Is sexual or asexual better

Answer 1

Asexual reproduction is favourable if horizontal gene transfer can make up for the lack of diversity within species. Horizontal gene transfer is when two mature organisms can switch or share different genes. (Many bacteria and archea can do this) Horizontal gene transfer is quite difficult for multi-cellular organisms, so sexual reproduction is preferable.

The goal of reproduction is to create offspring that will survive in changing environment - so there must be a mechanism to create many different kinds of offspring. Sexual reproduction affords this.

However - the optimal form of reproduction is to have the choice to reproduce either asexually and sexually. If there is a disaster (for humans) or a new antibiotic (for bacteria) it may be preferable to reproduce asexually for a while if no other similar species are around. Later, when the population is big enough, sexual reproduction can begin to recover genetic diversity. (I am assuming that clones don't reproduce with themselves the whole time).

This may be the new and improved 'bisexual' of the future.