A2 Science in Society 3.6
Sustaining the variety of life on Earth
This topic explores the importance of biodiversity, its origins, methods for recording biodiversity and threats to species
and habitats. Evidence for changes in biodiversity over time from the fossil record are discussed, along with the idea
that we are entering a sixth mass extinction as a result of human activity.
The main areas of science that are covered are:

Classification of living things, and the role of new DNA technologies in classification

Measures of biodiversity to plot trends over time and across geographical regions

The complex nature of ecosystems, relying on interdependencies

Evidence for changes in biodiversity over time, including mass extinctions
The topic provides opportunity for development of How Science Works ideas to A level standard from four areas:
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

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Data and their limitations
The scientific community
Relationships between science and society
Making decisions about science and technology
This scheme of work is divided into ten 2-hour sessions.
The references below to How Science Works (HSW) and to Science Explanations (SE) use the code letters found in
sections 3.5 and 3.6 of the specification.
Focus of session
Suggested activities
This session sets the scene for this topic, by
illustrating the conflicts and the complexity of the
relationship between humans and wildlife.
(SE Pg, i, l , m)
(HSW Hb, d, e, f)
Textbook pages 195 - 205
Questions 53 – 75
1
Also -set up ‘Carrying out a media watch on
biodiversity issues’ Media watch (Fb)
Activity: Madagascar, out of time?
This activity has a PowerPoint presentation to
introduce the context.
Introduce the Carrying out a media watch on
biodiversity activity.
Measuring and cataloguing biodiversity
2
Why is there such a range of species? What is
biodiversity? How can it be measured? and why is it
important to be able to classify species?
(SE Pa, b, c, d, e, f)
(HSW Ad, e, g, Ai, Eg )
Textbook pages 173 – 175
Questions 1-6
Textbook pages 186 -195
Questions 30 - 52
Activity: Exploring biodiversity
This activity ‘Exploring biodiversity’ uses the Natural
History Museum’s Website:
http://internt.nhm.ac.uk/eb/
3
Use of DNA technologies in classification
(SE Pb, c)
(HSW Ai, Eg, Fa)
Textbook pages 175 -178
Question 7- 11
Activity: DNA and classification
Use the PowerPoint presentation ‘DNA and
classifying species’ to illustrate the basic principle of
using DNA to identify species.
4
Classification and measurement of species
distribution globally is essential for programmes
which aim to protect species.
(SE Pb, m)
(HSW Fa)
Activity: Millennium Seed Bank
In this activity students watch a film about the
Millennium Seed Bank, and discuss its work.
http://www.nuffieldfoundation.org/millennium-seedbank-film
The value of biodiversity
5
6
The concept of ecosystem services and their
importance for human wellbeing. Threats from
human activities. Inferences from data vary in their
degree of certainty.
Activity: The value of ecosystems
(SE Pi,)
(HSW Ad, g, Ha,b,d,e)
In this activity students study diagrams and text from
a Millennium ecosystem assessment report:
Ecosystems and well-being. They then form ‘crossover groups’ to explain an area of importance to each
other.
Ecosystem services
(SE Pg, i)
Activity: Text book pages 196-201 and questions 5559 and 62-64 about ecosystem services.
(HSW Ag, Fa, Hb,d,e)
Exam-style question: Ecosystem functioning
Threats to biodiversity
7
Evidence from the fossil record on the past history
of biodiversity and on mass extinctions
(SE Pj Pg, I, j, k)
(HSW Af, g, i, Ce, Eg)
8
Invasive species can cause damage to species and
their habitats. A case study
Textbook pages 178 -186
Questions 12 - 29
Use
http://www.ucmp.berkeley.edu/education/explorations/
tours/fossil/9to12/intro.html animation and review to
revise the way fossils are formed and what they can
tell us about the past.
Activity: The Ordovician explosion
students use scanning and skim reading techniques
to find examples of evidence, references to scientists’
work and theories
Activity: Case study - Are aliens a bad thing?.
Students read a series of sources and answer
questions about the effects of invasive species.
(SE Hb, Pb, )
(HSW Ai, Hb, c, d, e, f)
Protecting biodiversity
9
10
Biodiversity hotspots
Problem based learning
(SE Pe, d)
(HSW Af, g, Ha, b, c, d, f, Fa)
Textbook pages 205 - 208
Questions 76 – 78
Biodiversity hotspots
(SE Pe, d)
(HSW Af, g, Ha, b, c, d, f, Fa)
Biodiversity hotspots presenting an argument
Topic review
At the end of this topic students should be given the
opportunity to show their online media watch. The
teacher should assess at least some of the entries,
and peer assessment could also be used.
June 2009
Activity: Biodiversity hotspots Defining the problem
In this problem–based activity, students create a Wiki
to discuss the strengths and drawbacks of the hotspot
initiative.
Textbook review questions 79 -82 page 208