Originally published as Genetics Published Articles Ahead of Print on June 3, 2005.

Genetics, Vol. 170, 1809-1820, August 2005, Copyright © 2005
doi:10.1534/genetics.104.036814

Genetic Diversity and Genetic Differentiation in Daphnia Metapopulations With Subpopulations of Known Age

Christoph R. Haag*,{dagger},{ddagger},§,1, Myriam Riek{dagger},{ddagger}, Jürgen W. Hottinger*,{dagger},{ddagger}, V. Ilmari Pajunen{dagger},§ and Dieter Ebert*,{dagger},{ddagger}

* Unité d'Ecologie et d'Evolution, Département de Biologie, Université de Fribourg, CH-1700 Fribourg, Switzerland
{dagger} Tvärminne Zoological Station, FIN-10900 Hanko, Finland
{ddagger} Zoologisches Institut, Universität Basel, CH-4051 Basel, Switzerland
§ Department of Biological and Environmental Sciences, University of Helsinki, FIN-00014 Helsinki, Finland

1 Corresponding author: Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh, West Mains Rd., Edinburgh EH9 3JT, United Kingdom.
E-mail: christoph.haag{at}ed.ac.uk

If colonization of empty habitat patches causes genetic bottlenecks, freshly founded, young populations should be genetically less diverse than older ones that may have experienced successive rounds of immigration. This can be studied in metapopulations with subpopulations of known age. We studied allozyme variation in metapopulations of two species of water fleas (Daphnia) in the skerry archipelago of southern Finland. These populations have been monitored since 1982. Screening 49 populations of D. longispina and 77 populations of D. magna, separated by distances of 1.5–2180 m, we found that local genetic diversity increased with population age whereas pairwise differentiation among pools decreased with population age. These patterns persisted even after controlling for several potentially confounding ecological variables, indicating that extinction and recolonization dynamics decrease local genetic diversity and increase genetic differentiation in these metapopulations by causing genetic bottlenecks during colonization. We suggest that the effect of these bottlenecks may be twofold, namely decreasing genetic diversity by random sampling and leading to population-wide inbreeding. Subsequent immigration then may not only introduce new genetic material, but also lead to the production of noninbred hybrids, selection for which may cause immigrant alleles to increase in frequency, thus leading to increased genetic diversity in older populations.




This article has been cited by other articles:


Home page
 Proc R Soc BHome page
L. J. Weider, D. Frisch, and P. D. N. Hebert
Long-term changes in metapopulation genetic structure: a quarter-century retrospective study on low-Arctic rock pool Daphnia
Proc R Soc B, October 7, 2009; (2009) rspb.2009.1326v1.
[Abstract] [Full Text] [PDF]

Home page
 J R Soc InterfaceHome page
D. Ebert, F. Altermatt, and S. Lass
A short term benefit for outcrossing in a Daphnia metapopulation in relation to parasitism
J R Soc Interface, October 22, 2007; 4(16): 777 - 785.
[Abstract] [Full Text] [PDF]