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03-29-2007, 02:36 PM | #21 |
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03-29-2007, 02:42 PM | #22 | |
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No bull about it! NPM |
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03-29-2007, 03:02 PM | #23 | |
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More initial variability means more eventual variability. A larger population spread over a larger environmental range has more probability to survive changes to that range. |
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03-29-2007, 03:07 PM | #24 | |
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Species can survive severe inbreeding. It needn't be all that bad if the founders are healthy. And rapid expansion of the population reduces the loss of diversity. Nevertheless, the amount of genetic diversity in existing species is evidence that they didn't go through any such genetic bottleneck in the last five or six thousand years. Humans, for example, show signs that their most recent bottleneck was a population of about 15,000 about 70,000 years ago. On the gripping hand, a god who could miraculously return the kangaroos to Australia, the kiwis and wetas to New Zealand, jaguars and tapirs to South America, and dodos to Mauritius after the Flood could easily have faked the genetic data. Just as He is supposed to have faked the fossils, faked the morphological evidence for evolution, faked the genetic evidence of common descent, and faked the light coming from distant stars. |
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03-29-2007, 03:15 PM | #25 | |
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There is a big difference when you are discussing a human controlled breeding program versus a herd in the wild. We will act as a 'god' of sorts and protect our little herd. We will provide it with antibiotics it might take thousands of generations to acquire and domesticate naturally. We will protect it against variations in environment, we will protect it against natural predation. If you were to reconstitute 20 unique mammoths and let them loose on their own in a human-less environment they would very likely die out with a few generations at most. The only way to tell would be to do so with a number of equally variable herds in similar environments. But my guess is they would succumb to disease, hunger or predation very quickly. That's why they were herd animals. Bigger herds, more variability and greater protection against threats. |
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03-29-2007, 06:20 PM | #26 | |
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I think this is a stronger argument (ie lack of bottleneck), in terms of genetic evidence, than an appeal to minimal viable population. Can you provide a specific source for your numbers? |
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03-29-2007, 10:17 PM | #27 | |
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I read about it in The Economist. A superficial Google search also throws up the following: http://www.sciencedaily.com/releases...0908074159.htm http://news.bbc.co.uk/2/hi/science/nature/166869.stm http://en.wikipedia.org/wiki/Toba_catastrophe_theory |
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03-29-2007, 10:29 PM | #28 | |
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Lions have to eat fairly often ya' know. |
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03-29-2007, 10:56 PM | #29 |
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04-03-2007, 01:47 PM | #30 |
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