Population Genetics of Seabirds

Seabirds inhabit some of the most extensive and dynamic marine environments on Earth, displaying life histories that combine long-distance dispersal, colonial breeding and strong site fidelity. Population genetics in these species examines how gene flow, genetic drift and natural selection shape patterns of genetic variation across colonies and ocean basins. Technological advances—ranging from microsatellite markers to whole-genome sequencing—have clarified the roles of effective population size, philopatry and oceanographic features as drivers of connectivity or isolation. Studies reveal that some seabirds form virtually panmictic populations on a global scale, while others exhibit fine-scale structure owing to extreme site fidelity or environmental barriers. Insights into past demographic expansions, contractions and adaptive responses to climatic fluctuations underpin the development of conservation units, inform risk assessments under ongoing environmental change and guide management of breeding colonies at local and international levels.

Research from Nature Portfolio

Recent studies have uncovered unexpected levels of genetic subdivision and unity across penguin and petrel species. Fine-scale sampling of a tropical petrel species revealed two genetically distinct clusters among colonies separated by only five kilometres, emphasising the power of extreme philopatry to restrict gene flow even at minimal distances. Comparative analyses of crested penguins highlighted that oceanographic fronts such as the Antarctic Polar Front and Subtropical Front act as semi-permeable barriers, driving speciation among rockhopper lineages while permitting connectivity in more mobile congeners. Genome-wide surveys of emperor penguins across the Antarctic continent demonstrated a single, panmictic population with shared demographic history, challenging assumptions that each colony functions as an independent management unit.

Population Genetics of Seabirds publication trend

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

Technical terms

Gene flow: Exchange of genetic material among populations through migration and breeding.

Genetic differentiation: Degree of genetic divergence between populations, often quantified by statistical indices.

Philopatry: Tendency of individuals to return to or remain at their natal breeding site.

Effective population size: Number of individuals contributing genetically to subsequent generations.

Microsatellite marker: Short, repetitive DNA sequence used to assess genetic variation within and between populations.

Single nucleotide polymorphism (SNP): Variation at a single base pair in the genome, serving as a high-resolution genetic marker.

RAD sequencing (RAD-Seq): Technique that yields genome-wide SNP data by sequencing regions adjacent to restriction enzyme cut sites.

Phylogeography: Study of geographical distributions of genealogical lineages, often to infer historical demography.

References

1. Full circumpolar migration ensures evolutionary unity in the Emperor penguin. Nature Communications (2016).
2. Contrasting phylogeographic pattern among Eudyptes penguins around the Southern Ocean. Scientific Reports (2018).
3. Extreme philopatry and genetic diversification at unprecedented scales in a seabird. Scientific Reports (2021).
4. Comparative population genomics reveals key barriers to dispersal in Southern Ocean penguins. Molecular Ecology (2018).
5. Population structure and phylogeography of the Gentoo Penguin (Pygoscelis papua) across the Scotia Arc. Ecology and Evolution (2016).
6. Dispersal in the sub-Antarctic: king penguins show remarkably little population genetic differentiation across their range. BMC Ecology and Evolution (2016).