MEN LOST THEIR PENIS BONE DUE TO MONOGAMY
- Ibone Thate Arrazola
- 19 dic 2016
- 1 Min. de lectura
The baculum is a bone placed in the penis that appears in most of the male mammals, including our nearest relatives, chimpanzees. Considered as "the most diverse bone" because of its variations in length, width and form, scientists have wondered why humans don´t have it. Why has Homo sapiens lost this bone? Is this loss advantageous?
Searchers of the University College of London have analyzed the baculum´s evolution in carnivores and primates, concluding that its disappearance concurs with the increasing levels of intra-sexual selection.
In order to understand this, first of all we have to explain the baculum´s function: its presence allows a long-lasting intercourse and increases the proximity to the uterine neck, improving reproductive success . This is advantageous for species that show poligamy and in which males are forced to compete among them in order to mate the highest amount of females.
And the strategy is very simple: increasing the time of copulation, this means, maintaining the female occupied. This way, the animal avoids that the female copulates with other males. At leasts, during the time he is with her.
Monogamy was established as the dominant reproductive strategy 1.9 million years ago during the time Homo erectus lived. During this period, the intra-sexual competence decreased and the baculum wasn´t needed any longer.
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