Ring Species!!

Hey everyoneIs there a better proof for evolution that the ring species? I don't think so.Unfortunately, I only know of 2.If anyone knows of any ring species, please post them here, with decent reference source that I could take a look at/buy.Shall I start with a classic example in case people do not know what I mean?Enstantina Salamanders (The Ancesotor's Tale, first edition Richard Dawkins) Buy it now, its superb!These salamanders are effectively a living fossil record. Each 'sub-species' dominates a different area of a valley in california. Each species can breed with the species next to it. However, if we walk around the perimeter of the valley northwards, (say we start at the south side), the species get less and less similair. Until we reach the end of the line, and the species at the end of the line can no longer breed with the species at the beginning of the line.

Thread moved here from the Proposed New Topics forum.

In Question about evolution, genetic bottlenecks, and inbreeding you have questions that might be explained if you think of evolution of new species as being like ring species in time instead of space.Does that make any sense to you?

No it does not because i don't think evolution happens in space instead of time.Surely being able to view how species A got to species B by looking at the species that they were in between points A and B is nothing to do with space just because they didnt die off.

Another well studied example is the Greenish warblers in Asia around the Tibetan plateau, which appear to have developed gradients of behavioural reproductive isolation associated with differences in mating songs. I don't know of a treatment of them in book form but there are a number of relevant papers published. I don't think most of them are open acces but at least one, 'Speciation by Distance in a Ring Species'(Irwin et al., 2005), only requires registering with the Science website to read.What might be called the 'classical' example of a ring species is the populations of herring gull distributed around the arctic circle. However more detailed genetic research and further evaluation has led to what was once held up as a nice clean example of a ring species to turn instead into a more complex mix of species and subspecies, see 'The herring gull complex is not a ring species' (Liebers et al., 2004).TTFN,WK

Evolution obviously happens in time.In the case of the ring species we see there are a series of populations separated by geography with some limitation on gene flow between them. You can visualize an original population gradually spreading out over some areas generation by generation. The individuals further from the source will have less gene flow back to that source and will have diverged farther from it.If we look at a population over time (let's use humans as an example) we get a similar situation. One hundred generations ago was the time of the ancient Egyptians. It is pretty darned sure that we could interbreed with them but time separates us so there is no gene flow just like geography can reduce (or stop) gene flow.If we go back 1,000 generations we are in the stone age and there are genetic differences between us and them but we could still (probably) interbreed with them. If we go back 2,000 generations that population could certainly interbreed with the population 1,000 generations in our past. So could we probably but there will be more genetic differences. This continues in time.At about 10,000 generations back we have a population that could certainly interbreed with the population from 9,000 generations back. However, that population (10k gens back) is probably no longer our own species. (Though interbreeding might be possibly successful we probably (most of us ) wouldn't want to try so speciation has happened).If we go back 100,000 generations we have a population that certainly could interbreed with the population 99,000 generations back and for many though (say) about 70,000 gens or closer. However, there is a very good chance that (100kgens) population could not interbreed with us and we would be about as interested as we would be in a chimp.This gradation in changes that never produces a sharp line of speciation anywhere over the many thousands of generations is exactly the same as the gradual change you see over geography in the case of ring species. There is not sharp line that marks a species boundary but at the extremes there are two different species. I don't understand this at all. Please explain.

Thankyou very much Wounded King, I was un-aware of your first example. I will take a look in more detail later on tonight.

A query for '"ring species" AND evolution' on pubmed only produces 15 results but some of those are putative ring species I hadn't come across before.These are the Trumpetfish complex (Bowen et al, 2001), a group of Australian parrots (Joseph et al., 2008) and the great tit (Kvist et al., 2003). In both the bird cases the story is similar to that of the herring gull where it may be a case of the formation of secondary contact zones of previously temporarily isolated groups rather than true examples of a ring species developing.TTFN,WK

Harry,Here are a couple of web links to rings species as well:Greenish warblers
http://www.zoology.ubc.ca/~irwin/PDFs/IrwinIrwin&Price2001
http://www.actionbioscience.org/evolution/irwin.htmlThe first is an article about the Greenish Warblers and the other two are papers.To my mind the Greenish Warblers show how little change is needed to produce speciation.Enjoy.

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Those birds are very beautiful, as is their environment.Does anyone know if they migrate though? I would have thought it would be harder for a bird to develop into a ring species as when they return from migration they could set up shop anywhere.If they migrate that is.

Hi Harry,One of the interesting things about bird migration is that whilst they could theoretically go anywhere, most birds end up exactly where they came from. Some birds will fly from the UK, across Southern Europe, Northern Africa and the Sahara desert, only to return and breed in the exact same tree they nested in the year before.Even more interestingly, this does not preclude diversification. Since the breeding group is always (more or less) in the same place each year (barring a small number of vagrants) their genetic diversification can progress unimpaired.A good example of this is the white wagtail (Motacilla alba), a pretty little black and white bird, which displays a great deal of variation across Eurasia (Added by Edit - it's not a ring species, but I mention it as an example of a highly variable migratory bird). Some are migratory, others (in the milder parts of their range) are resident. The Wiki page has some photo's to illustrate the wide variation between sub-species/clades.Basically, it doesn't matter so much where they are during the non-breeding season. What matters is where they are when they breed. Obviously though, the more geographically isolated a population, the stronger the tendency to diverge.Greenish warblers do migrate by the way. They winter in India.Mutate and SurviveEdited by Granny Magda, : No reason given.

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Is the japanese subspecies picture that of a juvenile?

There are a group of dragonflies in the genus Orthemis that appear to be a ring species. I am not sure if any papers have been published yet that document this fully, but a number of Odonate workers are studying it. These dragonflies are found from Florida, through the Caribbean, through northern South America, through Central America and Mexico, into Texas and across the southern states. One interesting thing is that several of the species in this complex have males with two or more color morphs.Photos of some of the members of this complex can be seen at: http://www.ups.edu/x6318.xml

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Thanks for that one!

Wow. It seems you could logically have more than one "ring" involved (where a "ring" is the extent of change necessary for interbreeding to cease).Do you know if anyone has tried to breed intermediate hybrids?.Enjoy

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we are limited in our ability to understand
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Rebel American Zen Deist
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to share.

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