By the end of this section, you will be able to do the following:

Define species and describe how scientists identify species as different
Describe genetic variables that lead to speciation
Identify prezygotic and postzygotic reproductive barriers
Explain allopatric and sympatric speciation
Describe adaptive radiation

By the end of this section, you will be able to do the following:

Describe pathways of species evolution in hybrid zones
Explain the two major theories on rates of speciation

By the end of this section, you will be able to do the following:

Describe how scientists developed the present-day theory of evolution
Define adaptation
Explain convergent and divergent evolution
Describe homologous and vestigial structures
Discuss misconceptions about the theory of evolution

By the end of this section, you will be able to do the following:

Compare homologous and analogous traits
Discuss the purpose of cladistics
Describe maximum parsimony

By the end of this section, you will be able to do the following:

Discuss the need for a comprehensive classification system
List the different levels of the taxonomic classification system
Describe how systematics and taxonomy relate to phylogeny
Discuss a phylogenetic tree's components and purpose

By the end of this section, you will be able to do the following:

Describe horizontal gene transfer
Illustrate how prokaryotes and eukaryotes transfer genes horizontally
Identify the web and ring models of phylogenetic relationships and describe how they differ from the original phylogenetic tree concept

Biology is designed for multi-semester biology courses for science majors. It is grounded on an evolutionary basis and includes exciting features that highlight careers in the biological sciences and everyday applications of the concepts at hand. To meet the needs of today’s instructors and students, some content has been strategically condensed while maintaining the overall scope and coverage of traditional texts for this course. Instructors can customize the book, adapting it to the approach that works best in their classroom. Biology also includes an innovative art program that incorporates critical thinking and clicker questions to help students understand—and apply—key concepts.

By the end of this section, you will be able to do the following:

Identify and describe the properties of life
Describe the levels of organization among living things
Recognize and interpret a phylogenetic tree
List examples of different subdisciplines in biology

Covers the evolution and ecology of amphibians.

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An overview of the major trends in animal evolution.

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This 18-minute video lesson looks at the the vocabulary of DNA: chromosomes, chromatids, chromatin, transcription, translation, and replication. [Biology playlist: Lesson 8 of 71].

Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.

Describes Darwin's observations on the Galapagos Islands that led to his theory of evolution.

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Describes Darwin's observations on the Galapagos Islands that led to his theory of evolution.

A free CK-12 account is required to view all materials.

Describes Darwin's observations on the Galapagos Islands that led to his theory of evolution.

A free CK-12 account is required to view all materials.