INTERSPECIFIC LABORATORY COMPETITION OF THE RECENTLY SYMPATRIC SPECIES DROSOPHILA SUBOBSCURA AND DROSOPHILA PSEUDOOBSCURA

Marta Pascual; Luis Serra; Francisco J Ayala

doi:10.1111/j.1558-5646.1998.tb05162.x

INTERSPECIFIC LABORATORY COMPETITION OF THE RECENTLY SYMPATRIC SPECIES DROSOPHILA SUBOBSCURA AND DROSOPHILA PSEUDOOBSCURA

Evolution. 1998 Feb;52(1):269-274. doi: 10.1111/j.1558-5646.1998.tb05162.x.

Authors

Marta Pascual¹, Luis Serra², Francisco J Ayala¹

Affiliations

¹ Department of Ecology and Evolutionary Biology, University of California, Irvine, California, 92717.
² Departament de Genètica, Universitat de Barcelona, 08071, Barcelona, Spain.

PMID: 28568145
DOI: 10.1111/j.1558-5646.1998.tb05162.x

Abstract

-Drosophila subobscura and D. pseudoobscura are closely related species coexisting on the West Coast of North America, which was recently colonized by D. subobscura. In competition experiments with overlapping generations, D. subobscura is eliminated by D. pseudoobscura in a few generations at all four temperatures and two initial frequencies tested. Yet in one-species cultures, D. subobscura thrives at all experimental conditions. Single-generation competition experiments reveal lower survivorship and productivity of D. subobscura at all temperatures and frequencies. Productivity per female is dependent on the initial frequencies: greater for D. subobscura as its initial frequency becomes higher, but lower for D. pseudoobscura as its frequency becomes higher. Strains of D. subobscura from three disparate geographic origins yield similar results.

Keywords: Colonizing species; Drosophila pseudoobscura; Drosophila subobscura; competition between species; relative fitness.