Repeated Habitat Disturbances by Fire Decrease Local Effective Population Size

Effective population size

What is it? An aid to calculation in population genetics, introduced by Sewall Wright. The rate of change of the genetic make-up of a population by genetic drift — fluctuations in allele frequencies caused by random sampling — is inversely related to the effective population size, Ne. Ne is measured with reference to an ideal ‘Wright–Fisher’ population. This has a fixed number of N diploid bree...

Drift by Drift : Effective Population Size Limited by Advection

Alternative reproductive tactics increase effective population size and decrease inbreeding in wild Atlantic salmon

While nonanadromous males (stream-resident and/or mature male parr) contribute to reproduction in anadromous salmonids, little is known about their impacts on key population genetic parameters. Here, we evaluated the contribution of Atlantic salmon mature male parr to the effective number of breeders (Nb) using both demographic (variance in reproductive success) and genetic (linkage disequilibr...

Effects of habitat fragmentation on effective population size in the endangered Rio Grande silvery minnow

We assessed spatial and temporal patterns of genetic diversity to evaluate effects of river fragmentation on remnant populations of the federally endangered Rio Grande silvery minnow (Hybognathus amarus). Analysis of microsatellite and mitochondrial (mt) DNA detected little spatial genetic structure over the current geographic range, consistent with high gene flow despite fragmentation by dams....

Preferred habitat and effective population size drive landscape genetic patterns in an endangered species

Landscape genetics provides a framework for pinpointing environmental features that determine the important exchange of migrants among populations. These studies usually test the significance of environmental variables on gene flow, yet ignore one fundamental driver of genetic variation in small populations, effective population size, N(e). W(e) combined both approaches in evaluating genetic co...