2. Biodiversity, Ancestry, & Rate of Evolution (15.3)
State Standard
SB5B. Explain the history of life in terms of biodiversity, ancestry, and the rates of evolution.

3. Speciation is the formation of a new species.
Chapter 15
Evolution
15.3 Natural Selection-Speciation-Resistance
Speciation
Speciation is the formation of a new species.
For speciation to occur a population must diverge and then be reproductively isolated.

4. Can occur in a relatively short time when one species gives rise to
Chapter 15
Evolution
15.3 Natural Selection-Speciation-Resistance
Adaptive Radiation – AKA Divergent Evolution/Speciation
Can occur in a relatively short time when one species
gives rise to
many different
species in
response to the
creation of new
habitat or some
other ecological
opportunity

5. Chapter 15
Evolution
15.3 Natural Selection-Speciation-Resistance
Convergent Evolution
Unrelated species evolve similar traits because of similar environmental pressures.

6. Associated with mutualism
Chapter 15
Evolution
15.3 Natural Selection-Speciation-Resistance
Coevolution
The relationship between two species might be so close that the evolution of one species affects the evolution of the other species.
Associated with mutualism

7. Chapter 15
Evolution
15.3 Natural Selection-Speciation-Resistance
Rate of Speciation
Evolution proceeds in small, gradual steps according to a theory called gradualism.
Punctuated equilibrium explains rapid spurts of genetic change causing species to diverge quickly.

8. Chapter 15
Evolution
15.3 Natural Selection-Speciation-Resistance

9. directional evolution divergent evolution
Chapter 15
Evolution
15.3 Formative Questions
Which evolutionary pattern is represented by the similarities between these two organisms that live on separate continents?
coevolution
convergent evolution
directional evolution
divergent evolution A B C D
FQ 14

10. The divergent evolution of these cichlid fish is
Chapter 15
Evolution
Chapter Assessment Questions
The divergent evolution of these cichlid fish is
an example of what type of speciation?
coevolution
mutation
adaptive radiation
convergent evolution A B C D
CAQ 2

11. What tempo of evolution does this model represent?
Chapter 15
Evolution
Chapter Assessment Questions
What tempo of evolution does this model represent?
gradual
elevated
sequential
punctuated A B C D
CAQ 3