“Thus organisms and environments are both causes and effects

in a coevolutionary process.”

—Richard C. Lewontin in The Triple Helix: Gene, Organism, and Environment.

Wednesday, November 5, 2014

Checkered snail


Yesterday, I was helping a fellow graduate student replace the recruitment collectors she had drilled to the rocks just outside the marine lab. The purpose of these is to collect the very tiny mussel larvae that would be settling on the rock to begin their development into adults. The collectors are small dish sponges called tuffys, about six inches in diameter, and we replaced five of them just below the mussel beds she is studying. 

A tuffy dish scrubber. Image from Google images.


Changing the tuffys wasn't the cool part, though (okay, it was kinda cool, but not the subject of this post). After we were done, we explored the local intertidal area a bit, trying to identify all the species present. I am still so overwhelmed by the diversity of organisms in this habitat. I had an eye out for whelks, of course, and we found a few with some nice stripes, as they usually have. After looking a bit closer, though, we found a snail with the coolest design I have ever seen! Instead of stripes, it had checkers! 




According to the PISCO* intertidal experts, this snail is Littorina scutulata. Now, I will always be on the lookout for snails with checkers!

*Partnership for the Interdisciplinary Studies of Coastal Oceans. www.piscoweb.org



Monday, November 3, 2014

Comprehensive Exam

As a graduate student in Ecology and Evolutionary Biology at UC Santa Cruz, when I take a class, I never have to take a test. There are no midterms or final exams. We don't even get graded. It's a self-motivated student's dream! Instead of learning in order to receive a good grade, we learn them to increase our personal knowledge and improve our own research.

We also learn in order to pass the most important exam we'll ever take. It is quite literally a final exam; there are no more exams after the Comprehensive Exam.


This upper room is where I took my Comprehensive Exam orals on Tuesday, October 28 at noon.

Preparing and taking the Comprehensive Exam happens in four main parts:

(1) Forming the committee of professors who will deliver the exam. In Ecology and Evolutionary Biology, this includes one ecologist, one evolutionary biologist, one study system specialist, and one scientist whose specialty you get to choose. These members assign you books and papers to read for the exam.

(2) Reading and studying the material assigned by the committee. This takes anywhere from two to four months and is extremely time consuming.

(3) Taking the written portion of the exam. You have four days to answer the questions the committee members ask of you. Answer one set per day.

(4) Being orally examined. This is distinct from dental care, because instead of opening up for someone to poke around inside your mouth, your committee members poke around in your head, trying to figure out the breadth and depth of your knowledge. Also unlike the dentist, this lasts about 2.5 hours, eating junk food is encouraged, and there is no relaxing fish tank. After the first hour of questioning, there is a ten minute break in in which the committee members deliberate in your absence. After twiddling your thumbs outside the room, you are allowed to reenter and continue to be drilled on things you've studied and things you may know nothing about, like banana slugs or corn refuges. After another hour, you leave, and they decide if you pass. When you reenter the room the second time, you are either greeted with furrowed brows or congratulations.

Can you guess with which I was greeted?! :D

In case you can't, I'll tell you: I passed unconditionally, meaning I proved to my committee I understood as much as any Ph.D. student should about ecology, evolution, my study system (intertidal), and behavioral ecology. It is an enormous relief to be done; now I can focus on applying for grants and getting collection permits so I can start my own experiments!

Here are some memorable questions I was asked:

Are banana slugs hermaphrodites? (Yes.)

What does this picture mean in the context of evolution in metapopulations?

(Plant a refuge crop of corn that is not genetically modified to have insect resistance, otherwise the insects will quickly evolve resistance to the modified corn.)

What else eats sea urchins? (California sheephead!)