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Evolution (Module 3)

4 dot points, in syllabus order. Each dot point has a focused answer, with exam-style questions and worked answers where available.

How does natural selection lead to adaptation in populations?

Evolution: life on Earth has changed and diversified over time; mutation is the ultimate source of genetic variation; natural selection occurs when environmental selection pressures confer a selective advantage on a specific phenotype, enhancing its survival and reproduction

TASC Biology Level 3 (BIO315124, criterion 8): the conditions for natural selection, selection pressures, structural, physiological and behavioural adaptations, mutation as the ultimate source of variation, and worked examples such as antibiotic resistance.

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How and why do allele frequencies change within a population over time?

Concepts of natural selection, mutation, gene flow and genetic drift as causes of change in allele frequencies; investigate how populations with reduced genetic diversity, such as those affected by population bottlenecks, have an increased risk of extinction

TASC Biology Level 3 (BIO315124, criterion 8): gene pools and allele frequencies, how mutation, natural selection, gene flow and genetic drift change them, why bottlenecks and small populations raise extinction risk, and background on the Hardy-Weinberg principle.

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How do new species arise from existing ones?

Analyse differing selection pressures between geographically isolated populations to demonstrate the process of speciation; represent and analyse the accumulation of micro-evolutionary changes over time and macro-evolutionary changes resulting in speciation

TASC Biology Level 3 (BIO315124, criterion 8): what a species is, how geographic isolation and differing selection pressures lead to reproductive isolation and new species, how micro-evolutionary change accumulates into macro-evolution, and background on isolating mechanisms and sympatric speciation.

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What evidence supports the theory of evolution by natural selection?

Describe and evaluate the lines of evidence that support evolution.

The main lines of evidence for evolution: fossils, comparative anatomy, biogeography, embryology, and molecular and biochemical data (background, not examined in TASC Biology Level 3 BIO315124).

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