Abstract
Explanations of diploidy have focused on advantages gained from masking deleterious mutations that are inherited. Recent theory has shown that these explanations are flawed. Indeed, we still lack any satisfactory explanation of diploidy in species that are asexual or that recombine only rarely. Here I consider a possibility first suggested by EFROIMSON in 1932, by MULLER in 1964 and by CROW and KIMURA in 1965: diploidy may provide protection against somatic, not inherited, mutations. I both compare the mean fitness of haploid and diploid populations that are asexual and investigate the invasion of ``diploidy'' alleles in sexual populations. When deleterious mutations are partially recessive and somatic mutation is sufficiently common, somatic mutation provides a clear advantage to diploidy in both asexual and sexual species.
Full Text
The Full Text of this article is available as a PDF (1.8 MB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bengtsson B. O. Deleterious mutations and the origin of the meiotic ploidy cycle. Genetics. 1992 Jul;131(3):741–744. doi: 10.1093/genetics/131.3.741. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Charlesworth B. Evolution. When to be diploid. Nature. 1991 May 23;351(6324):273–274. doi: 10.1038/351273a0. [DOI] [PubMed] [Google Scholar]
- Goldstein D. B. Heterozygote advantage and the evolution of a dominant diploid phase. Genetics. 1992 Dec;132(4):1195–1198. doi: 10.1093/genetics/132.4.1195. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kondrashov A. S., Crow J. F. Haploidy or diploidy: which is better? Nature. 1991 May 23;351(6324):314–315. doi: 10.1038/351314a0. [DOI] [PubMed] [Google Scholar]
- Kuick R. D., Neel J. V., Strahler J. R., Chu E. H., Bargal R., Fox D. A., Hanash S. M. Similarity of spontaneous germinal and in vitro somatic cell mutation rates in humans: implications for carcinogenesis and for the role of exogenous factors in "spontaneous" germinal mutagenesis. Proc Natl Acad Sci U S A. 1992 Aug 1;89(15):7036–7040. doi: 10.1073/pnas.89.15.7036. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Loeb L. A. Mutator phenotype may be required for multistage carcinogenesis. Cancer Res. 1991 Jun 15;51(12):3075–3079. [PubMed] [Google Scholar]
- Otto S. P., Goldstein D. B. Recombination and the evolution of diploidy. Genetics. 1992 Jul;131(3):745–751. doi: 10.1093/genetics/131.3.745. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Paquin C., Adams J. Frequency of fixation of adaptive mutations is higher in evolving diploid than haploid yeast populations. Nature. 1983 Apr 7;302(5908):495–500. doi: 10.1038/302495a0. [DOI] [PubMed] [Google Scholar]
- Perrot V., Richerd S., Valéro M. Transition from haploidy to diploidy. Nature. 1991 May 23;351(6324):315–317. doi: 10.1038/351315a0. [DOI] [PubMed] [Google Scholar]
- Vogelstein B., Fearon E. R., Hamilton S. R., Kern S. E., Preisinger A. C., Leppert M., Nakamura Y., White R., Smits A. M., Bos J. L. Genetic alterations during colorectal-tumor development. N Engl J Med. 1988 Sep 1;319(9):525–532. doi: 10.1056/NEJM198809013190901. [DOI] [PubMed] [Google Scholar]