Baculum

The baculum (Latin os penis, Os priapi or Baculum ) is a bone in the male reproductive organ (penis ) of many mammals.

The penis is a bone ossification of Penisschwellkörpers ( Corpus cavernosum penis ). A penis bone that most primates (excluding humans, some peg-tail monkeys and Sulawesi tarsiers ), almost all predators (except hyenas and Musangs ), guinea pig relatives and mice relatives, beaver, insectivores, bats, giant slides, bristle hedgehog and some moles. For some it's just a verknorpelte structure. Fossil in particular the structure of the cave bear (Ursus spelaeus ) is known.

The morphology of the penis bone is sometimes used to distinguish closely related species ( systematics). One of the penis bone -like structure can occur in people who suffer from rare genetic diseases.

Lack of Baculum in humans

The evolutionary biologist Richard Dawkins proposed the controversial hypothesis that human beings have lost the penis bone in the course of evolution, because men are supposed to have no penis bone allows the women you to check the health of the mating willing man. Because erection problems are often a result of various physical or mental illness and factors (such as diabetes mellitus or stress). Since an erection produced by a penis bone would permit no such opinion, the women might have preferred paired with men whose health they could better estimate. This was the necessary selection pressure for the reduction of the penis bone.

It should be noted, however, that evolution produces features or can disappear if it is not a disadvantage. The evolution does not necessarily lead to certain characteristics, because it is an advantage, let alone that they must have some meaning. In addition, other evolutionary advantages of the absence of Baculums are possible, which may be related, for example, with the upright posture of humans.