Chapter 4: Environmental change and extinction
A species can survive many changes, but rapid habitat loss can outrun its capacity to adapt or move.
Part of your national curriculum
- Biology: genetics and evolution: Understand changes in the environment that may leave individuals within a species, and some entire species, less well adapted to compete successfully and reproduce, which in turn may lead to extinction
Lesson overview
What you'll learn in this lesson
Understand changes in the environment that may leave individuals within a species, and some entire species, less well adapted to compete successfully and reproduce, which in turn may lead to extinction
Key learning points
- • Changing conditions
- • From decline to extinction
- • Evidence of risk
- • Conservation decisions
This lesson at a glance
- 30 minutes
- 19 parts to scroll through
- 3 quick checks
- Marked quiz at the end
- Gentle pace: short sittings with pauses
Words to know
Scroll down — the lesson carries on below
Watch & discover
Part 1 of 19
Visual introductionPicture this
Chapter 4: Environmental change and extinction
A species can survive many changes, but rapid habitat loss can outrun its capacity to adapt or move.
In a nutshell
Understand changes in the environment that may leave individuals within a species, and some entire species, less well adapted to compete successfully and reproduce, which in turn may lead to extinction
Learning cycle
Part 2 of 19
Learning cycle 1 of 2
Part 1 · Changing conditions
A short piece of teaching, then a check to make sure it has landed.
Explore the idea
Part 3 of 19
Learn
Changing conditions
Climate shifts, new predators, disease, competition, pollution and habitat destruction can change which traits are advantageous. The speed and scale of change matter.
Reset break
Part 4 of 19
Pause
That's sitting 1 of 5 done
Stretch, get a drink, look out of the window. There is no timer and nothing is counting down — your place is saved, so you can come back in five minutes or tomorrow.
Explore the idea
Part 5 of 19
Learn
From decline to extinction
If deaths repeatedly exceed births, a population shrinks. Small populations can lose genetic diversity and become vulnerable to chance events. Extinction occurs when the final member of a species dies.
Quick check
Part 6 of 19
Quick check
Part 7 of 19
Reset break
Part 8 of 19
Pause
That's sitting 2 of 5 done
Stretch, get a drink, look out of the window. There is no timer and nothing is counting down — your place is saved, so you can come back in five minutes or tomorrow.
Learning cycle
Part 9 of 19
Learning cycle 2 of 2
Part 2 · Evidence of risk
A short piece of teaching, then a check to make sure it has landed.
Explore the idea
Part 10 of 19
Learn
Evidence of risk
Scientists combine population counts, breeding success, habitat measurements and long-term trends. A single low count may be noise; repeated decline across reliable surveys is stronger evidence.
Explore the idea
Part 11 of 19
Learn
Conservation decisions
Protecting habitats, reconnecting populations, reducing pollution and carefully managed breeding can reduce risk. Each action should target the known causes of decline and be monitored.
Reset break
Part 12 of 19
Pause
That's sitting 3 of 5 done
Stretch, get a drink, look out of the window. There is no timer and nothing is counting down — your place is saved, so you can come back in five minutes or tomorrow.
Quick check
Part 13 of 19
Challenge round
Part 14 of 19
Game · Sort it
Which of these are true?
Drag each card into the right column. Tap a card first if dragging is fiddly.
True
Not true
Challenge round
Part 15 of 19
Game · Fill the gaps
Finish the sentences
Choose the word that belongs in each gap.
Extinction occurs when the final member of a ____ dies.
Reset break
Part 16 of 19
Pause
That's sitting 4 of 5 done
Stretch, get a drink, look out of the window. There is no timer and nothing is counting down — your place is saved, so you can come back in five minutes or tomorrow.
Challenge round
Part 17 of 19
Game · Recall cards
Natural selection acts on…
Card 1 of 4
Mastery quiz
Part 18 of 19
Marked quiz
End of lesson quiz: Chapter 4: Environmental change and extinction
4 questions, marked with the reasoning shown. No timer.
1. Natural selection acts on…
2. Migrating to avoid winter is which type of adaptation?
3. A population changes over generations because…
4. Which is an adaptation?
Lesson round-up
Part 19 of 19
Lesson round-up
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Understand changes in the environment that may leave individuals within a species, and some entire species, less well adapted to compete successfully and reproduce, which in turn may lead to extinction