This seems counter-intuitive, since when we think about natural selection, we often think about beneficial traits, like a mutant butterfly with camouflaged wings, which escapes predators and passes this advantageous color to its offspring. But in the case of Apert’s syndrome, the gene switches end up making fitter the mutant testis cell, while this is not the case in the human beings who develop from the resulting sperm. It just seems so odd that the testis that causes such a harmful disease for the kid apparently has an benefit over cells without the mutation, Calabrese said. While theories have already been suggested, it’s not however known what this advantage is for certain, he added.Coli was not the only microbe found via the tests. The CDC also discovered Cryptosporidium and Giardia, two parasites that are spread through feces and trigger diarrhea, in less than 2 % of samples. A mouthful of Cryptosporidium, referred to as Crypto, is enough enough to cause an infection, which may lead to stomach cramps, dehydration, nausea, vomiting, fever and weight loss. Symptoms will come and go over the course of month, but people who have weakened immune systems may develop fatal illness, based on the CDC. Giardia can cause symptoms for you to two weeks, including diarrhea, gas, stomach or adominal cramps, greasy stools and dehydration, according to the ongoing health agency.