A RUBY IN THE RUBBISH - BENEFICIAL MUTATIONS, DELETERIOUS MUTATIONS AND THE EVOLUTION OF SEX

This study presents a mathematical model in which a single beneficial mutation arises in a very large population that is subject to frequent deleterious mutations. The results suggest that, if the population is sexual, then the deleterious mutations will have little effect on the ultimate fate of the beneficial mutation. However, if most offspring are produced asexually, then the probability that the beneficial mutat ion will be lost from the population may be greatly enhanced by the de leterious mutations. Thus, sexual populations may adapt much more quic kly than populations where most reproduction is asexual. Some of the r esults were produced using computer simulation methods, and a techniqu e was developed that allows treatment of arbitrarily large numbers of individuals in a reasonable amount of computer time. This technique ma y be of prove useful for the analysis of a wide variety of models, tho ugh there are some constraints on its applicability. For example, the technique requires that reproduction can be described by Poisson proce sses.