The Very Hungry Hornworms

This week, intro bio lab students geared up for their Manduca sexta dissection. These tobacco hornworms had grown significantly since students placed them in their plastic “bachelor pad” cages last week. While all hornworms at least doubled in size, the largest of the group were almost 100 times their weight from last week. Thank goodness that’s pretty impossible for humans to do or Kenyon would need to invest in a better health plan now that Marco’s Pizza accepts K-Cards.

Hornworm fact #1: Time to expand your insult dictionary – the genus Manduca literally means glutton. Try that one at Thanksgiving.

Hornworm fact #2: After a good chomp on a tobacco leaf, Manduca have “toxic halitosis” aka poisonous bad breath from the nicotine which deters spiders from eating them.

Hornworm fact #3: Adult Manduca hawkmoths can eavesdrop on the sonar clicks of bats and drop out of the air to avoid being bat food.

If you know the story of The Very Hungry Caterpillar by Eric Carle, the life of a Manduca is quite similar. Rather than eating sausages and ice cream turning into a beautiful butterfly, though, Manduca hornworms eat the leaves of tobacco, tomatoes and other members of the nightshade family (Solanaceae), then metamorphose into a hawkmoth that can hover like a hummingbird. Reared in the lab, however, the Manduca is a beloved model organism with ease of care, rapid growth rate, and accessible anatomy.

This year, the bio lab sections are testing the effect of diet nutrition on overall growth of the organism. Some Manduca will have less nutrition per bite in their food for 48 hours, perhaps affecting how much they eat, absorb nutrients, or grow in a 48 hour period. After this diet change, students hit the microscopes to investigate.

Whether they named their Manduca after their TA (shoutout to Jeremy Moore ’19), took beautiful anatomical pictures under the microscope (see above), or made a video in their hornworm’s honor like Patrick Olmstead ’21 (below), students found a way to connect with their lab-reared pe(s)ts.

Intro biology lab students share snapshots from their independent research projects

As the culmination of the year-long introductory biology lab course, all students undertake a large independent research project to apply the skills they’ve learned through a wide array of lab exercises, and begin to specialize in their own interests within the broad field of biology. Whereas in the past students worked with their laboratory section instructors on their projects, this year, the course allowed students to select faculty mentors outside of their lab section so they could receive more specialized help in their particular field of interest.

“We aren’t all Renaissance people,” said Dr. Jennifer McMahon, lead instructor and director of introductory labs. In past years, faculty had a difficult time assisting students on projects that fell outside their areas of expertise, so allowing students to pick their own mentors alleviates some of the pressure on the faculty, and lets students find subjects they are truly passionate about. Additionally, the close partnership between students and faculty mentors who share their interests can turn short, 6 week projects into multi-year research endeavors.

“The recruitment component of this new approach is very important,” notes department chair, Dr. Drew Kerkhoff. “We want to help students identify potential faculty mentors as early as possible. Hopefully, the changes will break down the barrier for students who otherwise might hesitate to approach one of their professors about research opportunities. It also helps faculty identify talented young students who share their research interests.”

Student research proposals must be approved by both their lab instructor and their faculty member. At the end of the semester, after designing and conducting their research, the students write scientific papers on their project and present their work to their lab mates and instructors, joining a long line of young researchers stretching back 25 years. You can even read papers from past years via Digital Kenyon. And each year, the latest papers are added to the collection, giving students their first taste of scientific publication.

Check out a sample of our students’ diverse and exciting projects!

Ecology Students Model the Effects of Climate Change on Local Wildlife

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Professor Kerkhoff and his students mill around before the poster session begins in the Fischman 2nd floor poster gallery on Friday, November 18th.

Associate Professor of biology Andrew Kerkhoff’s ecology lab course is attempting to put a local face on a global problem with a new project modeling the potential responses of different Ohio wildlife to climate change.

As they gather for the culmination of their project: a public poster session for faculty and students, Professor Kerkhoff reminds his class of the importance of their work: “So often, climate change is viewed as this unmitigated disaster, and it just gets depressing and oftentimes paralyzing because it feels too big to really do something about it. But by making predictions about how climate change can affect specific organisms, it not only raises awareness, but it presents specific targets for conservation efforts.”

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Time Traveling in Ohio: Paleobiology in the Field

At 6 AM on a chilly November Saturday, Professor Eric Holdener’s Paleobiology class gathers in Peirce Dining Hall to grab a quick breakfast before hitting the road for our fossil collecting field trip. The entire class fits comfortably in one Kenyon van: me in the front, Sean Deryck ’18 and Jessie Griffith ’19 in the middle and Sarah Dendy ’19 and Nontokozo Mdluli 18′ in the back. Once we get about 5 miles out of campus, everyone in the back is dozing, and Professor Holdener and I listen to NPR and discuss the geology of the landscapes we pass. We stop once along the way to pick up some fossil fuel for the van, laughing as we acknowledge the irony.

It’s safe to say that Professor Holdener’s Biology 253: Paleobiology, fills a specific niche in the biology department. For some of us proud paleobiology students, we’ve been searching for trilobites and Australopithecine remains in our backyards for years, and for others it’s a convenient way to fill their environmental distribution requirement within the molecular biology major. But the field of paleobiology is truly a mosaic of the natural sciences, combining chemistry and geology with physiology, ecology, and evolution; there’s something for everyone’s curiosity. The course is advertised as a lecture, but Professor Holdener wants us to apply our knowledge to concrete examples and a lot of our class time is spent in the geology lab, analyzing and identifying specimens from his extensive personal collections. We are interested not only in what organisms are in the rock but how they were preserved and how they lived, using the scant fossil evidence and paleobiology publications as our guides, particularly the official Ohio fossils manual.

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Professor Holdener searches for fossils at Oakes Quarry, once a Silurian reef bed.

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