Founder Number and Allelic Diversity - Genetic Diversity in Establishing Plant Populations: Founder Number and Geometry - page 79

1.05

1.00

B

B

0.95

B

B

B

B

B

B

B

B
B

B

B
B

B
B

0.90

B

B B B B

B

B
B

B B

B

B

B

B

B

B B

0.85

B B

B

0.80

B B

0.75

1 10 100

FOUNDERS

Fig. 7.7 Variation in average heterozygosity for founding populations of different sizes. In
the source population from which founders are randomly drawn, there is only one locus
with 10 alleles of equal frequency (all 0.1). Each letter (B) represents the average value for
one trial (25 replicate runs per trial), there being fi ve separate trials for each founder number
category. Overlapping values are shown as one letter. As the number of founders increases,
the average heterozygosity converges on 0.9.

the number of individuals drawn from that ideal source population gets
larger, the mean value for heterozygosity across trials approaches 0.9. As
was apparent for the case of two alleles of equal frequency shown earlier,
variation in the number of alleles drawn appears to decrease more rapidly
than variation in heterozygosity across different draws of increasing
numbers of founders (e.g., compare Figs. 7.5 and 7.7). Variation in trial-
to-trial average heterozygosity is approximately 4% even when founding
populations number 400 individuals. This has implications for the sampling
of populations and the analysis of their heterozygosity, suggesting that
some degree of variation in fi ndings may exist even among large samples.
Still, as expected and shown previously, as the number of founders per run
increases, the standard deviation of average heterozygosity values decreases
to converge on 0 (Fig. 7.8).
What is the effect of adding 20 replicate loci, each locus with the exact
same characteristics as in the example immediately above (one locus with 10
unique alleles, each of equal frequency (0.1))? This can be accomplished by
inserting the following NEWGARDEN input fi le loci description code:

<locus>
<dpdpoint x=“0.1” y=“0”/><dpdpoint x=“0.1” y=“1”/><dpdpoint x=“0.1”
y=“2”/>
<dpdpoint x=“0.1” y=“3”/><dpdpoint x=“0.1” y=“4”/><dpdpoint x=“0.1”
y=“5”/>