Use information on
pages 424-426 and
pages 433 & 436 to
complete the
worksheet
Fossils
Provide a record of species
that lived long ago, and they
supply some of the most
significant evidence of
evolutionary change.
Use information on Page 424 to fill in
the chart comparing types of traits
Type of Trait
Derived
Trait
Ancestral
Traits
Definition
Example
Use information on Page 424 to fill in
the chart comparing types of traits
Type of Trait
Definition
Example
Derived
Trait
Newly evolved features
Feathers in early bird fossils
More primitive features
Teeth and tails in early bird
fossil, in common with
ancestors
Ancestral
Traits
Use information on Page 424-426 to fill in
the chart comparing types of structures
Homologous
Structures
Define
Example
and
Drawing
Analogous
Structures
Vestigial
Structures
Homologous Structures
 Anatomically similar structures inherited from a
common ancestor
Analogous Structures
 Structure used for the same purpose but not from
same ancestor and not similar in anatomy
Vestigial Structures
 Structures that are no longer functional and are
reduced in size
The fossil record, comparative
anatomy, comparative
embryology, comparative
biochemistry, and geographic
distribution all provide
evidence and support for the
Theory of
Genetic drift
Any change in the
allelic frequencies in
a population that
results from chance
Use information on Page 433 to fill in the
chart comparing types of genetic drift
Explanation
Founder
effect
Bottleneck
Example
Use information on Page 433 to fill in the
chart comparing types of genetic drift
Explanation
Example
Amish community
Founder
effect
Occurs when a small
population settles in a location
separate from the rest of the
population
Bottleneck
Occurs when the population
declines to a very low number
and then rebounds, reduces
genetic diversity
Cheetah population
Reduced and rebound
So genetically similar
appear inbred
Sexual Selection
Type of natural selection based
on the ability to attract a mate
Operates in populations where
sexual dimorphism is present
Sexual Dimorphism
Phenotypic difference
between males and females
within a species
May differ in size, coloration,
ornamentation, and behavior
Give examples of sexual dimorphism
with in a species that would have arose
by the process of sexual selection