The similar framework of bones in the hand of a man, wing of a bat, fin of the porpoise, and leg of the horse-the same number of vertebrae forming the neck of the giraffe and of the elephant-and innumerable other such facts, at once explain themselves on the theory of descent with slow and slight successive modifications.
hitzez adierazten da; eta genealogi lerroak ezaugarri iraunkorrenen bidez aurkitu behar ditugu, ezaugarriok direnak direla eta biziarentzat denik garrantzirik txikienekoak izanik ere.