[cripplecreek]

With 2 people its pretty unlikely without divine intervention. the odds increase a lot with every doubling of the number of people.

I know that for populating an alien planet, theorists say that around 40,000 is ideal.

[Vigilanteman]

We don't know for sure how long Eve lived, but doesn't the book of Genesis say Adam lived to 930. Assuming Eve lived about the same length of time and, as most women are, fecund for about half her life, that makes many opportunities for reproduction.

My grandpa was always fond of saying that it doesn't hurt a cow to have a calf every year.