1. Origin of Life Sunday, April 07, 2019 Learning Target…
students to describe the atmosphere of Earth from beginning of time until present

2. A. The Early Ideas
Spontaneous Generation: Idea that nonliving material can produce life
Example: People thought maggots grew out of decaying meat
Francesco Redi disproved this belief with his experiment
Pasteur disproved the spontaneous generation of microorganisms

3. B. The Modern Ideas Meteorites Divine Origins (Intelligent Design)
Life started when a meteorite containing organic matter collided with the Earth
Could explain how organic molecules that are necessary for cell formation arrived on Earth and entered the oceans
Divine Origins (Intelligent Design)
Major religions teach that life was created by supreme being
Explain it as life could not have been created without the intervention of a divine force

4. B. The Modern Ideas (continued)
Primordial Soup
Idea that Earth’s ancient atmosphere probably contained nitrogen, methane, ammonia, and a little free oxygen
Energy from sun, volcanoes, and lightning fueled chemical reactions among these gases, which combined into small organic molecules like amino acids
Rain washed these molecules into the oceans making…primordial soup!
Harold Urey and Stanley Miller provided evidence to support this.

5. C. Chemical Evolution
Urey and Miller conducted an experiment to simulate the conditions of early Earth
Steps to Experiment:
Mixed water vapor with ammonia, methane, and hydrogen gases
Then sent electric current (simulated lightning) through the mixture
Then cooled mixture and at same time produced a liquid to simulate rain
Collected the liquid in a flask

6. C. Chemical Evolution (continued)
After a week, they analyzed the liquid in the flask and found it to contain the following:
amino acids
sugars
other small organic molecules

7. C. Chemical Evolution (continued)