What was the process of evolution as described by Charles Darwin?

Question

Also what is the difference between evolution and speciation? And, what is the difference between natural selection and descent with modifications?

Answer 1

Darwinian theory involves the idea of natural selection (survival of the fittest). His theory is grounded in his observations of the finches of the galopogos(sp?) islands.

And example of evolution based on natural selection is the effect of pesticides on bugs. You spray the crop, and the pests seem to be eliminated. Actually not all have died. Some are born with natural defences agaisnt the pesticide, like an enzyme that can neutralize it or a harder shell that it can't penetrate. The surviving pests will breed with the other survivors and they're offspring will inherate the gene that makes them immune.