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Copyright © 2011 Pearson Canada Inc. 1.1Importance of Diversity: Levels of Biodiversity Biodiversity The variety of life in an area = biological diversity = biodiversity. Biodiversity allows for systems to adapt to changes over time. There are three levels of biodiversity: genetic, species, and ecosystem. 1.Genetic Diversity Genetic diversity is the sum of all of the different genes in a species. (Genes are units of information, inherited from parents, that determine the traits of living things.) A species includes all individuals that can breed freely in nature and produce fertile offspring. Small differences in genes make each individual unique, and allow the species to adapt better to change. Low genetic diversity in a species leaves it susceptible to disease, or changes in climate or predators and prey. See page 6
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Copyright © 2011 Pearson Canada Inc.
Chapter 1: Identifying and classifying livingthings require a common language.
"An Opassom hath an head like a Swine, and a taile like a Rat, and is of the bignes of a Cat.
Under her belly she hath a bagge, wherein she lodgeth, carrieth, and sucketh her young.”
- John Smith, Map of Virginia, 1608
Imagine what early explorers to North America must have thought when they first saw the opossum! As North America’s only marsupial, opossums are nomadic, nocturnal creatures with sharp teeth, who hiss when confronted. As you can see in the photograph, they faint, or “play possum” when threatened. Opossums can use their tail like a monkey to grasp branches. They are immune to the poison of rattlesnake bites.
Now imagine how difficult it would be to name a creature like this! What other creatures would it be related to? Where did it come from? Identifying and classifying living things was--and still is--quite a challenge.
Opossum “playing possum”
Copyright © 2011 Pearson Canada Inc.
1.1 Importance of Diversity: Spotlight on Honeybees
• Honeybees are very important to ecosystems. They pollinate flowers as they collect sugary nectar to
eat, allowing plants to reproduce. Since many terrestrial food chains begin with plants,
the honeybees play a very vital role. The honeybee is not native to North America, but it has
outcompeted almost all other pollinators.• Millions of honeybees are dying.
Theories include the overuse of pesticides, the parasitic Varroa mite, and the IAPV virus carried by the mites.
Breeding programs have left the bees with similar genes.
No other pollinators remain to take over from the honeybees.
See page 5
Copyright © 2011 Pearson Canada Inc.
1.1 Importance of Diversity: Levels of Biodiversity
Biodiversity•The variety of life in an area = biological diversity = biodiversity.
Biodiversity allows for systems to adapt to changes over time. There are three levels of biodiversity: genetic, species, and
ecosystem.
1.Genetic Diversity Genetic diversity is the sum of all of the different genes in a species.
(Genes are units of information, inherited from parents, that determine the traits of living things.)
A species includes all individuals that can breed freely in nature and produce fertile offspring.
Small differences in genes make each individual unique, and allow the species to adapt better to change.
Low genetic diversity in a species leaves it susceptible to disease, or changes in climate or predators and prey.
See page 6
Copyright © 2011 Pearson Canada Inc.
1.1 Importance of Diversity: Levels of Biodiversity
2. Species Diversity Species diversity refers to the variety of species in an
area. Ecosystems are healthier when they have a variety of
species to survive environmental changes. Since ecosystems are about connections, the more species
there are, the more complicated and robust the ecosystem is.
3. Ecosystem Diversity Ecosystem diversity refers to the range of habitats and
organisms, and the connections between them. Diverse ecosystems can be large or small, simple or
complicated. “Walking ecosystems” refers to the fact that many
organisms live on or inside other organisms.
See page 7
Copyright © 2011 Pearson Canada Inc.
1.1 Importance of Diversity: Valuing Biodiversity
• High levels of biodiversity result in healthier, more stable, and more resilient ecosystems. Biodiversity is due to the evolution
(change) in natural systems. Biodiversity provides humans with
medicines, food, fuel, oxygen, water, and clean, safe living conditions.
Keystone species, such as the honeybee, are especially important symbols of biodiversity. These species have a disproportionate
importance in their habitat, often supporting many organisms and processes.
See page 10
Some of Ontario’s keystone species include, from top to bottom, the lake trout, the honeybee, and the beaver.
Copyright © 2011 Pearson Canada Inc.
Unit A: Diversity of Living Things
Unit TaskThe variety of life on Earth is astounding. Using your imagination, design and present a “new” organism that the scientific community has never seen before.
Copyright © 2011 Pearson Canada Inc.
Chapter 1: Identifying and classifying living things require a common language.
Page 1.1 Sub-Heading5 Spotlight on Honeybees6 Levels of Biodiversity: Genetic Diversity7 Levels of Biodiversity: Species Diversity8 Levels of Biodiversity: Ecosystem
Diversity10 Valuing Biodiversity
1.1 Importance of BiodiversityHoneybees gather nectar and distribute pollen between flowers.
