The dark elf femme fatale Elainuk was the firstborn son of Robert and Lulu Bobblecork. She was born a healthy bouncy baby boy in the shire of Pedstand, which was part of the Cordially Aligned Tetrarchy of Halfling States.
As population increases, animal souls are promoted to human before they are spiritually advanced enough in terms of impulse control, etc.: this shouldn't have happened, but karmic progression is automatic, after all--it's a force of nature. But the 'animalization' of humankind bodes ill for civilization.
No doubt the same goes for elves, dwarves, and so on.