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All 12 Flashcards — What evolution is
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Question
Define evolution.
Answer
The **change in the heritable characteristics of a population over generations** (a change in allele frequency).
Question
What are the three key words in the definition of evolution?
Answer
**Heritable**, **population**, and **over generations**.
Question
At the genetic level, evolution is a change in what?
Answer
**Allele frequency** in the **gene pool** of a population.
Question
Define an allele.
Answer
One particular **version of a gene** (e.g. a dark or a light allele for fur colour).
Question
Define allele frequency.
Answer
How **common** a particular allele is in the gene pool (its proportion).
Question
What is a gene pool?
Answer
All the **alleles** present in a whole **population**.
Question
Can a single individual evolve?
Answer
**No** — evolution happens to a **population over generations**, not to one organism.
Question
Why must an evolutionary change be heritable?
Answer
Only **genetic** features can be **passed to offspring** — learned or lifestyle changes are not inherited.
Question
Define a population (for evolution).
Answer
All the members of **one species** in an area that can **interbreed**.
Question
Is a suntan an example of evolution? Why/why not?
Answer
**No** — it is a **non-heritable** change in **one individual** within its lifetime.
Question
A resistant allele becomes more common in a bacterial population over generations. Is this evolution?
Answer
**Yes** — it is a heritable change in **allele frequency** of a **population over generations**.
Question
Over what timescale does evolution act?
Answer
Across **many generations** — not within a single lifetime.
Read the notes
Full study notes for What evolution is
Topic 1.8 hub
Evolution and speciation
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