Understanding Adaptation and Phenotypic Plasticity

Adaptation

Trait enhancing fitness of an organism.

Adaptive Trait

Trait that increases survival and reproduction.

Adaptationist Paradigm

Framework for understanding adaptive significance of traits.

Experimental Methods

Strongest methods for inferring adaptive value.

Erick Greene

Researcher who manipulated fly wings experimentally.

Tephritid Flies

Flies mimicking predators to avoid spider attacks.

Observational Studies

Provide insights but lack experimental rigor.

Comparative Method

Identifies adaptations across multiple species.

Phylogeny

Evolutionary history affecting trait studies.

Male Testes Size

Larger in species with intense sexual selection.

Phenotypic Plasticity

Different phenotypes from the same genotype.

Adaptive Plasticity

Plasticity providing fitness benefits in varying environments.

Oak Caterpillars

Mimic oak catkins and twigs based on season.

Dung Beetles

Larvae size varies with food availability.

Ecdysone

Hormone influencing developmental pathways in beetles.

Daphnia Phototaxis

Behavioral response to predators in water fleas.

Genetic Differences

Variability in phenotypic plasticity among populations.

Coast Range Sculpin

Color variation matching substrate for predation avoidance.

Trade-offs

Adaptive traits counterbalanced by non-adaptive effects.

Begonia Involucrata

Plant with trade-off limiting female flower size.

Inflorescence Size

Trade-off between flower size and cluster size.

Physiological Constraints

Limitations preventing optimal trait evolution.

Fuchsia Flower Color

Color change signaling pollination status to insects.

Genetic Variation

Necessary for traits to evolve under selection.

Ophraella Leaf Beetles

Species lacking genetic variation for host adaptation.

Critical Tests

Experiments designed to differentiate competing hypotheses.

Replicability

Importance of repeating experiments for reliable results.

Adaptive Significance

Understanding the evolutionary advantages of traits.