Questions and Answers
Natural selection leads to a process of change in a population over time. What is this process called?
evolution
There are three requirements for natural selection. The requirements are __, __, and __.
variation, overpopulation, adaption
What is the evolutionary process through which new species emerge called?
speciation
What are the two phases of speciation?
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Can speciation occur in a situation where a population of wildflowers is separated by an eight-lane superhighway, and pollen is often carried by the wind across the highway?
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A population of deer is separated by an emerging volcano and later are incapable of breeding upon contact. What process occurred?
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Which piece of evidence would most go against the scientist's argument that two species of butterflies should be considered the same species?
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Which graph best represents disruptive selection?
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Which graph best represents directional selection?
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Identify which type of natural selection is described: Results in the evolution of the species:
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Identify which type of natural selection is described: Results in new species:
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Identify which type of natural selection is described: Favors traits at the two extremes:
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Identify which type of natural selection is described: No increase in diversity:
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Identify which type of natural selection is described: One extreme trait is favored:
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Identify which type of natural selection is described: Diversity decreases:
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Identify which type of natural selection is described: Diversity increases:
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The Weaver birds from the African savanna exhibit a trade-off between risking starvation and being hunted by predators. Which weight has the selective advantage?
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Starting in 1945, nets designed to catch the biggest salmon were used resulting in smaller salmon having an advantage. What occurred?
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Study Notes
Evolution and Natural Selection
- Natural selection drives evolution, reflecting population changes over time.
- Three essential requirements for natural selection include variation, overpopulation, and adaptation.
Speciation
- The process through which new species emerge is referred to as speciation.
- Speciation involves two main phases: divergence and reproductive isolation.
Examples of Speciation
- When a population of wildflowers is split by a highway that allows some pollen exchange, speciation may not occur due to the intermixing of genetic material.
- In the case of deer populations separated by a volcano, their inability to breed after reconnection exemplifies the process of speciation through isolation.
Classification Challenges
- Similar physical traits in butterflies, alongside DNA similarities, can lead to arguments for species classification; however, significant variations, such as different mating seasons or color patterns can indicate they are distinct species.
Types of Natural Selection
- Disruptive selection favors extreme traits and can lead to increased diversity in populations.
- Directional selection favors one extreme trait, resulting in decreased variability and a more homogenous population.
- Stabilizing selection minimizes extremes, leading to a decrease in diversity by favoring average trait expressions.
Case Studies in Natural Selection
- Weaver birds illustrate a trade-off between foraging safety and predation pressure; those of medium weight gain an advantage, showing stabilizing selection.
- Post-1945 fishing practices focusing on larger salmon resulted in smaller salmon thriving due to a survival advantage, demonstrating directional selection shifting population traits over generations.
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Description
Explore the key concepts of biological diversity and evolution with this quiz. Understand the role of natural selection and the requirements that drive evolutionary change. Test your knowledge on variation, overpopulation, and adaptation.
