Principles of Evolution
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.
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.
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.
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.
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.
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.
Discover the definition of a species and learn more about how species split. Find out common terms related to the splitting of species and study what role polyploidy plays in the development of a species.
We may take for granted why animals choose to mate with other animals of similar appearance, but it's not that simple. There are actually biological barriers to reproduction that can prevent even seemingly closely related species from reproducing. This lesson looks at one such category of hindrances, prezygotic barriers, which make fertilization impossible.
Do flying hamsters represent a separate species from your run-of-the-mill hamsters? We'll get to the bottom of this by performing crosses between the two hamster types. You'll explore postzygotic reproductive barriers and their possibly tragic consequences.
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About this chapter
Charles Darwin is widely known for his significant work on evolution. If he were around today, what do you think he might say if he saw a flying hamster? Based on our knowledge of Darwin, we can guess that he would probably look for its evolutionary advantages. Why did certain hamsters develop wings when others didn't? Are flying hamsters more likely to survive than their wingless counterparts? Why or why not? As you watch theselessons on the principles of evolution, you'll begin to understand what influential evolutionary theorists, like Charles Darwin, can teach us.
You'll delve deeper while studying the various ways in which certain species survive or fail to survive and what factors influence those outcomes. For example, you've probably heard of natural selection. Now you can learn about how species are affected by natural selection, as well as genetic drift, mutation, migration and extinction. Additionally, you'll watch lessons on the Hardy-Weinberg equilibrium, a concept that helps us to understand if evolutionary agents are present and affecting a population we want to study.
Evolution isn't only about species changing or dying out. It's also about the emergence of new species, like those flying hamsters. There are many ways that a species that previously didn't exist can come to be. Among the topics you'll learn about related to speciation are geographic speciation, temporal isolation and gametic isolation.
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