Using diploidy and dominance is one method to enhance the performance of genetic algorithms in dynamic environments. For diploidy genetic algorithms, there are two key design factors: the cardinality of genotypic alleles and the uncertainty in the dominance scheme. This paper investigates the effect of these two factors on the performance of diploidy genetic algorithms in dynamic environments. ...

Explanations of the evolution of diploidy have focused on the advantages gained from masking deleterious alleles. Recent theory has shown, however, that masking does not always provide an advantage to diploidy and would never favor diploidy in predominantly asexual organisms. We explore a neglected alternative theory which posits that, by doubling the genome size, diploids double the rate at wh...

According to the repair hypothesis, sex originated as a cooperative interaction-the benefit being damage repair. As with all cooperative strategies, cooperative sex may be vulnerable to selfish mutants. The purpose of the present paper is to understand what implications such selfish mutants may have both for the origin of sex, especially in competition with asexual diploidy, and for the elabora...

Sperm cells from 45 infertile patients were investigated for disomy rates of chromosomes 1, 7, 10, 17, X and Y as well as for diploidy by single- and double-target in-situ hybridization. The patients who attended the infertility clinic were aged 23-46 years. Semenograms showed that the patients had oligo-, astheno-, oligoastheno-, oligoterato-, oligoasthenoterato-, or asthenoteratozoospermia. T...

The use of diploidy and dominance in genetic algorithms (GAs) has long been used to improve performance in time-varying optimization problems. Diploidy increases diversity in GAs by allowing recessive genes to survive in a population and become active at some later time when changes in the environment make them more desirable. This paper suggests an intuitive way to implement diploidy and prese...

With two copies of every gene, a diploid organism is able to mask recessive deleterious mutations. In this paper we present the analysis of a two-locus model designed to determine when the masking of deleterious alleles favors the evolution of a dominant diploid phase in organisms that alternate between haploid and diploid phases ("alternation of generations"). It is hypothesized that diploidy ...

This paper investigates the use of diploid structures and the possibility of using diploidy in non-standard, non-binary Genetic Algorithms. Unlike the conventional implementation of diploidy in GAs, which typically involves the use of dominance operators, the diploid schemes presented in this paper avoid the use of dominance altogether, while still being rooted firmly in natural biology. The us...

There is concern that intracytoplasmic sperm injection (ICSI) may lead to offspring with a high frequency of chromosomal abnormalities. Accordingly, we studied spermatozoa sampled from eight infertile men with oligoasthenoteratozoospermia (OAT) by multi-colour fluorescence in-situ hybridization (FISH), using DNA probes for chromosomes 13, 18, 21, X and Y. Results were compared with those of spe...