Transcript Origin of Life

Origin of Life
THURSDAY, JUNE 2, 2016
LEARNING TARGET…
STUDENTS TO DESCRIBE THE
ATMOSPHERE OF EARTH FROM
BEGINNING OF TIME UNTIL PRESENT
A. The Early Ideas
Spontaneous Generation: Idea that nonliving material can
produce life
1.
Example: People thought maggots grew out of decaying meat
a.
1.
b.
Francesco Redi disproved this belief with his experiment
Pasteur disproved the spontaneous generation of
microorganisms
B. The Modern Ideas
Meteorites
1.
a.
Life started when a meteorite containing organic matter
collided with the Earth
b.
Could explain how organic molecules that are necessary
for cell formation arrived on Earth and entered the
oceans
2. Divine Origins (Intelligent Design)
Many major religions teach that life was created by supreme
being
a.
1.
Explain it as life could not have been created without the
intervention of a divine force
B. The Modern Ideas (continued)
3. Primordial Soup
Idea that Earth’s ancient atmosphere probably contained
nitrogen, methane, ammonia, and a little free oxygen
a.
b.
1.
Energy from sun, volcanoes, and lightning fueled chemical
reactions among these gases, which combined into small
organic molecules like amino acids
2.
Rain washed these molecules into the oceans
making…primordial soup!
Harold Urey and Stanley Miller provided evidence to support
this.
C. Chemical Evolution
Urey and Miller conducted an experiment to simulate
the conditions of early Earth
1.
Steps to Experiment:
a.
1.
Mixed water vapor with ammonia, methane, and
hydrogen gases
2.
Then sent electric current (simulated lightning) through
the mixture
3.
Then cooled mixture and at same time produced a liquid
to simulate rain
4.
Collected the liquid in a flask
C. Chemical Evolution (continued)
2. After a week, they analyzed the liquid in the flask
and found it to contain the following:
a. amino acids
b. sugars
c. other small organic molecules
C. Chemical Evolution (continued)