id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-264532-xfb94lq8	Bull, James J	Invasion thresholds and the evolution of nonequilibrium virulence	2008-01-09		.txt	text/plain	7332	333	50	Evolution following invasion may be slow to attain the optimum Following Day and Proulx (2004) , if the invading parasite persists and becomes established, it is expected that virulence and transmission will begin to evolve toward values that improve parasite fitness. Yet, the approach to optimum virulence may be slow for a few reasons: (i) the optimum may be changing (Lenski and May 1994) , (ii) virulence evolution will be influenced by the genetic covariance or mutational properties between virulence and transmission (Day and Gandon 2006) , and Conditions for the invasion of a host population of density S* by a parasite with parameters (d, b) are S* > d/b, where d is virulence and b is the transmission rate. Likewise, if hosts merely die from the infection and do not recover (and are not resistant), then the invasion threshold model cannot possibly apply after dynamical equilibrium has been reached, because there is no reservoir of immune or resistant hosts to be exploited by a mutant parasite.	./cache/cord-264532-xfb94lq8.txt	./txt/cord-264532-xfb94lq8.txt