Good Learning Co.
SavannahYear 8
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ScienceLiving things and a changing environment30 min★★ difficulty

When the environment changes: adaptation, competition and extinction

Being well adapted is not permanent - it is only ever a match to current conditions. Change the conditions and yesterday's advantage can become today's problem. That is the road to extinction, and to new species.

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

  • • Variation gives the raw material
  • • When change is faster than the species
  • • Competition and decline
  • • Extinction and what it costs

This lesson at a glance

  • 30 minutes
  • 19 parts to scroll through
  • 4 quick checks
  • Marked quiz at the end
  • Gentle pace: short sittings with pauses

Words to know

changesenvironmentindividualswithinspecies

Scroll down — the lesson carries on below

Part 1 of 19 · Discover5%
1

Watch & discover

Part 1 of 19

Watch first

When the environment changes: adaptation, competition and extinction

An English teaching video on this topic from MightyOwl. Watch it, then scroll down for the lesson.

Do it for real

The practicals below use what the film shows, with a full method you can follow at home.

How much feed is too much feed?

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

2

What you already know

Part 2 of 19

Before we start

What you already know

You should know that individuals of a species vary and that some variation is inherited.

Recap: How living things change their environment - and how poisons build up
3

Key words

Part 3 of 19

Key words

Words you'll need today

Adaptation
A feature that helps an organism survive in its environment.
Competition
The struggle between organisms for the same limited resource.
Extinction
The permanent loss of every member of a species.
Natural selection
Better-suited individuals surviving to reproduce more.
Biodiversity
The variety of living things in an area.
4

Learning cycle

Part 4 of 19

Learning cycle 1 of 2

Adaptation is only a match to now

A short piece of teaching, then a check to make sure it has landed.

5

Explore the idea

Part 5 of 19

Learn

Variation gives the raw material

Within any species, individuals differ - in thickness of coat, in tolerance of heat, in resistance to a disease. When conditions change, those differences stop being trivial. Individuals whose features suit the new conditions survive and reproduce more; the others leave fewer offspring. Nothing is trying to change; the environment simply filters what is already there.

6

Explore the idea

Part 6 of 19

Learn

When change is faster than the species

This filtering takes generations. Long-lived, slow-breeding species with little variation left - many big mammals - cannot track a fast change, so a rapid shift in temperature, rainfall or habitat can leave a whole species poorly adapted at once. Insects, with short generations and huge numbers, adapt far faster, which is why pesticide resistance appears within years.

7

Quick check

Part 7 of 19

Quick check

Adaptation happens over...

8

Quick check

Part 8 of 19

Quick check

Which species is most vulnerable to fast environmental change?

9

Reset break

Part 9 of 19

Pause

That's sitting 1 of 2 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.

Stop here for now
10

Learning cycle

Part 10 of 19

Learning cycle 2 of 2

Competition, decline and extinction

A short piece of teaching, then a check to make sure it has landed.

11

Explore the idea

Part 11 of 19

Learn

Competition and decline

Poorly adapted individuals lose out in competition for food, water, space, light and mates - often to a new arrival. Grey squirrels out-compete red squirrels for food and carry a virus that reds do not survive. Numbers fall, the range shrinks, and a scattered population struggles to find mates, which makes recovery harder still.

12

Explore the idea

Part 12 of 19

Learn

Extinction and what it costs

If reproduction cannot keep pace with deaths, the species disappears - permanently. Habitat destruction, climate change, over-hunting, pollution and introduced species are the usual causes, and often several combine. Extinction lowers biodiversity, which matters practically: fewer pollinators, less stable food webs, fewer sources of new medicines. Protected habitats, captive breeding and seed banks are attempts to slow it.

13

Quick check

Part 13 of 19

Quick check

Grey squirrels reduce red squirrel numbers mainly by...

14

Quick check

Part 14 of 19

Quick check

A species becomes extinct when...

15

Common mix-ups

Part 15 of 19

Common mix-ups

Things people often get wrong

  • Individuals do not adapt during their lives; populations change over generations.
  • Adaptation is a match to current conditions, not permanent perfection.
  • Extinction is permanent - species do not come back.
  • Extinction usually has several combined causes, not one.
16

Challenge round

Part 16 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

17

Challenge round

Part 17 of 19

Game · Fill the gaps

Finish the sentences

Choose the word that belongs in each gap.

Within any species, ____ differ - in thickness of coat, in tolerance of heat, in resistance to a disease.

Nothing is trying to change; the ____ simply filters what is already there.

Long-lived, slow-breeding ____ with little variation left - many big mammals - cannot track a fast change, so a rapid shift in temperature, rainfall or habitat can leave a whole species poorly adapted at once.

18

Mastery quiz

Part 18 of 19

Marked quiz

End of lesson quiz: When the environment changes: adaptation, competition and extinction

6 questions, marked with the reasoning shown. No timer.

  1. 1. Which is not a common cause of extinction?

  2. 2. Falling biodiversity matters partly because...

  3. 3. Pesticide resistance appears quickly in insects because they...

  4. 4. A small, scattered population struggles because...

  5. 5. Seed banks help by...

  6. 6. 'Well adapted' really means...

19

Lesson round-up

Part 19 of 19

Lesson round-up

Ready when you are

Quiz score

Not sat

Games

Not played

Points this lesson

0

Best run

0 in a row

Luna: 0 out of 4 on the practice checks. Only if you feel up to it — one more?

Ask Luna

Do the work

Your written work for this lesson

This is the part you'd do in your book at school. Pick the pieces below, write here or on paper, and photograph anything you draw or work out.

Case study

Why the school greenhouse failed

A science club grew tomato plants in the school greenhouse. In June the plants grew well: leaves were dark green and the fruit set quickly. In July the club went away for two weeks and left the greenhouse door shut. When they came back, the leaves were curled and pale and most of the fruit had dropped.

The club had a data logger inside. It showed the temperature reached 46 °C on several afternoons and the soil moisture fell close to zero. The club knew photosynthesis needs light, water and carbon dioxide, and that enzymes in a plant work best in a narrow range of temperature. Above that range the enzymes stop working properly.

The club repeated the summer with the door propped open and a water bottle drip on each pot. Temperature peaked at 31 °C and the plants survived.

Written for Good Learning Co.

Reading questions

  1. Name the variable the club changed the second time, and one variable they kept the same.
  2. Explain, using the words photosynthesis and enzymes, why the plants were damaged in July.
  3. Write a conclusion for the club's report, saying how far the evidence supports it.

  • Method and results

    Writing

    Write the aim, what you changed, what you measured and what you kept the same, then record your results in a table.

    1 page + results table

  • Conclusion

    Writing

    Explain what your results show and why, using the scientific words from the lesson. Say how you know you can trust them.

    6–8 sentences

  • Labelled diagram

    Diagram

    Draw the apparatus or the process in pencil, label it fully, and photograph it.

    1 labelled diagram

  • Reading and notes

    Reading

    Read the lesson text again and write the key ideas in your own words.

    Half a page of notes

Saved as you type.

Part 1 of 19 · Watch & discover

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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

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