Natural selection, genetic drift, and gene flow are the mechanisms that cause changes in allele frequencies over time. When one or more of these forces are acting in a population, the population ...

Genetic drift can even counteract natural selection. Many slightly beneficial mutations can be lost by chance, while mildly deleterious ones can spread and become fixed in a population.

"Regressive evolution," or the reduction of traits over time, is the result of either natural selection or genetic drift, according to a study on cavefish by researchers at New York University's ...

The result does not suggest that neutral evolution is unimportant—after all, some of the remaining 81 percent of genes may have diverged by genetic drift. But it does prove that natural ...

Both natural selection and genetic drift continue to affect our species, thus, humans are "undoubtedly" still evolving, Hodgson said.

Humans are still evolving – and scientists don't know why. Natural selection isn’t the only factor driving evolution, says Laurence D Hurst.And it’s happening faster than ever before ...

He noted that factors like small populations, geographic isolation and the harsh desert ecosystem that produced population bottlenecks favored genetic drift over natural selection in these pupfish ...

Natural selection, genetic drift, and gene flow are the mechanisms that cause changes in allele frequencies over time. When one or more of these forces are acting in a population, the population ...