Study warns about male chromosome [rt.com]
Everything is obsolete. You are not the same person you were yesterday. Most of us think we are, however. We live in the NOW but many can think of a past. There is no past to live in.
Some would argue that even "now" is an illusion and that we exist in a transience, where even the time taken to perceive the present is already past before it is registered in memory and understanding.
@LenHazell53 hence why it is advisable to look several cars in front of you when driving?