Evolution — FAQ

For Cambridge A-Level Biology 9700 topic 17.3, Evolution covers key concepts like natural selection (directional, stabilising, disruptive), the sources of genetic variation, allopatric and sympatric speciation, the Hardy-Weinberg principle for allele and genotype frequencies, and the impact of genetic drift on populations.

To ace Paper 4 Evolution questions, focus on explaining the mechanisms and interconnections between concepts. Don't just list facts; describe the sequence of events in natural selection, the roles of isolation in speciation, and the assumptions of Hardy-Weinberg. Practise applying formulas and interpreting graphs.

Natural selection is a non-random process where individuals with advantageous traits are more likely to survive and reproduce, leading to adaptations. Genetic drift, however, is a random process of allele frequency change due to chance events, particularly significant in small populations. While both alter allele frequencies, only natural selection leads to adaptation.