Biology Reference
In-Depth Information
the selfi ng rate in different NEWGARDEN trials with other conditions held
constant illuminates how selfi ng affects genetic diversity in developing
populations and, further, may suggest the most critical points at which
enforced outcrossing intervention might be most effective in protecting
diversity.
Random Mating
Under true Hardy-Weinberg modeling, selfi ng is permitted and should occur
with a probability equal to that of any other potential mating. Some species
that can both outcross and self may approximate that model, in which case
Random Mating value should be set to true, even if the selfi ng rate is very
low or set to 0. In other words, even if selfi ng rate is set to 0, if random
mating is designated as true, then selfi ng will occur with a probability equal
to any other eligible mating. For species with self-incompatibility systems
that absolutely inhibit any selfi ng, the Random Mating value should be set
to false. We have found that in many cases setting this value to true or false
is of little consequence once a population size exceeds 50 to 100 individuals.
When there are only a few individuals available for mating, under random
mating = true, chances of selfi ng increase compared to a population with a
large number of potential mates.
Offspring Distribution Method Options
The offspring distribution method does not refer to how the offspring
are dispersed or distributed across the virtual potential habitat grid.
Instead, it refers to the three different options available that determine the
NEWGARDEN selection process for the number of offspring produced by
each individual female.
We recommend using the Poisson distribution method:
<Offspring_Distribution method=“poisson”/>
The method “poisson” selects females to produce offspring in a fashion by
which the overall average reproduction rate equals that designated in the
Reproduction_Rate statement (see above), but eligible females are selected
at random to produce offspring in a manner that approximates a Poisson
distribution for the number of offspring produced per eligible female.
Some females will thus be randomly more prolifi c than others according
to the Poisson.
Another option that can be used to refl ect the fact that in most populations
different female individuals of an age cohort contribute at different rates to
offspring reproduction can be designated with the command:
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