And Click on Case Two
Part 1: Case Two
1. Watch the crime scene video and read the Case Two introduction on the first slide.
a. In Case One, you were looking for a match with an individual elephant. How does
Case Two differ from Case One?
2. Click on Building a Reference Map.
a. Watch the short video. Elephant populations differ from one another. These differences are due to geographic distance and the length of time since their ancestors separated from one another. Explain how this relationship affects their relatedness.
3. Click on Technique in the Building a Reference Map section.
a. How does this gel differ from the gels you studied in Case One?
4. Click on the Application section.
a. Study the gel. Why does the ivory sample contain only two bands while the other lanes (samples A and B) have multiple bands?
b. If an ivory sample has two alleles that are also found in a population sample, does that tell you with certainty that the ivory sample came from that population? Explain your answer.
5. Click on the Review Section.
a. If the scientist had collected 20 dung samples, would you expect more bands, fewer bands, or the same number of bands on the gel? Explain your answer.
6. Proceed to the Finding a Location section.
a. Forest elephants and savanna elephants diverged over 2.5 million years ago, so some researchers think they should be classified as different species. Knowing this information, which genetic profiles would you predict would be more similar to one another: those of a forest elephant and a savanna elephant that are geographically close to one another, or those of two forest elephants that live far apart from one another? Explain your reasoning.
b. On the Eliminating North, East, or South page, which population did you eliminate? Which marker(s) allowed you to make this choice?
c. On the next elimination, which population did you choose? Which marker(s) helped you make this choice?
d. By analyzing many more markers and all the populations, Dr. Wasser linked these seized ivory tusks to which country?
Part 2: Ivory Trade
1. Watch the video on the Stopping Illegal Poaching slide.
a. Name two reasons elephant populations are threatened.
b. In summary, elephants are a keystone species. Based on your knowledge from this lab (Case 1 and Case 2), explain in your own words why it is important to the ecology and ecosystems of Africa to save the elephant populations.
Adapted from: Click and Learn “CSI Wildlife” (2016). CSI Wildlife Explorer Worksheet. HHMI Biointeractive Teaching Materials.