A spectacular tale of 19th-century exploration and the conflict between science and religion, all based on Charles Darwin's famous voyage of discovery aboard HMS Beagle. Skillfully juxtaposing parallel narratives set (at first) 30 years apart, Australian writer McDonald (Slipstream, 1983, etc.) tells the story of the great scientist's ""servant,"" amanuensis, and ""shooter"" Simon (""Syms"") Covington, a devoutly religious English youth from a family of ""horse-butchers"" who is lured away to sea by a silver-tongued sailor (John Phipps, a kind of evangelical Pied Piper), spends three years as a fledgling naval surveyor, then joins the crew of Captain Fitzroy's Beagle, a nondescript vessel whose wanderings throughout the Southern Hemisphere obey the will of her distinguished passenger ""a Mr. Darwin of Derbyshire, 23-years-old, a bug-catcher."" The story of Syms's intellectual and sexual maturing, complicated when he realizes his phlegmatic ""gentleman's"" theories challenge biblical troths, is expertly counterpointed against McDonald's portrait of Covington in middle age, after be has settled in Australia, struck up a volatile friendship with a young physician (David MacCracken) whose intellectual pride simultaneously bonds and estranges them, and come to anticipate with mingled curiosity and resentment the arrival of Darwin's revolutionary book (The Origin of Species). This is an impressively learned novel (McDonald describes in exhaustive and fascinating detail Syms's duties ""examining, pickling, packing, labeling, and stowing,"" among other arcana and minutiae). But its learning is worn lightly, and the drama never flags. The triumphant characterization of the embattled Syms--a man in whom intellect, appetite, and religious impulse coexist credibly and explosively--is deepened as the story plays increasingly intriguing variations on the concepts of singularity and class both as scientific definition and as a more clumsy way of clarifying human relations. Brilliant work: an Australian novel that merits comparison with Patrick White's masterpiece, A Fringe of Leaves.