The 50/500 –100 –1000 –5000 Ne Rules, Actual Population Size, and Loss of Diversity to Random Drift - Genetic Diversity in Establishing Plant Populations: Founder Number and Geometry - page 206

The source population has 10 loci, each locus with 100 different alleles of
equal frequency = 0.01 (1,000 unique alleles in the source population).
The species is self-incompatible with a reproductive offspring Poisson
production rate of 1.1, 1.2, or 1.3 as designated in Fig. 13.1.
Offspring and pollen maximum dispersal = 10 grid units (for one individual,
its genes can be exchanged-dispersed at distances that could include as
many as the nearest 441 individuals).
The square preserve borders (lower left corner = -2560, -2560; upper right
= 2559, 2559; 26,214,400 average density potential establishment points are
available) are so distant from the founders that no individuals are dispersed
off the preserve in these analyses.

28000

B

B

B B

B

B B B

21000

B B

B B B B

C

B B B B B B B B B B B B B B B B B B B B B B B B B B

14000

C

AA AA AA AA AA A AA A A AA A A A A AA A A A A A A A A A A A AA A A A A A A A A A A A A A A A A A A A A A A A A A

C

C

C

C

C

7000

C

C

C C C C C C C C

0

0 20 40 60

GENERATION

Fig. 13.1 Population growth for three populations (900 founders each) of bisexual, self-
incompatible annuals with identical NEWGARDEN input parameter values except that
reproductive values are A = 1.1, B = 1.2, and C = 1.3.

The data points depicted in Fig. 13.1 are mean values of 30 replicate
runs for each set of trial conditions, which were allowed to continue for
different numbers of generations (see fi gure) because of time constraints.
In each trial, all conditions were identical except that reproduction rates
varied as indicated above. The growth of these populations refl ects plausible
scenarios for the establishment of a stand from 900 founders and achieves
numbers in the thousands at the end of each trial. All of these populations
experience initial declines in observed heterozygosity, but the rates of
decline seem to become relatively level after the fi rst fi ve (population C)
to 12 (population A) generations ( Fig. 13.2A ). Differences in heterozygosity
are not pronounced: population A has an observed heterozygosity value
that is approximately 3.8% lower than population C at the 16th generation.