The distribution of life-history variation in the Daphnia pulex complex

Michael Lynch, K. Spitze, T. Crease

Research output: Contribution to journalArticle

49 Citations (Scopus)

Abstract

In the midwestern USA the Daphnia pulex complex consists of a mosaic of sexual and asexual populations, providing a useful model system for studying the evolutionary forces underlying the maintenance of sex. One asexual and two sexual populations were surveyed for genetic variation for isozymes, mitochondrial DNA, and life-history characters. While the sexual populations exhibited substantial levels of genetic variance for fitness characters, no variation was detected in the asexual population at any level. However, a parallel survey among asexual clones derived from other ponds revealed large amounts of quantitative variation among clones, even among those with the same molecular profile. As a group, asexuals are more variable for life histories that are sexual populations. Molecular data indicate a relatively recent origin for the extant asexual D. pulex. The polyphyletic origin of these clones, combined with their microevolutionary potential, provides an explanation for their broad geographic distribution. Although the frequency of asexuality may be driven by the spread of a sex-limited meiosis suppressor through sexual populations, the complete displacement of sexuality may be prevented by ecological distinctions between the two classes of individuals. On average, asexuals are larger but produce smaller clutches than sexuals. -from Authors

Original languageEnglish (US)
Pages (from-to)1724-1736
Number of pages13
JournalEvolution
Volume43
Issue number8
StatePublished - Jan 1 1989
Externally publishedYes

Fingerprint

Daphnia
Daphnia pulex
clone
life history
Population
sexuality
Clone Cells
clones
mitochondrial DNA
genetic variation
fitness
pond
Genetic Fitness
gender
Meiosis
Sexuality
genetic variance
Mitochondrial DNA
meiosis
Isoenzymes

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Genetics
  • Agricultural and Biological Sciences(all)

Cite this

The distribution of life-history variation in the Daphnia pulex complex. / Lynch, Michael; Spitze, K.; Crease, T.

In: Evolution, Vol. 43, No. 8, 01.01.1989, p. 1724-1736.

Research output: Contribution to journalArticle

Lynch, M, Spitze, K & Crease, T 1989, 'The distribution of life-history variation in the Daphnia pulex complex', Evolution, vol. 43, no. 8, pp. 1724-1736.
Lynch, Michael ; Spitze, K. ; Crease, T. / The distribution of life-history variation in the Daphnia pulex complex. In: Evolution. 1989 ; Vol. 43, No. 8. pp. 1724-1736.
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