Genetic evidence for long-term population decline in a Savannah-dwelling primate: Inferences from a hierarchical Bayesian model

Jay F. Storz, Mark A. Beaumont, Susan C. Alberts

Research output: Contribution to journalArticle

56 Citations (Scopus)

Abstract

The purpose of this study was to test for evidence that savannah baboons (Papio cynocephalus) underwent a population expansion in concert with a hypothesized expansion of African human and chimpanzee populations during the late Pleistocene. The rationale is that any type of environmental event sufficient to cause simultaneous population expansions in African humans and chimpanzees would also be expected to affect other codistributed mammals. To test for genetic evidence of population expansion or contraction, we performed a coalescent analysis of multilocus microsatellite data using a hierarchical Bayesian model. Markov chain Monte Carlo (MCMC) simulations were used to estimate the posterior probability density of demographic and genealogical parameters. The model was designed to allow interlocus variation in mutational and demographic parameters, which made it possible to detect aberrant patterns of variation at individual loci that could result from heterogeneity in mutational dynamics or from the effects of selection at linked sites. Results of the MCMC simulations were consistent with zero variance in demographic parameters among loci, but there was evidence for a 10- to 20-fold difference in mutation rate between the most slowly and most rapidly evolving loci. Results of the model provided strong evidence that savannah baboons have undergone a long-term historical decline in population size. The mode of the highest posterior density for the joint distribution of current and ancestral population size indicated a roughly eightfold contraction over the past 1,000 to 250,000 years. These results indicate that savannah baboons apparently did not share a common demographic history with other codistributed primate species.

Original languageEnglish (US)
Pages (from-to)1981-1990
Number of pages10
JournalMolecular biology and evolution
Volume19
Issue number11
DOIs
StatePublished - Nov 2002

Fingerprint

population decline
primate
Primates
savannas
Papio
demographic statistics
Demography
Markov chain
Markov Chains
contraction
Pan troglodytes
population size
Population Density
Markov processes
Population
loci
demographic history
Papio cynocephalus
Mammals
simulation

Keywords

  • Baboon
  • Bayesian inference
  • Coalescent
  • Demographic history
  • Markov chain Monte Carlo
  • Microsatellite DNA
  • Papio cynocephalus

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Molecular Biology
  • Genetics

Cite this

Genetic evidence for long-term population decline in a Savannah-dwelling primate : Inferences from a hierarchical Bayesian model. / Storz, Jay F.; Beaumont, Mark A.; Alberts, Susan C.

In: Molecular biology and evolution, Vol. 19, No. 11, 11.2002, p. 1981-1990.

Research output: Contribution to journalArticle

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