We are studying the origin of PCD as a means of coping with deleterious mutation. While accepting the importance of variability in the evolutionary process and the role of sex in creating variation, my research has led me to explore alternative explanations for the ubiquity of sex, especially the role of sex in coping with genetic error. The most obvious consequences of sex are its risks and costs. I believe that individuals would not undertake such an inherently risky and costly process as sex, unless they were in trouble to begin with. Genetic error, both mutation and damage are a constant threat to the integrity of the organism and the vitality of life.
Sex efficiently repairs damage while masking the effects of mutation.
In addition, the nonlinearities involved in mating, help explain the existence of species as relatively distinct entities. These themes are developed in my book Eros and Evolution, a Natural Philosophy of Sex .