Life as We Know It

Learning Target

• Investigate the idea that living things are made of cells and describe the cycling of matter and flow of energy among living and nonliving parts of an ecosystem.

Success Criteria

• I can describe the prevailing theory of how life began on planet Earth.
• I can recognize the distinction between living and nonliving factors.
• I can begin to develop a conceptual model of how living and nonliving factors interact.

Questions to Ponder

• How did life begin on our planet?
• How do we differentiate between living and nonliving things?

Events

1. Oceans and continents start to form – 4400 million years ago – 4.4 meters from present day (end of timeline)
2. First evidence of life –3500 million years ago – 3.5 meters from present day
3. Initial of atmospheric oxygen –2400 million years ago – 2.4 meters from present day
4. Evolution of eukaryotic (non-bacterial) life—1800 million years ago – 1.8 meters from present day
5. Cambrian Radiation of Animals—542 million years ago – 54.2 centimeters from present day
6. Plants move on to Land—450 million years ago – 45 centimeters from present day
7. Animals move on to Land—430 million years ago – 43 centimeters from present day
8. Permo-Triassic Mass Extinction – largest known!—251 million years ago – 25.1 centimeters from present day
9. Evolution of Mammals –195 million years ago – 19.5 centimeters from present day
10. Opening of the Atlantic Ocean—160 million years ago - 16 centimeters from present day
11. Extinction of the Dinosaurs—65 million years ago – 6.5 centimeters from present day
12. Rise of the Himalayan Mountains—20 million years ago - 2 centimeters from present day
13. Evolution of our species, Homo sapiens—200,000 years ago - 0.2 million years ago – 0.02 centimeters from present day (0.2 mm)
14. Extinction of the Wooly Mammoth—10,000 years ago – 0.01 million years ago – 0.001 centimeters from present day (0.01 mm)

Sorting Activity

• Observe the following images. Come up with ways to sort them into groups.
• After you have come up with the criteria for inclusion in your groups add several other things that you think should be in your groups.

Sorting the World - Biotic vs. Abiotic

• Things in the world can be divided into two categories; Biotic and Abiotic factors.
• Biotic factors are living or once-living organisms in the ecosystem. These are obtained from the biosphere and are capable of reproduction. Examples of biotic factors are animals, birds, plants, fungi, and other similar organisms.
• Abiotic factors refer to non-living physical and chemical elements in the ecosystem. Abiotic resources are usually obtained from the lithosphere, atmosphere, and hydrosphere. Examples of abiotic factors are water, air, soil, sunlight, and minerals.

In Your Notebook

• Create your own chart showing the difference between Biotic and Abiotic Factors.
• Try to use examples that were not shown above!