Page 1“Crazy About Cryptids!” by Matthew P. Rowe

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Part I – Introduction Victoria adored her older brother Travis. She had good reason: their father had died when they were kids, leaving them and their younger twin sisters to be raised by their mother and grandmother. Growing up was tough; their mother’s salary as a social worker was meager, and their grandmother suff ered from a chronic medical condition that took much of the family’s income. As the oldest, Travis started working early to help support the family, a sacrifi ce not lost on Victoria and her sisters. Victoria so respected her brother that she couldn’t help comparing her high school and now her college suitors to Travis, and the admirers always fell short. Travis was kind, courageous, generous to a fault, and oh so smart—he even, while helping raise his siblings, put himself through law school and was now working as a public defender in Chicago. But he had a weakness that worried Victoria. Outside of the courtroom, Travis was gullible. He had a fondness for all things extraordinary—from ghosts to alien abductions to new-age therapies. His true passion, however, was cryptids. He was simply crazy about cryptids.

Victoria was majoring in Integrative Biology at Michigan State. Her training, including courses in ecology, wildlife biology, and the philosophy of science, made her appropriately skeptical of chupacabras, yetis, bigfoot, the Loch Ness monster, and other storied beasts. Th e fact that her brother, a lawyer whose career depended on the critical examination of evidence, could be so credulous was unsettling to her. While sensitive to his feelings, she hoped she could use her growing understanding of science in general, and ecology in particular, to empower her brother. A “just touching base” phone call from Travis presented Victoria with an opportunity.

“Hi sis, how are classes?” Travis asked supportively when Victoria picked up the phone.

“Great,” she replied, “in my wildlife techniques course, we’re studying all the cool things you can learn about an animal just by analyzing a tiny drop of its feces, or a hair or two snagged on a scratching post. It’s pretty amazing.”

“Yeah,” Travis replied with unrestrained enthusiasm, “did you hear about the recent study of hair samples collected from a bunch of diff erent sites in the U.S. and Canada that proved the existence of bigfoot, and showed they were interbreeding with humans?”

Victoria, remembering one of the principles she learned in her philosophy course, responded: “Travis, science isn’t about ‘proving’ an idea or explanation, it’s about marshaling all of the evidence you can to determine which of various competing explanations is best supported.” She continued, “I don’t mean to sound scientifi cally snobbish or anything, but the study you mention by Melba Ketchum and her coauthors lacks credibility. A team led by Bryan Sykes published a more rigorous analysis of hair sent in by bigfoot and yeti enthusiasts from around the world; the results showed that the hair belonged to bears and raccoons and other mammals one would expect to be wandering around in the woods, not to bigfoot or a bigfoot-human hybrid.”

by Matthew P. Rowe Department of Integrative Biology Michigan State University, East Lansing, MI

Crazy About Cryptids! An Ecological Hunt for Nessie and Other Legendary Creatures

NATIONAL CENTER FOR CASE STUDY TEACHING IN SCIENCE

Page 2“Crazy About Cryptids!” by Matthew P. Rowe

“You’re breaking my heart here kiddo, you know I’m a true believer in Sasquatch,” Travis replied with feigned sadness. “Besides, isn’t it possible that a species of giant man-ape unknown to science exists somewhere on the planet?”

“Sure,” Victoria chimed encouragingly, “species unknown to science are occasionally discovered, like the mega-mouth shark or the saola. And creatures that scientists thought went extinct millions of years ago like the coelacanth are rediscovered. So I’m not saying that bigfoot doesn’t exist, only that the evidence presented so far is insuffi cient for me to accept that it does.”

After a short pause, Travis responded thoughtfully, “Ok, little sister, I think I see where you are coming from; in a jury trial, which is something I know about, the guilt or innocence of a suspect is determined by the preponderance of the evidence. Th e jury has to determine whether the accused is guilty beyond a reasonable doubt, not beyond any shadow of a doubt. Absolute certainty is unlikely. What matters is that the jurists, before reaching a verdict, carefully examine each of the explanations and all of the evidence off ered by both the prosecution and the defense. I guess it’s the same thing in science.”

