Biology Reference
In-Depth Information
r = 1.18
r = 1.18
r = 1.5
r = 1.8
w
y
c
e
1000
w
e
y
c
900
e
800
c
e
e
e
e
e e
e eeee
eeeeeee
700
y
w
c
c
600
c
c
y
w
c
c
c c
c c
ccccc
cccccc
500
w
y
w
400
y
w
w
w
w
w
w
w
w
w
w
ww
w
w w
ww
w w ww
wwww
w
y
300
y
y
y
y
y
y
y
y
y
y
y
y
y y y
y yyy
yyyyy
y
200
100
0
10
20
30
GENERATION
Fig. 10.5
Mean (of 30 runs per trial population) number of unique alleles retained across
generations for four populations with mostly identical initial input conditions (including
20 founders with adjacent individuals in closest spacing) except that: w = founders placed
in two, centrally placed lines of 10 each; populations c, y, and e = founders broken into four
groups of fi ve founders each, each group removed from the preserve center towards one of
the four corners, with the founder nearest the center being displaced by 15 units in the x and
y directions. Populations have the reproduction rate values (r) indicated above. Different
numbers of generations were examined for different populations. Means are based on 30
replicate runs per trial. Preserves and placement of founders not drawn to scale (preserve
includes 26,214,400 grid units).
The number of generations variable, but often fi ve or six only.
Thirty replicate runs per trial. Values presented are averages of these 30
runs for one set of trial conditions.
Adjacent founders separated by 5 grid points.
Founders are always placed in the center of the preserve (at approximately
0,0).
We start with a founding population of 10 individuals placed in a square
(3 by 3 with one founder separated to one side by 5 grid points) and vary
r from 1.5 to 18
(
Fig. 10.6)
.
Obviously, populations with a higher r grow at
a faster rate, with population a growing to approximately 67 individuals
and population j generating a mean of 9529 individuals after fi ve rounds of
reproduction. Populations with a higher r experience lower losses of both
observed heterozygosity and unique alleles, with populations having the
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