New study suggests viruses are deadlier to men than women.
Charles Darwin’s Origin of the Species has changed the world of science since its first publication in 1859. In the book, Darwin argues that evolution of animals is based around natural selection, fitness, and genetics.
Now a study by researchers, Francisco Úbeda and Vincent Jansen from the Royal Halloway University, take Darwin’s theory of evolution one step further. Úbeda and Jansen latest research discovery argues viruses have evolved to affect men in more harmful ways than women.
Published in “Nature Communications”, the study titled The evolution of sex-specific virulence in infectious diseases, explains that viruses may have evolved to be less harmful to women than on men in order for the virus to be passed onto future generations.
Tuberculosis, the human papillomavirus (HPV) and the Epstein-Barr virus affect men differently than women. In fact, if a man becomes infected with tuberculosis they are 150% more likely to die. Or, if a man is infected with HPV they are 500% more likely to develop cancer.
Why does this happen?
Viruses work by replicating themselves inside of a host. Whether it be a single cell organism such as a bacteria or a human white blood cell. The goal of the virus is to hijack the cell’s DNA replication pathway to produce more and more copies and spread to other hosts.
Ultimately, the virus’ goal is to use the host and spread it to the next host. An unfortunate consequence of this replication pathway, is that the host becomes too sick to serve as the virus’ home.
After testing, researchers discovered that while pathogens affect both men and women, natural selection favors viruses to become less harmful to women than men. Why? Because the virus is more likely to spread through nursing.
Researchers argue that if viruses are too aggressive in women, than they decrease their chances of spreading. Ultimately, evolution has pressured viruses to become less aggressive in women in order to spread.
At the moment, how a virus is able to affect women differently than men have scientists confused. But, scientists believe they have an idea on how it works. Researchers argue that a virus may be able to detect the different hormone levels between men and women, consequently changing their virulence – the amount of damage the virus is causing the host.