Back to the full dot-point answer
WAHuman BiologyQuick questions
Unit 4: Human Variation and Evolution
Quick questions on Population genetics and change: WACE Year 12 Human Biology Unit 4
4short Q&A pairs drawn directly from our worked dot-point answer. For full context and worked exam questions, read the parent dot-point page.
What is natural selection?Show answer
Natural selection is the main mechanism of adaptive evolution. It follows a clear logic:
What is gene flow?Show answer
Gene flow (migration) is the movement of alleles between populations when individuals or gametes move and breed. Immigration adds alleles to a gene pool and emigration removes them. Gene flow tends to make populations more genetically similar and can introduce new alleles to a population. If gene flow is blocked, populations diverge more easily.
What is genetic drift?Show answer
Genetic drift is a change in allele frequencies due to random chance rather than selection. It has the biggest effect in small populations, where chance events can remove or fix alleles regardless of whether they are beneficial. Two special cases matter:
What is mutation?Show answer
Mutation is the original source of new alleles and so the ultimate source of all genetic variation. On its own it changes allele frequencies only slowly, but it continually supplies the new variation that selection and drift then act on. Without mutation, the other mechanisms would eventually run out of variation to work with.
Have a question we have not covered?
This dot-point answer is short enough that we have not extracted many short questions yet. Read the full dot-point answer or ask Mo, our study assistant, in the chat for follow ups.