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- Identify the lessons in the Holt McDougal Evolution of Populations chapter with which you need help.
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Students will learn:
- Genetic variation types
- Kinds of natural selection
- The definition for sexual selection
- Hardy-Weinberg equilibrium
- Differences between temporal and mechanical isolation
- Descriptions of convergent and divergent evolution
- Adaptive radiation and punctuated equilibrium
- What coevolution is
- Basics of extinction
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1. What Is Genetic Variation? - Sources, Definition & Types
Genetic variation is the diversification of alleles and genes within a specific population to create a healthy gene pool. Learn about the types of genetic variation, continuous and discrete traits and the sources of genetic variation.
2. 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.
3. Gene Flow: Definition & Examples
Gene flow is the movement of genes from one population to another population and, more specifically, the movement of different alleles or forms of genes. Learn more about gene flow through its definition, examples and influence on genetic diversity.
4. Genetic Drift: Definition, Examples & Types
Genetic drift happens when chance events cause changes in the genetic variations of a population. Examine the definition and learn the types of genetic drift. See examples of population bottlenecking and the founder effect.
5. Sexual Selection: Definition & Forms
Why are you attracted to someone? One reason may be due to the forces of sexual selection. This lesson will explain sexual selection and will investigate types of sexual selection.
6. Hardy-Weinberg Equilibrium I: Overview
The Hardy-Weinberg equilibrium equation is regularly used to describe genotypic frequency in a population. Learn more on Hardy-Weinberg Equilibrium I, the five criteria and it's usage in the genetics of a population.
7. Hardy-Weinberg Equilibrium II: The Equation
The Hardy-Weinberg equilibrium equation helps in analyzing and understanding the gene pool of a population. Learn about this equation, including the variables it represents and where to find these variables, understand alleles and genotypes, and explore the significance of allelic and genotypic frequencies.
8. Hardy-Weinberg Equilibrium III: Evolutionary Agents
The Hardy-Weinberg equilibrium equation has been developed to be used to test the evolutionary status of a population. Learn more about evolutionary agents, non-random mating, natural selection, genetic drift, population bottleneck and the founder effect.
9. Mechanical Isolation: Definition & Example
Mechanical isolation is a type of reproductive barrier that prevents mating from happening. Explore mechanical isolation in animals and plants, and learn some examples.
10. Temporal Isolation: Example & Definition
Reproductive barriers prevent different species of similar animals from reproducing, while temporal isolation stops interbreeding between closely related species. Know the definition of reproductive barriers, its two types, and examples of how temporal isolation promotes speciation.
11. Convergent & Divergent Evolution: Definition & Examples
All living organisms, including humans, have undergone periods of evolution that can be described as divergent or convergent. Learn the definition of evolution and examples of organisms that have diverged and become unique species, and others that have taken on, or converged, the traits of two or more organisms.
12. Coevolution: Examples & Definition
Coevolution is when species trigger evolutionary changes in each other. Dive deeper into the definition of coevolution, the two types of coevolution, examples, the mutualistic coevolution of moths and orchids, the predator and prey coevolution of snakes and newts, and the parasite and host coevolution of brood parasites and birds.
13. What Is Extinction? - Defining Background and Mass Extinction
Learn about extinction, which occurs when an organism ceases to exist anywhere on Earth. Learn the definition and background of extinction, explore mass extinction, and discover humanity's role in extinction rates.
14. Punctuated Equilibrium: Definition, Theory & Examples
Punctuated equilibrium is a scientific hypothesis of the reasons why curious patterns found in the fossil record signify the presence of a new species previously unknown to have appeared on Earth. Explore a definition and explanation of the theory of punctuated equilibrium, and find examples of curious patterns in fossil records.
15. Adaptive Radiation: Definition & Example
Adaptive radiation refers to the evolutionary adaptation of a single lineage into many different forms, usually based on habitat or available resources. Discover the definition of adaptive radiation, examples of how it works, the influence of selective pressures, and how adaptive radiation functions in nature.
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Other chapters within the Holt McDougal Biology: Online Textbook Help course
- Holt McDougal Biology Chapter 1: Biology in the 21st Century
- Holt McDougal Biology Chapter 2: Chemistry of Life
- Holt McDougal Biology Chapter 3: Cell Structure & Function
- Holt McDougal Biology Chapter 4: Cells & Energy
- Holt McDougal Biology Chapter 5: Cell Growth & Division
- Holt McDougal Biology Chapter 6: Meiosis & Mendel
- Holt McDougal Biology Chapter 7: Extending Mendelian Genetics
- Holt McDougal Biology Chapter 8: From DNA to Proteins
- Holt McDougal Biology Chapter 9: Frontiers of Biotechnology
- Holt McDougal Biology Chapter 10: Principles of Evolution
- Holt McDougal Biology Chapter 12: The History of Life
- Holt McDougal Biology Chapter 13: Principles of Ecology
- Holt McDougal Biology Chapter 14: Interactions in Ecosystems
- Holt McDougal Biology Chapter 15: The Biosphere
- Holt McDougal Biology Chapter 16: Human Impact on Ecosystems
- Holt McDougal Biology Chapter 17: The Tree of Life
- Holt McDougal Biology Chapter 18: Viruses & Prokaryotes
- Holt McDougal Biology Chapter 19: Protists & Fungi
- Holt McDougal Biology Chapter 20: Plant Diversity
- Holt McDougal Biology Chapter 21: Plant Structure & Function
- Holt McDougal Biology Chapter 22: Plant Growth, Reproduction & Response
- Holt McDougal Biology Chapter 23: Invertebrate Diversity
- Holt McDougal Biology Chapter 24: A Closer Look at Arthropods
- Holt McDougal Biology Chapter 25: Vertebrate Diversity
- Holt McDougal Biology Chapter 26: A Closer Look at Amniotes
- Holt McDougal Biology Chapter 27: Animal Behavior
- Holt McDougal Biology Chapter 28: Human Systems & Homeostasis
- Holt McDougal Biology Chapter 29: Nervous & Endocrine Systems
- Holt McDougal Biology Chapter 30: Respiratory & Circulatory Systems
- Holt McDougal Biology Chapter 31: Immune System & Disease
- Holt McDougal Biology Chapter 32: Digestive & Excretory Systems
- Holt McDougal Biology Chapter 33: Protection, Support & Movement
- Holt McDougal Biology Chapter 34: Reproduction & Development