How the Y Chromosome Drives Evolution

Dr. Marianne Legato explains that the male "Y chromosome", which at one point was called a wasteland, has genes responsible for the "housekeeping issues" in tissues. It's not just dedicated exclusively to male fertility and determining the male sex in the developing fetus. The aspect that is not appreciated about the Y chromosome, is that because it's exterior, and because so many sperm are produced in any given day, the mutations are enormous. And It is the Y chromosome, actually, that is driving evolution. It gives us a huge palette of mutations to choose from as we go on from generation to generation. It's the Y chromosome that drives evolution in a very important way.

The location of sperm is outside the body, where it's subjected to radiation and temperature changes. It's not protected like the ovum is. The first thing is that it's very vulnerable to environmental stresses. The second thing is that there are millions of sperm produced each day. So there is an enormous turnover in the rate in which DNA mutations and damage occurs in these sperm. So these mutations give us a huge palette of traits to choose from when selecting individuals best suited for the environment into which they were born. So the Y chromosome is a very important "engine" for developing newer and better candidates for the world in which we live.

Dr. Marianne J. Legato, MD, FACP, a specialist in Gender Specific Medicine, or Women's Medicine and Men's Medicine respectively. Dr. Legato is part of the Women's Heart Foundation, an international gathering of nurse executives, civic leaders, community health directors, member hospitals, partners, providers and corporate sponsors who want something done to fight women's heart disease. Dr. Legato promotes the inclusion of women in clinical trials of relevance to the health of both men and women. She furthers the study of biological differences in men and women, and how gender plays a role in the diagnosis and treatment of disease, all to benefit patients.