early nest environment and genes have lifetime effects on the expression of a colorful sexual signal...
TRANSCRIPT
Early nest environment and genes have lifetime
effects on the expression of a colorful sexual signal
Joey K. Hubbard, Brittany R. Jenkins, Rebecca J. [email protected]
Animal Behavior SocietyJuly 30, 2013
GenesSelective pressure
Phenotypic change over generations
EnvironmentEnvironmental change
Phenotypic change over a short time
period
Sexually-Selected Traits
Phenotypic Variation
Environmental Control
Genetic Control
Indirect Benefits
Direct Benefits
North American Barn Swallows
• Sexual trait
• Socially Monogamous
• Extra-pair paternity
• Monitoring Boulder County breeding population since 2008
Safran & McGraw 2004; Safran et al. 2005
Animal Model
• Univariate animal model to partition sources of variance for each color descriptor
• Determine key variance components• Calculate variance ratios
VP = VA + VT + VCE + VME + VR
Variance Ratios
h2 VA/VP: Narrow sense heritability
t2 VT/VP: Effect of seasonal variation
ce2 VCE/VP: Effect of common environment
me2 VME/VP: Effect of maternal environment
VP = VA + VT + VCE + VME + VR
Influences on Juvenile Color
Variance Ratios Avg. Brightness
h2
heritability 0.10 (0.23)
t2
seasonal effect 0.05 (0.04)
ce2
common environment
0.11 (0.08)
me2
maternal environment
0.05 (0.09)
Hubbard et al. in prep(Standard Error)
Influences on Juvenile Color
Variance Ratios Avg. Brightness Hue
h2
heritability 0.10 (0.23) 1.1-07 (7.1e-09)
t2
seasonal effect 0.05 (0.04) 0.03 (0.04)
ce2
common environment
0.11 (0.08) 0.09 (0.08)
me2
maternal environment
0.05 (0.09) 0.12 (0.07)
Hubbard et al. in prep(Standard Error)
Influences on Juvenile Color
Variance Ratios Avg. Brightness Hue Chroma
h2
heritability 0.10 (0.23) 1.1-07 (7.1e-09) 0.19 (0.15)
t2
seasonal effect 0.05 (0.04) 0.03 (0.04) 0.05 (0.04)
ce2
common environment
0.11 (0.08) 0.09 (0.08) 0.13 (0.08)
me2
maternal environment
0.05 (0.09) 0.12 (0.07) 4.3-07 (7.5e-08)
Hubbard et al. in prep(Standard Error)
Within-Individual Variation
Hatch Year Second Year
Year 1 Year 2
54 individuals(out of ~4000 nestlings)
205 individuals
Within-Individual Variation
b R2 pBrightness 0.48 0.22 <
0.001Hue 0.10 0 0.49
Chroma 0.87 0.29 < 0.001
Hat
ch Y
ear t
oSe
cond
Yea
r
Within-Individual Variation
b R2 pBrightness 0.48 0.22 <
0.001Hue 0.10 0 0.49
Chroma 0.87 0.29 < 0.001
b R2 pBrightness 0.41 0.21 <
0.001Hue 0.21 0.04 0.003
Chroma 0.53 0.30 < 0.001
Year
1 to
Ye
ar 2
Hat
ch Y
ear t
oSe
cond
Yea
r
For the Swallows
• Early environment has long-term effects on signal development
• Females gain both indirect and direct benefits
Heritability Estimates
Ignoring other sources of non-independence results in overestimation of heritability
AM with environment
AM no environment
P-O Regression
Sibling Correlation
h2 = 0.10 h2 = 0.45 h2 = 0.36 h2 = 0.84
Average Brightness
Cross-fostering experiments
• Experimentally tease apart effects of shared genes and shared environment
• Explore specific environmental influences
Thanks!
Funding:American Ornithologists UnionAnimal Behavior SocietyCU EBIO DepartmentCU Graduate SchoolNSFCU BURST and UROP programs
Lab and Field Help:Amazing Field Crews! Site OwnersStephen Alderfer Monica BrandhuberAndrew Flynn Amanda HundEric Lord Julie MarlingLiz Scordato Audrey TobinTy Tuff Courtney van der LindenRachel Wildrick Matt Wilkins
Photo Credit:Matt WilkinsIan Harold
Quantitative GeneticsVariance
Components Avg. Brightness Hue Chroma
Trait Mean 29.98% (0.015) 618.94 nm (0.04) 0.41 (5.04e-5)
VA5.91 (12.82)
p = 0.6965.23e-05 (3.81e-06)
p = 0.9991.16e-04 (9.44e-05)
p = 0.326
VT2.97 (2.55)
p = 016.87 (20.15)
p = 0.3623.11e-05 (2.63e-05)
p = 0.167
VCE6.46 (4.57)p = 0.125
41.56 (38.22)p = 0.263
7.63e-05 (4.80e-05)p = 0.090
VME2.57 (5.39)p = 0.664
60.92 (35.40)p = 0.088
2.63e-10 (4.43e-11)p = 0.999
VR 38.92 (8.14) 369.60 (26.93) 3.86e-04 (6.50e-05)
VP 56.84 (0.303) 488.95 (0.088) 6.09e-04 (1.06e-04)