According to research studies done recently, the Y chromosome is in a state of genetic decay. The Y chromosome apparently once had 600 genes in common with the X chromosome, but over the duration of its evolution throughout the years, lost all but 19 of them. There is a debate in the science world about this currently, but many scientists, called the “rotting Y” group, believe that since the chromosome has lost so many genes already, its extinction is likely if not inevitable. Another group of scientists has chosen to view this data in a completely different light and see it as the Y chromosome shedding all but the genes completely necessary for survival . Scientists Dr.Bellott and Dr. Page argue that XX cells are “subtly but fundamentally different” from the XY. And, “they are different throughout the body in tissues and organs that show no obvious anatomic differentiation.” They are using this knowledge to try and customize medicine to tailor to the differences between the cells, a concept that could possibly lead to major developments in the medical world.