In a new study published in the American Journal of Human Genetics, University of Pennsylvania researchers Joseph Lachance and Sarah A. Tishkoff investigated a process called gene conversion in the context of the evolution of human populations. They found that a bias toward certain types of DNA sequences during gene conversion may be an important factor in why certain heritable diseases persist in populations around the world.
It’s an early lesson in genetics: we get half our DNA from Mom, half from Dad.
But that straightforward explanation does not account for a process that sometimes occurs when cells divide. Called gene conversion, the copy of a gene from Mom can replace the one from Dad, or vice versa, making the two copies identical.