Biology Reference
In-Depth Information
3000
o
o
o
o
o
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M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
M
MM
M
M
MM
MMM
MMM
MMMMM
MMMMMMM
MMMMMMMM
MMM
MMMMMMMMM
MMMMMMMM
2900
m
m
m
m
m
m
m
m
m
m
m
m
m
m
m
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m
m
mm
m
mm
m
mm
mmm
mmm
mmm
mmmmm
mmmmmmm
mm
mmm
mmm
mmmmmmmmmm
mmmm
n
n
n
n
n
n
n
n
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n
n
n
n
n
n
n
n
n
nn
n
n
nn
nn
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nn
nnn
nnnnn
nnnnn
nnnnnn
nn
nnn
nnnnnnnnnnnn
nnn
p
p
p
p
p
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p
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pp
p
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ppp
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pppp
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p
ppp
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pppppppp
2900
P
P
P
P
P
P
P
P
P
P
P
P
P
P
P
PP
P
P
PP
PP
P
PPP
PPP
PPPP
PPPPPPP
PPPPPPP
PPP
PPPPPPP
PPPPPPPPPPP
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
NNN
N
NNN
NNN
NNNN
NNNNN
NNNNNNNN
NNN
NNNN
NNNNNNNNN
NNNNNN
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
OO
O
OO
OO
OO
OOO
OOOO
OOO
OOOOOO
OOOOOO
OO
OOOOOO
OOOOOOOO
OOOO
A
B
2800
2800
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2300
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0
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GENERATION
GENERATION
Fig. 15.4
Unique alleles retained across generations 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 trials M or 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)
.
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.
is a sudden large increase in cohort size due to a 62% jump in offspring
output at that round of mating by the founders (again, see the reproduction
rate input information for trial M). After this increase, successive cohorts
decrease slightly in size through age 19, after which each new cohort is
larger than the last. The slight decrease in successive cohort sizes between
ages 14 and 19 is likely due to an interaction of age-specifi c mortality (the
effects of this are shown in
Fig. 15.1,
in which the entire population declines
from 172 individuals to approximately 80 individuals before reproduction
commences), age-specifi c reproduction (new cohorts do not reproduce
until their generation 8 and not at the highest rate until generation 13),
and the effects of density-dependent mortality of newly produced, but not
established, offspring. The last effect is refl ected by the fact that population
N, in which potential offspring are disproportionately distributed near
their maternal plant, suffers the greatest decline in successive cohort size
between ages 14 and 19 (this can be clearly seen by graphing only ages 0
through 23 or so, such a graph not being presented here). From age 19, new
cohorts of all trial populations are larger than the previous cohort. At age
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