Mating Postures and the AAT/H
That many aquatic mammals copulate
facing each other is due to constraints imposed by their anatomy.
Tails which have become flukes, for instance, simply get in the way.
Moreover, not all aquatic mammals copulate facing each other, despite the fact that
AAT/H proponents claim -- or at least very strongly imply-- they do.
In some cases -- sea otters, for example -- observers are actually surprised that they don't do so ("it would seem simpler," one said), but they don't, despite their mating in the water.
In fact, only those aquatic mammals which, due to anatomy, are unable to mate any other way, copulate front to front, and these are all animals which have been aquatic for tens of millions of years (ranging from 20-50 million years).
This is several times longer than the entire existence of hominids, from our divergence from apes to the present day.
Further, there are terrestrial mammals which commonly copulate facing each other, and they are close to
Two of our close primate relatives, orangutans and pygmy chimps (bonobos)
do so regularly, as well as black-handed spider monkeys; gorillas do so occasionally, as do woolly spider monkeys.
(My thanks to Steve Foster for the info about gorillas and the spider monkeys -- see
his web site link on my Links page.)
And lastly, does it really have to be pointed out that humans don't always copulate facing each other?
Since this sexual position is not uncommon among higher primates, it shouldn't be surprising to find
humans doing it.
Why does this surprise AAT/H proponents so? I don't know.