If, over 4,300 years ago, 3 couples began the repopulation of the earth--the population today should be around the 7 billion mark where it is. If, on the other hand, humans have been here close to a million years, then we should have more than two hundred trillion trillion.
In the selfsame day entered Noah,
and Shem,
and Ham,
and Japheth,
the sons of Noah, and Noah's wife,
and the three wives of his sons with them,
into the ark;
Genesis 7:13