Y chromosome is steadier than science used to think
                                
                                
                                    (Newser) -
                                    Relax, guys. It's no longer certain at all that you'll be extinct in 100,000 years, as one genetics professor predicted. Another scientist had decided that the all-important (to men) Y chromosome was losing genes at a rate that would make it non-existent in some 5 million years,...