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T HE DIVERSITY OF THE POWDERY MILDEW IS DEMONSTRATED BY THE SHAPES OF THEIR APPENDAGES. THIS ENGRAVING WAS DONE IN 1861 BY CHARLES TULASNE. B i o l o g i c a l 14 D i v e r s i t y
environment. For almost 3 billion years, life was limited to the oceans and consisted of bacteria, blue-green algae, and other relatively simple one-celled forms. Then complex cells evolved, incorporating organelles such as nuclear membranes, chloroplasts, and cilia. Soon afterward, these cells evolved into still more complex multicellular animals and plants. About 600 million years ago, the concentration of oxygen in the atmosphere climbed rather quickly (by geological standards) to near its current level, destroying most of the anaerobic life in the oceans and on land surfaces. A shield of ozone accumulated in the stratosphere, protecting life from harmful ultraviolet irradiation. For the first time, substantial numbers of larger animals filled the seas, and the global variety of life climbed sharply. Plants invaded the land, then animals, represented first by small arthropods and other invertebrates, then jawless fishes. The diversity of life continued to rise. Biodiversity stalled on a plateau during most of the Mesozoic Era, then climbed gradually to its current high level. It is a supreme irony that mankind, the great destroyer of life, began as one of the products of the living world’s maximum proliferation. A second major principle of biodiversity is that smaller organisms are generally more diverse than larger ones. The reason appears to be simply that they fit into smaller spaces, consume less food individually, complete their life cycles more quickly, and hence are able to divide the habitats in which they live into smaller and more numerous niches. And the more numerous the niches, the more species that can be packed into the same location. Take a typical epiphyte-laden tree in the rainforest of Peru. It may be the home of several hundred species of beetles, 40 species of ants, and as many as 50 species of orchids and other epiphytes. But it can only be the partial home for a flock of parrots, which must range over portions of the forest that contain many thousands of such trees in order to obtain enough food for survival. Among smaller animals, insects dominate diversity. About 750,000 of the 1 million animal species described to date are insects, and some estimates have placed the actual number as high as 80 million. The reason for this amazing disproportion is uncertain. It seems likely due to the metamorphosis experienced by the majority of kinds of insects during the individual life cycle: egg to larva to pupa to adult, with the egg and pupa as passive transitional stages and the larva and adult as the active stage. Larvae and adults are radically different in appearance (recall the caterpillar and butterfly), typically feed on different foods, and even live in different sites. As B i o l o g i c a l 15 D i v e r s i t y
Page 1: Biological Diversity: T H E O L D E
Page 4 and 5: THE UNIVERSITY OF THE STATE OF NEW
Page 6 and 7: Copyright © 1999 by The New York S
Page 9 and 10: Preface This book is based on a man
Page 11 and 12: Additional information on the activ
Page 13 and 14: Biological Diversity: T H E O L D E
Page 15 and 16: some degree of potency. A much high
Page 17 and 18: Some groups of organisms, such as f
Page 19 and 20: to their environment and to one ano
Page 21 and 22: N EW YORK’S BIODIVERSITY IS THREA
Page 23 and 24: 12 10 Number of Butterflies Observe
Page 25: It is possible that the next hundre
Page 29 and 30: W ITH ITS WISPINESS AND LIGHT-AND-D
Page 31 and 32: sophisticated microscopic and bioch
Page 33 and 34: The tropical zones generally have a
Page 35 and 36: average as well as greater ecologic
Page 37 and 38: early extinction within the next 30
Page 39 and 40: perished. As the paleontologist Dav
Page 41 and 42: collected in the stream in 1936 and
Page 43 and 44: Systematics, or taxonomy, is at the
Page 45 and 46: Community ecology addresses the man
Page 47 and 48: Biological field stations from four
Page 49 and 50: Biogeography 1 The scientific study
Page 51 and 52: Dispersal In biology, the way a spe
Page 53 and 54: Global warming An increase in the c
Page 55 and 56: Ozone A form of oxygen (O 3 ) that
Page 57 and 58: Termites A group of insects that is
Page 59 and 60: Grifo, Francesca, and J. Rosenthal
Page 61 and 62: diverse and why the threat to that
Page 63 and 64: Mitchell, Richard S., L. Danaher, a
Page 65 and 66: 9. Is an ecologist the same as a ta
Page 67 and 68: 31. Do you know of a biological res
Page 69 and 70: B i o l o g i c a l 57 D i v e r s
Page 72: THE NEW YORK STATE MUSEUM IS A PROG

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