Sensing an opening, Victoria slyly suggested, “Didn’t you say you wanted to see a Spartan football game? Well, homecoming is in two weeks; why don’t you come for a visit. We can catch the game, and then afterwards we’ll go hunting for the Loch Ness Monster.”

Nessie was Travis’s favorite cryptid, so his sister’s off er aroused his curiosity. “How can we go hunting for a population of aquatic monsters in Scotland from your apartment in the middle of Michigan?” Travis asked inquisitively.

“We’ll track her down using the science of ecology,” Victoria answered.

Questions 1. Two articles were mentioned in the story. Th e fi rst, titled “Novel North American Hominins, Next Generation

Sequencing of Th ree Whole Genomes and Associated Studies” by lead author Melba Ketchum and her co- authors, was published in the journal DeNovo. Th e second, titled “Genetic Analysis of Hair Samples Attributed To Yeti, Bigfoot, and Other Anomalous Primates” by Bryan Sykes and his team, was published in the journal Proceedings of the Royal Society B: Biological Sciences. Th e two reports apply similar techniques using similarly obtained samples but reach diff erent conclusions. Summarize the main conclusions of each.

2. Credibility is an important concept both in science and in courts-of-law. Which of the two publications is more credible, and why?

3. Occam’s Razor, also known as the Principle of Parsimony, can be useful when trying to determine which explanation, among two or more, is most likely to be correct. What is the Principle of Parsimony? Apply the principle to the diff erent explanations off ered by Ketchum’s team and Syke’s team. Which of the competing explanations best passes the razor test, and why?

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THE EUKARYOTIC CELL CYCLE AND CANCER: AN OVERVIEW

ABOUT THIS WORKSHEET This worksheet complements the Click and Learn “The Eukaryotic Cell Cycle and Cancer” and is intended as a straightforward introduction to the cell cycle and how that relates to cancer. For a more comprehensive student worksheet, please see the in depth version.

PROCEDURE Read through the Click and Learn at (http://www.hhmi.org/biointeractive/eukaryotic-cell-cycle-and- cancer) to learn about the cell cycle. Answer the questions below. Click on the “Background” tab on the right side. Read the information and watch the videos. 1. Why is cell division important for both unicellular and multicellular organisms?

2. Why does cell division remain important to an adult organism even after it is fully developed?

3. Cells divide, differentiate, or die. What is differentiation?

4. What is apoptosis? What is its purpose?

5. What are cell cycle regulators?

6. What happens if cell cycle regulators don’t function properly?

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Click on the purple section labeled “Cell Cycle Phases” as well as the words “Mitosis” and “Interphase” to read an overview of the cell cycle. You can also click on the various phases. 7. Cells go through periods of growth and division. Cell division occurs during _______________.

8. The rest of the cell cycle is called interphase, during which _____________________________

_____________________________________________________________________________.

9. Fill in the details about what happens during the three phases of interphase labeled in the

diagram.

10. In general, what is the purpose of a checkpoint in the cell cycle?

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11. What is the G0 phase of the cell cycle? Which factors determine whether a cell enters G0? Can cells leave G0?

Click on “Cell Cycle Regulators and Cancer” in the center purple circle. Read the Regulators Overview and then read through the Cancer Overview and watch the videos. 12. What are cell cycle regulators?

a. Stimulatory proteins are encoded by _________________________________. Examples include: ______________________________________________________

b. Inhibitory proteins are encoded by ___________________________________________. Examples include: ______________________________________________________

13. Cancer is the result of an improperly regulated cell cycle. Describe two reasons why cells can form tumors.

14. In some types of colon cancer, stem cells have a mutation in the APC gene. What happens if the APC gene is mutated?

15. Normally, proto-oncogenes stimulate the cell cycle. What are oncogenes and how do they affect the cell cycle?

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a. To cause cancer, proto-oncogenes require _________ allele(s) to be mutated and therefore are considered ____________________. The mutation results in a __________ of function.

16. Normally, tumor suppressor genes inhibit the cell cycle. How do mutated tumor suppressor genes affect the cell cycle?

a. To cause cancer, tumor suppressor genes require _________ allele(s) to be mutated and therefore are considered ____________________. The mutation results in a __________ of function.