Term
| What is adaptation at the species level? |
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Definition
Physical adaptations that allow a species to survive in a given environment. For example, as a sled dog species’ year round thick coat of hair.
CHAPTER 3, p. 50 |
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Term
| How is natural selection demonstrated? |
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Definition
When a species successfully produces a new generation.
CHAPTER 3, p. 50 |
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Term
| What is natural selection at the population level? |
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Definition
The mechanism for evolutionary change in which environmental pressures (such as seasonal colder temperatures) cause certain genetic combinations in a population to become more abundant. For example, dogs that adapt to cold temperatures in the fall by growing thickened coats.
CHAPTER 3, p. 50 |
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Term
| What is the zone of physiological stress? |
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Definition
The range along the environmental gradient for that factor (e.g., temperature), at which a species becomes infrequent as life becomes harder.
[image]
CHAPTER 3, p. 51 |
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Term
| What are endemic species? |
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Definition
Habitat specialists that may occupy a very narrow niche.
CHAPTER 3, pp. 52&53; glossary, p. 381 |
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Term
| What is the competitive exclusion principle? |
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Definition
No two species can occupy the same niche indefinitely.
CHAPTER 3, p. 53; Glossary, p. 380 |
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Term
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Definition
The process by which new species arise or develop.
CHAPTER 3, p. 54; Glossary, p. 387 |
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Term
| What is resource partitioning? |
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Definition
No two species can occupy the same ecological niche for long. The one that is more efficient in using available resources will exclude the other, reducing intraspecific competition.
CHAPTER 3, pp. 52, 53, & 57; Glossary, p. 386 |
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Term
| What is Batesian mimicry? |
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Definition
Certain species that are harmless resemble poisonous or distasteful ones, gaining protection against predators who remember a bad experience with the actual toxic organism. For example, the monarch and viceroy butterflies.
Glossary, p. 379; CHAPTER 3, pp. 58&59 |
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Term
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Definition
The intimate living together of members of two species. For example, in lichens, a fungus and a photosynthetic partner (either an alga or a cyanobacterium) combine tissues to mutual benefit.
[image]
CHAPTER 3, p. 59; Glossary, p. 387 |
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Term
| What is an invasive species? |
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Definition
A generalist or pioneering species that is moved into a new ecosystem. For example, the kudzu, water hyacinth, and walking catfish are all invasive species in the U.S.
CHAPTER 3, pp. 52&60; CHAPTER 5, p. 115; Glossary, p. 383 |
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Term
| What are keystone species? |
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Definition
A keystone species plays has complex ties to the foundations of the ecosystem that is out of proportion to its abundance. For example, salmon in the Northwest.
CHAPTER 3, p. 60; Glossary, p. 383 |
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Term
| When does a dieback or population crash occur? |
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Definition
When a population overshoots or exceeds the carrying capacity of its environment, resources become limited and death rates rise. If deaths exceed births, the growth rate becomes negative and the population may suddenly decrease, a change called a population crash or dieback.
[image]
CHAPTER 3, p. 61 |
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Term
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Definition
The mathematical expression or graph of exponential population growth.
[image]
CHAPTER 3, pp. 61-62; Glossary, p. 383 |
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