According to the PdS8age, of the following, who was the earliest contributor to the technological develop- ment of fixed images? F, Hawthorne Niepce ACT.7 35 GO ON TO THE NEXT PAGE. Passage IV 55 he put it, swallowed up or sucked in, But he didn't think his observations important, and they slipped into oblivion. NATURAL SCIENCE: Thls passage is 8dapt8d from Chance in the House of Fate.. A Natural History of Heredily by J8nnifer Ackerrnan {Icfd001 by Jennifer Ackerman). Twenty years later, scientists observing metamor- phosib in flies, ants, and beetles noied in the Changing 60 muscles and glands the wholesale death of cells. Laier studies of developillg bon¢,s, muscles, and other tissues in mammals suggested that the shaping of c(Ir, eye, nose, tongue, intesiinal Iract, and tiachea involves ,some removal of excess cells. By the turn of the century it 65 was clear: to have shapely toads. butterflies, babies, one must have cell death. I once chanced on a collection of brilliantly col- ored palntings ot" South American insects, somc of them nightmarish-a giant cockroach scaling a pineapple, for example-but most of them showing the metamorpho- 5 .¥is of moths and butterflies from egg to winged insect, the life stages presented as if they were happening dll at once. Thc paintings were the work of Maria Sybilla MeIian. a naturalist and artist who Icft her home in 10 Amsterdam in 1699 at the age of fifty-two and Siiiled to South Atnerica to paint the life cycles of insect8 in the junglcs of Suriname. The journey would have been remarkable in any century, but W¢lS especially so in the late 1600s, when savants were still poking for answers 15 to nature's riddles in the ruins of the classical world, quoting the authority of Pliny, the natural philosopher who had confidently proposed that butterflies were born from dew, and drawing their knowledge of ani- mgils from medieval bestiaries. Birds were categorized 20 according to notions of nobility, from most noble (eagles and hawks), to wise (owls), to big (05triches), and on down the line. Caterpillars, if they were con%id- ered at all, were classified apart from winged insects and lumped together wilh worms and .8erpents. Frorn the Suriname capital, Paramaribo, Merian sailed up Ihe Surinarne River, stopping along it,5 banks to collect caterpillars, then watching them closely for signs of metamorphosis ¢ind painling them ai the pivotal moment. Two years later, sick of heat and fever, she 30 returned home, loaded with .8pecimens and hundrcds of paintingg of iguanas and geckos, fighting snakes and frog-eating scoipions, and dozens of moths and buiier- flies in vaTiOUS life stages on their native cassava, guava, batata, and pawpaw plants. The idea that death would chaperone growth was not easy to accept. But at least the role of cell death in the miracle of development seemed of minor 70 importance. Then, in the early 1970s, a team of Scottish pathologists eAatnined different kinds of tissue and dis- covered that cells have two radically different ways of expiring. Those that die accidentally, by injury or poi- soning, swell up and pop like balloon8-a visually 75 obvious process the team called necrosis. But those that die naturally during dcvcloptnent do so by quiet, effi- cient, nearly invisible means. This way of dying (which the team called apoptosis from the Greek for fallillg") may be inconspicuou8, but it goes on all the 80 time in every kind of tAssue, in nearly every kind of animal. Cell deaih is the night-side of growth. Cells die en masse at incredible speed, not jusi to gculpt our body structures before wc arc born. but throughout oui life, 85 about ten billion each day, to adjust cell numbers, elim- inate the injured, and dispose of cells deemed obsolete. We don't ditninish in the face of such massive, inces- sant loss for the sirnpIe reason that new cells are born in trade for those that die. The body precisely balances 90 cell birth and cell death. 25 35 If we are to believe her journal, Merian knew Ihe details of mctamorphosis perhap.s rnore intimately than the savants. Her paintings and journal% address the step-by-step transfiguration not just of Lepidoptera (butterflies and moths) but al.so of amphibians. In 1686 40 she had precociously noted the dcvclopmental odyssey of frogs from black grains that "fed on the white slime that surrounded them," to tiny creatures that grew little tails so that they could %win], then eyes, then, eighi days later. two little feet 'from thc skin at the back dnd 45 after a further eight days two little leet at the front [like] small crocodiles, Thereafter the tail rotted away and they beLame proper frogs and jumped onio the land,
