We don't know exactly why men are taller than women on average, but we have some genetic clues. On average, human males tend ...

Sex chromosomes are the genetic elements that define a person's biological sex. Learn about the XX and XY chromosomes, the sex determination system, and other chromosome combinations.

The octopus just revealed another one of its secrets: what determines its sex. University of Oregon researchers have ...

That is because sex chromosomes are normally very old; having evolved such a long time ago, all kinds of other effects from the environment will have contributed to genetic evolution in the meantime.

The exception was the hypothesized sex chromosome, which was present in two copies in some individuals and in a single copy in others—exactly as one would expect from a ZZ/Z0 system of sex ...

Human biological sex is determined by the sex chromosomes X and Y. In most cases, females possess two X chromosomes, while males have one X and one Y. However, there is some evidence that the Y ...

University of Adelaide researchers discovered monotremes use a completely different sex determination system than other mammals.

Researchers have identified a sex chromosome in the California two-spot octopus. This chromosome has likely been around for 480 million years, since before octopuses split apart from the nautilus ...

Other ancient sex chromosomes have been discovered in plant groups like mosses and liverworts, which were some of the first plants to evolve. And insect sex chromosomes might be 450 million years ...

University of Oregon researchers have identified a sex chromosome in the California two-spot octopus. This chromosome has likely been around for 480 million years, since before octopuses split apart ...