Biology Reference
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Since it is unlikely that one of the common unique alleles would be lost in
founding populations of 100 or more founders, the losses are of the rare
unique alleles. As expected, when only 50 rare alleles are present (about
6.5 lost on average in B), approximately half are lost compared to when 100
rare unique alleles are present (12.8 alleles lost in A). Once levels of 300-400
founders are achieved, it becomes increasingly likely that 99-100% of the
100 unique alleles will be retained (the mean number of unique alleles
retained when drawing from source population one versus two does not
differ at these numbers of founders (p > 0.05)).
A B C D E F G H
102.0
96.5
91.0
85.5
80.0
0
100
200
300
400
500
FOUNDERS
Fig. 7.11.
Effects of loci array characteristics on the number of unique alleles retained in a
founding population of different sizes, when founders are drawn from a source population
with either one locus with 100 unique alleles of equal frequency = 0.01 (letters A, C, E, or
G); or where the source population has 50 loci, each with two alleles (one with frequency =
0.99, the other = 0.01; B, D, F, or H). Both founding populations have a potential maximum
total of 100 unique alleles that can be drawn from the source population . The extent of the
range of 25 founder group samplings (sample founder groups had either 100, 200, 300, or
400 founders) is shown plus means (horizontal lines). Outliers are indicated by an asterisk,
while singletons are shown with circles. The means for A versus B, as well as for C versus
D are signifi cantly different (t-tests; p < 0.05), while for E versus F, or G versus H, there was
no difference (p >> 0.05). These results suggest that, for the case were there are 100 unique
alleles of frequency = 0.01, if one were to establish 25 different founding populations of 300
individuals each, capturing fewer than 100% of the unique alleles would occur infrequently
(in this case, twice out of 25 times; represented by the letter E), and even in those infrequent
cases, a high percentage of all alleles would still be captured.
Using the formula given earlier for calculating gene diversity (H,
expected heterozygosity), a large founding population drawn from source
population one should have a mean expected heterozygosity of 0.99, while
the mean for population two should be 0.0198. Figure 7.12 demonstrates
that not only do the same NEWGARDEN analyses used above in creating
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