Darwin argument?

Question

Darwin’s argument for the idea that evolution has occurred is largely inductive, while his argument for the mechanism of natural selection is essentially deductive. Summarize in your own words the inductive and deductive components of Darwin’s theory.

Answer 1

Interesting question. I don't know if I've ever seen it presented like that.

Induction is seeing specific examples and then generating a general statement. An example would be seeing specific species on the Galapagos islands as being similar to, but different in important ways from, mainland species. From these very specific examples, he induced the general idea that all of these species were being affected by the same process ... i.e. that evolution (change) can make a subpopulation of organisms different from other members of their parent species, and that such change can be concentrated by isolation.

Deduction is seeing general observations and then deriving a specific principle that unites them. The three general observations (observations that seem true for many, if not all, species) that led to natural selection are:
1. Variation (not all members of a species are identical).
2. Inheritance (individuals pass traits on to offspring).
3. Competition (more individuals are born than can survive and reproduce).
From these three general observations he derived the specific principle that unites them:
4. Natural selection (those individuals born with characteristics that provide some advantage in that competition, will pass those traits on to offspring in greater numbers).

Hope that helps.