The Sea Urchins and Me

Fri, 2013-01-04 02:23 am | By Amar Sarkar '12


The purple spines bristled as I lifted the sea urchin from its container. Water dripped down the curve of its body as I turned it over to examine the whitish underside. Nestled in the center was a tiny mouth that also functioned as an anus (sea urchins are much less complex than mammals). Remembering that the rest of the class was watching, I raised the syringe and pierced the sea urchin in the region surrounding its mouth, pumping it with hydrochloride. I turned it over. As Professor Sullivan had predicted, sea urchin eggs were bubbling up around the spines and dripping down its sides. I placed it upside down over a beaker of seawater, and thus we began collecting sea urchin eggs.

The exact same process is used to collect sea urchin sperm.

I haven’t explained very much, have I? My apologies. This is the Biology 150 lab: Introduction to Biological Inquiry. For those of you are considering biology as a major, you will begin with this course. There are four or five sections of the class offered every semester, each with a distinct theme, and not all of them involve sea urchins. Our section focused on cell differentiation, while other sections studied climate change or bacteria or neurons. Though each section has a distinct theme, all of them aim to prepare us for more advanced work in biology by letting us prepare our own research projects in an area within our theme.

I am not a biology major, but when reading the course descriptions for that semester, the opportunity seemed too good to miss. Nor was I disappointed. It was less than three weeks before we were introduced to our sea urchin friends, which we used to study how cells differentiate. It’s a fascinating question: how does a cell in an embryo know it’s to become a neuron or a cardiac muscle cell? How do the eyes form in the head, and how do some cells know they have to become eyes while others know they will become the head itself? These were the questions we tried to answer as we progressed through the semester.

The second half of the course was devoted largely to a research project. We were free to decide the topic, find the relevant research articles, and combine the methods and results from those articles to create and carry out our own experiments.

If there was one thing Biology 150 was, it was a hands-on. The entire class ran on students’ curiosity and the questions we asked. In fact, Professor Sullivan structured his lectures specifically around questions we wrote down and handed in before class.

I must admit there were times when I felt frustrated. Focusing a microscope, using a micropipette, and making a footed coverslip were things I had trouble learning. But those difficulties seem petty when you see in front of you with your own two eyes the sperm and egg of two sea urchins meet and an embryo emerge, an embryo that will, in its own time, become a sea urchin. When you see life unfolding in front of you, it becomes difficult to complain about technicalities.

As I said, I am not a biology major. I am a mathematics major. But now I am a math major who can type out a laboratory report and conduct my own research. Most important, I am a math major who has seen, with his own eyes, the point at which life begins.

Amar Sarkar '12 is a Mathmatics and Statistics major and Neuroscience concentrator from Gurgaon, India.