1. Environmental Science 5e
Chapter 7
Biological Diversity
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Environmental Science 5e

2. Biological Diversity and Biological Evolution
The variety of life-forms commonly expressed as the number of species in an area
Biological Evolution
The change in inherited characteristics of a population from generation to generation
One of the features that distinguishes life from everything else in the universe
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Environmental Science 5e

3. Four Processes that Lead to Evolution
Mutation
Natural Selection
Migration
Genetic Shift
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Environmental Science 5e

4. Environmental Science 5e
Mutation
A chemical change in a DNA molecule
Affects the expressed characteristics when cells or individual organisms reproduce
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Environmental Science 5e

5. Environmental Science 5e
Natural Selection
4 Characteristics:
Genetic Variability
Environmental Variability
Differential Reproduction
Environmental Influence
Species:
a group of individuals that reproduce with each other
Botkin and Keller
Environmental Science 5e

6. Environmental Science 5e
Migration
Two new species evolve from an original species due to isolation
Ex: land bridge
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Environmental Science 5e

7. Environmental Science 5e
Genetic Drift
Changes in the frequency of a gene in a population due to chance
Can be a problem for rare or endangered species
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Environmental Science 5e

8. Basic Concepts of Biological Diversity
Genetic Diversity
Habitat Diversity
Species Diversity
Species Richness
Species Evenness
Species Dominance
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Environmental Science 5e

9. Environmental Science 5e
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Environmental Science 5e

10. Environmental Science 5e
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Environmental Science 5e

11. Environmental Science 5e
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Environmental Science 5e

12. The Number of Species of Life on Earth
No one knows the exact number
About 1.4 million species have been identified and named
Insects and plants make up moth of these species
Number will increase
Botkin and Keller
Environmental Science 5e

13. The Competitive Exclusion Principles
2 species that have exactly the same requirements cannot coexist in exactly the same habitat
Ex) introduction of the gray squirrel into Great Britain
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Environmental Science 5e

14. Environmental Science 5e
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Environmental Science 5e

15. Professions and Places: The Ecological Niche and the Habitat
Habitat: where a species lives
Ecological Niche: a species profession
The reason more species do not die out from competition is that they have developed a niche, and thus avoid competition
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Environmental Science 5e

16. Environmental Science 5e
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Environmental Science 5e

17. Species Engage in 3 Basic Interactions
1. Competition
2. Symbiosis
3. Predation-Parasitism
Each affect evolution, persistence of a species and the overall diversity of life
Organisms have evolved together and therefore adjusted to one another
Human interventions upset these adjustments
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Environmental Science 5e

18. Environmental Science 5e
Symbiosis
The relationship between 2 organisms that is beneficial to both and enhances each organisms chances of persisting
Obligate symbionts:
a symbiotic relationship between two organisms in which neither by themselves can exist without the other
Ex) stomach of a reindeer
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Environmental Science 5e

19. Environmental Science 5e
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Environmental Science 5e

20. Environmental Science 5e
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Environmental Science 5e

21. Environmental Science 5e
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Environmental Science 5e

22. Environmental Science 5e
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Environmental Science 5e