10 Worst Evolutionary Designs

Citation :

1 Sea mammal blowhole. Any animal that spends
appreciable time in the ocean should be able to extract oxygen from
water via gills. Enlarging the lungs and moving a nostril to the back
of the head is a poor work-around.
2 Hyena clitoris. When engorged, this "pseudopenis," which doubles as the birth canal, becomes so hard it can crush babies to death during exit.
3 Kangaroo teat. In order to nurse, the just-born
joey, a frail and squishy jellybean, must clamber up Mom's torso and
into her pouch for a nipple.
4 Giraffe birth canal. Mama giraffes stand up while giving birth, so baby's entry into the world is a 5-foot drop. Wheeee! Crack.
5 Goliath bird-eating spider exoskeleton. This
giant spider can climb trees to hunt very mobile prey. Yet it has a
shell so fragile it practically explodes when it falls? Well, at least
it can produce silk to make a sail. Oh, wait — it can't!
6 Shark-fetus teeth. A few shark species have live
births (instead of laying eggs). The Jaws juniors grow teeth in the
womb. The first sibling or two to mature sometimes eat their siblings in utero. Mmm ... siblings.
7 Human stomach. People can digest a lot — except
for cellulose, the primary component of plant matter. Why don't we have
commensal bacteria in our guts to do it? They're busy helping termites.
8 Slug genitalia. Some hermaphroditic species breed
by wrapping their sex organs around each other. If one of said members
gets stuck, the slug simply chews it off. What. The. Hell?
9 Quadrupeds. Let's say you're a four-footed
animal. Now let's say you get a wound on your back, or an itch, or a
bug wandering up there. Tough luck, kid. You probably can't do much
about it. Hope there's a low branch around.
10 Narwhal tusk. The unicorn-like protuberance on a
male narwhal's head is actually a tooth that erupts through the front
of the jaw and keeps on growing, up to 9 feet. Narwhal: "Doc, I have a
toothache." Dentist: "Indeed."

je trouve ça rigolo mais un être qui est parfaitement adapté à son environnement a plus de chance de disparaitre si ce dernier venait à changer.Ses petits défauls seront peut être salutaire pour le future de l'espéce,qui sait.

http://www.wired.com/science/discoveries/magazine/17-08/st_best#