@article{parsons_absorption_2008,
Author = {Parsons, Todd L. and Quince, Christopher and Plotkin,
Joshua B.},
Title = {Absorption and fixation times for neutral and
quasi-neutral populations with density dependence},
Journal = {Theoretical Population Biology},
Volume = {74},
Number = {4},
Pages = {302--310},
abstract = {We study a generalisation of Moran's
population-genetic model that incorporates density
dependence. Rather than assuming fixed population size,
we allow the number of individuals to vary
stochastically with the same events that change allele
number, according to a logistic growth process with
density dependent mortality. We analyse the expected
time to absorption and fixation in the 'quasi-neutral'
case: both types have the same carrying capacity,
achieved through a trade-off of birth and death rates.
Such types would be competitively neutral in a
classical, fixed-population Wright-Fisher model.
Nonetheless, we find that absorption times are skewed
compared to the Wright-Fisher model. The absorption
time is longer than the Wright-Fisher prediction when
the initial proportion of the type with higher birth
rate is large, and shorter when it is small. By
contrast, demographic stochasticity has no effect on
the fixation or absorption times of truly neutral
alleles in a large population. Our calculations provide
the first analytic results on hitting times in a
two-allele model, when the population size varies
stochastically.},
doi = {10.1016/j.tpb.2008.09.001},
issn = {1096-0325},
language = {eng},
month = dec,
pmid = {18835288},
year = 2008
}