The chromosome may contain regions that promote their DNA’s spread by killing sperm that carry Y chromosomes. However, Y chromosomes may have evolved counter mechanisms over time
Humans 23 November 2022
Some modern humans that had not long left Africa may have evolved an X chromosome that carried “selfish” DNA
SCIEPRO/SCIENCE PHOTO LIBRARY
Around 50,000 years ago, a new X chromosome appears to have been introduced into modern humans that had not long left Africa.
There was probably exceptionally strong selection for parts of this chromosome because, today, most people of less-recent African ancestry have inherited those regions.
Kasper Munch Terkelsen at Aarhus University in Denmark, who led the research, thinks these regions may contain bits of so-called selfish DNA that promote their …