Document: SER-3-92-8

Dynamics of diversification in a metapopulation.

GAVRILETS, S.*

University of Tennessee, Knoxville, TN 37996 USA ¹

Abstract:
I describe a simple framework for modeling the dynamics of diversification in a metapopulation as a continuous process of accumulation of genetic (or morphological) differences accompanied by species and subpopulation extinction and/or range expansion. This framework can be used to approach a number of questions such as species-area distribution, species-range size distribution, the rate of ecological turnover, asymmetries of range division between sister species, waiting time until speciation and extinction, the relationship between the geographic range size and the probability of speciation, the relationships between subpopulation-level parameters and metapopulation-level parameters, and the effects of taxonomic level on these rates, distributions and parameters. I used numerical simulations and analytical approximations to study the dependence of the number of different taxonomic units, S, their average range size, R, and the rate of their turnover, T, on the system size, n, the rate of fixation of genetic (or morphological) changes in local demes, , and the rate of local extinction and colonization, d. For one-dimensional systems, S=( p/2 d K/)^(1/2), R=n (2/p /(d K)^(1/2), and T = /K, where K is the minimal number of genetic (or morphological) differences required to assign two subpopulations to different taxonomic groups at a given taxonomic level (e.g., subspecies, species, genera, families etc.).

Keywords: metapopulation, diversification, speciation, extinction, modeling

This abstract is being presented at: 11:45 AM in session:
Oral Session #56: Metapopulation Analysis.