Global patterns of nuclear and mitochondrial genetic diversity in marine fishes
Creators: name: Clark, Rene
name: Pinksy, Malin
Publisher: name: Zenodo
Year: 2024
Subjects: latitudinal gradient
macrogenetics
Marine fish
Mitochondrial genetic diversity
Nuclear genetic diversity
Population genetics

description: Genetic diversity is a fundamental component of biodiversity. Examination of global patterns of genetic diversity can help highlight mechanisms underlying species diversity, though a recurring challenge has been that patterns may vary by molecular marker. Here, we compiled 6862 observations of genetic diversity from 492 species of marine fish and tested among hypotheses for diversity gradients: the founder effect hypothesis, the kinetic energy hypothesis, and the productivity-diversity hypothesis. We fit generalized linear mixed effect models (GLMMs) and explored the extent to which various macroecological drivers (latitude, longitude, temperature (SST), and chlorophyll-a concentration) explained variation in genetic diversity. We found that mitochondrial genetic diversity followed geographic gradients similar to those of species diversity, being highest near the Equator, particularly in the Coral Triangle, while nuclear genetic diversity did not follow clear geographic patterns. Despite these differences, all genetic diversity metrics were correlated with chlorophyll-a concentration, while mitochondrial diversity was also positively associated with SST. Our results provide support for the kinetic energy hypothesis, which predicts that elevated mutation rates at higher temperatures increase mitochondrial but not necessarily nuclear diversity, and the productivity-diversity hypothesis, which posits that resource-rich regions support larger populations with greater genetic diversity. Overall, these findings reveal how environmental variables can influence mutation rates and genetic drift in the ocean, caution against using mitochondrial macro-genetic patterns as proxies for whole-genome diversity, and aid in defining global gradients of genetic diversity.
description: Funding provided by: National Science FoundationROR ID: https://ror.org/021nxhr62Award Number: 1426891
Funding provided by: National Science FoundationROR ID: https://ror.org/021nxhr62Award Number: 2129351
Funding provided by: National Science FoundationROR ID: https://ror.org/021nxhr62Award Number: 1743711
Funding provided by: Society for Conservation BiologyROR ID: https://ror.org/00p954x71Award Number: 
Funding provided by: Alfred P. Sloan FoundationROR ID: https://ror.org/052csg198Award Number: BR2014-044
description: This dataset was collected via a literature search in Web of Science with the following keywords: fish microsatellite (marine OR ocean OR sea) and fish mtDNA (marine OR ocean OR sea). Only studies published before January 5, 2020, were included.

We retained studies that recorded genetic diversity (mitochondrial or nuclear) from wild marine fish populations. To do this, we first conducted a title/abstract filter by hand and then recorded data for each paper, following the guidelines listed in either msat_data_entry_instructions.md or mtDNA_data_entry_instructions.md.