Evolution in Action: Ring Species

0

David Wake, an evolutionary biologist at the University of California, Berkeley, explains why members of the same species of California salamander look and behave so differently. It's a case study of Darwin's theory of evolution by natural selection, and an example, Wake says, that Darwin himself would have loved.


Written By: YouTube
continue to source article at youtube.com

NO COMMENTS

  1. Of course creationist would say…., ” it is still a salamander! “

    I would hate to have such a restricted view of the living world. One can see what one is taught in school with this simple ring species example. One realizes how ridiculous crockaducks would really be.

    ” Gradual, adaptive divergence. ” The thing in a nut shell, albeit technically phrased!

    • In reply to #1 by Neodarwinian:

      Of course creationist would say…., ” it is still a salamander! “

      Yes, it is amazing how some people insist on missing the point. This example of a ring species is simply very neat.

    • In reply to #1 by Neodarwinian:

      Of course creationist would say…., ” it is still a salamander! “

      I would hate to have such a restricted view of the living world. One can see what one is taught in school with this simple ring species example. One realizes how ridiculous crockaducks would really be.

      ” Gradual, adaptive divergenc…

      Oh heck with the creationists. This is very interesting and fascinating. I want more.

      • In reply to #4 by QuestioningKat:

        In reply to #1 by Neodarwinian:

        Of course creationist would say…., ” it is still a salamander! “

        I would hate to have such a restricted view of the living world. One can see what one is taught in school with this simple ring species example. One realizes how ridiculous crockaducks would really b…

        Did you mean, the hell with creationists?

  2. In my opinion, ring species (especially california salamanders) are the most compelling (and hardest to argue with) evidence for evolution. Explain this phenomenon with any other idea. Go ahead.

    Oh, and BTW, what does everyone think about humans originating from a ring species around the central rift valley of africa??

    • In reply to #3 by crookedshoes:

      In my opinion, ring species (especially california salamanders) are the most compelling (and hardest to argue with) evidence for evolution. Explain this phenomenon with any other idea. Go ahead.

      Oh, and BTW, what does everyone think about humans originating from a ring species around the central…

      Tell you Monday when I have given the matter some thought. Interesting idea.

    • In reply to #3 by crookedshoes:

      “… what does everyone think about humans originating from a ring species around the central rift valley of africa??”

      That is a piquant idea, but is there enough evidence for it? I, for one, would certainly be interested to know about it. The established view seems to be that Homo sapiens emerged from an evolutionary bottleneck, so I would be looking to see how this might have occurred in the case of a hominid or hominin ring species.

  3. I think this is what he is implying: You get variation attuned to different geography. Though interbreeding is possible, it is unwise since the offspring are not as well adapted as either pure strain. So eventually they stop interbreeding or stop interbreeding because of geography.. This allows even more genetic drift. Eventually you get a chromosomal mutation that seals the new species.

    Have I got that righ?

  4. Line species, ring species and species complexes are very common – particularly in plants.

    A species complex is a group of closely related species, where the exact demarcation between species is often unclear or cryptic owing to their recent and as yet, usually, incomplete reproductive isolation.

    Ring species complexes, superspecies complexes and cryptic species complexes are some different examples of species complexes. Such groups of species with a complex-type relationship between species may occur in a line – undergoing rapid speciation – or where such speciaton has recently occurred, meaning species separation mechanisms or traits which distinguish species have yet to develop in full. Such cases may leave some species paraphyletic at the species level and lead to hybrid species, making phylogeny/phylogenetic analysis difficult.

    In places such as the Chilean fiord coastline, there are literally thousands of miles of strips altitude-specific habitat (say at cloud-level), up each valley, back to the ocean, and then off up the next valley of the high Andes, – all the way from the glaciers in the south, snaking north for thousands of miles. – a linear habitat thousands of miles long with many isolated sections.

    wikipedia continued – Species complexes are more common among plants, but animal examples exist, such as the dog-wolf-coyote complex (the genus Canis) and the cobras (genus Naja). Often such complexes only become evident when a new species is introduced into the system, breaking down existing species barriers. An example is the introduction of the Spanish slug in Northern Europe, where interbreeding with the local black slug and red slug, traditionally considered clearly separate species that did not interbreed, shows they may be actually just subspecies of the same species.

  5. Well crookedshoes, maybe not just the rift valley but an even greater area in Africa, with the rift valley being one area of a large ‘ring’. We are no more fixed a species than these salamanders are.

    • I just always have wondered about the assortment of hominid skulls. Australopithecines and Homo groups all bunched up and perhaps competing for resources…. I think of the rift valley (I guess) due to the salamanders.

      In reply to #10 by finchfinder:

      Well crookedshoes, maybe not just the rift valley but an even greater area in Africa, with the rift valley being one area of a large ‘ring’. We are no more fixed a species than these salamanders are.

      • In reply to #11 by crookedshoes:

        I just always have wondered about the assortment of hominid skulls. Australopithecines and Homo groups all bunched up and perhaps competing for resources…. I think of the rift valley (I guess) due to the salamanders.

        In reply to #10 by finchfinder:

        Well crookedshoes, maybe not just the rift va…

        If you could show Homo’s gradual and adaptive divergence around the Rift valley ( analogous to salamanders around the Central Valley ) then you could be on to something.

  6. A very neat example of speciation; but I always get confused – actually I could leave it at that – is this sympatric and allopatric speciation?

    Do these areas overlapp or not? they’re obviously immediately adjacant.

    This isn’t a rhetorical question by the way!

    The professor doesn’t really explain the mimicking very well; he makes it sounds as if the animals made a collective decision to do it. He should explain that environmental pressures drove the adaptation.

  7. Watching this, I somehow can’t help but think of Jim Morrison. In the late 60s, he would hitchhike out to the Mojave desert, either smoke or ingest some sort of hallucinogenic substance, and spend hours watching these California salamanders crawling over rocks. It was the main inspiration for his pages and pages of poetry all centering around lizards, which he probably thought were telepathically communicating with him in his “altered” state.

Leave a Reply