---
res:
bibo_abstract:
- 'We investigate the establishment and spread of new adaptive peaks within Wright''s
‘shifting balance’. The third phase of the ‘shifting balance’ involves a kind
of group selection, since demes in which a superior peak has been established
contain more individuals, and so send out more migrants. We assume that population
size, N, increases with mean fitness, , according to the exponential relation,
. Here, k is a measure of the weakness of density-dependent regulation, and equals
the inverse of the regression of log (fitness) on log(N). In the island model,
we find that just as with soft selection (k = 0), two distinct types of behaviour
exist: group selection makes no qualitative difference. With low numbers of migrants,
demes fluctuate almost independently, and only one equilibrium exists. With large
numbers of migrants, all the demes evolve towards the same adaptive peak, and
so the whole population can move towards one or other of the peaks. Group selection
can be understood in terms of an effective mean fitness function. Its main consequence
is to increase the effect of selection relative to drift (Ns), and so increase
the bias towards the fitter peak. However, this increased bias depends on the
ratio between k and the deme size (k/N), and so is very small when density-dependence
is reasonably strong.@eng'
bibo_authorlist:
- foaf_Person:
foaf_givenName: Shahin
foaf_name: Rouhani, Shahin
foaf_surname: Rouhani
- foaf_Person:
foaf_givenName: Nicholas H
foaf_name: Nicholas Barton
foaf_surname: Barton
foaf_workInfoHomepage: http://www.librecat.org/personId=4880FE40-F248-11E8-B48F-1D18A9856A87
orcid: 0000-0002-8548-5240
bibo_doi: 10.1017/S0016672300031232
bibo_issue: '2'
bibo_volume: 61
dct_date: 1993^xs_gYear
dct_publisher: Cambridge University Press@
dct_title: Group selection and the 'shifting balance'@
...