When I came home for lunch today, Claudia, in between driving the ambulance, doing the washing, finishing a craft project and beginning a spectacular cake, had photographed a pair of mating stick insects in the yard. Their proper name is phasmids (from the Ancient Greek word phasma, meaning ghost or apparition). I did some reading about them and found that some of them reproduce by parthenogenesis — the females give birth to other females if there are no males around. Makes sense in the desert, where a partner might be a long way away. In Papua New Guinea there’s a phasmid that secretes a substance used for antiseptic and antibacterial purposes. Apparently people in Sarawak eat some of them, which also makes sense since that island has the richest diversity of phasmids on the planet. Over three hundred kinds live there. Some of them must be tasty.
Crabs and oysters are good to eat and grasshoppers may be too. I’ve heard of people who cultivate cockroach and fly larvae (that would be a maggot, right?) in order to make compost of their food scraps. I respect their appetite to live harmoniously with nature and their courage to counter human prejudices. Even if I’m not quite ready to have a box of roaches working for me at my home, I have two decades of deep respect and even affection for them.
In the nineties, I studied invertebrates as part of my science degree. Partly, I was hoping that dissecting cockroaches and tapeworms would harden me up a bit. As kids, my brothers would catch lizards and gut fish while I lived in the world of books. I was still a bookish, squeamish grown-up when I decided to study medicine and I figured that if I was unafraid of bugs and worms, then spleens, brains and bladders couldn’t harm me. It worked pretty well.
But that was one part of it. Inspired by a book, I was also beginning to find invertebrates fascinating in their own right. In 1992, I read Stephen Jay Gould’s Wonderful Life. It’s about a collection of fossils which had sat uncared-for in a drawer in a Canadian museum until scientists changed their mindset and were able to see the creatures preserved there as they really were. The fossils came from the Burgess Shale, a fossil deposit discovered in the Canadian Rockies. The bodies of many soft-bodied creatures were marvelously preserved in its fossil beds. They were sea creatures with never-before-seen limbs, fins and strange appendages, resulting in names such as Anomalocaris, Wiwaxia and Hallucigenia. Once these fossils were observed for what they were, rather than made to fit into our current ideas of what an animal looks like, they hinted at the explosion of possibility during the early days of life on the planet. The four-limbs-on-a-spine pattern, which is more typical today, evolved from a chordate worm which had survived the massive extinction that had happened to the majority of the Burgess Shale creatures. They were among the estimated ninety-five percent of life which became extinct 250 million years ago. Scientists think the mass extinction was a result of a change in the weather.
As I studied the surviving invertebrate creatures — insects, sea animals, spiders and worms, which now make up over ninety percent of the animals living on Earth – I found a world of exquisite beauty and peculiar form and function. Spiders with egg packages, cockroaches with many tiny brains and elaborate, brilliant orange ovaries. Even the stringy uteri and strange robotic heads of tapeworms were fascinating. The squid had a brilliant blue systemic heart. All very strange.
As part of the course, my class and our teachers went to Smith’s Lake in New South Wales, where we spent days scraping tiny mites off tree trunks, or scooping miniscule shrimp from the freshwater lake and carrying them carefully to the microscopes set up in a tent, where we discussed, classified and learned. We had brought big books with us on the bus. Around a fire at night, the tutors told us about phosphorescent plankton, but it sounded like a fireside fantasy. We slept in bunk beds in thin-walled shacks.
One night, a wild storm unsettled me and I went outside in the moonlight. The grass was cold under my feet and the lofty eucalypts were bending and thrashing. I went to the lake’s edge, inhaling the negative ions. The water was black but the white light of the quarter moon, coming and going between torn clouds, lit up the edges of the choppy waves. I stood on flooded grass, looking over the lake, feeling myself part of untold generations of people who had enjoyed being there. After a while my eyes adjusted and I could make out shapes in the dark. It was then that I saw it, the shimmer of brilliant green flecks in the waves. The microscopic plankton lit up when disturbed. The storm was making them sparkle. After watching for a long, deep moment, while being pounded by icy raindrops, I crept back to my room, towelled off and slid gratefully into my blessedly dry sleeping bag. Someone was snoring, someone else breathing loudly, but I was exhilarated. I was grateful to share a planet with the plankton, and today, twenty years later, to share my yard with the phasmids.