| Presentation Detail
SSB Symposium: Ernst Mayr Symposium Wade, Elizabeth [1]. Species boundaries, mitochondrial phylogeny, and the geographic extent of introgression in New Zealand cicadas: species or species swarms? Understanding species boundaries and evolutionary history is integral to the field of systematics. This study explores multiple lines of evidence to delimit boundaries, understand evolutionary history, and postulate the evolutionary future of a group of six species in the New Zealand cicada genus Kikihia based on genetic, behavioral, distributional and ecological data. These data suggest that these species have undergone repeated secondary contact and hybridization during interglacial periods followed by isolation and genetic differentiation during glacial maxima. This study characterizes genetic introgression between K. "northwestlandica", K. "southwestlandica", K. "murihikua", K. muta, K."tuta", and K. "nelsonensis" at five contact zones. The mitochondrial gene cytochrome c oxidase 1(COI) and six highly variable microsatellite loci were characterized and analyzed for over a thousand specimens from locations throughout New Zealand's South Island. Mitochondrial phylogenies of the entire genus with an emphasis on species involved in the five contact zones were constructed using Garli and MrBayes with the best partitions and models of evolution found by PartitionFinder. Divergence times are estimated with BEAST using a relaxed clock and mitochondrial rates of evolution that span the range of rates estimated for mtDNA for a variety of insect taxa. Microsatellite loci were analyzed using Structure and IMa2. Ecological distribution models (EDMs) were created using MaxEnt. Morphology and species-specific male courtship songs characters were used to identify specimens and species. Results indicate that there is widespread introgression of both nuclear and mitochondrial genomes, however, different patterns of introgression are observed at each of the five distinct contact zones. EDM's based on species distributions for present and past environmental data reveal ecological constraints for each species. Genetic data revealed interactions involving more than two species at several of the contact zones and in some cases transfer of microsatellite alleles far beyond the initial contact zones. Differences in levels of introgression of nuclear and mitochondrial DNA between pairs of hybridizing taxa are not explained solely by genetic distance. Ecology and pre-mating courtship songs and behaviors also appear to play a role. Patterns of genetic introgression, ecology and songs suggest that all but the most closely-related species are expected to remain distinct despite gene flow over large geographic distances.
Log in to add this item to your schedule
1 - University of Connecticut, Ecology and Evolutionary Biology, 75 N. Eagleville Rd., Unit 3043, Storrs, CT, 06269, USA
Keywords:
introgression
New Zealand
hybridization
Insect
species delimitation.
Presentation Type: Symposium Presentation
Session: 212
Location: Ballroom 2/Cliff Lodge
Date: Sunday, June 23rd, 2013
Time: 10:45 AM
Number: 212002
Abstract ID:1066
Candidate for Awards:Ernst Mayr Award |
