It’s almost hard to believe, but there is a new theory that suggests that sex between humans may have evolved as a defense against parasites. It sounds a bit far-fetched, but below is the hypothesis that scientists are currently discussing and recently published in the July 09 issue of American Naturalist.
The theory presented in the [...]

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According to a recent study, many common protozoans living in the human gut are extremely contagious, and likely to be widespread in many animal species, causing unsettling digestive disorders.
The study was conducted by the Norwegian School of Veterinary Science, in early 2009. They found that parasites of the groups Cryptosporidium and Giardia are enormously widespread [...]