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Odyssey of Life, Part I—The Ultimate Journey
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Viewing Ideas
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Before Watching
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Distinguishing fact from theory can prove challenging. It is,
for example, a fact that life on Earth has changed over geologic
time. There are many theories concerning precisely how life
began, by what mechanism or mechanisms life evolves, through
what stages evolving life forms may have passed and how quickly
evolution takes place. Discuss with students what makes
something a fact and what makes it a theory. Have students work
in groups to collect resources about evolution. Then have each
group create two lists: one enumerating facts about the history
of life on Earth, and the other describing theories that attempt
to explain those facts. Review students' findings and facilitate
a discussion in which they debate and defend their reasoning for
why something is a fact or a theory.
After Watching
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Have students use a piece of string to represent the Earth's
geologic history. Have them devise a scale to calculate the
length of string they will need to represent the planet's entire
geologic history and the length of each geologic period.
(If they use a scale of 1 inch = 10 million years, for
example, the string would be 41.7 feet long.)
Then have them measure out the string and mark each period to
scale, noting how much string represents the periods that
include the evolution of life.
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