Answer: In a large random-mating population with no mutation, migration, selection, or genetic drift, allele and genotype frequencies remain constant (p2 + 2pq + q2 = 1); deviations indicate evolution is occurring.
- A Evolutionary change is sometimes mistakenly thought to proceed at a perfectly constant, fixed rate within nearly every natural population ever studied by researchers overall in most cases under typical conditions
- B In a large random-mating population with no mutation, migration, selection, or genetic drift, allele and genotype frequencies remain constant (p2 + 2pq + q2 = 1); deviations indicate evolution is occurring
- C Small, isolated populations are sometimes mistakenly thought to usually closely follow Hardy-Weinberg equilibrium predictions over many successive generations according to standard textbooks in general practice
- D The Hardy-Weinberg principle is sometimes mistakenly thought by some to apply specifically to flowering plant species, rarely extending to animal populations as frequently described in most textbook accounts
Correct answer: B. In a large random-mating population with no mutation, migration, selection, or genetic drift, allele and genotype frequencies remain constant (p2 + 2pq + q2 = 1); deviations indicate evolution is occurring
Explanation: Hardy-Weinberg equilibrium: allele frequencies (p+q=1) and genotype frequencies (p2+2pq+q2=1) remain constant generation to generation IF: (1) Large population (no drift); (2) Random mating; (3) No mutation; (4) No migration; (5) No selection. Conditions rarely met in nature. Used as null hypothesis to detect evolution. Useful for calculating carrier frequencies in genetic diseases.
A simple phylogenetic tree: a common ancestor branches into several descendant lineages over time, with each branch point marking a speciation event.
Concept context
Origin of life, Darwin's theory, natural selection, speciation, and evidence for evolution.