Fluctuating fortunes: genomes and habitat reconstructions reveal global climate-mediated changes in bats' genetic diversity.

Balaji Chattopadhyay,Kritika M Garg,Frank E Rheindt,Rajasri Ray

doi:10.1098/rspb.2019.0304

Abstract

Over the last approximately 2.6 Myr, Earth's climate has been dominated by cyclical ice ages that have profoundly affected species' population sizes, but the impact of impending anthropogenic climate change on species' extinction potential remains a worrying problem. We investigated 11 bat species from different taxonomic, ecological and geographical backgrounds using combined information from palaeoclimatic habitat reconstructions and genomes to analyse biotic impacts of historic climate change. We discover tightly correlated fluctuations between species' historic distribution and effective population size, identify frugivores as particularly susceptible to global warming, pinpoint large insectivores as having overall low effective population size and flag the onset of the Holocene (approx. 10-12 000 years ago) as the period with the generally lowest effective population sizes across the last approximately 1 Myr. Our study shows that combining genomic and palaeoclimatological approaches reveals effects of climatic shifts on genetic diversity and may help predict impacts of future climate change.

Highlights

Quaternary climatic fluctuations have produced recurrent glacial periods resulting in global habitat shifts that affect a multitude of organisms [1,2,3]
If we could characterize these Quaternary fluctuations across a wide panel of species with different ecological backgrounds, it would allow us to pinpoint species groups with specific ecological requirements that will be extinction-prone with impending anthropogenic climate change [10]
Quaternary climatic fluctuations have played a major role in shaping evolutionary trajectories of populations and species across all major biomes and taxonomic groups [1,7,8,54,55]

Summary

Introduction

Quaternary climatic fluctuations (i.e. those over the last approx. 2.6 Myr) have produced recurrent glacial periods resulting in global habitat shifts that affect a multitude of organisms [1,2,3]. Colder climatic episodes have generally led to significant drops in global temperatures and increased glaciation, shrinking habitat space for many taxa (especially at higher latitudes) and forcing them into isolated pockets of local refugia. These periods have produced reductions in global sea levels, thereby connecting isolated landmasses in shelf areas and expanding habitat space for many other organisms [1,4]. We reconstructed fluctuations in species distribution during the most recent glacial cycles This new approach of directly comparing palaeo-distributions with fluctuations in Ne allowed us to make inferences about the long-term survival potential of species across different niches and ecological requirements. We predicted that fluctuations in species distribution would correlate with fluctuations in population Ne, and that species biology would affect long-term fluctuations in Ne depending on diet, body size and other ecological factors

Methods

Results

Discussion

15. Bhak Y et al 2017 Myotis rufoniger genome

Findings

49. Elith JH et al 2006 Novel methods improve