How many people do you need to start a civilization without imbreeding?

Answer 1

Inbreeding is a problem because of harmful genetic mutations. The system of dominant and recessive genes (as explained by Mendelian inheritance laws) serves as a check and balance to prevent genetic mutations from being passed on. If a genetic mutation/disease is on a recessive gene, it will only be passed on to offspring if both parents have the flaw in their recessive genes. If the parents are closely related, there is more of a chance of that happening.

Your question is religious in nature because if the Biblical account of Creation is correct, then God created only 1 couple, Adam & Eve, and their offspring would have had to marry siblings or cousins for the first few generations.

There are two reasons why this would not have been a problem. One is that Adam and Eve had brand new genes, with no mutations to pass on. The other is the extremely long lifespans of the people who lived before the flood. The Bible only names the first 3 sons of Adam & Eve, and then it says that Adam lived 930 years and had other sons and daughters. Eve could have given birth to hundreds of children. I don't envy her!

Answer 2

It is difficult to provide an exact number, as it depends on factors such as genetic diversity and population size. However, a general rule of thumb is around 160 individuals to maintain genetic diversity and prevent inbreeding in a small isolated population.