Natural selection experiments

Activity Introduction

Quick summary: Students model the effect of camouflage and feeding strategies on natural selection by conducting two experiments. In the first experiment they are asked to pick up coloured toothpicks off coloured paper using tweezers. In the second they are asked to use different implements to pick up dried beans.

Learning goals:

Students understand what is meant by the term ‘natural selection’.
Students recognise what is meant by the term ‘selective agent’.
Students understand that variations in camouflage or feeding strategies can influence natural selection.

21st century skills:

evolution experiments skills

Australian Curriculum Mapping

Content description:

Year 10 Science

The theory of evolution by natural selection explains the diversity of living things and is supported by a range of scientific evidence (ACSSU185)

Syllabus Outcomes: SC5-14LW.

General capabilities: Critical and creative thinking.

Cross-curriculum priority: Sustainability OI.2.

Relevant parts of Year 10 Science achievement standards: Students explain the processes that underpin heredity and evolution.

Topic: Evolution.

Time required: 60 mins.

Level of teacher scaffolding: Low – oversee activity, facilitate discussion.

Resources required: Natural selection factsheet. Student Worksheet – one copy per student OR computers/tablets to access the online worksheet. For each group you will need:

Experiment 1

two different coloured A3 sheets of paper
two sets of 20 toothpicks of two different colours to match the sheets of paper
stopwatch
tweezers
cup
bubble wrap or muslin material

Experiment 2

40 dried beans
stopwatch
tweezers
peg
two cups labeled with ‘peg’ and ‘tweezers’

Digital technology opportunities: Digital sharing capabilities.

Homework and extension opportunities: Includes opportunities for homework or extension.

Keywords: Natural selection, camouflage, feeding strategies.

Cool Australia’s curriculum team continually reviews and refines our resources to be in line with changes to the Australian Curriculum.

Worksheets

Teacher Worksheet

Teacher Preparation

Overarching learning goal: By participating in this lesson students will understand that variations in camouflage or beak shape in birds can influence natural selection.

Teacher content information: Natural selection is the process where an environmental factor acts on a population and results in some organisms having more offspring than others. Darwin concluded that natural selection will only occur where there is variation (natural differences) in a population. These natural differences can now be explained through genetics - however at the time when Darwin reached his conclusions about natural selection genetics was unknown.

Biologists call the environmental factor that acts on the population the 'selective agent' and the effect of natural selection on the population is known as 'selective pressure'. The selective agent may be a natural occurring factor such as predation, bacterial infection, competition, temperature, fire, water, or soil nutrients.

Some sele

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Student Worksheet

Thought starter: What’s the difference between natural and artificial selection?

Preparation

Read the Natural selection factsheet and answer the following questions:

1. Describe two things about natural selection that you already knew:

2. Describe three things that are new to you:

3. In your own words, describe the term 'natural selection':

4. Where does the term 'natural selection' come from?

5. Describe one example of natural selection:

6. In your own words, describe the term 'selective agent':

In this activity you will be conducting two experiments aimed at modeling the effect of camouflage and different beaks on feeding behaviour and natural selection.

Experiment 1.

Work in pairs - in this experiment you are to imagine that you are birds of similar size eating foods of different colours, some of which will be camouflaged.

Materials required for each group

two different coloured A3 sheets of paper
two sets of 20

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