A researcher compared evolutionary mechanisms in two populations of the same brassica species: Population 1 was a wild population undergoing natural selection in response to a prolonged drought, and Population 2 was a cultivated crop undergoing selective breeding for high seed-oil content.
Which of the following statements correctly identifies a key difference in the genetic or evolutionary outcomes between these two populations?
Natural selection increases the frequency of alleles that enhance reproductive success in the wild, whereas selective breeding can lead to the accumulation of alleles that reduce overall survival in a natural habitat.
Natural selection acts directly on the genotype of the wild population, whereas selective breeding acts directly on the phenotype of the cultivated population.
Selective breeding increases the overall genetic diversity of the population by generating novel alleles, whereas natural selection consistently decreases genetic diversity.
In natural selection, environmental changes induce specific beneficial mutations to occur, whereas selective breeding relies purely on random mutations.
38 exam-style questions on OCR GCSE Biology 5.2 Natural selection and evolution, covering 5.2.1 Genetic variation within a population, 5.2.2 Developments in classification systems, 5.2.3 How evolution occurs through natural selection, 5.2.4 Evolution as change over time, 5.2.5 Evidence for evolution, and 5.2.6 Darwin and Wallace. Each one has a worked solution and a mark scheme showing where the marks go.