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
Extinction Failure 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 Functional Ecology 21:397 Reaction Norms – low cost to fitness persistence of plasticity “Release” of cryptic variation in 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), T b 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 Condition Maternal 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 Decreasing rainfall Rising Temperatures Altered Population Dynamics Altered niche attributes initiate stress response How does elevated CORT effects and costs of immune response mediate offspring quality Population dynamics Consequences
Maternal Effects & Developmental Plasticity ¥ ¥ Stressor Dispersal Growth Rate Philopatry Maternal Survival Energy Stores Clutch Size/Offspring Size Trade-off CORT Offspring “Quality” Could be T a
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 T a during Gestation x August T a 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 F 3,349 = 3.05, p < 0.02 Speed differed between years F 3,349 = 7.82, p < Speed differed between morphs F 3,349 = 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)