An excellent book that teaches children about the evolution of plants, insects, and fish.
What was life like before the dinosaurs roamed the Earth? When Fish Got Feet, Sharks Got Teeth, and Bugs Began to Swarm by Hannah Bonner (National Geographic Children's Books, ISBN: 987-1-4263-0078-3) takes a look at what life was like for fish, plants, and bugs in the Silurian and Devonian periods.
The Evolution of Plants
430 million years ago, land was covered with rock, gravel, sand, and silt. The plant life during this time period was small and sparse. There was lichen, moss, and algae. Fast forward 400 million years ago. Plants are getting bigger. There are more patches of plants on the land. However, trees have not yet evolved. It isn't until the Devonian period that trees begin to grow upwards and change from sending out spores to dropping seeds.
Bugs Evolving
With more plant life came more bugs. Some bugs ate other bugs and some bugs feasted on dying plant matter. There were centipedes, millipedes, and distant relatives of spiders. As plants became large trees, new bugs arrived on the scene, as well as scorpions and the first flying insects.
Fish: From Swimming to Walking
Fish also underwent dramatic changes during the Silurian and Devonian periods. At first they were slow and clumsy. They had a tail, but no fins. These fish were also jawless and their mouths could only take in small bits of food.
In the Devonian period, new kinds of fish evolved. They had fins and, most importantly, jaws. Some of these new fish had body armor, such as the placoderms. Sharks also arrived on the scene. They had mouths full of replaceable teeth.
During the late Devonian, some fish took a giant evolutionary leap and began to grow legs. These tetrapods could crawl onto land and breathe air with their lungs, but they continued to spend most of their lives in the water.
A Good Intro to Evolution
Written for children ages 9 to 12, When Fish Got Feet provides young readers insight into how evolution occurs. Children learn how plants evolved into looming trees, how insects adapted to the new green environment, and how fish evolved into fast swimmers and vicious predators.
The cartoon illustrations lighten up the topic by providing humor. There's the great fish race, silly little comment boxes, as well as an excellent life on Earth timeline at the back of the book.
Altogether, author Hannah Bonner has done a fantastic job of bringing to life the story of evolution during the Silurian and Devonian time periods.
