 |
 |
 |
|
Genetic consequences of population biology in chemoautotrophic tubeworms and clamsAndrew Peek, Ph.D. Wednesday, April 5, 2000 Chemoautotrophic microbes that depend on sulfide-rich waters are the base of hydrothermal-vent and cold-seep food chains. Some of these microbes, in the gamma-subdivision Proteobacteria, are symbiotic with various invertebrates. The symbiotic relationships between bacteria and invertebrates imposes population structure on these bacteria that can be recognized in the patterns of molecular evolutionary change in both the bacterial symbiont and the invertebrate host. Additionally, these patterns of evolutionary change differ between symbiotic bacteria that undergo maternal (vertical) versus those that undergo environmental (horizontal) transmission strategies. The maternally transmitted bacterial symbionts in vesicomyid clams cospeciate with their invertebrate host, have overall accelerated rates of nearly-neutral molecular evolution consistent with small effective bacterial population sizes, and the relative rates of evolution of the symbionts within host lineages correspond with host effective population sizes. By contrast, environmentally transmitted bacterial symbionts in vestimentiferan tubeworms do not cospeciate with their invertebrate host and have overall decelerated rates of nearly-neutral molecular evolution consistent with large effective bacterial population sizes. Next: Transport patterns for currents and suspended particulate matter in Monterey Submarine Canyon Last updated: December 19, 2000
|
