Weak Convergence of Non-neutral Genealogies to Kingman's Coalescent

Suzie Brown, Paul A. Jenkins, Adam M. Johansen, Jere Koskela

Published 2021-10-11, updated 2022-09-15Version 2

Interacting particle systems undergoing repeated mutation and selection steps model genetic evolution, and also describe a broad class of sequential Monte Carlo methods. The genealogical tree embedded into the system is important in both applications. Under neutrality, when fitnesses of particles are independent from those of their parents, rescaled genealogies are known to converge to Kingman's coalescent. Recent work has established convergence under non-neutrality, but only for finite-dimensional distributions. We prove weak convergence of non-neutral genealogies on the space of c\`adl\`ag paths under standard assumptions, enabling analysis of the whole genealogical tree.