Posted by Pangea to Christian Scholar (188.8.131.52) on May 19, 2004 at 16:04:57:
In Reply to: Re: continued from last post posted by Christian Scholar on May 19, 2004 at 14:29:15:
In terms of the primrose, the speciation process resulted from a doubling of the chromosome number. Since each species, by definition, has a definitive chromosome number, the new primrose is recognized as a new species. The information contained in DNA was not new, nor was it shuffled. It was simply compounded. However, the resulting new phenotype (i.e., outward appearance) was distinctly different from the parent phenotype. Since natural selection only works on phenotype, the new species can respond differently from the parent species to the same environmental conditions. The new species is also reproductively isolated from the parent species.
The best example of "new" information arising by random mutation, however, is in the mosquito that carries West Nile virus. A mutation in an enzyme controlling one of the metabolic pathways normally disrupted by an insecticide allowed the new variety of mosquito to adapt to the pesticide-rich environment. The new variety of mosquito is not yet reproductively isolated from the parent species. But it only arrived on the scene in the last 2 years. Only time will tell if it becomes isolated enough to be considereda a new species.
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