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Practice your science skills
1. Text Analysis: Identify one ecological claim about the 3. Scientific Experiments: Identify a research method
benefit of biodiversity made by the author. used to determine the importance of biodiversity in
2. Concept Explanation: Explain why an increase in nature.
ecosystem biodiversity will also increase ecosystem
resilience.

s we have just learned, biodiversity is an important part of any ecosystem
because of the role it plays in making ecosystems productive and stable over
time. In this unit, we will examine biodiversity in depth, including biodiver-
sity from the level of genes to ecosystems. We will also see how this diversity
A allows ecosystems to provide us with a number of important services. Then we
explore how the number of species in an ecosystem is the net result of some species coloniz-
ing places they can tolerate and other species going extinct due to unsuitable biotic or abi-
otic conditions. Given that many ecosystems experience various disruptions over time, we
examine how short- and long-term disruptions can vary in magnitude and alter the com-
position of species in different ecosystems. Whether an ecosystem is frequently disrupted or
not, species can evolve traits to persist in a given ecosystem as a result of natural selection.
Over long periods of time, the initial species that colonize an area are eventually replaced by
other species that possess traits that are better suited to the changing environmental condi-
tions. Collectively, the modules in this unit will provide an excellent discussion of how we
obtain biodiversity in different ecosystems and the consequences of doing so.

96 UNIT 2 ■ The Living World: Biodiversity
Uncorrected proofs have been used in this sample.
Copyright © Bedford, Freeman & Worth Publishers.
Distributed by Bedford, Freeman & Worth Publishers. Not for redistribution.

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