Central limit theorems describing isolation by distance under various forms of power-law dispersal

¹ INRAE, BioSP, 84914 Avignon, France
² Department of Statistics, University of Oxford, Oxford OX1 3LB, UK

^* Corresponding author: bastian.wiederhold@wadham.ox.ac.uk

Received: 22 March 2024
Accepted: 2 January 2025

Abstract

In this paper, we uncover new asymptotic isolation by distance patterns occurring under long-range dispersal of offspring. We extend a recent work of the first author, in which this information was obtained from forwards-in-time dynamics using a novel stochastic partial differential equations approach for spatial Λ–Fleming–Viot models. The latter were introduced by Barton, Etheridge and V´eber as a framework to model the evolution of the genetic composition of a spatially structured population. Reproduction takes place through extinction-recolonisation events driven by a Poisson point process. During an event, in certain ball-shaped areas, a parent is sampled and a proportion of the population is replaced. We generalize the previous approach of the first author by allowing the area from which a parent is sampled during events to differ from the area in which offspring are dispersed, and the radii of these regions follow power-law distributions. In particular, while in previous works the motion of ancestral lineages and coalescence behaviour were closely linked, we demonstrate that local and non-local coalescence is possible for ancestral lineages governed by both fractional and standard Laplacians.