The debacle of the Darwin-Wedgwood family

Much is known about Charles Darwin (1809-1882) and his fascinating studies, such as the Origin of the Species (1859) or The Descent of Man, and Selection in Relation to Sex (1871). But, what could you tell me about his family? Did you know that he had ten children? And did you know that he was married with his first cousin? Come with us to discover more about this prodigious man and the old and ugly habit of inbreeding.

Charles Darwin and Emma Wedgwood

Inbreeding

Today's topic: Inbreeding. What is inbreeding and which problems brings with it?

For sure we all have heard about inbreeding. When we hear about the Amish, about some royal families or even in some historical games (Crusader Kings I and II), inbreeding is almost always present. It means marriage, union or reproduction between individuals of common ancestry, ie. of the same family or lineage.

Picture from xenohistorian.faithweb.com

Also, inbreeding usually represents something bad. Some traits come with it, such as reduced fertility, facial asymmetry, lower birth rate or increased genetic disorders (albinism, hexadactilia, etc.). But, genetically, why is inbreeding so deleterious?