About This Chapter
The Role of Natural Selection in Biological Evolution - Chapter Summary
Our instructors cover the role of natural selection in biological evolution for your review. Just a few of the subjects outlined here include the theories of Charles Darwin and the definition of natural selection. Once you've watched all these videos, you should be able to:
- Provide examples of the different types of natural selection
- Explain how genetic variation is promoted by meiosis and fertilization
- Discuss why natural selection acts on phenotype and not genotype
- Detail how a group's survival potential is affected by gene pool diversity
- Outline the Hardy Weinberg equilibrium its equation as well as the evolutionary agents associated with it
- Identify the different types of genetic drift
- Give examples of reproductive isolation
- Describe convergent and divergent evolution
Move at your own pace as you review these subjects, using the video tabs to quickly go back to review any portion of a video lesson that you need to. With each video, we've included a short self-assessment quiz to test your knowledge. These quizzes, along with the comprehensive chapter test, provide helpful tools for test preparation.
1. Who Was Charles Darwin? - Theory of Evolution & Natural Selection
When you hear the name Charles Darwin, you probably think of evolution. However, Darwin did not come up with evolution. He explained a way for evolution to occur called natural selection. Learn more about Darwin and natural selection in this lesson.
2. Natural Selection: Definition, Types & Examples
We'll take a look at the types of natural selection that can occur. From flying hamsters to moths, you'll start to grasp the different paths organisms can take as they respond to their changing environments over time.
3. How Meiosis & Fertilization Promote Genetic Variation
Individuals are different because of their genetic variation. Even two siblings who come from the same parents have different genetic make-ups. This variation comes from both meiosis and fertilization, which are components of sexual reproduction.
4. Why Natural Selection Acts on Phenotype, Not Genotype
Evolution works through the mechanism of natural selection. This mechanism influences the genetic make-up of populations, acting on the population's physical traits. In this lesson, we'll explore examples of why this is.
5. How Gene Pool Diversity Affects a Group's Survival Potential
Humans are genetically the same yet very different. These differences are important, not just for humans but for all species because it makes it possible for populations to adapt to changing environmental conditions, which is essential to their survival.
6. Hardy-Weinberg Equilibrium I: Overview
In this lesson, we'll examine population genetics in greater detail. We'll also explore notions of Hardy-Weinberg equilibrium for large, stable populations. Is the genetic makeup of our flying hamster population changing? The Hardy-Weinberg equilibrium can serve as a reference point as we try to answer population genetics questions.
7. Hardy-Weinberg Equilibrium II: The Equation
The Hardy-Weinberg equilibrium equation is represented by a polynomial, so we'll have to do some calculations. Don't be intimidated; a few coin tosses can help us make sense of allelic frequencies in a given gene pool.
8. Hardy-Weinberg Equilibrium III: Evolutionary Agents
In this lesson, you'll learn how the Hardy-Weinberg equation relates to different evolutionary agents and population changes. Discover how the equation may be used to discover populations that are not in equilibrium.
9. Genetic Drift: Definition, Examples & Types
Genetic drift reduces genetic variability of a population by decreasing the size of the population. The change in population size and variability often leads to new species and unique populations.
10. Reproductive Isolation: Definition, Types & Examples
Typically, animals can only mate within their own species. In this lesson, you will learn about reproductive isolation, or when two species are unable to reproduce, including types and examples of isolation.
11. Divergent & Convergent Evolution: Definitions & Examples
Two types of macroevolution are essential to the understanding of evolutionary theory. Explore this lesson and learn more about convergent evolution and divergent evolution.
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Other chapters within the CSET Science Subtest II Life Sciences (217): Practice & Study Guide course
- Principles of Cell Structure & Function
- The Organization & Function of Multicellular Organisms
- The Cell Cycle, Mitosis & Meoisis
- Matter & Energy Flow in Organisms
- Interdependent Relationships in Ecosystems
- Cycles of Matter & Energy Transfer in Ecosystems
- Biodiversity & Sustainability
- DNA & Gene Expression
- Genetics & Inheritance
- Genetic Variation & Engineering
- Overview of Biological Evolution on Earth
- Adaptation in Biological Evolution
- CSET Science Subtest 2 Life Sciences Flashcards