Demographic influences on mitochondrial DNA lineage survivorship in animal populations

Abstract

Probability models of branching processes and computer simulations of these models are used to examine stochastic survivorship of female lineages under a variety of demographic scenarios. A parameter II, defined as the probability of survival of two or more independent lineages over G generations, is monitored as a function of founding size of a population, population size at carrying capacity, and the frequency distributions of surviving progeny. Stochastic lineage extinction can be very rapid under certain biologically plausible demographic conditions. For stable-sized populations initiated by n females and/or regulated about carrying capacity k = n, it is highly probable that within about 4n generations all descendants will trace their ancestries to a single founder female. For a given mean family size, increased variance decreases lineage survivorship. In expanding populations, however, lineage extinction is dramatically slowed, and the final k value is a far more important determinant of II than is the size of the population at founding. The results are discussed in the context of recent empirical observations of low mitochondrial DNA (mtDNA) sequence heterogeneity in humans and expected distributions of asexually transmitted traits among sexually reproducing species.

Insight into the population structure of hardhead silverside,Atherinomorus stipes(Teleostei: Atherinidae), in Belize and the Florida Keys usingnd2

“…Combined, these genetic characteristics are consistent with island‐group populations that have experienced a recent rapid expansion with subsequent accumulation of novel mutations after one or more bottleneck events (Avise, Neigel, & Arnold, 1984; Grant & Bowen, 1998; Tipton et al., 2011). The haplotype divergence patterns among populations within island‐groups were very different.…”

Mitochondrial DNA variability in natural populations of Hawaiian Drosophila. I. Methods and levels of variability in D. silvestris and D. heteroneura populations

“…Because of the recent divergence of these two species (more recent than the age of the island of Hawaii which is about 500,000 years [McDougall and Swanson, 1972]) convergence of restriction site state is unlikely to explain the high genetic similarity among these individuals (see Templeton, 1983 a). Hybridisation between the two species (Ferris et a!., 1983;Powell, 1983) and the effects of stochastic branching processes on maternal lineage survivorship (Avise et a!., 1983;Avise et al, 1984) as discussed in the next section are two possible explanations for this observation.…”

“…The genetic similarity observed between some west side D. silvestris and D. heteroneura individuals may alternatively be related to the stochastic branching processes involved in matriarchal lineage survivorship (Avise et aL, 1983;Avise et al, 1984). silvestris populations that are not suspected of being hybrids with D. heteroneura might result from such processes; but might also result from migration, strong local population subdivision or both.…”

Genetic mosaic in a marine species flock

“…For neutral markers, the length of time before there is a strong correspondence between recognized species boundaries and mtDNA lineages or multilocus genotypic clusters depends on the genetic structure of the ancestral population, the demographic history of speciation and the effective population sizes of the emergent forms (Avise et al 1984;Neigel & Avise 1983;Pamilo & Nei 1988;Hudson 1992;Edwards & Beerli 2000). In marine species such as hamlets, broad geographical ranges and large population sizes will retard the lineage sorting process.…”