This year the theme for the AMI Refresher Course was “The Child’s Place in Time.” In the elementary classroom, the perfect place to start digging deeply into the study of time would be with our second Great Story, where we unroll the Timeline of Life and imagine how life must have developed on our planet over the course of millions of years. Our presenter was Carla Foster, a current AMI Montessori elementary trainer and professor at University College of Vestfold in Norway. All the elementary trained teachers spent the weekend with her on a journey of literature, music, art, ecology, biology, and, of course, history centered upon our Timeline of Life and the Timelines of Human Beings.
Upon returning to the classroom last week, I was so excited to share this information with the children. We unrolled the timeline and I shared a story about the Cambrian Period of the Paleozoic Era, the first period on our timeline, ranging from 540 to 490 million years ago. The continents on Earth at the time were located mostly in the southern hemisphere and there were no ice caps. This meant that sea levels were high, creating shallow seas along the continental shelf areas. This was the perfect place for an explosion of sea life.
At that point, all life was located in the sea and the land was completely barren. So, the critters of the time had to develop in such a way that they were already adapted to their water environment, experimenting with how to solve such circumstances as:
– How to develop propulsion for movement – There is greater resistance to movements in water than in air, so what types of bodies and movements allowed critters to move about?
– How to be physically stable in 3 dimensions – How did critters manage the effects of the force of buoyancy?
-How to reduce drag in movement – What types of body cover or body shapes would allow a critter to reduce drag in order to move forward through water with ease?
-How to breathe – At this point in history there are no fish as we know them. How much oxygen did these creatures need and how did they go about getting that oxygen into their bodies?
-How to find a balance between salt and water in the body – How was the body structure created so that creatures could find this balance?
-How to stay warm – Living creatures get cold 24 times faster in a water environment. How warm did the early critters have to be to survive? Did they need to generate that heat themselves, and, if so, how did they both generate the heat and retain it?
-How to sense your environment – Both light and sound travels differently underwater than on land. Color and light penetrate water at different rates. In addition to the senses we commonly discuss, some creatures were able to sense motion around them, magnetic fields and electrical fields.
As we considered the shallow seas environment of the Cambrian Period, we looked into what creatures were successful at the time: single-celled organisms, early shelled creatures, sponges, mollusks, brachiopods, and pikaia (the first animal to possess the hints of a backbone, an ancient ancestor to all our vertebrate classes!). One of the most successful creatures of the time that our students enjoy learning about is the trilobite. We learned a song about trilobites, baked cookies in the shapes of trilobites, and hosted a short trilobite celebration for all the elementary students last Friday.
The children so enjoyed this exploration of history through stories, songs, and baking that when I unrolled the Timeline of Life again this week to give a story about the next period, the Ordovician, children excitedly gathered around in a group on the rug for another celebration of the history of life on our planet. We love digging deeply into history, knowing that we are a part of that living history and can extend our own stories into the history yet to be written!
Here are a few resources you can access in case you or your child want to learn more about prehistoric time: