Introduction to
Evolution
Video Summary: After watching the Simpsons video, describe how Homer changed over time?
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-The Earth is estimated to be 4.6 billion years old.
-The planet has changed a great deal during that long
period of time. Since the beginning of life, many species
have lived and died and have been replaced by newer
species.
Differences Among Organisms
Living things that share the same characteristics and adaptations may be members of the same
species.
A species- is a group of organisms that can mate with one another to produce fertile offspring.
Different Frogs
The strawberry dart-poison
frog's bright colors warns
predators that it is
poisonous.
The smokey jungle frog
blends into the forest floor.
The red-eyed tree frog
hides among a tree's
leaves during the day and
comes out at night.
Animal Adaptations
Adaptations- is a characteristics that helps an
organism survive and reproduce in its
environment.
Adaptations can include structures and
behaviors for finding food, for protection, and
for moving from place to place.
Evolution- is the process by which populations
accumulate inherited changes over time.
Scientists use fossils as evidence of change in species
over time
Fossil - the solidified remains or imprint of once-living
organisms.
Fossils are found in different layers of the earth.
Usually the deeper the fossil is found, the older
the fossil is.
Scientists have described and named close to
300,000 fossil species. The collection of these
fossils show the historical sequence of life known
as the fossil record
Fossils found earlier and deeper in the earth are
now extinct.
Whales do not have hind limbs but there are
bones inside their bodies which was common
among earlier ancestors. These remnants of
once-useful structures are known as vestigial
structures
Comparing Organisms
Along with looking at the fossil record, scientists look at different kinds of evidence that
support the theory of evolution:
A) Comparing Skeletal Structures
B) Comparing DNA
C) Comparing Embryonic Structures