially, they are saying that the ring MOSTLY made it around in either direction, and that the overlap with speciation difference is from migration in both directions, rather than from migration in only one direction, making two "mostly" ring-species rather than one complete ring species.Certainly, it goes against the classic classification of the Herring Gull complex, so we'll have to wait and see what the peer review does with this. Certainly, I have not before seen claims thet the LBBG arose simultaneously with the HG.But it still shows speciation quite nicely, though.I did look at the raw data on the cytochrome differentiation in the mitochondrial DNA by Leibers and Helbig, two of the authors, and it seems that he bvase this on regression analysis that shows both contiguous range expansion, allopatric fragmentation and long distance colonication, so I am not sure that the paper's claim is that ironclad. We'll wait and see what the statiticians say about this.
http://www.stanford.edu/...anuscripts/Leibers_and_Helbig.pdf

i'm from an hour or two south of there. brown anoles are ALL OVER the place, and have been since i was born. your story was very nice and convincing even, except for the fact that i've lived around these things all my life.they can change the lightness and darkness of their skin, and i think the patterns, according to environment. they're nowhere near as good at it as chameleons, but that is probably the origin on the statistical differences.-- although, the anoles surviving the colder weather up in g'ville may indeed be evidence of speciation.

Hello, Steen.As I commented on JonF's revelation before, even if the Herring/Blackheaded Gull is no longer an example of ring species, it is still a marvelous example of speciation that is occurring right before our eyes. Just as you said.

Now, get a creationist to acknowledge any of that

i believe the reply will go something like this "i don't believe it! it's not happening god says so!"or better yet "wow, microevolution, but a lot of little changes can't possibly add up to big ones"

But then try to make them explain the difference between micro- and macro-evolution as they use it, and you'll get a bunch of vague "its when the difference is big" or something like that.Or they will talk about a new "kind," but then not be able to define what that is either.

because, you know, they don't believe in addition.

Since that would sacrifice their salvation, they wouldn't dare What happened to JonF?This message has been edited by Steen, 06-07-2004 10:09 PM

now, THAT i don't understand. it was after all the sign of addition on which the savior was sacrificed, was it not?