Inbreeding

[desertrat]

Why does inbreeding cause an increased risk in genetic damage?

[simon_says]

If a family has any genetic defects, any inbreeding will "multiply" that defect, thus exaggerating the problem. The Royal Family in days gone by have suffered this problem. I know this isn't a technical explanation, but this is my understanding of it

[snaykz]

It's quite difficult to explain without diagrams, but I'll try. Human characteristics (as with all animals) are defined by a combination of genes from BOTH parents. If, for example, someone has blue eyes, they must have received 1 blue eye gene from each parent. If they have brown eyes they COULD have received 1 brown eye gene from each parent. However, because the brown eye gene is dominant over the blue eye gene, one of each gene would result in brown eyes. Nevertheless, the blue eye gene would still be present within the person, even if it is not visible externally. This is known as a recessive gene. Obviously the genes which cause birth defects (which I think is what you are referring to) are much rarer than the blue eye gene, but the principal is the same. Because family members have a similar genetic makeup, the likelyhood of transference of these rare genes is greatly increased. I'm not quite sure what you mean by genetic damage, most defects from birth are caused by natural genetic processes. Only external factors such as radiation can cause damage to the genes themselves.

[christina801]

Because its nasty