Preface

In some quarters it is fashionable to try and argue that mating males (especially human ones) are surplus to requirements when it comes to the progress and continuation of their species. That animals can be cloned and that technology enables some men without sperms in their ejaculate to father children appear to confirm this. But this book aims to dispel any such contention and to explain how, through mating, a male mammal fulfils an indispensable role in the maintenance of its own species.

Reproduction by means of cloning can only have a stultifying effect in the long run, and is ultimately likely to be lethal. Like those of a clockwork toy, the mechanisms of survival need to be wound up from time to time, if for no other reason than to survive the vagaries of the environment. In mammals, including man, this is achieved by the periodic injection of new and randomly different genes through sexual reproduction. The evolutionary development of sex has thereby introduced an extra dimension to the natural selection (survival of the fittest through accidental mutation) of asexually reproducing species.

In mammals, the unison of eggs and sperms, each having half of the normal complement of chromosomes, has facilitated a reduction in the incidence of too many morbid mutations, whilst enhancing the possibility of good ones being introduced. The importance of this arrangement is that favourable characteristics can be achieved in one generation, or a few, without significantly affecting the phenotype (overall body characteristics) of the species. Survival in mammals has depended upon this method of ensuring adequate genetic variation. It is facilitated by having males in the population in addition to females. The wider the mix of genes by different types within a species, or even from a closely related species, the tougher the offspring are likely to be. Cross breeding (hybridization) between different species of baboons has demonstrated that new and doubtless beneficial characteristics can soon make their appearance in a group.