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T HE MASSASAUGA IS A SMALL SPECIES OF RATTLESNAKE THAT IS ENDANGERED. IT IS KNOWN IN NEW YORK FROM ONLY TWO SWAMPS IN THE CENTRAL AND WESTERN PARTS OF THE STATE. If insects and other small invertebrate animals are so much more diverse than vertebrates and larger invertebrates due to size alone, is it true by extension of the same principle that still smaller creatures such as roundworms, fungi, and bacteria are even more diverse? The conventional answer is that for some unknown reason, they are not. But the conventional answer may prove to be wrong. The truth is that we know very little about the smallest of organisms. Because of their microscopic size and the difficulty of collecting and preserving them, they tend to be collected less frequently. Furthermore, many of the species can be distinguished only by B i o l o g i c a l 18 D i v e r s i t y
sophisticated microscopic and biochemical techniques. Take the roundworms, for example. Vast numbers occur throughout the world, with untold varieties of species living free in the soil or in the bodies of insects and other animals. Since roundworms can specialize in particular species of hosts, which are excessively diverse themselves, or even certain parts of the bodies of their hosts, they have the potential for spectacular diversification. We simply have no idea how many kinds of roundworms live on earth. The same is true for fungi and bacteria. The number of recognized bacterial species is about 4,000, but most specialists on the subject agree that this is only a tiny fraction of the real number. Bacterial species usually exist in numbers too low to detect by direct inspection, and become apparent only when given the right nutrients, temperature, and chemical environment to create obvious population blooms. Many also flourish in very odd places, such as thermal springs or the intestines of termites. In the late 1980s, deep drilling in South Carolina uncovered an entire new flora of bacteria living 1,000 feet or more below the soil surface on nutrients carried to them by water seepage. The terra incognita of the smallest organisms is the reason why students of biodiversity, in giddier moments, are sometimes willing to entertain the idea of 100 million or more species of organisms on earth. Yet another peculiarity of global biodiversity is its inordinate concentration in tropical rainforests. This habitat, or biome-type as it is called by ecologists, is defined as a forest growing in tropical areas with 80 inches or more of annual rainfall, allowing the growth of broad-leaved evergreen trees that form several layers of dense canopies. Tropical rainforests today cover only about 6% of the land surface (9 million square kilometers), but they are generally thought to contain more than half the species of organisms on earth. The diversity of rainforest organisms is legendary, the common stuff of gossip among field biologists. For example, as many as 300 species of trees have been identified in a single hectare (2.5 acres) in the Peruvian Amazon; this compares with 700 native species found in all of North America. Each tree harbors as many as a thousand species of insects. One tree that I analyzed yielded 43 kinds of ants, approximately the same number found in the entire British Isles. B i o l o g i c a l 19 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 and 26: It is possible that the next hundre
Page 27 and 28: environment. For almost 3 billion y
Page 29: W ITH ITS WISPINESS AND LIGHT-AND-D
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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