Sequential Sympatric Speciation Across Trophic Levels

• Published in: Science (American Association for the Advancement of Science) Vol. 323; no. 5915; pp. 776 - 779
• Main Authors: Forbes, Andrew A, Powell, Thomas H.Q, Stelinski, Lukasz L, Smith, James J, Feder, Jeffrey L
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 06.02.2009; The American Association for the Advancement of Science
• Subjects: Adaptation, Biological; Alleles; Animals; Biodiversity; Biological and medical sciences; Biological evolution; Braconidae; Cues; Diptera; DNA, Mitochondrial - genetics; Eclosion; Ecological genetics; Evolutionary biology; Female; Fruit; Fundamental and applied biological sciences. Psychology; Gene Flow; Gene Frequency; Genes, Insect; Genetic loci; Genetic Speciation; Genetic Variation; Genetics of eukaryotes. Biological and molecular evolution; Haplotypes; Host plants; Host-Parasite Interactions; Hymenoptera; Insect ecology; Insects; Male; Microsatellite Repeats; Mitochondrial DNA; Molecular Sequence Data; Odorants; Parasite hosts; Parasites; Population ecology; Rhagoletis pomonella; Sexual Behavior, Animal; Speciation; Tephritidae; Tephritidae - genetics; Tephritidae - growth & development; Tephritidae - parasitology; Tephritidae - physiology; Wasps - genetics; Wasps - growth & development; Wasps - physiology; Tephritidae; Insecta; Biological evolution; Trophic relation; Mitochondrial DNA; Genetic distance; Satellite DNA; Pest; Parasitoid; Phytophagous; Entomophagous; Arthropoda; Host plant; Hymenoptera; Invertebrata; Braconidae; Diptera; Rhagoletis pomonella; Speciation
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1166981

A major cause for biodiversity may be biodiversity itself. As new species form, they may create new niches for others to exploit, potentially catalyzing a chain reaction of speciation events across trophic levels. We tested for such sequential radiation in the Rhagoletis pomonella (Diptera: Tephritidae) complex, a model for sympatric speciation via host plant shifting. We report that the parasitic wasp Diachasma alloeum (Hymenoptera: Braconidae) has formed new incipient species as a result of specializing on diversifying fly hosts, including the recently derived apple-infesting race of R. pomonella. Furthermore, we show that traits that differentially adapt R. pomonella flies to their host plants have also quickly evolved and serve as ecological barriers to reproduction, isolating the wasps. Speciation therefore cascades as the effects of new niche construction move across trophic levels.