My new & hot this week is an article in Medical News Today this past Monday.
The article talks about research on fruit flies that may shed light on the issue of if survival of the fittest is true, then why is there is so much natural genetic diversity. It is an interesting paradox; you'd think that if the best fit survived, when all the surviving individuals in the long run would have very similar genomes. However, as can be seen on all levels of organisms, genetic diversity runs rampant and also allows natural selection to occur.
Anyway, the article explains how there are two types of foraging genes in fruit flies (which are also found in humans...I wonder what we forage for...), the Rover gene and the Sitter gene. The experiment involve the idea of "negative frequency-dependent selection," which says that individuals that are not the same as everyone else has a better chance of surviving. The experiment found that Rovers in a population predominated by Sitters survive better and that Sitters in a population predominated by Rovers have higher survival rates. This is because these unique individuals in the population have unique ways of finding food and thus are competitively advantageous. This data shows that there isn't always one best fit variant, but that one variation helps to promote the other, and thus genetic diversity is maintained in the population, and natural selection can occur.