Loading subjects
Evolutionary processes leading to speciation · Part 1 of 4
9 exam-style questions with model answers, plus 12 quick multi-choice questions — every question on this part of the standard, grouped by the 3 pages of notes they come from.
Write a full answer before you reveal the model one. That comparison is where the learning happens.
Describe what a mutation is, and explain why mutation is essential for evolution to occur.
A bacterial population is exposed to an antibiotic for the first time. Within weeks, almost all bacteria present are resistant. Explain how this happened, making clear the relationship between mutation and selection.
Mutation rates are very low, and most mutations are harmful or neutral. Discuss how such a process can nonetheless be the foundation of adaptation, and evaluate the claim that evolution is 'random'.
Describe the difference between natural selection and genetic drift, and describe what is meant by the founder effect.
The kākāpō population fell to fewer than 60 birds before recovering under management. Explain how this affected the population's genetics, and why it matters for the species' future.
Two isolated populations of the same species live in identical environments, yet after many generations they have diverged genetically. Discuss how this is possible, and evaluate the relative importance of selection and drift in causing populations to diverge.
Describe what is meant by gene flow, and describe its effect on the genetic differences between two populations.
A native plant grows on two mountain ranges separated by 40 km of lowland. Its pollen is carried by insects that rarely travel more than 2 km. Explain why the two populations are likely to diverge, and why they might eventually become separate species.
Habitat fragmentation reduces gene flow, and conservation managers sometimes respond by moving individuals between fragments. Discuss the genetic consequences of fragmentation, and evaluate when such translocations are appropriate.