Sex is an extremely inefficient method of multiplication. An animal that forsakes sex can reproduce twice as quickly as one that does not. Once, long ago in the history of life, sex offered sufficient advantages to overcome that inefficiency. In particular it offered greater variety, to cope with changing environmental circumstances. But for the vast majority of animals alive today, including ourselves, that is no longer true. Males exist solely to fertilise females, and it is females who control the reproductive process. In evolutionary terms, males are redundant...