Neither pulled nor pushed: Genetic drift and front wandering uncover a new class of reaction-diffusion waves
Abstract
Traveling waves describe diverse natural phenomena from crystal growth in physics to range expansions in biology. Two classes of waves exist with very different properties: pulled and pushed. Pulled waves are driven by high growth rates at the expansion edge, where the number of organisms is small and fluctuations are large. In contrast, fluctuations are suppressed in pushed waves because the region of maximal growth is shifted towards the population bulk. Although it is commonly believed that expansions are either pulled or pushed, we found an intermediate class of waves with bulk-driven growth, but exceedingly large fluctuations. These waves are unusual because their properties are controlled by both the leading edge and the bulk of the front.
Keywords
Cite
@article{arxiv.1709.01601,
title = {Neither pulled nor pushed: Genetic drift and front wandering uncover a new class of reaction-diffusion waves},
author = {Gabriel Birzu and Oskar Hallatschek and Kirill S. Korolev},
journal= {arXiv preprint arXiv:1709.01601},
year = {2018}
}
Comments
81 pages, 15 figures. v2: clarified references to related work; added discussion on prevalence of semi-pushed waves; other minor corrections