BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//wp-events-plugin.com//7.2.3.1//EN
TZID:Europe/Paris
X-WR-TIMEZONE:Europe/Paris
BEGIN:VEVENT
UID:1027@i2m.univ-amu.fr
DTSTART;TZID=Europe/Paris:20160120T112000
DTEND;TZID=Europe/Paris:20160120T122000
DTSTAMP:20160105T102000Z
URL:https://www.i2m.univ-amu.fr/evenements/un-modele-nul-pour-la-distribut
 ion-de-l-effet-des-mutations-sur-la-fitness-application-de-la-theorie-des-
 matrices-aleatoires-dans-un-reseau-phenotypique-complexe-et-integre/
SUMMARY: (...): Un modèle nul pour la distribution de l'effet des mutation
 s sur la fitness: application de la théorie des matrices aléatoires dans
  un réseau phénotypique complexe et intégré
DESCRIPTION:: Models relating phenotype space to fitness (phenotype-fitness
  landscapes) have seen important developments recently. They can roughly b
 e divided into mechanistic models (e.g.\, metabolic networks) and more heu
 ristic models like Fisher's geometrical model. Each has its own drawbacks\
 , but both yield testable predictions on how the context (genomic backgrou
 nd or environment) affects the distribution of mutation effects on fitness
  and thus adaptation. Both have received some empirical validation. This a
 rticle aims at bridging the gap between these approaches. A derivation of 
 the Fisher model "from first principles" is proposed\, where the basic ass
 umptions emerge from a more general model\, inspired by mechanistic networ
 ks. I start from a general phenotypic network relating unspecified phenoty
 pic traits and fitness. A limited set of qualitative assumptions is then i
 mposed\, mostly corresponding to known features of phenotypic networks: a 
 large set of traits is pleiotropically affected by mutations and determine
 s a much smaller set of traits under optimizing selection. Otherwise\, the
  model remains fairly general regarding the phenotypic processes involved 
 or the distribution of mutation effects affecting the network. A statistic
 al treatment (random matrix theory) and a local approximation close to a f
 itness optimum yield a landscape that is effectively the isotropic Fisher 
 model or its extension with a single dominant phenotypic direction. The fi
 t of the resulting alternative distributions is illustrated in an empirica
 l data set. These results bear implications on the validity of Fisher's mo
 del's assumptions and on which features of mutation fitness effects may va
 ry (or not) across genomic or environmental contexts.l'article corresponda
 nt est le suivant:Martin (2014)Fisher's geometrical model emerges as a pro
 perty of complex integrated phenotypic networksGenetics. 2014 May\;197(1):
 237-55Webpage
CATEGORIES:Séminaire,Mathématiques-Évolution-Biologie
END:VEVENT
BEGIN:VTIMEZONE
TZID:Europe/Paris
X-LIC-LOCATION:Europe/Paris
BEGIN:STANDARD
DTSTART:20151025T020000
TZOFFSETFROM:+0200
TZOFFSETTO:+0100
TZNAME:CET
END:STANDARD
END:VTIMEZONE
END:VCALENDAR