Home

Article Search

TABLE 1. Genetic parameters from which the shell morphology was generated. Parameters 1-10 defined the overall shape of the shell, parameters 11-14 the surface sculpture. The shape of the aperture curve used 8 parameters, see Figure 2.3. For the effect of parameters λ, q, fr and fc, see Figure 3. By reducing parameter a from 1 to 0, the sculptures of the sculptured examples in Figure 3 would be linearly reduced to a smooth surface.

 
 

Variable

Range

Parameter description

1

αh

[30°, 120°]

hinge angle

2

rh

[0, 1]

hinge radius

3

α3

[0°, 360° –αh]

angle of 3rd control point

4

r3

[0, 1]

radius of 3rd control point

5

α4

[0°, 360° –αh]

angle of 4th control point

6

r4

[0, 1]

radius of 4th control point

7

α5

[0°, 360° –αh]

angle of 5th control point

8

r5

[0, 1]

radius of 5th control point

9

λ

[1.00339, 1.04086]

growth scaling factor

10

ϑ

[0°, 90°]

shell rotation towards anterior

11

q

[0, 1]

radial/commarginal mixture

12

a

[0, 1]

sculpture amplitude

13

fr

[10..100]

radial ridge frequency

14

fc

[18..180]

commarginal ridge frequency

TABLE 2. Phenotypic (morphometric) parameters. In addition to the parameters listed in Table 1 that were used to generate the shells, we used this set of phenotypic parameters computed from the final shells to find possible correlations with the fitness.

 
 

Variable

Unit/Range

Parameter description

1

L

[mm]

length, dimension parallel to hinge axis

2

H

[mm]

height, dimension orthogonal to length

3

B

[mm]

broadness, dimension orthogonal to burrowing direction

4

T

[mm]

tallness, dim. parallel to burrowing direction

5

J

[mm]

major axis length, largest diameter

6

N

[mm]

minor axis length, dimension orthogonal to major axis

7

W

[mm]

width, dimension orthogonal to aperture plane (over both valves)

8

lA

[mm]

aperture curve length, circumference of aperture

9

AA

[mm2]

aperture area

10

γ

[0, 1]

non-convexity, part of aperture area bending inwards

11

pu

[0, 1]

relative umbo position (along L)

12

pc

[0, 1]

relative centre position (along L)

13

S1

[0, 1]

streamlining, (Watters, 1993, based on L and H)

14

S2

[0, 1]

streamlining, (Watters, 1993, based on B and T)

15

S3

[0, 1]

streamlining, average angle between faces and burrowing direction

TABLE 3. Correlations of genetic and phenotypic parameters and the burrowing depth D with fitness (original and shift 2, see Figure 6). We computed Pearson and Spearman correlation. The p-values and the correlation coefficients r are given.

 
 

Pearson correlation

Spearman correlation

 

Fitness (orig.)

Fitness (shift 2)

Fitness (orig.)

Fitness (shift 2)

Variable

p-value

r

p-value

r

p-value

r

p-value

r

D – T

3E-40

0.92

4E-29

0.85

0

0.84

6E-08

0.52

T

2E-14

-0.68

0

-0.73

5E-03

-0.28

5E-03

-0.28

L

3E-10

-0.58

7E-12

-0.62

0.14

-0.15

0.18

-0.14

S2

6E-10

-0.57

2E-11

-0.62

9E-03

-0.26

9E-03

-0.26

lA

4E-08

-0.52

2E-09

-0.56

2E-04

-0.37

1E-04

-0.38

pc

5E-08

0.52

8E-10

0.57

0.3

0.11

0.3

0.1

fr

6E-08

0.51

6E-09

0.55

0.55

0.06

0.93

0.01

S1

9E-07

-0.47

1E-07

-0.5

0.19

-0.13

0.21

-0.13

α5

1E-06

-0.47

2E-08

-0.53

0.06

-0.19

0.03

-0.22

α4

2E-06

-0.46

2E-08

-0.53

0.01

-0.26

2E-03

-0.31

S3

5E-06

0.44

2E-06

0.46

0.25

0.12

0.15

0.15

r4

2E-05

0.42

7E-07

0.48

0.38

0.09

0.17

0.14

γ

5E-05

-0.4

5E-06

-0.44

0.06

0.19

0.02

0.24

rh

1E-04

0.37

2E-06

0.46

2E-03

0.31

4E-06

0.45

α3

4E-04

0.35

3E-05

0.41

0.44

-0.08

0.37

-0.09

J

5E-04

-0.35

2E-04

-0.37

3E-03

-0.3

2E-03

-0.31

B

1E-03

0.33

5E-04

0.35

0.48

0.07

0.49

0.07

H

1E-03

0.33

5E-04

0.35

0.68

0.04

0.76

0.03

q

4E-03

-0.29

8E-04

-0.33

0.07

0.18

3E-03

0.3

r3

6E-03

0.28

2E-03

0.31

0.86

0.02

0.72

-0.04

λ

0.02

0.24

0.01

0.25

0.45

-0.08

0.23

-0.12

D

0.03

0.23

0.01

0.26

7E-07

0.48

2E-04

0.37

a

0.03

-0.22

0.02

-0.24

2E-04

-0.37

1E-06

-0.47

ϑ

0.04

0.21

6E-03

0.28

0.46

-0.08

0.39

-0.09

AA

0.04

-0.21

0.04

-0.21

0.03

-0.22

0.04

-0.2

N

0.08

-0.18

0.05

-0.2

0.41

-0.08

0.41

-0.08

αh

0.22

-0.13

0.3

-0.11

0.28

0.11

0.04

0.21

r5

0.24

-0.12

0.26

-0.11

0.02

-0.23

0.03

-0.22

pu

0.27

0.11

0.2

0.13

0.02

-0.24

3E-03

-0.3

fc

0.38

0.09

0.18

0.14

0.2

-0.13

0.06

-0.19

W

0.48

-0.07

0.42

-0.08

0.12

0.16

0.11

0.16

logo smallPalaeontologia Electronica
Webmaster
1998–2021
24 years of electronic palaeontology

PE is archived by CLOCKSS and LOCKSS programs.