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What you will learn in How populations change

1. Variation is everywhere
Before any mechanism: a real population, measured. Variation is the fact that needs explaining, not noise around a type.
2. Where variation comes from
Mutation and recombination — and the experiment that showed mutations do not arrive in response to what a population is facing.
3. Selection, with nothing needing anything
The module's centrepiece. Heritable variation in a variable environment, and no parameter anywhere that says what the population needs.
4. Four mechanisms, not one
Selection, drift, gene flow and mutation — and the one of them that shows evolution is not a synonym for improvement.
5. A null model
Hardy-Weinberg as the statement of what happens when nothing is happening — and five assumptions you can break one at a time.
6. Five independent lines
Build a tree from anatomy, then build one from a protein over the same seven animals, and put them side by side.
7. How one species becomes two
Reproductive isolation, geography, and the cases where the definition of a species stops working cleanly.
8. Beginnings, and ourselves
What is established about the origin of life and what is not, a hominin record that is a bush rather than a march, and evolution happening this week in a hospital.

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1. Variation is everywhere
Before any mechanism: a real population, measured. Variation is the fact that needs explaining, not noise around a type.
2. Where variation comes from
Mutation and recombination — and the experiment that showed mutations do not arrive in response to what a population is facing.
3. Selection, with nothing needing anything
The module's centrepiece. Heritable variation in a variable environment, and no parameter anywhere that says what the population needs.
4. Four mechanisms, not one
Selection, drift, gene flow and mutation — and the one of them that shows evolution is not a synonym for improvement.
5. A null model
Hardy-Weinberg as the statement of what happens when nothing is happening — and five assumptions you can break one at a time.
6. Five independent lines
Build a tree from anatomy, then build one from a protein over the same seven animals, and put them side by side.
7. How one species becomes two
Reproductive isolation, geography, and the cases where the definition of a species stops working cleanly.
8. Beginnings, and ourselves
What is established about the origin of life and what is not, a hominin record that is a bush rather than a march, and evolution happening this week in a hospital.