Gene drive is a natural phenomenon whereby a certain version of a gene is passed on preferentially to the next generation and thus can quickly spread throughout a sexually reproducing population.
Scientists already knew that a version of a gene called huntingtin caused the disease.
A folk song is a meme, an evolutionary biologist might say the cultural version of a gene.
This happens when a new version of a gene confers such a survival advantage that it sweeps through the population.
For instance, people with a certain version of a gene called ApoE are much less likely to develop Alzheimer's.
Each set is known as a haplotype; each specific version of a gene is called an allele.
In them, a variant version of a gene called DCT may contribute to light skin.
On the practical side, many genes have more than one effect, and swapping out the bad version of a gene can have unpredictable complications.
Compared with male smokers, women who smoke also have a more active version of a gene that makes chemicals in cigarette smoke more harmful to cells.
Even more strikingly, Dr. Williamson's group reported that a version of a gene called DAB1 had become universal in Chinese but not in other populations.
Most Europeans have wet earwax, because they have at least one copy of the "wet" version of a gene (catchily called ABCC11).
