Lowry, David , Willis, John H .
The genetic and ecological mechanisms of incipient speciation through ecogeographic race formation.
Ecogeographic race formation is thought to be one of the major mechanisms of speciation in plants. However, little is known about how ecogeographic races are formed and whether gene flow is actually restricted among ecogeographic races. Here we examine the coast and inland races of the Yellow Monkeyflower, Mimulus guttatus, and determine the genetic and ecological mechanisms that drive reproductive isolation in this system. We demonstrate that the coast and inland races are highly divergent and locally adapted through differences in salt tolerance, drought tolerance, and flowering time using a combination of reciprocal transplant and greenhouse experiments. We show that this pattern holds along a 1200 kilometer range of the races in multiple comparisons of latitudinally paired coast and inland populations. Further, we confirm that gene flow is restricted between the coast and inland races through population structure analysis and argue that local adaptation is responsible for most of the reproductive isolation in this system. Finally, we use a novel method of replicated QTL mapping to demonstrate that the same genomic regions are responsible for adaptive flowering time divergence between coast and inland populations over the range of the races.
Log in to add this item to your schedule
1 - Duke University, University Program in Genetics and Genomics, 124 Science Drive, 3332 French Family Science Center, Durham, NC, 27708, USA
2 - Duke University, Department of Biology, 124 Science Drive, 3332 French Family Science Center, Durham, NC, 27708, USA
Presentation Type: Oral Paper:Papers for Sections
Location: Lake Huron/Hilton
Date: Monday, July 9th, 2007
Time: 4:30 PM