Natural Selection and Adaptation Quiz

Natural Selection and Adaptation

• Adaptation is a characteristic that improves survival or reproduction.
• Sword-billed hummingbird (Ensifera ensifera) has a bill longer than its body, adapted for reaching nectar in tubular flowers.
• Bird must use feet to preen and apply oil, due to its long bill.
• Snakes have movable skull bones, allowing swallowing prey larger than their heads.
• Jaw bones move independently to pull prey into the throat.
• Cacti in arid environments have adaptations to reduce water loss, like thick stems and few leaves.
• Hair in some cacti is an adaptation to cool the temperature.
• Adaptations are characteristics that enhance survival and reproduction, resulting from natural selection.
• Natural selection is a mechanism of evolution, not an agent.
• It explains the apparent design of the living world without a supernatural designer.
• Darwin's alternative to intelligent design was natural selection.

Evolutionary Changes

• Soapberry bugs have evolved beak length in response to changes in the size of seeds available as host plants.
• Resistance to pesticides and herbicides can evolve rapidly.
• Metal tolerance can evolve in plants exposed to heavy metals in soil.
• Overexploitation of species can lead to evolutionary shifts, like earlier sexual maturity at smaller sizes and smaller horns (in some cases).
• Species undergo adaptation to environmental change due to human activities.

Adaptation and Natural Selection

• Evolutionary changes in response to particular situations can be rapid, especially when species are introduced to new environments.
• Day length plays a role in the timing of insect diapause (hibernation).
• Evolutionary changes can be rapid due to adaptations in genetically diverse populations that are exposed to selection pressures.

Natural Selection

• Natural selection is any consistent difference in fitness among different classes of biological entities.
• Fitness is the number of offspring an organism leaves.
• Fitness is sometimes used interchangeably with reproductive success, as dead organisms cannot reproduce
• Natural selection occurs if there's a correlation between an individual's phenotype, fitness, and between parental phenotypes and those of offspring.
• Natural selection is not synonymous with evolution.
• Natural selection can maintain the status quo (not cause evolution).
• Genetic drift introduces chance variations to genotype frequencies.

Comparing Alleles

• Random events (genetic drift) can cause changes in allele frequencies, but without differences in fitness, no adaptation occurs.
• Fitness is an average, and averages will change based on numerous measurements.
• Natural selection is the antithesis of chance.