We spent much of class exploring the history of life on earth. Our timeline included:
- the formation of our planet, earth, 4.6 billion years ago
- life's beginning on earth, with simple, single-celled, bacteria-like organisms, 3.6 billion years ago
- complex cells (eukaryotes), 2 billion years ago
- multicellular organisms (like protists), 1 billion years ago
- simple animals, 600 million years ago
- arthropods, 570 million years ago
- fish, 500 million years ago
- land plants, 475 million years ago
- insects and seeds, 400 million years ago
- reptiles, eventually including dinosaurs, 300 million years ago
- mammals, which were small until the dinosaurs went extinct, 200 million years ago
- birds, which may have evolved from dinosaurs, 150 million years ago
- flowers, 130 million years ago
- the extinction of dinosaurs, 65 million years ago
- the Genus Homo, which now includes modern humans, appeared 2.5 million years ago
- Homo sapiens, our species, appeared 150,000 to 200,000 years ago
(this is pretty much from Wikipedia)
We also talked about Darwin and how he gathered the information that later led to his theories about the origin of species and evolution. Mainly, we learned that he went on a voyage to several places around the world, including the Galapagos Islands, and collected many specimens -- various plant and animal species to learn about. The trip ended up being five years, and Darwin didn't initially know much about what he was doing or the significance of what he was seeing and collecting.
We went outside to look at what species we could see right in the back yard, and we saw insects (bumblebees, a hornet, and a junebug), birds, trees, flowering plants, grasses, and two mammals (squirrels and a rabbit). So we got a feel for what it was like on Darwin's trip, looking at and collecting specimens of life forms.
Lastly, we divided into teams and had a quiz show about what we learned in class. The final score was 2 to 1, but the point, of course, was just to have fun!
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