Book contents
- Understanding the Tree of Life
- Series page
- Understanding the Tree of Life
- Copyright page
- Reviews
- Epigraph
- Contents
- Foreword
- Preface
- Acknowledgments
- 1 Introduction to the Tree of Life: Drawing Trees and Why There Is No Trunk
- 2 Human Origins: We Are African … Mostly
- 3 Primates: Our Closest Living Cousins
- 4 Which Mammals Are the Most Primitive? None of Us
- 5 Birds Are Reptiles, Birds Are Theropod Dinosaurs
- 6 The Crawl Onto Land: Tetrapod Evolution and the Gain and Loss of Limbs
- 7 Which Fishes Are “Primitive”? Do Fish Even Exist?
- 8 Animal Evolution: Sponges and Comb Jellies Are Our Cousins
- 9 Plants, Animals, Fungi, and “Protists”: We Are Eukaryotes
- 10 Archaea Then Bacteria Are Our Most Distant Cousins
- Concluding Remarks: The Success, Importance, and Conservation of All Life
- Summary of Common Misunderstandings
- References and Further Reading
- Figure Credits
- Index
9 - Plants, Animals, Fungi, and “Protists”: We Are Eukaryotes
Published online by Cambridge University Press: 19 September 2025
Book contents
- Understanding the Tree of Life
- Series page
- Understanding the Tree of Life
- Copyright page
- Reviews
- Epigraph
- Contents
- Foreword
- Preface
- Acknowledgments
- 1 Introduction to the Tree of Life: Drawing Trees and Why There Is No Trunk
- 2 Human Origins: We Are African … Mostly
- 3 Primates: Our Closest Living Cousins
- 4 Which Mammals Are the Most Primitive? None of Us
- 5 Birds Are Reptiles, Birds Are Theropod Dinosaurs
- 6 The Crawl Onto Land: Tetrapod Evolution and the Gain and Loss of Limbs
- 7 Which Fishes Are “Primitive”? Do Fish Even Exist?
- 8 Animal Evolution: Sponges and Comb Jellies Are Our Cousins
- 9 Plants, Animals, Fungi, and “Protists”: We Are Eukaryotes
- 10 Archaea Then Bacteria Are Our Most Distant Cousins
- Concluding Remarks: The Success, Importance, and Conservation of All Life
- Summary of Common Misunderstandings
- References and Further Reading
- Figure Credits
- Index
Summary
According to Aristotle and Linnaeus, there were only two “kingdoms” – Plantae and Animalia. In the 1800s, Haeckel carved kingdom “Protista” off of Linnaeus’ Plantae. Kingdoms for Fungi and Bacteria (Monera) were later added. By the time I was in secondary school, I learned a five-kingdom system. The five “kingdoms” that I learned are still frequently used in biology lessons: animals, plants, fungi, protists, and bacteria. But we now know that a five-kingdom story is so simplified as to be misleading, and it tells us very little about the broad tree of life. Back then, in the 1900s, our limited understanding made things seem more simple, but recent DNA sequence data indicate that the groupings are much more complex.
The five-kingdom system was first proposed in 1969. (1) Animalia were multicellular creatures that eat other organisms. (2) Fungi were generally multicellular decomposers that fed by a network of filamentous cells. (3) Plantae included especially the land plants.
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- Understanding the Tree of Life , pp. 153 - 167Publisher: Cambridge University PressPrint publication year: 2025
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