Natural Selection Study Guide
1. List and describe out the 4 principles of natural selection
2. Describe what happens to a population over time as natural selection occurs.
3. Define adaptation and then describe how a population gets an adaptation.
4. What determines which adaptation a species will need and develop?
5. Snowy owls are beautiful white owls that live in the arctic. They are able to withstand the frigid temps of the
arctic. They usually migrate south to southern Canada during the middle of the arctic winter, but soon return far
north. Explain how the population would respond in the following scenarios:
a. The snowy owls usually return to the north after migrating, but a group of then do not return and stay
farther south. They end up isolated from the others for several years in an area that has more forests
throughout the year.
b. The snowy owls environment is warming up very quickly and going from very frigid temperatures to very
warm. This change is happening so quickly that the snowy owls are too visible to their prey since there is
less snow. They have started having a hard time finding food and many are starving. The warmth has
also messed up their migration/breeding patterns.
c. The snowy owls environment has been warming slowly over the last 70 years. The forests do not stay as
snow covered throughout the year. The owls have a harder not being seen by prey for a few months out
of the year. There is a mutation that allows the owls feathers to change to brown during the warmer
months.
Light
Phenotypes:
Dark
During the industrial revolution, pollution was distributed throughout industrial
areas causing the trees to get darker.
1. ______________________ – populations have differences. What is the variation
in the peppered moth population? ___________________
2. Some variations are ________________________. After the Industrial Revolution,
which phenotype is most favorable? __________________
3. ________________________– More offspring are produced than survive. After
the Industrial Revolution, which phenotype survived at a greater rate?
_______________________
4. _____________________– those that survive are the ones with the favorable
traits and they pass down those traits.
5________– the population will change over time as a result of passing inheritable
traits from adaptations. In time, most of the moth population were of the
_____________ variation.
This diagram demonstrates the process of ________________. It demonstrates that
changes in the variation of a population can change the traits of a population. Before
the introduction of the predator, each color occurred in equal numbers in the
population. After the introduction of the predator the __ ____________ variation is
most common. This is because they were able to survive and
______________________ at a greater rate.
Another line of evidence cited in the theory of evolution is represented by this
diagram. It is an example of ___________________ structures, body parts that are
reduced in size and unused in present day organisms.
Suggests that as body part was no longer needed in environment they were lost
List another example:
The diagram below shows __________ structures, which may not have the same
use, but do have a common evolutionary origin, and thus structure. These
similarities in body parts suggest a ____________ ancestor.
The diagram below shows ___________________________structures, which may
have the same use, but do not have a common evolutionary origin. These
similarities in body parts suggest a similar ______________________ that was
needed to survive in their environments.
A population of insects is sprayed with a new insecticide. Most of the insects are
killed but a few survive. In the next generation, many more of the insects are
unaffected by the insecticide. Which of the following BEST explains these results?
a. The insecticide caused a mutation in the species.
b. A few insects in the first population were immune and passed this
trait to their offspring.
c. The insecticide caused a side effect of immunity that was passed
on to the next generation of insects.
d. The insects learned to fight off the insecticide.
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