STEM Friday #Kidlit One Iguana, Two Iguanas: A Story of Accident, Natural Selection, and Evolution

Prolific and award-winning children’s book author Sneed B. Collard III is not afraid to tackle tough STEM topics, such as fire ecology (Fire Birds) and climate change (Hopping Ahead of Climate Change). Now he’s taken on evolution with his new middle grade book One Iguana, Two Iguanas: A Story of Accident, Natural Selection, and Evolution, which is a Junior Library Guild selection and earned a starred Kirkus Review.

You may have heard about the Darwin’s finches that live on the Galápagos islands, but did you know that there are two related, but very different species of iguana found there? One of the species lives on land and eats the fruit of the prickly pear cactus. The other species is the only iguana in the world that can swim in the ocean. It is the marine iguana, shown in this video grazing on algae underwater.


Genetic testing have shown that the two species are related. Collard introduces the reader to a puzzle how the two such divergent lifestyles may have come about and how they ended up on an island chain 900 miles from their nearest relatives. He also discusses the geology and history of the islands, and how that impacts the iguanas and the other creatures that live there.

Although this is a middle grade book by text level and content, it is illustrated with many large color photographs. Many of the photographs were taken by the author, who is also a photographer. Others were taken by his friend Jack Grove.

As the author states in the back matter, “considering how important evolution is to the history of the earth, it’s surprising how few books for young people have been written about it.” One Iguana, Two Iguanas: A Story of Accident, Natural Selection, and Evolution steps in to fill the gap. This book is a must have for budding scientists and anyone interested in nature. Scoop up a copy today!

Related Activity Suggestions:

This book would be great to accompany lessons on lizards, as well as evolution. See our Growing with Science post with information and activities inspired by Sneed Collard III’s All About Lizards book.

National Geographic Kids has a Galápagos islands page.

Age Range: 8 – 12 years
Publisher: Tilbury House Publishers; 1 edition (December 4, 2018)
ISBN-10: 0884486494
ISBN-13: 978-0884486497

Photograph of marine iguanas from



Disclosure: This book was provided by the publisher for review. Also, I am an affiliate with Amazon so I can provide you with cover images and links to more information about books and products. As you probably are aware, if you click through the highlighted title link and purchase a product, I will receive a very small commission, at no extra cost to you. Any proceeds help defray the costs of hosting and maintaining this website.

Come visit the STEM Friday blog each week to find more great Science, Technology, Engineering and Math books.Opens in a new window Note: this is a new link as of 1/2019.