Selection can also work at the gene level. When a diploid individual (one that has two copies of its genome) produces haploid gametes (sperm cells or eggs, which have only one copy of the genome), each parental gene has a 50-50 chance of ending up in the gamete population — usually. Sometimes, though, for reasons that are poorly understood, one gene is better than another at making it into the gametes. This phenomenon is selection at the gene level, or meiotic drive.
Meiotic drive occurs when a particular gene has better than a 50 percent chance of making it into the gamete pool and from there to the offspring. Although on its face, selection at the gene level seems to be at odds with how you expect evolution to work, by taking a closer look at meiotic drive, you can see that the same evolutionary forces are at play.
Was this article helpful?