Download Case Study 2: Gray Wolves Sub-Species

Student Materials ModelSim Evolution 2014v3.0- Center for Connected Learning at Northwestern University
Case Study 2: Gray Wolves Sub-Species
Canis lupus has 39 subspecies currently described, including two subspecies of domestic dog, Canis lupus dingo and Canis
lupus familiaris, and many subspecies of wild wolf throughout the Northern hemisphere
Domestic dogs show a great deal of trait variation between different breeds. Likewise, wolves show a great deal of trait
variation between sub-species, though they can interbreed. The Zoological Gardens of London for example once successfully
managed to mate a male European wolf to an Indian female wolf.
Wild gray wolves (Canis lupus) species historically ranged over most of the Northwern Hemisphere. There historical range is
shown in the map below. Green represents their present range, and red represents where they have been extirpated from (no
longer exist in that region).
Image credit: http://commons.wikimedia.org/wiki/File:Gray_Wolf_Range.png
This reduced range is believed to be largely due to human impacts such as hunting, urbanization, ecosystem fragmentation,
and intentional eradication of native wolf populations in the past. Other factors that may have led to the reduced range of
wolves inlcude polluation, climate change, and extripation of native prey species.
1 Case Study #2 – Activity Sheet Student Materials ModelSim Evolution 2014v3.0- Center for Connected Learning at Northwestern University
Populations of wolves are not all identical. Scientists have classified different populatons of wolves by the physical traits,
behavioral traits, their DNA, and where they are found in the wild. They classify these populations as sub-species1. A subspecies is kind of similar to a “breed” for domestic dog. But unlike domestic dogs, these sub-species were not selectively bred
by humans to have different traits. The following map shows the historic range of some of these sub-species.
Image credit: http://upload.wikimedia.org/wikipedia/commons/c/cd/Original_distribution_of_wolf_subspecies.GIF
1 The most recent comprehensive review (in October 2012) of the genetics studies concluded that the red wolf, eastern wolf, and gray wolf should be re-classified as three distinct species,
instead of as sub-species of Canis lupus.. This reclassification helps support conservation efforts for this animals. As, individuals of all these populations can interbreed, we will consider
them sub-species of gray wolf for the purposes of this activity. 2 Case Study #2 – Activity Sheet Student Materials ModelSim Evolution 2014v3.0- Center for Connected Learning at Northwestern University
Though these sub-species were not selectively bred by humans to have different traits, scientists use differences in traits as
one way to tell these these groups of wolves apart.
Predict
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Will there be a relationship between the typical size of a wolf sub-species and the environments in which they live?
Will there be a relationship between the fur coloration found in a wolf sub-species and the environments in which they live?
Will there be a relationship between the fur length in wolf sub-species and the environments in which they live?
Will there be a relationship between the preferred pack size in a wolf sub-species and the environments in which they live?
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Explain your predictions:_________________________________________________________________________________________
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Procedure
1. Your teacher will assign you to a research team. Which trait are you researching?__________________________
2. Each member should use analyze the attached data packet. Study the data for your assigned trait and the related
enviornments for each sub-species of wolf. You may highlight and annotate the data packet. Each member should help
summarize the findings in this table:
Question to
Investigate
Is there a relationship between the trait you were assigned and the environments in which wolves with certain
variations of this trait live?
Discoveries
your group
made
3 Case Study #2 – Activity Sheet Student Materials ModelSim Evolution 2014v3.0- Center for Connected Learning at Northwestern University
3. The group should create/add an additional new key for the map below to represent showdifferent variations of their trait and
then use this key to annotte the map, showing where these variations are found. This is a map model the group will present
to class to support their claims.
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Skeletal structure (based on length & height: Your group map should show where (a) smaller vs. (b) larger wolf sub-species are found.
Fur color: Your group map should show where (a) whitish, (b) tan/yellowish, and c) darker furred sub-species of wolves are found.
Fur length: Your group map should show where (a) shorter vs. (b) longer haired wolf sub-species are found.
Preferred pack size: Your group map should show where (a) smallest vs. (b) largest pack sizes are found.
Image credit: http://upload.wikimedia.org/wikipedia/commons/c/cd/Original_distribution_of_wolf_subspecies.GIF
4 Case Study #2 – Activity Sheet Student Materials ModelSim Evolution 2014v3.0- Center for Connected Learning at Northwestern University
4. Before presenting, the group should make a claim based on their analysis of the data. For this trait, do the trait variations
between sub-species appear to be result of genetic drift or the result of natural selection? The group fill in the first row
below.
5. As each group presents, make sure to record the claim of the group, whether their map/model supports their claim, and the
reasons the additional reasoning the group provided to support their claim.
Trait this group
studied
Claim: Are the patterns
in trait variations due to
natural selection or due
to genetic drift?
Did their map
model
support this
claim?
What additional reasoning related to mechanisms of natural
selection or genetic drift did the group provide to support their
claim?
5 Case Study #2 – Activity Sheet