Download Evidence of Variation

EVIDENCE OF VARIATION, ADAPTATION AND EVOLUTION
AT THE ZOO/AQUARIUM
In this exercise you will visit the zoo/aquarium and observe one species. You will then
answer a number of questions based on your observations. You may find it helpful to
bring a clipboard and scratch paper to take your observations. This is partly an exercise
in observation skills. To receive credit for this assignment you must staple your ticket
stub to the assignment. The assignment will be graded looking for thoroughness of your
answers. The points given for this assignment aren’t just given to you for going. This
exercise is based on one by William McComas printed in Investigating Evolutionary
Biology in the Laboratory by William McComas (Lancaster Press, Lancaster, PA, 1994).
Part I – Variation Within a Species
In biology, genetic variation occurs and can cause phenotypic differences in
species. In this part of this assignment, you will observe variation within a non-human
species.
1. Choose one species in the zoo/aquarium of interest to you. There must be at
least three individuals of this species in the zoo’s/aquarium’s collection. More
would be better, so long as you are able to distinguish individuals. Write the
name of your choice below:
Common name _________________
Scientific Name ______________________
2. Study the animals of this species. List at least 6 physical characteristics which
vary between individuals. (e.g. Hair length – two have long, one has medium
length, and one has short hair). A thorough job on this question will make the rest
of the assignment easier.
Part II – Adaptation to the Environment
In this exercise you will attempt to determine what characteristics of your species
make it able to survive in its particular environment.
1. Describe the environment of your animal. Be specific. You may need to do a
little outside research, but don’t get carried away. Be sure to reference any
material used which is not your own!!!
2. List characteristics you believe help this organism survive and breed in its
environment. Be sure to indicate how you think this characteristic helps (e.g.
“because grizzly bears live as far north as Canada and Alaska, they benefit from
their thick fur coat in winter months”).
3. List characteristics you believe will make it difficult for this organism to survive
and breed in its environment. Be sure to indicate how you think this characteristic
makes it difficult (e.g. “the great size of a grizzly bear requires it to eat enormous
amounts of food, much more than a smaller animal would”).
4. Were there any characteristics that appear as both advantages and disadvantages?
What do you think is the result of natural selection on this trait? (e.g. Bigger
animals are safer from predators, but need more food, so medium sized may be
best for some animals”).
5. What has the zoo/aquarium done to enhance the conditions for the animals you
have chosen? What could be done to improve the exhibit? (e.g. Grizzly bears live
in mountainous areas and the zoo has built a small mountain area for the bear but
Grizzlies usually travel distances and the exhibit is fairly small”).
Part III – Future Evolution
In this exercise you will try to predict how natural selection would affect your
species in the future if your animal were forced to live in a new environment. If your
animal lives in a changing environment (perhaps due to the prescience of humans)
you may describe this new environment. If not, you may pick any new environment
for your species. (e.g. you could move a desert animal to the jungle, or a swamp
animal to the desert, etc.)
1. Name and describe the new environment in which your species will have to try to
survive in.
2. Choose three characteristics of your species that will have to change for the
species to survive in its new environment. Describe the new characteristics that
will be favored..
Present
Characteristic
1.
2.
3.
Future
Characteristic
Reason for change
3. If the environment change is gradual, do you think your species could survive?
To answer, think about the normal variation you observed in Part I and Part II.
Does your population have any variation in the characteristics needed to survive?
Why or why not?
4. Now consider what would happen if the environmental change were sudden. Do
you think your species could survive? Are any individuals that could survive the
new environment with their present characteristics? Why or why not?
Part IVA – Convergent Evolution
1.
Choose an animal from the same environment as yours, with similar
characteristics, but different ancestry (e.g. a bird and a mammal, or a lizard and
a crab). Write the name of your choice below:
Common name ________________ Scientific Name ______________________
2.
List 6 characteristics this species has in common with your species.
Part IVA – Divergent Evolution
1. Choose an animal you believe to be closely related to yours (e.g. zebra and
horses, lions and tigers). If possible, choose one from a different environment.
Write the name of your choice below:
Common name ________________ Scientific Name ______________________
2. List four reasons for believing these species are related (similar characteristics).
3. List four differences from your species.