7 Ekim 2008 Salı

Scientists claim to observe Evolution in action

I have tried to stay out of the Creaion/Evolution debate because in general I think it does more harm than good. But this article has the potential to drive the debate for the next decade. Evolutionary biologists claim to have actual observations of speciation in action. A species of fish in Lake Victoria appears to be diverging into two different species, based on pollution which is changing how they hunt and are hunted.

It should be noted that if this is true, then it is fundamentally different from the "coal moth" experiment which to now has been held up as the best experimental evidence of macroevolution in nature. That was simply a case where location conditions changed the proportion of dark and light moths in a population. This case instead may actually show one species becoming incapable or unlikely to ever interbreed.

6 yorum:

  1. I understand that it is different than the "coal moth", but how is this not just chihuahua's tend to mate with chihuahua's and great danes tend to mate with great danes? It may just be that I'm tired, but I'm seeing that fish that have better vision at deeper levels hang out and mate with other fish at deeper levels and fish that have better vision at shallower levels hang out and mate with other fish at shallower levels.

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  2. Wedge, The difference is that if you put a chihuahua and a great dane of opposite sexes together, they will WANT to mate. And ultimately, will probably find a way. This case is setting up a situation where the two divergent groups are less and less likely to mate and are attracted to significantly different stimuli. Two dogs are attracted to each other by scent queues whether they are large or small. These two kinds of fish are attracted to different colorations and body structures.

    Again, this is not "proof" but it is far more compelling than anything that has come before, in my ever-so-humble opinion. And it offers a situation where ongoing observation can confirm or deny the ultimate speciation event (i.e. when it becomes impossible for the two populations to interbreed).

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  3. It sounds to me more like the way Africans have very dark skin and Europeans have light skin. Separated by distance, but still humans and no different in their essence from each other. If you look at an African man, his hair is very different, his eye color is often darker, the features are different, even differences in muscles and lungs. It's not a different species, just that people who have shorter hair and darker skin and certain muscle types are better able to live in the climate of Africa.

    The fish may see better in dark or light, but they are still fish, and I don't see why they couldn't mate together.

    Also, this is a loss of genetic information. One fish sees red, the other blue, they haven't developed the ability to see both well. The genetic information to see the other color is being lost, which is what usually happens in mutation. Evolution would require that genetic information to be gained, a fish that could see both. I know the answer will be that evolution requires a species to adapt to it's environment, but like I said above, it only means that those without the skill to do x (see red) can't live in that area, which isn't evolution.

    It will be interesting to see what happens, but ultimately I don't think this will convince either side. The creation/evolution debate is more about abstract concepts of God, humanity and morality than about observed science.

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  4. Oh, I remembered my example... this is more like why a great dane tends to mate with another large dog, not a yorkie. They are still dogs, still descended from some kind of mutt, but bred (loss of genetic information) to be very big or very small.

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  5. Again, I encourage folks to take this for what it is: our first chance to possibly OBSERVE whether speciation occurs or not. This is not a computer simulating macroevolution, it is not "inferring" macroevolution from the fossil record. It is an actual natural event which can be objectively observed and reported upon.

    I agree, it won't end the debate - too many people have invested too much philosophy and vanity into the science - but it provides a unique chance to give those with open minds a look into the way nature actually works. I really think this may be akin to the two-slit experiment in physics which finally provided clear and convincing evidence of the wave-particle duality of light.

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  6. I understand what you are saying, but I think they are inferring a lot of things from from this because they want it to end up one way.

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