thinking about... boobs...

or, more exactly, mammories... I bought a new T-shirt on saturday: the drawing on it is... well, here's a picture of it:
the picture of the little mammal sucking his mother's tits got me thinking... how's it that cows have their mammories close to the hind legs, while women have them closer to the upper part? I can see a clear advantage for the primates to have nipples on the upper body - it make it easier to keep their infants with the hands - young veils/zebras/antelopes do instead walk on their own...

but... how the position of the nipples is decided during development? I always thought they were 'linked' to the chest, but that's very anthropomorphic... I wish I had an evolutionary biologist at hand to ask him... may be I should contact Richard Dawkins... or may be PZ Myers will answer...