phenotypic plasticity and maternal effects
DESCRIPTION
Phenotypic Plasticity and Maternal Effects. Short-term responses to changing climates?. Changing Thermal Environments. Current Climate Models Predict an Increasingly Warmer World. Organismal response to rising temperatures. Ecological Response. Shifts in Distribution. Δ Phenology. - PowerPoint PPT PresentationTRANSCRIPT
Phenotypic Plasticity and Maternal Effects
Short-term responses to changing climates?
Current Climate Models Predict an Increasingly Warmer World
Changing Thermal Environments
Organismal response to rising temperatures
Shifts in Distribution
Ecological Response
Δ Phenology
Evolutionary Response: Adaptation
ExtinctionFailure to Adapt
Creative Commons/Bart Heird
Another response (short term)
Maternal Effects
&
φ
Normal Range of Developmental Temperatures
Novel HighNovel Low
Adaptive Plasticity in Novel Environments
after Ghalambor et al. 2007. Functional Ecology 21:397
Reaction Norms – low cost to fitnesspersistence of plasticity
“Release” of cryptic variationin novel environments.Selection on G x E..
Acclimitization is one form of Plasticity
BAH, CIB, etc.
• Most tests of these hypotheses involve Developmental Plasticity– i.e., irreversible phenotypic changes induced by
rearing conditions
Plasticity in Reproduction
• How do gravid (pregnant) females respond to warming?
Reproductive Plasticity in Females
Manipulation of thermal regime experienced by gravid females
Developmental stage is sensitive to thermal conditions experienced by
gravid females
Reproductive Investment
Why Females?
Females can manipulate the phenotype of her offspring depending on intrinsic and extrinsic conditions
Hormones (Cort, Androgens), Tb of dam
How can females affect offspring phenotype?
• Hormones• Offspring Provisioning• Incubation Temperatures during embryonic
development– Viviparous Lizards
• Maternal Tb
– Oviparous Lizards• Nest Site Selection
Repro- Success/Offspring
Traits
Repro- Success/Offspring
Traits
Maternal ConditionMaternal Condition
Adaptive maternal effects (mainly organizational effect of hormones and immunity products) modify individual strategy and survival later on. One outcome is the induction of offspring phenotypes to cope with novel environments.
Extended Warm Spells
Extended Warm Spells
Decreasingrainfall
Rising Temperatures
Altered Population Dynamics
Altered Population Dynamics
Altered niche attributes initiate stress response
How does elevated CORT effects and costs of immune response mediate offspring quality
Population dynamicsConsequences
Maternal Effects & Developmental Plasticity
¥¥
Stressor
Dispersal
Growth Rate
Philopatry
Maternal Survival
Energy Stores
Clutch Size/Offspring SizeTrade-off
CORT
Offspring “Quality”
Could be Ta
Body size affected by incubation temperature
Speed is sensitive to incubation temperature
Hormones and Offspring Phenotype
CORT treated lizards remained in shelters longer than controls
Plasticity in Dorsal Pattern
Zootoca (=Lacerta) vivipara
Mechanism of Induction
Juvenile dorsal pattern affected by: May Ta during Gestation
xAugust Ta year before pregnancy
Significance of Dorsal Pattern
Behavior and performance covary with dorsal pattern
Brodie 1992 Evolution
Frequency of Reticulate females decreased with elevation only in 2008“Cool” Year
Temporal variation in % reticulated morphs
Evidence for plasticity in morphs
Maximum velocity increased with habitat openness
F3,349 = 3.05, p < 0.02
Speed differed between years
F3,349 = 7.82, p < 0.001
Speed differed between morphs
F3,349 = 3.35, p < 0.01
Number of stops increases with habitat openness
Reticulate females stopped more frequently than linear females
Chi-square = 5.42, P < 0.01
Conclusions
• Climate can induce variation in reproductive performance
• Variation in conditions experienced by females can affect offspring phenotype– Whether female manipulation benefits offspring
depends on conditions at hatching (birth)