About This Chapter
Evolution, Adaptation & Extinction - Chapter Summary
Our instructors cover subjects related to extinction, evolution and adaptation in this fun chapter. Lesson topics include the theory of evolution, genetic variability, random mutation, adaptation and natural selection. Each lesson is accompanied by a multiple-choice quiz to test your understanding. You can use the video tabs feature in the Timeline to skip to a specific section in any of our video lessons. If you need help along the way, feel free to contact an instructor. This chapter is designed to help you do the following:
- Define evolutionary change
- Explain how Darwin's observations showed the processes of natural selection
- Detail some of the scientific evidence for evolution
- Read a diagram explaining evolutionary relationships
- Give examples of fossil records
- Describe the cause of species extinction
1. Theories of Evolution: Lamarck vs. Darwin
We'll look at the interplay between population genetics and environment. Are traits individually acquired or do entire populations evolve? The flying hamsters and a few other notable experiments will provide the answers.
2. Evolutionary Change: Definition and Forms
You've probably heard of Charles Darwin and evolution. We know that evolution is change over time, but here we will look at how these changes may have occurred during Earth's history.
3. Genetic Variability and Random Mutation
Evolution is driven by variation among populations. The amount of variability determines how well a population can adapt to environmental changes, while random mutations can provide new variations that help a population adapt to unexpected changes.
4. How Darwin's Observations Showed the Process of Natural Selection
In this lesson, we will learn about the observations that led to the development of Darwin's theory of natural selection. We'll explore how natural selection happens and how this brings about genetic diversity.
5. Natural Selection & Adaptation: Definition, Theory & Examples
How does natural selection help shape the amazing types of animals we witness around us? In this lesson, we'll explore adaptations and what they can tell us about a species' past evolution.
6. Evidence for Evolution: Paleontology, Biogeography, Embryology, Comparative Anatomy & Molecular Biology
There is much support for the theory of evolution. This evidence comes from a variety of scientific fields and provides information that helps us trace changes in species over time. In this lesson, we'll look at this evidence and explore how it supports the theory of evolution.
7. Evolutionary Relationships: Definition & Diagram
Just like you can build a family tree to show the relationships of your ancestors and their descendants, scientists can build trees to show the evolutionary relationships of species. In this lesson, learn how to interpret these evolutionary trees.
8. Fossil Record: Definition & Examples
This lesson teaches you about the fossil record. It explains how scientists learn about Earth's distant past and highlights what fossils can tell scientists about ourselves and other organisms.
9. The Causes of Species Extinction
What do dinosaurs, passenger pigeons, and a species of Australian rat all have in common? They have all gone extinct. This lesson will examine the causes of species extinction from mass extinctions in the past to human-caused extinctions today.
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Other chapters within the 7th Grade Science: Life Science course