Variation in Living Things

It seems obvious that a pig will never give birth to a puppy, but why should that be the case? Variation in Living Things explains the causes and limits of variation in species - such as blood groups and disposition to disease - and why it is so important to their survival.

Pare evident ca un porc nu va naste niciodata un catelus, dar de ce ar trebui sa fie asa? Variatia in lucrurile vii explica cauzele si limitele variatiei speciilor - cum ar fi grupele de sange si dispozitia fata de boli - si de ce este atat de importanta pentru supravietuirea lor.