Biological Adaptation: Natural Selection & Phenotypic Plasticity Explained

Adaptation = process by which organisms become better suited to their environment.

Two Mechanisms

• Natural Selection (Generational): Heritable traits enhancing survival/reproduction increase in frequency over generations. Slow, genetic.
• Phenotypic Plasticity (Within Lifetime): Same genotype expresses different phenotypes (morphology, physiology, behavior) in response to environmental cues. Fast, non-genetic.

Examples

• Selection: Antibiotic resistance, peppered moth coloration, beak size in drought.
• Plasticity: Plant shade avoidance, Daphnia helmet formation (predator cues), human heat acclimatization, muscle hypertrophy.

Both essential for persistence; plasticity buffers against rapid change, selection refines genomes long-term.