Biology Reference
In-Depth Information
(a)
(b)
40
2.8
Fig. 10.11
Size
and fitness in the
shrimp
Gammarus
duebeni
. (a)
Larger females
laid more eggs.
(b) Larger males
were more likely
to mate. (c) Larger
males mated with
larger females.
(d) When all of
the consequences
of size are
summed, the
relative fitness of
males increases
more rapidly with
size than that
of females
(photograph of a
mating pair,
where male is the
larger individual).
From McCabe
and Dunn (1997).
Photo © Alison
Dunn.
Male
35
2.4
30
2.0
25
1.6
20
1.2
Female
15
0.8
10
0.4
5
0.0
10
15
20
25
30
35
40
45
0
20
40
60
80
100
Female weight (mg)
Size (mg wet weight)
(c)
(d)
120
10.0
Male
100
8.0
80
6.0
60
4.0
40
Female
2.0
20
0
0.0
0
20
40
60
80
100
120
0
20
40
60
80
100
Male weight (mg)
Percentiles of the size range
