Dawkins' books, especially the earlier ones (e.g. Blind Watchmaker), are quite a good and gentle introduction.
Yes, you are right that life originally started as asexual reproduction and sexual reproduction appeared later; my answer was more about the likelihood of a species that already reproduces sexually moving towards asexual reproduction.
Regarding the question of why the asexual->sexual shift happened in the first place, the wikipedia article on asexual reproduction has this to say:
Current hypotheses [2] suggest that asexual reproduction may have short term benefits when rapid population growth is important or in stable environments, while sexual reproduction offers a net advantage by allowing more rapid generation of genetic diversity, allowing adaptation to changing environments.
>> Yes, you are right that life originally started as asexual reproduction and sexual reproduction appeared later
No, that's a hot research topic.
E.g. a popular hypothesis is than in an RNA world very early and simple organisms had inefficient metabolism and error-prone genetic copy. They didn't have enough energy to sustain a backup of their genetic information, RNA is not very stable, etc. So the only way to keep functioning was to constantly mate with other organisms and exchange good replacements for broken genes.
Thanks for your replies (Need to think more about them) and book recommendation.
These topics are truly fascinating. Many seem to consider them 'soft' compared to Physics, but in some ways, I find some of the questions involved at least as deep and fundamental (or even more) as those currently being asked in the Physics discipline.
Yes, you are right that life originally started as asexual reproduction and sexual reproduction appeared later; my answer was more about the likelihood of a species that already reproduces sexually moving towards asexual reproduction.
Regarding the question of why the asexual->sexual shift happened in the first place, the wikipedia article on asexual reproduction has this to say:
Current hypotheses [2] suggest that asexual reproduction may have short term benefits when rapid population growth is important or in stable environments, while sexual reproduction offers a net advantage by allowing more rapid generation of genetic diversity, allowing adaptation to changing environments.