Why Do Some Male Orangutans Have a Flange While Others Do Not?

It might not have been keeping you awake at night but here’s a question.  Why do some male orangutans have a flange – that big flap of skin around their faces – while others don’t? The answer is we probably know the why but only possibly the how.  The Ark in Space has the story, and yes – it is all about the passing on of genes but there's more.  Even if you have a flange, as an orangutan you still would not be out of the woods (which, if they could speak, would probably not be the idiom they would use as generally, they seem to like being in the woods…).

Image Credit LK-GA