Range size variably predicts genetic diversity in Gehyra geckos

This is a Preprint and has not been peer reviewed. This is version 1 of this Preprint.

Add a Comment

You must log in to post a comment.


Comments

There are no comments or no comments have been made public for this article.

Downloads

Download Preprint

Supplementary Files
Authors

Ching Ching Lau, Keith Allen Christian , Jessica Fenker, Rebecca J Laver, Kate O'Hara, Stephen M Zozaya, Craig Moritz , Emily Roycroft 

Abstract

Genetic diversity is a fundamental population genetic parameter, and predicts adaptive capacity. Neutral theory predicts a positive correlation between population (or range) size and genetic diversity, but this can be confounded by other demographic processes. To investigate the role of range size, population fluctuation and introgression in determining genetic diversity, we generate and analyse population-level, genomic-scale SNP data from 21 species of Australian Gehyra geckos (769 samples) that vary in range size over three orders of magnitude. Using a best-practice approach to estimate SNP-based heterozygosity, we found a significantly positive overall correlation between range size and heterozygosity, although with a shallow slope (R2 = 0.30), consistent with Lewontin’s Paradox. At a clade level, we show a stronger relationship between range size and heterozygosity in the australis group (R2 = 0.74, p < 0.01) than the nana group (R2 = 0.15, n.s.). A significantly negative correlation between Tajima’s D and range size in both groups, and evidence for introgression in the nana group, suggest a role for both population fluctuation and introgression in driving deviations from theoretical expectations. Our results provide insight into the biological and demographic processes that influence genetic diversity, in addition to neutral expectations.

DOI

https://doi.org/10.32942/X2PW49

Subjects

Biodiversity, Ecology and Evolutionary Biology, Genetics and Genomics, Life Sciences

Keywords

heterozygosity, introgression, Lewontin’s Paradox, population genomics, RAD-seq

Dates

Published: 2024-06-26 01:37

License

CC-By Attribution-NonCommercial-NoDerivatives 4.0 International

Additional Metadata

Language:
English

Data and Code Availability Statement:
Raw sequence data, final variant call files, final alignment files and the 62-lineage Gehyra phylogeny have been deposited in Dryad and will be made public on manuscript acceptance.