male body facts

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They’re Designed to Keep Other Men from Coming Between Them and Their Beloved
Talk about competitive! A 2004 study in the journal Evolutionary Psychology suggests that the unique shape of the human penis evolved not only as a way deposit sperm into a vagina but also to displace the semen of a recent rival. Researchers from SUNY Albany tested an array of artificial phallus shapes and found that the penile head, with its pronounced ridge, does a fine job of ousting sperm that had been left behind and replacing it with new contenders.
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