The truth of the matter is, yes. God allowed this for man to multiply witht he intent that it would cease once the earth was populated, thus making it an abomination in the book of Leviticus.
Pardon my ignorance, but why would God do that? Why not just set a non-changing set of rules down and lay it out REAL clear.
As a complete aside, there is strong evidence that all humans currently alive stem from a single woman stumbling out of Africa some several hundred thousand years ago. They call her Mitochondrial Eve, in case you've got a penchant for Googling. She wasn't the only one to get out of Africa, but she was the only one to survive and have girls that passed on her mitochondrial DNA. Kind of interesting.