The coalescent in a continuous, finite, linear population

Area of Science:

• Population Genetics
• Evolutionary Biology
• Ecological Modeling

Background:

• Understanding genetic diversity is crucial for conservation and evolutionary studies.
• Linear habitats with restricted gene flow present unique challenges for population genetic analysis.

Purpose of the Study:

• To develop and validate a model for analyzing genetic diversity patterns in continuous, finite, linear habitats.
• To investigate the influence of sequence distance and location within the habitat on coalescence times.
• To compare model predictions with empirical data for estimating demographic parameters.

Main Methods:

• Derivation of coalescent time and location distributions for sequences in a linear habitat.
• Simulation of genetic diversity patterns to compare with model predictions.
• Application of the model to analyze nucleotide difference data from sardine populations.

Main Results:

• Mean time to coalescence increases with sequence separation and is greater near the habitat center.
• Coalescent events are biased toward the center, while non-coalesced lineages are more likely at habitat ends.
• Model predictions align with sardine population data, demonstrating its utility for demographic inference.

Conclusions:

• The developed model accurately captures genetic diversity patterns in linear populations.
• Habitat geometry and gene flow significantly impact coalescence dynamics.
• The model provides a framework for estimating demographic parameters in spatially structured populations.