Posted on 12/11/2002 3:19:35 PM PST by jennyp
Perhaps because no one has ever managed to remain alive for the millions of years required to do so? Hrmnn? Yet microbiological evolution has been observed, even forced. One could make the argument that the various breeds of livestock humans have crafted over generations of selective breeding illustrate the principles of natural speciation, in fast-forward.
Better than that. "Macroevolution" is, by definition, evolution at (or beyond) the species level. Any event leading to the origination of new species is "macroevolution," and some instances of speciation have been observed, or can be securely inferred to recently occured. Therefore "macroevolution" has actually been observed:
"They're like Napoleon's army in Moscow. They have occupied a lot of territory, and they think they've won the war. And yet they are very exposed in a hostile climate with a population that's very much unfriendly."
"That's the case with the Darwinists in the United States. The majority of the people are skeptical of the theory. And if the theory starts to waver a bit, it could all collapse, as Napoleon's army did in a rout."
Yes they did, and multiple examples are cited right in the file you declared, apparently without inspection, to be "B.S." Here are a couple instances in which complete reprodutive isolation (the criteria of speciation) was acheived. (Others merely acheived statistically significant assortive mating):
5.3.1 Drosophila paulistorum Dobzhansky and Pavlovsky (1971) reported a speciation event that occurred in a laboratory culture of Drosophila paulistorum sometime between 1958 and 1963. The culture was descended from a single inseminated female that was captured in the Llanos of Colombia. In 1958 this strain produced fertile hybrids when crossed with conspecifics of different strains from Orinocan. From 1963 onward crosses with Orinocan strains produced only sterile males. Initially no assortative mating or behavioral isolation was seen between the Llanos strain and the Orinocan strains. Later on Dobzhansky produced assortative mating (Dobzhansky 1972).
5.3.5 Sympatric Speciation in Drosophila melanogaster In a series of papers (Rice 1985, Rice and Salt 1988 and Rice and Salt 1990) Rice and Salt presented experimental evidence for the possibility of sympatric speciation. They started from the premise that whenever organisms sort themselves into the environment first and then mate locally, individuals with the same habitat preferences will necessarily mate assortatively. They established a stock population of D. melanogaster with flies collected in an orchard near Davis, California. Pupae from the culture were placed into a habitat maze. Newly emerged flies had to negotiate the maze to find food. The maze simulated several environmental gradients simultaneously. The flies had to make three choices of which way to go. The first was between light and dark (phototaxis). The second was between up and down (geotaxis). The last was between the scent of acetaldehyde and the scent of ethanol (chemotaxis). This divided the flies among eight habitats. The flies were further divided by the time of day of emergence. In total the flies were divided among 24 spatio-temporal habitats.
They next cultured two strains of flies that had chosen opposite habitats. One strain emerged early, flew upward and was attracted to dark and acetaldehyde. The other emerged late, flew downward and was attracted to light and ethanol. Pupae from these two strains were placed together in the maze. They were allowed to mate at the food site and were collected. Eye color differences between the strains allowed Rice and Salt to distinguish between the two strains. A selective penalty was imposed on flies that switched habitats. Females that switched habitats were destroyed. None of their gametes passed into the next generation. Males that switched habitats received no penalty. After 25 generations of this mating tests showed reproductive isolation between the two strains. Habitat specialization was also produced.
They next repeated the experiment without the penalty against habitat switching. The result was the same -- reproductive isolation was produced. They argued that a switching penalty is not necessary to produce reproductive isolation. Their results, they stated, show the possibility of sympatric speciation.
When you deal with creationists, all definitions are subject to drastic modifications to suit their purposes. A "Christian" is a creationist. A "conservative" is a creationist. A "patriot" is a creationist. A "good person" is a creationist. A "scientist" is a creationist. If you're not a creationist, then according to their definitions, you're none of the above-defined terms. That's why it's impossible to debate with a creationist.
Never heard of social darwinism...marx---ayn rand??
Then comes the real stunner: "There are no creationists!"
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