It has been reported that Charles Darwin was birth through incest and that he married his cousin; who birthed children that were born of ill defects.
According to reports:
Charles Darwin, the author of the theory of evolution, may have been right to worry that his children’s health had been affected by the inbreeding in his own family, especially that of his wife, Emma Wedgwood, who was his first cousin.
A calculation based on first-cousin marriages over four generations of the two dynasties suggests that Darwin’s children had a mild degree of inbreeding, measured by the chance of inheriting the same version of a gene from both parents. Possible consequences of inbreeding can be seen in the children’s illnesses and degree of infertility, three researchers report in the current issue of BioScience.
Darwin, after discovering the lack of vigor in inbred plants, worried that first-cousin marriages like his own might have adverse genetic effects, and that his own children might be affected.