This lesson explains how genetics became integrated with Darwinian evolution and shows how evolutionary thinking helps scientists anticipate changes in influenza viruses.
When Charles Darwin and Alfred Russel Wallace developed the idea of natural selection, scientists did not yet understand genes or the mechanisms of inheritance. The widespread theory of blending inheritance incorrectly suggested that offspring inherit a permanent mixture of their parents’ traits. This made it difficult to explain how useful variations could persist and spread.
All flashcards
What was blending inheritance?
An incorrect early theory that offspring inherit a permanent mixture of their parents’ traits, making it difficult to explain how useful variations persist.
What did Mendel’s work contribute to evolutionary biology?
Mendel described inherited traits as being passed through discrete units, helping explain how variation can persist across generations.
What is the modern synthesis?
The integration of genetics with evolutionary theory, explaining how population-level genetic change contributes to evolution over time.
What is the Hardy–Weinberg principle?
A model predicting stable allele and genotype frequencies when specified evolutionary forces are absent.
Why does influenza evolution matter for vaccination?
Rapid viral evolution can change circulating strains, so evidence about recent seasons informs vaccine strain predictions.
Quiz questions
In population genetics, what constitutes evolution?Answer: A change in a population’s allele frequencies over time.
How does genetic drift differ from natural selection?Answer: Drift changes allele frequencies by chance, without necessarily reflecting fitness differences.
What happens in a founder effect?Answer: A small group establishes a population whose allele frequencies differ from the original population.
What can a departure from Hardy–Weinberg expectations indicate?Answer: Evolution may be occurring, or one or more model assumptions may not hold.
How do scientists use evidence about influenza evolution when planning vaccines?Answer: They use recent strain changes to predict which strains may become widespread and harmful.
Based on Biology 2e by Mary Ann Clark, Matthew Douglas, Jung Choi (OpenStax), licensed CC BY 4.0. Adapted into a summary, flashcards and quizzes.