Download Chapter 5: Expert Questions What are the five pieces of evidence for

Chapter 5: Expert Questions
1. What are the five pieces of evidence for evolution? Describe how each one proves
evolution.
a. Fossils - Fossil record shows how some species have changed over time.
b. Homologous Structures - Body parts are similar in related animals so there must
be a common ancestor.
c. Vestigial Structures - There are structures present in modern day organisms but
are not even used, so they may have been used by a common ancestor.
d. Molecular Biology - Similar species of organisms have more common DNA than do
organisms that are more different!
e. Fetal Similarities - The unborn offspring of many species resemble each other,
suggesting a common ancestor.
2. Who is Charles Darwin? Describe why he traveled to the Galapagos Islands?
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Charles Darwin is a scientist who developed “The Theory of Natural Selection”. He
went to the Galapagos Islands to study and collect thousands of plants and animal
samples and kept detailed notes of his observations. He learned how they were
successful in their environment.
3. List and explain the 4 steps of natural selection.
a. Overproduction - Organisms have more offspring than can possibly survive.
b. Inherited Variation - Variations are caused by mutations which are random
changes in our DNA that cause changes in an organisms characteristics. Some of
these changes are bad, some are neutral, & some are good.
c. Struggle to Survive (Competition) - A natural environment does not have enough
resources to keep all offspring alive. Offspring have to compete for the following:
food, water, shelter, mates, land, etc. Some variations give them an advantage and
makes them more likely to survive which is called an adaptation
d. Successful Reproduction- Individuals who survive are more likely to successfully
reproduce and pass on the variations that made them more successful.
4. Using the four steps of natural selection, describe how sharks have sharp teeth.
a. Overproduction – lots of baby sharks are born.
b. Variation - Some sharks have sharp teeth, and some sharks have dull.
c. Competition - The sharks with dull teeth can’t attack pray and eat as well as
sharks with sharp teeth and will die.
d. Successful Reproduction - The sharks with sharp teeth will survive, reproduce,
and pass their sharp teeth on to their offspring.
5. What is speciation?
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The formation of a new species as a result of natural selection
6. Describe the three steps of speciation.
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Separation - portion of the population becomes isolated.
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Adaptation- the part of the population that got separated has a different
environment to adapt to.
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Division- over hundreds to thousands of generations, the 2 groups became so
different that they are no longer the same species and can no longer interbreed.
7. What are 4 things that could cause speciation to occur?
 Canyon Forms
 Mountain Range
 Volcano
 Tsunami
8. What are 4 things that species could compete over?
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Food

Water

Shelter

Mates

Land
9. Lizards originated from a habitat where they eat 50% bugs and 50% plants.

Describe what would happen to lizards that were moved to a new habitat where
they could only eat bugs. How would these new conditions affect the species?
They
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may develop the following:
New digestive system
Smaller heads with quick reflexes
Softer bite
Long and skinny tongue
Darwin’s Theory of Natural Selection would come into play.
•
Overproduction – lots of baby lizards are born.
•
Inherited Variation – Some inherit the traits above & some don’t
•
Competition - Lizards that do not inherit the traits above will die.
•
Successful Reproduction - The lizards with the traits above will survive,
reproduce, and pass their sharp teeth on to their offspring.

Describe what would happen to lizards that were moved to a new habitat where
they could only eat plants. How would these new conditions affect the species?
They may develop the following:
•
New digestive system
•
Larger heads
•
Harder bite
•
Short and thick tongue
Darwin’s Theory of Natural Selection would come into play.
•
Overproduction – lots of baby lizards are born.
•
Inherited Variation – Some inherit the traits above & some don’t
•
Competition - Lizards that do not inherit the traits above will die.
•
Successful Reproduction - The lizards with the traits above will survive,
reproduce, and pass their sharp teeth on to their offspring.