Because genes encode instructions for building animal bodies, biologists once expected to find significant genetic differences among animals, reflecing their great diversity of forms. Instead very dissimilar animals have turned out to have very similar genes.
Mutations in DNA “switches” that control body-shaping genes, rather than in the genes themselves, have been a significant source of evolving differences among animals.
If humans want to understand what distinguishes animals, including ourselves, from one another, we have to look beyond genes.
At first glance, the list of animals could suggest any zoo. There’s an elephant, an armadillo, an opossum, a dolphin, a sloth, a hedgehog, big and small bats, a couple of shrews, some fish, a macaque, an orangutan, a chimpanzee and a gorilla—to name a few of the more familiar creatures. But this menagerie is not at all like any zoo that has been constructed before
It is a “virtual” zoo that contains only the DNA
clipped from: www.sciam.com 