i learned how to do a mail merge. and now a break.

[twinklery]

recent discussion has lead me to the knowledge of cloaca. and then of course i must insist that you look up persistant cloaca as well, just so you know it exists.

some sea turtle breathe out of an orifice also used to defecate! small parasites live in other hosts cloacea!

evolutionary (maybe) question: if other animals (reptiles, birds, and

Comments

[city_billy]

all placental mammals have the split, not just humans.

[city_billy]

oh, the other thing: i'm guessing it's because it worked at some point in the past and continues to work millions of years later. nature makes lots of mistakes, but they usually die or don't reproduce.

[fiendishx]

assuming their survival today as an expression of their fitness
This is the key. The phrase "survival of the fittest" is actually a tautology. It would be aptly reworded as "the winners are the ones that win".
Don't try to apply teleology to evolution. Just think of it in terms of something happened one day, and it didn't statistically harm the host's ability to reproduce.