This article, reprinted from the fall 1979 LBL News Magazine, was written about Dr. Luis Alvarez and his part in the study of geological sediments and the great extinctions.
Biology 2e is designed to cover the scope and sequence requirements of a typical two-semester biology course for science majors. The text provides comprehensive coverage of foundational research and core biology concepts through an evolutionary lens. Biology includes rich features that engage students in scientific inquiry, highlight careers in the biological sciences, and offer everyday applications. The book also includes various types of practice and homework questions that help students understand—and apply—key concepts. The 2nd edition has been revised to incorporate clearer, more current, and more dynamic explanations, while maintaining the same organization as the first edition. Art and illustrations have been substantially improved, and the textbook features additional assessments and related resources.
By the end of this section, you will be able to do the following:
Describe the features that characterized the earliest animals and approximately when they appeared on earth
Explain the significance of the Cambrian period for animal evolution and the changes in animal diversity that took place during that time
Describe some of the unresolved questions surrounding the Cambrian explosion
Discuss the implications of mass animal extinctions that have occurred in evolutionary history
By the end of this section, you will be able to do the following:
Define biodiversity in terms of species diversity and abundance
Describe biodiversity as the equilibrium of naturally fluctuating rates of extinction and speciation
Identify historical causes of high extinction rates in Earth’s history
This comprehensive study guide covers the main terms and concepts needed for a unit on the biodiversity crisis.
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Describes how human actions are resulting in a sixth mass extinction.
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Describes how human actions are resulting in a sixth mass extinction.
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Describes how species die out, and how new ones evolve to fill the vacant niches.
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Use this study guide to understand extinction and radiation of life.
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This video focuses on what causes the extinction of the dinosaurs. Learn about Luis Alvarez's research that led to the discovery that an asteroid caused the mass extinction. Video includes embedded quizzes that check from students' understanding of the concepts explored in the video. [33:43]
Find out how this paleontologist believes dinosaurs rose to higher grounds following a mass extinction hundreds of thousands of years ago. [36:38]
Discover how mass extinctions play a part in Earth's life history.
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An organism goes extinct when all of the members of a species die out and no more members remain. Extinctions are part of natural selection. Species often go extinct when their environment changes, and they do not have the traits they need to survive. Only those individuals with the traits needed to live in a changed environment survive. Learn more about mass extinctions in this learning module produced by CK-12.
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Presentation of an emerging theory that explains the mass extinction of life that occurred at the end of the Permian period. [4:51]
Dinosaurs were not the only life to go extinct and leave a trail to their history. This webcast presents a paleobotanist who has studied extinction at a site in North Dakota. He discusses mass extinction. [29:16]
