Sympatric speciation through intraspecific social parasitism
- Department of Ecology and Systematics, University of Helsinki, P.O. Box 65, FIN-00014 Helsinki, Finland
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Edited by Edward O. Wilson, Harvard University, Cambridge, MA (received for review November 8, 2002)
Abstract
Sympatric speciation through intraspecific social parasitism has been proposed for the evolution of Hymenopteran workerless parasites. Such inquilines exploit related host taxa to produce their own sexual offspring. The relatedness of inquilines to their hosts has been generalized in Emery's rule, suggesting that social parasites are close or the closest relatives to their host species. If the closest relative of each parasite is its host, then multiple independent origins of the parasite species are implied even within a single genus, probably through sympatric speciation. To test the plausibility of sympatric speciation in inquilines, we conducted a mitochondrial DNA phylogenetic analysis in three inquiline–host pairs of Myrmica ant species. We show that congeneric inquilines have originated independently several times. We also show that two of the inqulines are more closely related to their hosts than to any other species. Our results suggest sympatric speciation of Myrmica inquilines. Sympatric speciation is probably facilitated by the social biology and ecology of Myrmica, with polygyny as a prerequisite for the evolution of intraspecific parasitism.
Footnotes
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↵ * To whom correspondence should be addressed. E-mail: riitta.savolainen{at}helsinki.fi.
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This paper was submitted directly (Track II) to the PNAS office.
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Abbreviations: COI, cytochrome oxidase one; COII, cytochrome oxidase two; Cyt b, cytochrome b.
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Data deposition: The sequences reported in this paper have been deposited in the GenBank database [accession nos. AY280591–AY280606 (COI and COII) and AY280575–AY280590 (Cyt b)].
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See commentary on page 6896.
- Copyright © 2003, The National Academy of Sciences
