Personally I don't think I'd marry a third cousin.
chen - It's not that they'll necessarily have an abnormal baby. But any genetic deficiencies or weaknesses that are common to that families DNA will potentially be strengthened by the inter-breeding, and after many generations the defect or weakness may manifest itself in some way.
Dogs are a good example of this. Mixed breeds generally have longer life spans than pure breeds. The pure breeds mate within their breed and strengthen the defects common to that breead. For example, dalmation dogs are prone to deafness because this is a genetic defect common to their breed.
Personally I don't think I'd marry a third cousin.
chen - It's not that they'll necessarily have an abnormal baby. But any genetic deficiencies or weaknesses that are common to that families DNA will potentially be strengthened by the inter-breeding, and after many generations the defect or weakness may manifest itself in some way.
Dogs are a good example of this. Mixed breeds generally have longer life spans than pure breeds. The pure breeds mate within their breed and strengthen the defects common to that breead. For example, dalmation dogs are prone to deafness because this is a genetic defect common to their breed.