Long-term insitu persistence of biodiversity in tropical sky islands revealed by landscape genomics

TY - JOUR

T1 - Long-term insitu persistence of biodiversity in tropical sky islands revealed by landscape genomics

AU - Mastretta-Yanes, Alicia

AU - Xue, Alexander T.

AU - Moreno-Letelier, Alejandra

AU - Jorgensen, Tove H.

AU - Alvarez, Nadir

AU - Pinero, Daniel

AU - Emerson, Brent C.

PY - 2018/1

Y1 - 2018/1

N2 - Tropical mountains are areas of high species richness and endemism. Two historical phenomena may have contributed to this: (i) fragmentation and isolation of habitats may have promoted the genetic differentiation of populations and increased the possibility of allopatric divergence and speciation and (ii) the mountain areas may have allowed long-term population persistence during global climate fluctuations. These two phenomena have been studied using either species occurrence data or estimating species divergence times. However, only few studies have used intraspecific genetic data to analyse the mechanisms by which endemism may emerge at the microevolutionary scale. Here, we use landscape analysis of genomic SNP data sampled from two high-elevation plant species from an archipelago of tropical sky islands (the Trans-Mexican Volcanic Belt) to test for population genetic differentiation, synchronous demographic changes and habitat persistence. We show that genetic differentiation can be explained by the degree of glacial habitat connectivity among mountains and that mountains have facilitated the persistence of populations throughout glacial/interglacial cycles. Our results support the ongoing role of tropical mountains as cradles for biodiversity by uncovering cryptic differentiation and limits to gene flow.

AB - Tropical mountains are areas of high species richness and endemism. Two historical phenomena may have contributed to this: (i) fragmentation and isolation of habitats may have promoted the genetic differentiation of populations and increased the possibility of allopatric divergence and speciation and (ii) the mountain areas may have allowed long-term population persistence during global climate fluctuations. These two phenomena have been studied using either species occurrence data or estimating species divergence times. However, only few studies have used intraspecific genetic data to analyse the mechanisms by which endemism may emerge at the microevolutionary scale. Here, we use landscape analysis of genomic SNP data sampled from two high-elevation plant species from an archipelago of tropical sky islands (the Trans-Mexican Volcanic Belt) to test for population genetic differentiation, synchronous demographic changes and habitat persistence. We show that genetic differentiation can be explained by the degree of glacial habitat connectivity among mountains and that mountains have facilitated the persistence of populations throughout glacial/interglacial cycles. Our results support the ongoing role of tropical mountains as cradles for biodiversity by uncovering cryptic differentiation and limits to gene flow.

KW - aggregate site frequency spectrum

KW - alpine

KW - Berberis alpina

KW - biodiversity distribution

KW - Juniperus monticola

KW - Trans-Mexican Volcanic Belt

KW - QUATERNARY CLIMATE-CHANGE

KW - MEXICAN VOLCANIC BELT

KW - SPECIES RICHNESS

KW - GENE FLOW

KW - PHYLOGEOGRAPHIC PATTERNS

KW - POPULATION GENOMICS

KW - CIRCUIT-THEORY

KW - DIVERSIFICATION

KW - ENDEMISM

KW - HIGHLANDS

UR - http://www.scopus.com/inward/record.url?scp=85040651011&partnerID=8YFLogxK

U2 - 10.1111/mec.14461

DO - 10.1111/mec.14461

M3 - Journal article

C2 - 29226496

SN - 0962-1083

VL - 27

SP - 432

EP - 448

JO - Molecular Ecology

JF - Molecular Ecology

IS - 2

ER -