wHein Craig Venter, one of the mappers of the human genome, set out on a sailboat cruise to map DNA in seawater around the world, finding that a teaspoon of seawater contained an average of 50 million viruses. Although this doesn’t sound particularly reassuring, the bad news is mitigated by the fact that most of these are phages that infect marine bacteria and are of no interest to us.
Viruses are parasites, and like all their parasite types, they get free passage from living organisms. The whole purpose of multicellular life is to create a comfortable environment for cells to live, and evolution has invented all kinds of stowaways that seek this comfort and manage to live either outside or sometimes inside the cells themselves. Although it is usually not in the parasite’s best interests to kill its host and be forced to find a new home, some come dangerously close. Most diseases in developing countries are linked to some form of parasitic infection.
Dino Martins’ book is a fascinating collection of all the creatures, some large, some small, some harmless and some deadly, that lie in wait for unsuspecting warm-blooded creatures. It comes out with four different authored tracks. The first involves lyrical descriptions of nature written by a keen observer loving what he sees. The lyricism extends to scenes of horror: wonderful prose, for example, comes from the description of an elephant’s rotting carcass in the Kenyan afternoon sun, slowly being dissolved by a swarm of insects. “A boiling cauldron of maggot stew billows in steaming waves,” and Martins happily sampled maggot species by plunging his hands into the fluid pulp, while carefully noting that the air was “shimmering and stinking.” The tone then changes from lyrical to taxonomic, listing the various animal species and orders included. Martins and readers also marvel at nature’s creativity.
Then comes the charge sheet. One of the most frightening sections deals with the life cycle of eye worms. I had never heard of them and can’t read the book. They live in the eye socket – eyelids, conjunctiva, tear glands. Female insects lay eggs which hatch and the larvae come out by swimming in the tears. Flies attracted by that “cry of insects” take up the larvae; Inside the fly, the larvae migrate from the intestine to the testicles or egg follicles, mature, then move to the head of the fly and wait. When that fly gets into another animal’s eyes to drink water, the larvae hatch out and the cycle begins again.
Apparently, at several points in the book Martins, perhaps reluctantly, switches to “destroy animals” mode after explaining the fiendish ingenuity, indeed beauty, of the life cycles of certain creatures, which still causes continued suffering or vile, debilitating disease in millions of people. Finally, just when you think you can’t utter a single word about any creature other than the domestic cat, he delights the reader with innocently charming anecdotes from his field visits in Kenya and interactions with students and farmers.
I once worked in a marine station at a time when zoology was diversifying into molecular biology and ecology, and I worried that zoology itself was one of the endangered species. I was wrong to worry: the zoologist has simply adapted, and now he must be master of half a dozen trades to understand what nature is doing for him. In Martins’ multi-subjective narrative, the parasites evoke in the reader the kind of emotion reserved for clever, creative criminals: admiration for the genius of the scam, disgust at the details of the sting, a determination to end it. But in the end, perhaps the most enduring feeling, and one that Martins conveys beautifully, is awe at the sheer diversity and inventiveness of the living world.
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