EVOLUTION:. Descent with modification. Age of the Earth. Scientists estimate Earth to be 4.6 billion years old Does not look today as it once did, nor do the organisms on it. Change over time. Earth is very old! Has changed a great deal. Different atmosphere Different temp.
billion years old
nor do the organisms on it
How is this behavior an adaptation?
C "Struggle for Existence"
and passing on the trait”
C Giraffes with longer
necks get better food,
have more babies
(have an advantage in
the struggle for existence)
C Longer necks make more
(so that trait gets inherited)
**New species can form
**Extinctions may occur, which allow others to take over
when adaptations fail
to keep up with
changes to the
Okapi (relative of the giraffe)
3. Vestigial Structures
think that the
be a vestigial
4. Comparing DNA from different species
5. Embryonic Structures
1. What is evolution?
2. Organisms are considered members of the same species if….
3. What are the 3 steps to speciation (the forming of a new species)
4. What are 5 examples of evidence in support of the Theory of Evolution?
Which groups of animals are still alive today?
How can you tell?
Why do the lines get wider or thinner?
What does the branching tree diagram tell us about snakes and lizards?