luke verburgt prof j.w.h. fergusondr t. weber a critical examination of “symmetry in the songs of...
TRANSCRIPT
Luke Verburgt
Prof J.W.H. Ferguson Dr T. Weber
A critical examination of “Symmetry in the songs of crickets”
Simmons & Ritchie (1996)
The importance of symmetry in an insect communication system.
Introduction
Males sing to attract females
Gryllus bimaculatus
5.3
4.9kHz
Introduction Bandwidth
~ 150ms
0.4kHz
-15 -10 -5 0 5 10 15
0
10
20
30
40
50
60
Introduction FA
Fluctuating Asymmetry (R-L)
Developmental Instability
-10 -5 0 5 10 15 20
0
5
10
15
20
25
30
35
Directional Asymmetry (R-L)
Genetically determined
Introduction DA
Simmons & Ritchie (summary)
MALES
•Harp size is correlated with body size
•Call frequency is correlated with harp size
•Call bandwidth is correlated with DA of harp
•FA morph is correlated with DA of harp
Therefore: Females can “hear” how symmetrical a male is
FEMALES
•Prefer pure-tones indicative of a symmetrical male
Therefore:
Females can “choose” symmetrical males acoustically
The Male Wing….
The Male Wing….
Body size (PL x PW), mm2
0 20 25 30 35 40 45 50 55
Mea
n H
arp
Are
a (m
m2)
0
16
18
20
22
24
26
r²=0.805p<0.001
Male Harp Area vs Size
Mean Harp Area (mm2)
0 16 18 20 22 24 26
Fre
qu
ency
(H
z)
0
4400
4600
4800
5000
5200
5400
5600
r²=0.125p=0.008
Male Frequency Results
(R-L) Harp Area( mm2)
[Size-corrected]
-0.04 -0.03 -0.02 -0.01 0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08
Ba
nd
wid
th (
-10
dB
) , H
z
0
100
200
300
400
500
600
700
800
900r²=0.022p=0.255
Male Bandwidth Results
Asymmetry (FA14)
0.0 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
Ban
dw
idth
(-1
0dB
), H
z
0
100
200
300
400
500
600
700
800
900r²<0.001p=0.85
Male Bandwidth Results
Asymmetry (FA14)
0.0 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
(R-L
) H
arp
Are
a( m
m2 )
[Siz
e-co
rrec
ted
]
-0.04
-0.02
0.00
0.02
0.04
0.06
0.08r²<0.001p=0.82
Male FA Results
Conclusion for Males
Harp size is correlated with body size
Call frequency is correlated with harp size
Call bandwidth is correlated with DA of harp
FA morph is correlated with DA of harp
Therefore: Females can NOT “hear” how symmetrical a male is
Cricket
Sphere
Speaker
Kramer spherical treadmill
Female frequency response….
Frequency (kHz)
0.0 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0
Bat
chel
et D
evia
tio
n
0
20
40
60
80
100
Female frequency response….
Female frequency response….
Frequency (kHz)
0.0 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0
Bat
chel
et D
evia
tio
n
0
20
40
60
80
100
y = -0.7364067647x8+30.9904983205x7-563.878302226x6+5795.0167254032x5-36803.3533238713x4+147952.6446x3-367735.2038x2+516575.2812x-313757.8008
Female frequency response….
Frequency (kHz)
0.0 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0
Bat
chel
et D
evia
tio
n
0
20
40
60
80
100
Frequency (kHz)
0.0 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0
Bat
chel
et D
evia
tio
n
0
20
40
60
80
100
Female frequency response….
Frequency (kHz)
0.0 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0
Bat
chel
et D
evia
tio
n
0
20
40
60
80
100
Female frequency response….
Female bandwidth response….
5
4.8
Bandwidth (kHz)
3.8 4.0 4.2 4.4 4.6 4.8 5.0
Bat
chel
et D
evia
tio
n
0
10
20
30
40
50
60
70
Bandwidth (kHz)
3.8 4.0 4.2 4.4 4.6 4.8 5.0
Bat
chel
et D
evia
tio
n
0
10
20
30
40
50
60
70
Bandwidth (kHz)
3.8 4.0 4.2 4.4 4.6 4.8 5.0
Bat
chel
et D
evia
tio
n
0
10
20
30
40
50
60
70
Bandwidth (kHz)
3.8 4.0 4.2 4.4 4.6 4.8 5.0
Bat
chel
et D
evia
tio
n
0
20
40
60
Female bandwidth response….
Bandwidth (5 - end frequency; kHz)
3.8 4.0 4.2 4.4 4.6 4.8 5.0
Ba
tch
ele
t D
evi
ati
on
0
10
20
30
40
Frequency (kHz)
0.0 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0
Bat
chel
et D
evia
tio
n
0
20
40
60
80
100
Female bandwidth response….
Area under Frequency curve
0 10 20 30
Are
a u
nd
er B
and
wid
th c
urv
e
0
5
10
15
20
25
r2=0.16p<0.001
Female bandwidth response….
Frequency (kHz)
0.0 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0
Bat
chel
et D
evia
tio
n
0
20
40
60
80
100
Female bandwidth response….
Area under BW curve
1) Area under Frequency curve
2) Poly-predicted Frequency preference
Multiple regression….
F2,109 = 15.24; R2 = 0.22; p<0.001
Area under Frequency curve p=0.008
Poly-predicted Frequency preference p = 0.005
Conclusion for Females
FEMALES
•Prefer pure-tones indicative of a symmetrical male
Therefore:
Females can NOT “choose” symmetrical males acoustically
rather
A female will tolerate a certain bandwidth range which is pre-defined by her frequency
response range
•Dr. H.U. Kleindienst
•Heidrun Bamberg
•Marna Ferreira
•Dr. Xim Cerda
Funding & logistics
Acknowledgements