Have you ever heard of Haldane’s Dilemma? If you’re an evolutionist, probably not – it is not a popular discussion. In 1957, J.B.S. Haldane, a geneticist, calculated that new beneficial mutations only occur once every 300 generations (or approx. 6000 years). Evolution requires millions of beneficial mutations to have occurred to transform an ape-like creature into a recognizable human species. Giving human evolution an inflated amount of 10 million years to have occurred (much more than typical evolutionary timelines), only 1667 beneficial mutations could have occurred. No way near enough for crucial physical changes such as tripling the brain size, upright posture, hand dexterity, vocal speech organs, distribution of hair, and much much more.
This site offers the technical details of Haldane’s calculation methods and the most popular evolutionary responses.