Discovery News & Views has a good post on the problem sex presents for Darwinism. No, not the act of sexual intercourse, but the origin of sexual organisms (male and female). Asexual organisms have the ability to produce offspring at twice the rate as sexual organisms, and they never fail to reproduce on the grounds that they can’t find a mate. Given these clear biological advantages of asexual reproduction, how did sexuality ever evolve? How did it come to dominate in the struggle for survival? Sexuality should have been outcompeted very early on. Even more intriguing is the question of how asexual organisms could gradually evolve into sexual organisms without dying out in the process. A partially formed reproductive system does not result in progeny. Even if we find a way to hurdle the problem of a gradual transition, what is the likelihood that random mutations would create two different, and completely complimentary reproduction systems? And what is the likelihood that this would happen at the same time? Apparently chance is just really lucky.
A couple of new Darwinian explanations have been offered to solve this long-standing Darwinian conundrum. The post explores these explanations and shows how they fall short of explaining what needs to be explained. Check it out.