---
res:
bibo_abstract:
- We consider the evolution of populations under the joint action of mutation and
differential reproduction, or selection. The population is modelled as a finite-type
Markov branching process in continuous time, and the associated genealogical tree
is viewed both in the forward and the backward direction of time. The stationary
type distribution of the reversed process, the so-called ancestral distribution,
turns out as a key for the study of mutation-selection balance. This balance can
be expressed in the form of a variational principle that quantifies the respective
roles of reproduction and mutation for any possible type distribution. It shows
that the mean growth rate of the population results from a competition for a maximal
long-term growth rate, as given by the difference between the current mean reproduction
rate, and an asymptotic decay rate related to the mutation process; this tradeoff
is won by the ancestral distribution. We then focus on the case when the type
is determined by a sequence of letters (like nucleotides or matches/mismatches
relative to a reference sequence), and we ask how much of the above competition
can still be seen by observing only the letter composition (as given by the frequencies
of the various letters within the sequence). If mutation and reproduction rates
can be approximated in a smooth way, the fitness of letter compositions resulting
from the interplay of reproduction and mutation is determined in the limit as
the number of sequence sites tends to infinity. Our main application is the quasispecies
model of sequence evolution with mutation coupled to reproduction but independent
across sites, and a fitness function that is invariant under permutation of sites.
In this model, the fitness of letter compositions is worked out explicitly. In
certain cases, their competition leads to a phase transition.@eng
bibo_authorlist:
- autoren_ansetzung:
- Baake, Ellen
- Baake
- Ellen Baake
- Baake, E
- Baake, E.
- E Baake
- E. Baake
foaf_Person:
foaf_givenName: Ellen
foaf_name: Baake, Ellen
foaf_surname: Baake
foaf_workInfoHomepage: http://www.librecat.org/personId=161046
- autoren_ansetzung:
- Georgii, Hans-Otto
- Georgii
- Hans-Otto Georgii
- Georgii, H
- Georgii, H.
- H Georgii
- H. Georgii
foaf_Person:
foaf_givenName: Hans-Otto
foaf_name: Georgii, Hans-Otto
foaf_surname: Georgii
bibo_doi: 10.1007/s00285-006-0039-5
bibo_issue: '2'
bibo_volume: '54'
dct_date: 2007^xs_gYear
dct_identifier:
- UT:000243906600005
dct_isPartOf:
- http://id.crossref.org/issn/0303-6812
- http://id.crossref.org/issn/1432-1416
dct_language: eng
dct_publisher: SPRINGER@
dct_subject:
- mutation-selection models
- quasispecies model
- large deviations
- variational analysis
- branching processes
dct_title: 'Mutation, selection, and ancestry in branching models: a variational
approach@'
fabio_hasPubmedId: '17075709'
...