AP Biology · Unit 7
Natural Selection
Connect heritable variation and population genetics to evolutionary evidence, phylogeny, speciation, resilience, and origins-of-life models.
Learning sequence
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Topic 7.1
Introduction to Natural Selection
State what natural selection requires, and distinguish the source of variation from the sorting of it.
Topic 7.2
Natural Selection in Populations
Measure fitness by reproductive contribution and name the selection pattern from a distribution.
Topics 7.3–7.4
Artificial Selection & Population Genetics
Compare human-imposed selection with natural selection, then sort drift, gene flow, mutation, and selection.
Topic 7.5
Hardy–Weinberg: The Null Model
State the model's five conditions and read a departure as evidence that something is acting.
Topic 7.5
Hardy–Weinberg: Calculation & Inference
Calculate allele and genotype frequencies, then justify what a match or mismatch supports.
Topics 7.6–7.7
Evidence of Evolution & Common Ancestry
Evaluate fossil, homology, biogeographic, and sequence evidence as independent lines.
Topics 7.8–7.9
Continuing Evolution & Reading Trees
Document evolution in living populations, then read ancestry from nodes rather than tip position.
Topic 7.9
Constructing & Revising Trees
Build a tree from shared derived characters and revise it as molecular evidence arrives.
Topic 7.10
Speciation & Evolutionary Patterns
Explain reproductive isolation, allopatric and sympatric routes, and divergence patterns.
Topics 7.11–7.12
Genetic Diversity & Origins of Life
Connect genetic diversity to resilience, and evaluate evidence about the origin of life.
Topics 7.1–7.12
Unit 7 Assessment
Apply selection, population calculations, evidence, tree reasoning, speciation, and origin models.