Biology Reference
In-Depth Information
Unique alleles retained in distinct successive cohorts for these
comparative trials are shown in Fig. 15.8. All of the founders in these
populations have unique allele numbers approaching 3,000. Since founders
arrive as “seeds” and mating does not immediately commence, early
subsequent generations produce no new offspring, and thus no alleles
are present after the fi rst rounds of potential reproduction. Once founder
reproduction begins (age = 8), the number of unique alleles increases in
each successive cohort as more and more individuals are produced by
the aging original founders (offspring production increases with age).
However, even at cohort 13, only 800-1,000 unique alleles out of the
approximately 2,925 original unique alleles in the founding populations are
present. At that point, there is a “sudden jump” in the number of unique
alleles retained by the next cohort since the age-specifi c rate of offspring
production increases by 62% at that point. Although this rate of offspring
production continues, there is then a slight decline in retained unique alleles
per cohort, since founder mortality proceeds according to the specifi ed age-
3000
3000 M
m
n
o
p
O
N
P
B
A
P P PPP PPP PP P P P P P P P P P PP P PP P PP P P P PPP PP PPP PPP PP PPPPP PPPPPP P
2000
2000
M M MM M MM MM M M M M M M M M M M MM M MM M M M M M M MM MMMM MM MM MMM MMMM MMMMM MMM
n n nnn n n n n n n n n n n n nn n n nn nn n n n n n nn nn n nnn nn nnn nnn nnnn nnnn nn
m m m m m m m m m m m m m m m m m m mm m m m m mm m mm mm mmm mm mm mm mmmm mmmm mm
N N NN N N N NN NN N N N N NN N N N NN N N N NN NN N N NNN NNN NNN NNN NNN NNNN NNNNN
O O O O O O OO O OO O O O O OOO O O OO OOOO O OOO OO OOO OOOO OOOOO
p p p p p p ppp p p p p p p p p p pp p p p p p p p pp pp p pp ppp pp pp ppp ppp pppp pppp
o o o ooo oo o o o oo o o o o o o o o o oo o oo o o o o o o oooo oo oo oo ooo oo ooooo oo
O O OO O OOO OO O
mm m m m
1000
1000
O
P
M
N
O
m m
n n
M
P
o o
p
N N
p
O
M
P
n
m
p
o
O
P
N
m
M
n
o
p
P
N
M
m
O
n
o
p
0
0
nnnnnnnn
oooooooo
pppppppp
mmmmmmmm
OOOOOOOO
PPPPPPPP
NNNNNNNN
MMMMMMMM
0
10
20
30
40
50
60
70
0
10
20
30
40
50
60
70
GENERATION
GENERATION
Fig. 15.8 Original founder unique alleles retained in successive new cohorts for trials modeling
establishment of the dioecious shrub Lindera benzoin . 172 founders were placed either in squares
of 43 at each corner with no founder closer than 80 grid units from a border (A, lowercase
letters), or in a single central square in the preserve (B, uppercase letters). In every trial, there
were 4 grid points between all adjacent founders. The different trials are compared to basic
trial M, in which 25% of offspring are dispersed to, and 25% of pollen comes from, each of
the four dispersal distance frames (see Table 15.1) . To summarize, comparative trials differ
as follows:
In trials N and n, more offspring are dispersed more closely to the maternal plant; 25% pollen
from each frame.
In trials O and o, 25% of an individual's offspring are dispersed to each frame; more pollen
comes from nearer the maternal plant.
In trials P and p, 25% of an individual's offspring are dispersed to each frame; more pollen
comes from a greater distance from the maternal plant.
For complete details on the trials, see text and Table 15.1.
 
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