RT Journal Article
T1 Evolution on neutral networks accelerates the ticking rate of the molecular clock
A1 Manrubia, Susanna C.
A1 Cuesta, José A.
AB Large sets of genotypes give rise to the same phenotype because phenotypic expression is highly redundant. Accordingly, a population can accept mutations without altering its phenotype, as long as they transform its genotype into another one on the same set. By linking every pair of genotypes that are mutually accessible through mutation, genotypes organize themselves into genotype networks (GN). These networks are known to be heterogeneous and assortative. As these features condition the probability that mutations keep the phenotype unchanged---hence becoming blind to natural selection---it follows that the topology of the GN will influence the evolutionary dynamics of the population. In this letter we analyze this effect by studying the dynamics of random walks (RW) on assortative networks with arbitrary topology. We find that the probability that a RW leaves the network is smaller the longer the time spent in it---i.e., the process is not Markovian. From the biological viewpoint, this "phenotypic entrapment" entails an acceleration in the fixation of neutral mutations, thus implying a non-uniform increase in the ticking rate of the molecular clock with the age of branches in phylogenetic trees. We also show that this effect is stronger the larger the fitness of the current phenotype relative to that of neighboring phenotypes.
PB The Royal Society
SN 1742-5689
YR 2014
FD 2014-11-12
LK https://hdl.handle.net/10016/20081
UL https://hdl.handle.net/10016/20081
LA eng
NO The authors acknowledge the Fnancial support ofthe Spanish Ministerio de Ciencia e Innovación underprojects FIS2011-27569, PRODIEVO (FIS2011-22449),and Complexity-NET RESINEE, and of Comunidad deMadrid under project MODELICO-CM (S2009/ESP-1691).
DS e-Archivo
RD 1 sept. 2024