Who or what is driving evolution?
Evolution is a process that
results in heritable changes in a population spread over many generations.
This is a good working scientific definition of evolution; one that
can be used to distinguish between evolution and similar changes that are not
evolution. Another common short definition of evolution can be found in many textbooks:
“In fact, evolution can be precisely defined as any change in the frequency of
alleles within a gene pool from one generation to the next.” Helena Curtis and
N. Sue Barnes, Biology, 5th ed. 1989 Worth Publishers, p.974
That definition is extremely general.
It is simply telling us that heritable genes change from generation to
generation; over long enough time this change is likely (but not necessarily)
to entail phenotypical changes as well. It is notable that this definition
stops short of stating just what produces the change. In fact this catch-all
definition is not much stronger than saying that organic forms change over
time: Because the fossil record betrays phenotypical changes over long periods
this in turn implies genetic change and therefore evolution. It follows then
that the fossil record is strong evidence that evolution, in the very general sense of mere change, has occurred.
Neil deGrasse Tyson said that the theory of evolution is a fact.
This is not correct. Evolution is a fact. Evolutionary theory attempts to
explain how evolution occurs. Some of the explanations, like natural selection,
are facts but many aspects of modern evolutionary theory are still hotly
debated in the scientific community.
That’s intriguing; so Larry
accepts that the detailed engine/mechanism of evolution is a theory and not a fact! Too true! But the definition of evolution
he has given is so general that it could also include changes due to the tinkerings of a homunculus intelligent
designer or anything else for that matter!
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