This is a pedagogic function to show what is the coalescent in a simple population model with discrete generations and asexual reproduction.
sim.coalescent(n = 5, TIME = 50, growth.rate = NULL, N.0 = 50, N.final = 20,
col.lin = "grey", col.coal = "blue", pch = NULL, ...)the sample size.
the number of generations.
the growth rate of the population.
the initial size of the population.
the final size of the population (i.e., at present).
the colour used to show links of ancestry in the population.
the colour used to show the coalescent of the
the symbol used to show individuals (none by default).
further arguments passed to points if pch
is used.
The simulation works along the following steps. The number of
individuals at each generation is calculated. For each individual, a
(unique) parent is randomly chosen at the previous generation. All
individuals are then plotted and the ancestry lines are shown; the
individuals are eventually ordered to avoid line-crossings. A sample
of
The first (oldest) generation is at the bottom, and the final (present) one is at the top of the plot.
The population size at each generation is determined from the four
arguments: TIME, growth.rate, N.0, and
N.final. At least three of them must be given by the user. If
TIME is not given, its value is calculated with
log(N.final/N.0) / growth.rate.
This code was used to make the figures in Emerson et al. (2001).
Emerson, B., Paradis, E. and Thebaud, C. (2001). Revealing the demographic histories of species using DNA sequences. Trends in Ecology and Evolution, 16, 707--716.
# NOT RUN {
sim.coalescent()
sim.coalescent(N.0 = 20) # constant population size
# }
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