Because of me, I have to be amorous

Children and grandchildren of male rats that mate with many female mice have higher health and fertility than descendants of "guys" who comply with the "monogamous" regime.

Artwork: mustknowhow.com.

A previous study demonstrated that flies of the fly that ate the Drosophia fruit would produce healthier babies if they mate with many female flies. Flies are invertebrates, so the scientific community does not know the same trend occurs in vertebrates - including humans - or not. So Renee Firman and Leigh Simmons - two scientists from the University of Western Australia - decided to find out.

Two researchers raised a number of mice - one of the vertebrate animals. When they reach adulthood they divide the males into two groups. One group mates with many female mice, and each one in the other group only does ' that ' with a partner, Livescience said.

After eight generations of two researchers, the sperm of male mice mating with more females became stronger and faster than those that mated with a female mouse. In addition, the number of sperms of 'pluripotent' mice is also greater.

To find out the possibility of mating success of the two groups, experts for male mice ' faithful ' and ' lovebirds ' mate with a female. The results showed that the male did ' that ' first, his sperm would swim to the egg first. But if the male ' sexually ' male mice mate later, their fatherhood is still higher than the ' faithful ' mice by 19%. Thus, overall, the ability to successfully fertilize the ' polygon ' mice is still higher.

The competition between sperm is a form of natural selection in the animal world. Males with healthy sperm always have a higher chance of fathering than rivals. The race between sperms only occurs when a female mates with many males. In order to increase the generation of next generation genesang, males must produce strong and fast "sperms ".