Our genes tell a great deal about us and the history of our species, including details about ancient migrations, subpopulation size and structure, and even estimates of the overall human population size in the past (1).
Researchers developed a new method of comparing paternally inherited Y-chromosome (NRY) and maternally inherited mitochondrial DNA (mtDNA). The new method revealed a greater female population throughout history.
According to a new genetics study published by Investigative Genetics on Tuesday, females have had a greater population than males throughout history.
Researchers from the Max Planck Institute of Evolutionary Anthropology developed a high resolution Y chromosome sequencing assay that allows them to get paternal and maternal histories of similar quality and resolution, to make a direct comparison.
The study compared the paternally inherited Y-chromosome (NRY) and maternally inherited mitochondrial DNA (mtDNA) of 623 males from 53 countries. The Y chromosome is passed on through the male line, and can provide information about paternal family history. Conversely, we inherit our mitochondrial DNA from our mothers, providing insights into our maternal branch ancestors. Results indicated that there was a greater female population prior to the out-of-Africa migration and many other migrations that subsequently followed (2).
One driver of a larger female population may be the practice of polygyny, where one male would mate with several females in a community. Women thus had a greater genetic contribution to the global population than their male counterparts.
The study’s results confirmed previous findings that indicated a greater genetic difference in paternal NRY than in maternal mtDNA. The new techniques revealed however, that the genetic differences were not as large as they were previously thought to be.
Mark Stoneking, an author on the paper said, “Our new sequencing technique removes previous biases, giving us a richer source of information about our genetic history. It allows us to take a closer look at the regional differences in populations, providing insights into the impact of sex-biased processes on human genetic variation.” (3)
Sources:
1. Rose, S. (n.d.). Females Dominate throughout History. BioMed Central blog. Retrieved September 27, 2014, from http://blogs.biomedcentral.com/bmcblog/
2. Lippold, S. (2014). Human Paternal and Maternal Demographic Histories: Insights from High-Resolution Y Chromosome and mtDNA Sequences. Investigative Genetics, 5(1), 13.
3. New Analysis of Human Genetic History Reveals Female Dominance. (2014, September 24). ScienceDaily. Retrieved September 27, 2014, from http://www.sciencedaily.com/