Patterns of speciation and diversification
Practice Flashcards
Flip to reveal answersDefine speciation.
Track your progress — Sign up free to save your progress and get smart review reminders based on spaced repetition.
All 11 Flashcards — Patterns of speciation and diversification
Sign up free to track progress and get spaced-repetition review schedules.
Question
Define speciation.
Answer
The **formation of a new species** from an existing one.
Question
Define adaptive radiation.
Answer
The **rapid evolution of many new species** from a single ancestor, each adapted to a **different niche**.
Question
What is a niche?
Answer
The particular **role and way of life** of a species — what it eats, where it lives and how it behaves.
Question
Adaptive radiation often follows what event?
Answer
Reaching **new, empty habitats** (for example a fresh island chain) with many unfilled niches.
Question
On a graph, what signals adaptive radiation?
Answer
A **sharp rise in the number of species** in one group over a relatively short time.
Question
Define gradual speciation.
Answer
Speciation by the **slow build-up of small heritable changes** over a long time.
Question
Define abrupt speciation.
Answer
Speciation that happens **suddenly**, over a short time (for example by a **chromosome-number change**).
Question
In the fossil record, what does gradual speciation look like?
Answer
A **smooth series of in-between forms**, each only slightly different from the one before.
Question
Give one common cause of abrupt speciation in plants.
Answer
A **change in chromosome number**, which instantly stops the plant breeding with its parent population.
Question
Do these patterns still need natural selection?
Answer
**Yes** — adaptive radiation, gradual and abrupt speciation all rely on **natural selection** and **reproductive isolation**.
Question
What does diversification mean here?
Answer
One group **becoming more varied** — splitting into **many** different species over time.
Read the notes
Full study notes for Patterns of speciation and diversification
Topic 1.8 hub
Evolution and speciation
More from Topic 1.8
All flashcards in this topic
Biology exam skills
Paper structures & tips
Track your progress with spaced repetition
Sign up free — Aimnova tells you exactly which cards to review and when, so you remember everything before your IB exam.
Start Free