If we consider Adam and Eve as the first human beings on earth.

Thought #1: Suppose Adam had a son and daughter. In order to get further down the
human population chain - who did adam and eve's next generation mate with ??

Thought # 2: If Adam and Eve just had a son - who was the mother of adam and eve's
grandchild?

Thought # 3: If Adam and Eve just had a daughter - who was the son in law for their daughter?

Incest is strictly forbidden in every section of society. Can anybody throw some light on the evolution of humans from the above theory?

In the old testament I had quite many shocks when I read it since it was prescribed for our literature syllabus!!! Socio- religious-political-cultural tangles in explanations can be unconvincing and hard to digest many historical facts. In very primitive stage of development with no civilisation awareness man seems to have been not very different from beasts which do not consider incest objectionable. It is our later enlightened, sophisticated healthy ideas which drew the differentiating rules, I suppose!!!!

According to Christianity, Adam and Eve were the first humans. what about the rest of the numerous religions and it's first human couples? I guess.. christian Adam mated with Hindu girl. and christian Eve mated with a muslim guy ..So..it was not incest at all as many make out! After all..Greeks and Hindus are the oldest race...with Africa thrown in!

You must be kidding, umbrella! At least your supposition pleases our sense of propriety as we have grown up with! In the Bible after the destruction of Sodom and Gomorrah for their evil sexual ways generations were produced from the daughters and father left out from the inferno! I felt yucky and asked my Catholic nun teacher about it and without giving direct, convincing explanation she told me there are many more such shocks in the Bible! What a horrid 'fact' about survival/procreation! Literally beastly! Similar unpalatable stories in Hindu mythology rather amuse me than revolt me!