One for the Many, Two for the Slow

See allHide authors and affiliations

Science  24 Jan 2003:
Vol. 299, Issue 5606, pp. 469
DOI: 10.1126/science.299.5606.469e

Most plants and animals are diploid, with two copies of each chromosome, but some eukaryotes are haploid and carry just one copy. Both schemes have relative advantages—diploid organisms should be better protected against deleterious mutations, and haploid organisms should acquire beneficial mutations more readily. Zeyl et al. (p. 555; see the Perspective by Grieg and Travisano) experimentally tested these ideas by propagating both haploid and diploid yeast populations for 2000 generations and measuring their rates of adaptation to the culture conditions. Haploid populations adapted significantly at large population sizes, but this advantage was eliminated in much smaller population sizes. Mating in diploids, which was not allowed in these experiments, would likely lead to further selection advantages in small populations.

Navigate This Article