Observing Species Jumps
Bruce Tomaso, in The Dallas Morning News Opinion blog, brings us a "dog bites man" kind of story, headlined, "Scientists think science should be taught in science class."
As obvious as you might think that opinion is, nevertheless the reader comments inevitably brought forth complaints that evolution is preposterous. One skeptic demanded examples of "macro-evolution," "where a lizard changed to a dog (or whatever). ... Changes within a species are not sufficient to prove that jumps EVER happened."
Scientists agree with creationists on one thing: species "jumps" never happen. The offspring of a lizard always a lizard. If it were a new species, say a fubar, who would the new fubar mate with, being the only one of its kind.
Nevertheless we can "observe" species jumps over time. The fossil record shows slow changes in a species over time, so much so that there's no doubt that the individual at the beginning of the chain is a different species than the individual at the end, even though each step along the way was the offspring of the previous generation.
We can also observe species jumps over distance. A species spread along, say, a coastline sometimes exhibits a remarkable trait. Individuals living in close proximity have no trouble mating, but individuals at one end of the range cannot mate with an individual at the other end. If a natural disaster, say an earthquake or volcano, separates the range permanently, scientists would identify the individuals at each end as being of different species.
But don't expect these cases to keep the creationists from continuing to repeat the falsehood that "macro evolution" has never been observed.
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