Population Genetics of Turtle Species

Population genetics of turtles investigates the patterns and processes governing genetic variation within and between turtle populations. By analysing molecular markers such as mitochondrial DNA and microsatellites, researchers can reconstruct historical demographic events—glacial refugia, riverine barriers and ancient range expansions—as well as detect contemporary impacts including habitat fragmentation, climate shifts and human‐mediated translocations. Key metrics such as genetic diversity, population structure and effective population size underpin our understanding of connectivity and resilience. These insights guide conservation strategies by identifying isolated or inbred populations, informing the design of habitat corridors, captive‐breeding programmes and managed relocations to preserve evolutionary potential and species survival on a global scale.

Research from Nature Portfolio

Studies on a critically endangered South Asian river turtle have combined mitochondrial cytochrome b sequences with nuclear microsatellites to reveal remarkably low nucleotide diversity alongside moderate heterozygosity. Demographic reconstructions indicate long periods of stability followed by recent declines, and clustering analyses expose weak genetic structure with admixed lineages, underscoring the need for coordinated rehabilitation and translocation efforts. In North America, genome‐wide SNP data from desert tortoises have delineated several spatially discrete clusters shaped by landscape features—elevation, soil depth and vegetation cover—and identified outlier loci linked to physiological functions, offering targets for adaptive management. An earlier examination of secondary contact in Mediterranean tortoises demonstrated sex‐biased introgression, where introduced males of one subspecies carried distinct mitochondrial haplotypes, highlighting the transient nature of hybrid zones and implications for genetic boundary maintenance.

Population Genetics of Turtle Species publication trend

The graph below shows the total number of articles in population genetics of turtle species across all publications each year (not limited to Nature Index journals).

Technical terms

Genetic diversity: The total variation of genetic traits within and among populations.

Microsatellite markers: Short, repetitive DNA sequences used to measure genetic variation and relatedness.

Mitochondrial DNA (mtDNA): Circular DNA transmitted maternally, useful for tracing maternal lineages and demographic history.

Population structure: The organisation of genetic variation into distinct subpopulations due to barriers, distance or selection.

Effective population size (Ne): The size of an idealised population that would show the same genetic drift as the observed population.

Introgression: The incorporation of genes from one population or species into another through hybridisation.

References

1. Population genetics of the critically endangered three-striped turtle, Batagur dhongoka, from the Ganga river system using mitochondrial DNA and microsatellite analysis. Scientific Reports (2024).
2. Landscape limits gene flow and drives population structure in Agassiz’s desert tortoise (Gopherus agassizii). Scientific Reports (2018).
3. Human-mediated secondary contact of two tortoise lineages results in sex-biased introgression. Scientific Reports (2017).
4. Conservation Genetic Analysis of Blanding’s Turtles across Ohio, Indiana, and Michigan. Diversity (2023).
5. Hybridization and low genetic diversity in the endangered Alabama red‐bellied turtle (Pseudemys alabamensis). Ecology and Evolution (2022).
6. A Comparison of the Population Genetic Structure and Diversity between a Common (Chrysemys p. picta) and an Endangered (Clemmys guttata) Freshwater Turtle. Diversity (2019).