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Updated: Jun 17, 2025
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Temporal Ordering of Dynamic Expression Data from Detailed Spatial Expression Maps
Published on: February 9, 2017
5.9K
Range expansions across landscapes with quenched noise
Jimmy Gonzalez Nuñez1, Jayson Paulose2, Wolfram Möbius3,4
1Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218.
Summary
Environmental heterogeneity can dominate genetic drift in expanding populations. Landscape features dictate evolutionary paths, influencing genetic diversity and potentially masking demographic history signals.
Area of Science:
- Evolutionary biology
- Population genetics
- Ecological dynamics
Background:
- Biological populations expanding into new territories face evolutionary pressures from genetic drift and environmental heterogeneity.
- The interplay between intrinsic demographic noise and extrinsic environmental noise in population dynamics is not well understood.
- Distinguishing the population genetics signatures of genetic drift versus environmental influences is a key challenge.
Purpose of the Study:
- To investigate the interplay between demographic noise and environmental heterogeneity in population expansion.
- To determine when environmental heterogeneity dominates over genetic drift and vice versa.
- To understand how environmental variability affects genealogical tree structure and genetic diversity.
Main Methods:
- Utilized a multispecies Eden model for population expansion simulations.
- Simulated populations expanding over landscapes with spatially varying local growth rates.
- Analyzed the effects of landscape variability on genealogical tree structure and genetic diversity.
Main Results:
- Strong environmental heterogeneity predetermined the genetic makeup of the expansion front via fastest paths.
- Landscape-dependent statistics of optimal paths superseded intrinsic demographic noise as the primary evolutionary determinant.
- Coalescence statistics derived from deterministic paths mimicked those from demographic noise in uniform landscapes.
Conclusions:
- Environmental heterogeneity can be a stronger driver of evolutionary dynamics than genetic drift in expanding populations.
- Interpreting genetic coalescence statistics requires caution, as they can resemble those from demographic noise alone.
- The findings present new challenges for inferring past population dynamics from genetic data.
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