Skip to ContentGo to accessibility pageKeyboard shortcuts menu
OpenStax Logo
Biology for AP® Courses

Introduction

Biology for AP® CoursesIntroduction
Photo shows a bee collecting nectar from a flower.
Figure 20.1 The life of a bee is very different from the life of a flower, but the two organisms are related. Both are members of the domain Eukarya and have cells containing many similar organelles, genes, and proteins. (credit: modification of work by John Beetham)

Chapter Outline

20.1 Organizing Life on Earth
20.2 Determining Evolutionary Relationships
20.3 Perspectives on the Phylogenetic Tree

This bee and Echinacea flower (Figure 20.1) could not look more different, yet they are related, as are all living organisms on Earth. By following pathways of similarities and changes—both visible and genetic—scientists seek to map the evolutionary past of how life developed from single-celled organisms to the tremendous variety of creatures that have germinated, crawled, floated, swam, flown, and walked on this planet.

New species are discovered with frequent regularity, but it’s not too common to discover a new large mammal. However, that’s what scientists did in Australia when they named a new species of cetacean the Australian humpback dolphin, Souse sahulensis. The dolphin had originally been classified as another closely related species, but a closer look at its coloration, skeletal structure, habitat, and DNA determined that it was in fact a separate species.

For more information, read the research article yourself.

PreviousNext
Order a print copy
Citation/Attribution

This book may not be used in the training of large language models or otherwise be ingested into large language models or generative AI offerings without OpenStax's permission.

Want to cite, share, or modify this book? This book uses the Creative Commons Attribution License and you must attribute OpenStax.

Attribution information
  • If you are redistributing all or part of this book in a print format, then you must include on every physical page the following attribution:
    Access for free at https://openstax.org/books/biology-ap-courses/pages/1-introduction
  • If you are redistributing all or part of this book in a digital format, then you must include on every digital page view the following attribution:
    Access for free at https://openstax.org/books/biology-ap-courses/pages/1-introduction
Citation information

© Sep 19, 2024 OpenStax. Textbook content produced by OpenStax is licensed under a Creative Commons Attribution License . The OpenStax name, OpenStax logo, OpenStax book covers, OpenStax CNX name, and OpenStax CNX logo are not subject to the Creative Commons license and may not be reproduced without the prior and express written consent of Rice University.