From The Telegraph:
Evolution could already be at an end, leaving the human race more uniform than ever, argues Steve Jones:
Things ain’t what they used to be – but when were they? Not in 18th-century Japan, when the poet Ejima Kiseki wrote: “The shrewd observer of the modern scene will note that sons are altogether inferior to their fathers, and that the grandson rarely offers hope for improvement.” Plato felt much the same and Simon Heffer, the Plato de nos jours, agrees. Markets, crime, education; every day, in every way, things seem to get worse and worse. If the philosophers have it right, the human race is in decline – social, moral and, in the end, biological. Now science can test at least the last of those claims.
Because we understand how evolution happens, we can also guess where it will go next. It is, in Darwin’s words, “descent with modification” – genetics plus time. The process turns on differences: in genes themselve, and on natural selection – on inherited variation in the ability to copy them. Isolation helps changes to build up and, in time bears, Bushmen and Britons evolve from a common ancestor. Human diversity is so great that every sperm and egg ever made is unique.