> Neither do we say that chihuahua's and labradors have evolved into their present form.
This is artificial selection. When it occurs naturally, it's called Natural selection & it's the basis of evolution. The mechanism of both artificial and natural selection is the same -- increase of a trait in the population by selecting only animals with that trait to reproduce. Speciation is merely a result of this process.
Btw the pulitzer winning book "The beak of the finch" discusses how evolution actually doesn't need many generations to happen. What it needs is selection pressure -- events (such as severe draught) that force natural selection to happen within a handful of generations. It's a fascinating book on a fascinating study.
This is artificial selection. When it occurs naturally, it's called Natural selection & it's the basis of evolution. The mechanism of both artificial and natural selection is the same -- increase of a trait in the population by selecting only animals with that trait to reproduce. Speciation is merely a result of this process.
Btw the pulitzer winning book "The beak of the finch" discusses how evolution actually doesn't need many generations to happen. What it needs is selection pressure -- events (such as severe draught) that force natural selection to happen within a handful of generations. It's a fascinating book on a fascinating study.