Instruction from Invertebrates

Aeginura_grimaldii_by_HaeckelThe scent of brine wafts all around. A chill breeze blows in from the west. I am seated on a bluff above a small cove ringed by a sandy beach. After midnight, the solitude nearly palpable, the sound of the surging Pacific Ocean is like the sound of breathing as each wave rolls in, breaks with a low rumble, then recedes. Holding a clipboard, I gaze toward the dark horizon. Every fifteen minutes I refocus on my work and record the positions of shrimp-like ‘beach hoppers‘ as they move around the circular enclosure I built with high mesh walls to keep the animals from jumping out (though I have since learned that they seldom jump when undisturbed: they crawl around a bit, but mostly they settle down and do nothing).

Prior observers have noted that beach hoppers move down the beach during the night, then up again at dawn. What remains unknown are the sensory cues by which they find their way. My experiment is meant to determine whether they orient according to slope. I have set the platform at a fifteen degree angle, and on successive nights I vary the direction of slope to rule out the possibility of the critters using other signals, such as sight, odor, sound, or moonlight, to direct their movements.

Most of the night I sit in reverie Since recording the positions takes only a few minutes, much of every quarter hour is spent waiting. I grow calm and receptive. Nature permeates my soul. It occurs to me, with growing conviction, that this is how I want to spend my life: outdoors, studying biology in the field. Seldom have I felt so sure of anything.

This all happened thirty-five years ago, during a summer field course at Bodega Marine Laboratory. Today I look back on that class, and my time with the beach hoppers, with fond nostalgia. I don’t feel the stinging regret that used to plague me as I struggled with medical training, spending nights on stressful wards with desperately ill patients and overburdened clinicians. Now, I feel compassion for that young man who at one point knew what he wanted but lost sight of his dream.

This all comes to mind because I am reading a book I bought nearly ten years ago, back when I was volunteering at the California Academy of Sciences. During docent training, we studied some of the same animals I had seen during my summer field class, but to only superficial depth. Wanting more exposure, I purchased Animals Without Backbones, by Buchsbaum, Buchsbaum, Pearse, and Pearse. Lately I’ve been working my way through the text, which is aimed at undergraduates taking their first course in invertebrate zoology. I’ve been re-learning much of the material that so fascinated me during that summer at Bodega Bay.

The subject delights me as much now as it did then. What strikes me is the way Life operates in these animals that seem so alien but have been growing on this planet far longer than humans, or even mammals. Each form is adapted to its ecological niche. Each has the means to obtain and digest food, eliminate wastes, and reproduce. Some animals, like clams, filter sea water to collect particles of food. Others, like coral polyps, have formed symbiotic relationships with photosynthetic microbes and get their energy from solar radiation. Others are active predators who seek out and capture prey. Reproductive modes are equally diverse. For instance, some sea worms break into two pieces; their front ends continue sedentary lives on the ocean bottom, while their back ends rise to the surface. Thousands of animals behave this way simultaneously in cycles timed by the moon; their detached reproductive systems congregate in teeming masses and emit sperm and eggs into the water. Life’s creativity, its surprising ways of solving problems, stirs in me feelings of awe so strong that I sometimes wonder if biology textbooks aren’t, in effect, my scriptures.

That Life is capable of elaborating so much diversity, of exploring so many solutions, reassures me. It reminds me that my personal, individual experience grows out of a vast collective biosphere that has been at work for hundreds of millions (indeed, billions) of years. My body operates within this larger sphere and is moved by the same creative power. My few decades on this planet are moments of life, beautiful and transient. It makes little sense to take my daily concerns very seriously, no matter how wounded and discouraged I sometimes feel. By reminding myself that Life is ancient and adaptive, and that it has survived asteroid impacts and other global catastrophes, and that it never stops growing, I feel enlarged and reassured.