TITLE:
Demographic Expansion and Contraction in a Neotropical Fish during the Late Pleistocene-Holocene
AUTHORS:
Carolina L. N. Costa, S. Ivan Perez, José Louvise, Carlos H. Tonhatti, Rute B. G. Clemente-Carvalho, Ana C. Petry, S. F. dos Reis
KEYWORDS:
Ancestral Population Dynamics, Coalescence, Bayesian Skyline Plot, Mitochondrial DNA, Last Glacial Maximum
JOURNAL NAME:
Open Journal of Statistics,
Vol.9 No.4,
August
13,
2019
ABSTRACT: Demographic
changes during the late Pleistocene-Holocene left signatures in the DNA of
contemporary populations. These signatures reveal demographic phenomena like
the increase or decrease in effective population size. In this paper we
searched for signatures of demographic change in the DNA of the Neotropical
freshwater fish Poecilia vivipara.
Also, we investigated whether demographic changes are correlated with
palaeoclimatic events of the late Pleistocene-Holocene, in
particular, if changes in effective population size are correlated with
expansion and contraction of available habitats, induced by global ice-volume
changes and sea-level fluctuations. We used Bayesian Skyline Plot (BSP)
analysis with sequences from the mitochondrial gene cytochrome b to estimate the ancestral demography
of the Neotropical freshwater fish P.
vivipara. To test the assumptions of neutrality and absence of population
structure we used Tajima’s D and
Spatial Analysis of Molecular Variance (SAMOVA), respectively. Effective
population size of P. vivipara remained
stable until 75,000 years ago, increased by 10-fold reaching a maximum at
approximately 25,000 years ago, then suddenly declined at the Pleistocene-Holocene
boundary. Variation in effective population size in P. vivipara correlates with expansion and contraction of habitats
induced by sea-level fluctuations, caused by the advance and retreat of ice
sheets during the Last Glacial Maximum (LGM).