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)