Evolution by natural selection may disappear in homo sapiens but may be replaced with evolution by human intervention?

Answer 1

It means scientist using clone technology to breed a super-human, as it may be called. Humans have intervened in the natural selection of the species by using medical means to prolong life and to allow people to procreate when they could not have done so naturally. (This only affects the natural selection of the species when it affects whether or not a person can procreate, so medical intervention that prolongs life well after the age of being able to procreate is unlikely to have an effect on natural selection, unless it allows procreation with aged and therefore less healthy sperm or eggs.) This will eventually have an effect on the species by increasing the likelihood of heritable traits being passed on that are not to the benefit of the species. Evolution by human intervention would require that the intervention changes the set of people able to procreate. In vitro fertilisation would be one means by which this occurs if the difficulty with conceiving is a heritable one. The abortion of foetuses of the less desired sex, or bearing undesired traits or diseases is another.