The current wisdom on cousins marrying is that it's not all that genetically dangerous -unless it happens over several generations. That is exactly what happened in Charles Darwin's family, according to James Moore, professor of science history at the Open University, who studied Darwin's family tree. Charles Darwin married his first cousin Emma Wedgewood. Of their ten children, three died young and three more had no children. Some notes:
Link -via Arbroath
- Darwin's maternal grandfather, Josiah Wedgwood, the founder of the pottery dynasty, had married his own third cousin, Sarah, and had eight children.
- The couple's eldest daughter, Susannah Wedgwood, married Robert Darwin, her cousin. Charles was their child.
- Meanwhile, Josiah and Sarah's second eldest son, also Josiah, had nine children, of whom four, including Emma, married first cousins.
Moore, who is about to publish a research paper on Darwin, said: "The results of this unintended experiment in close-cousin breeding are striking — 26 children were born from these first-cousin marriages, yet 19 of the offspring did not reproduce. Five died prematurely, five were unmarried and considered deficient, and nine married without issue.
Link -via Arbroath
Maybe they just had genes for infertility that were getting passed around. *shrug*