Aposthia
Aposthia is a rare congenital condition in humans, in which the foreskin of the penis is missing.
Toward the end of the nineteenth century, E. S. Talbot claimed in Medicine that aposthia among Jews was evidence for the now-discredited Lamarckian theory of evolution. In his work, "The Variation of Animals and Plants under Domestication", Charles Darwin also mentioned cases of "born circumcised" babies as "conclusive evidence" for the now-discredited blending inheritance.