About This Chapter
Basics of Evolution - Chapter Summary
Evolution is the theory that all living organisms change over time, and there are various factors and processes that cause these changes. In these lessons, you will go over details about the theories associated with evolution, how evolutionary processes work, and other related concepts. Our instructors have prepared these lessons to guide you through the basics, making sure to go over definitions, terminology, and important information about scientists who have contributed to the theories about evolution. Use your favorite device to go through the lesson materials, and remember that everything we offer is online, so you can always take your study materials with you. Plus, if you get stuck, you can send any of your questions to our instructors. In these lessons, you will learn:
- To understand the concept of evolution and related theories
- What are adaptation and the natural selection process
- How to identify different kinds of natural selection
1. Theories of Evolution: Lamarck vs. Darwin
Evolution is possible because of the vast genetic variation that exists and is inherited within a population. Learn more about the theories of evolution such as Lamarck versus Darwin through reviewing examples.
2. Natural Selection & Adaptation: Definition, Theory & Examples
Evolutionary fitness is a trait's ability to change the contribution of offspring by an individual for the next generation. Explore natural selection, adaption, and the different traits that determine fitness in this lesson.
3. Natural Selection: Definition, Types & Examples
Natural selection is a process in the evolution and adaptation of organisms to increase primary characteristics. Learn about the process of natural selection, the different types of natural selection, and the concept of polymorphism.
4. Speciation: Allopatric and Sympatric Speciation
A species is a particular group of organisms. Speciation is the process of a species splitting into new species. Discover the two different types of speciation - allopatric or geographic speciation, and sympatric speciation.
5. Prezygotic Reproductive Barriers & Speciation: Definition & Examples
Prezygotic barriers prevent the fertilization of an egg cell. Explore the types of prezygotic barriers - spatial isolation, temporal isolation, mechanical isolation, gametic isolation, and behavioral isolation.
6. Postzygotic Reproductive Barriers: Definition & Examples
Postzygotic reproductive barriers reduce the reproductive capacity of hybrid offspring. Discover the three types of postzygotic barriers - hybrid zygote abnormality, hybrid infertility, and low hybrid viability.
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Other chapters within the Science 101: Intro to Life Sciences course
- Introduction to Life Science
- Cell Biology Fundamentals
- Introduction to Molecular Biology
- Molecular Genetics Overview
- Cellular Reproduction Processes
- Introduction to Biochemistry
- Plant Anatomy, Physiology & Processes
- Animal Reproduction, Growth and Development
- Animal Anatomy, Physiology & Functions
- Human Anatomy & Physiology
- Environmental Science Fundamentals
- Introduction to Ecology
- The Origin and History of Life On Earth
- Phylogeny and the Classification of Organisms
- Studying for Science 101