n. The process whereby new species arise typically as a result of gradual changes that occur in populations or organisms over a long period of time.
By Nancy Burnett, Founder of Shape of Life
While working on the original PBS Shape of Life series, I learned about the discovery of fossil animals that first appeared during the Cambrian Explosion. When I realized that the most famous Cambrian site is in the Burgess Shale of British Columbia, I knew I had to visit it.
The Cambrian Explosion was a burst of animal evolution that occurred in the ocean about 540 million years ago.
For most of Earth's early history, there simply was no fossil record. Only recently have we come to discover otherwise: Life is virtually as old as the planet itself, and even the most ancient sedimentary rocks have yielded fossilized remains of primitive forms of life.
The paleontological evidence of the first animal to hunt is tiny trails that have been fossilized in rocks. To start this lesson, students will consider the tracks and traces left by modern animals and what they can learn about an animal from its tracks. They then think about which animal might have been the first hunter. The class considers what it takes to be a hunter and what kind of evidence can we use to figure out what was the first hunter. Students write their ideas in their science notebooks and the teacher shares the ideas with the entire class.
The evolutionary tree shown here was drawn by Charles Darwin, a scientist who lived more than 150 years ago. It was Darwin, and another man named Alfred Russel Wallace that came up with the idea of natural selection, which is one of the ways that life evolves. Darwin wasn’t the first person to suggest that life evolves, the idea had been around for a while, but he was one of the first to use evidence to explain his observations about life.
In this lesson, students will watch a short film about the Cambrian Explosion and the extraordinary fossils of the Burgess Shale. Students will address preconceptions and misconceptions about early Cambrian life, and complete a timeline activity that will enable them to better appreciate just how recently—relatively speaking—multicellular life evolved on Earth.
This collection consists of six lesson plans designed to help students construct an explanation of the geologic time scale based on personal connections, science concepts and nature of science ideas.
Scientists use a tree with branches to represent the common ancestry and evolutionary relationships of earth’s different kinds of organisms. In 1859 Charles Darwin sketched a Tree of Life in his book, “The Origin of Species”. He was explaining how a genus of related species might have originated from a common ancestor. This was the beginning of using a tree as a model for evolution. Since then there have been thousands of Tree of Life drawings as our knowledge has increased.
In 1992 a friend of ours, the artist Ray Troll, created his own gorgeous and quirky version. Since then he has created trees for various animal groups, which we think are delightful and engaging. So, when our friend, biologist Chuck Baxter, was turning 90, we decided to ask Ray to create a new animal Tree of Life for him and for the Shape of Life. Ray agreed, saying “It was a great honor to be asked to do something for Chuck Baxter on such a momentous occasion!”
“If you think the ocean isn't important, imagine Earth without it. Mars comes to mind. No ocean, no life support system.” Sylvia Earle
The ocean covers 71 percent of our planet. Ocean scientists, educators and policy specialists came together to define ocean literacy and to create seven principles.
‘Ocean literacy is defined as an understanding of the ocean’s influence on you and your influence on the ocean.’
Here are the seven ocean literacy principles....
