Shortcut Navigation:

The Biodiversity Crisis: Losing What Counts


adaptation Biological characteristic that improves the chance of survival of an animal and its descendants.

aesthetic Relating to beauty.

allocate To assign where portions of a resource will go.

archipelago A chain of islands.

asset Something one has that is of benefit.

biodiversity The variety and interdependence of all living things. Biodiversity includes all living organisms, the genetic differences among them, the communities, cultures, habitats and ecosystems in which they evolve and coexist, and the ecological and evolutionary processes that support them.

biological control The reduction or management of harmful organisms by using other organisms.

biome Large area dominated by a certain type of plant community, such as desert, temperate grassland, or coniferous forest.

biosphere The totality of living things on Earth, along with their habitats—the largest ecosystem.

botanical Relating to the study of plants.

canopy In a forest, the zone above the ground with the bulk of the tree branches.

chlorofluorocarbons Synthetic chemicals used in refrigeration, solvents, and Styrofoam manufacture. In the upper atmosphere they break down, releasing chlorine atoms that destroy ozone.

community, biological All the species living together in an area.

concession, resource The rights given by a government to a private organization to extract a resource, such as timber or petroleum, for the organization’s benefit. 

conservation The management and protection of the natural world.

conservation biology The scientific discipline concerned with the study and protection of the world’s ecosystems and biodiversity.

Cretaceous The period of geologic time lasting from 144 to 65 million years ago. The end of the Cretaceous Period coincides with the extinction of the dinosaurs.

deforestation Removal of forests, usually rapidly and over large areas.

demography The study of population.

development In economic terms, the creation of industries in an area which allow a higher standard of living for the inhabitants.

dispersal The movement of organisms to new areas of habitat.

DNA A complex molecule, found in every cell, that contains the genetic code. Every organism has variations in the code contained in its DNA.

domestication The development of an interdependent relationship between humans and another species.

ecology The study of the interactions of living things with each other and their physical environment.

economy of scale The advantage that a larger producer or consumer enjoys over a smaller one because of costs that do not increase proportionately with size. For instance, a large lawn does not cost ten times as much to care for as a lawn one-tenth as big because it does not require ten times as many lawn mowers.

ecosystem A community of interacting organisms and their physical environment.

empirical Based on observation or measurement, rather than on theory.

endangered In danger of extinction in the foreseeable future.

Endangered Species Act (ESA) Legislation, passed by Congress in 1973, which protects listed species.

Endangered Species List List of species protected under the Endangered Species Act.

eon A major division of the entire 4.5 billion years of geologic time, lasting half a billion years or more.

epizootic An epidemic in an animal population.

epoch An interval of geologic time, a subdivision of a geologic period.

equilibrium (pl. equilibria) Balance.

era An interval of geologic time; a subdivision of a geologic eon.

estuary A place where freshwater enters the sea (e.g., at river mouth).

eutrophication The overfertilization of a body of water through the natural or artificial (human-caused) accumulation of nutrients, ultimately leading to excessive growth of algae. The mats of algae may block the sunlight, causing the death and decomposition of shaded algae, which leads to a bacterial population explosion and oxygen depletion.

exotic A species introduced by humans into a place where it was not previously found. Many exotics thrive in their new environment when freed from their natural enemies, allowing them to displace native species.

exponential An increasing rate of change. Exponential processes often go from barely noticeable to astronomical in a short time.

extrapolate To guess at what is not known by using what is known.

family A group of related genera. The species of a family are similar, such as those of the grass family.

fixing See nitrogen fixing .

fossil The remains or traces of an organism turned to stone by geochemical processes.

fossil record The form, variety, and distribution of fossils in space and time.

gene An inherited piece of information contained in a cell’s dna . The information from each gene is used to make a unique type of protein, which has a specific function for the cell.

gene flow The movement of genes among populations of a species. Genes are carried by pollen, spores, seeds, sperm, eggs, and whole organisms.

gene pool All the genes within a particular population; that is, total genetic variation.

genetic diversity The number of different genes in a population that perform approximately the same function, and lead to variation be tween individuals in that population.

genus (pl. genera) A group of related species. The species of a genus are basically the same kind of organism, such as the pines.

glaciation The formation of glaciers, vast fields of ice and compacted snow. In the Pleistocene Epoch glaciers covered much of North America and Europe.

global warming An increase in Earth’s average temperature.

greenhouse gas A gas in the atmosphere that reflects back downward the heat radiated from Earth’s surface, keeping the atmosphere and Earth’s surface warmer than the frigid temperatures of outer space. Important greenhouse gases are water vapor, carbon dioxide, methane, and nitrous oxide.

guild A group of species that perform the same function within an ecosystem.

gymnosperm A plant that reproduces by seeds that are formed in cones or other structures that are not flowers—literally “naked seed.”

habitat The environment where an organism can and does live.

Holocene The geologic epoch extending from the end of the last Ice Age, 10,000 years ago, to the present.

ichthyology The study of fish.

insectivore An animal that eats insects.

isotope A form of a chemical element that is distinguishable by its atomic weight. The atomic weight of the isotope is written in superscript to the left of the chemical symbol, such as 14C.

keystone An important species whose presence in an ecosystem seem especially critical in maintaining ecosystem processes and regulating populations of other species.

latex A milky, bitter liquid found in some plants. Some latexes are used for making rubber.

lichen A plantlike composite consisting of a fungus and an alga. The alga provides food for the lichen through photosynthesis, and the fungus provides protection for the alga, allowing the lichen to grow in places where other organisms could not.

mangrove A tree that roots offshore on tropical ocean banks. Mangrove stands protect shorelines from erosion and support many other species, making mangroves keystone species. They are often associated with estuaries.

n-dimensional hyperspace A mathematical concept used to describe a set of associated ranges of measurements. If a subject has a measured trait that exists as a range, such as the heart rate of a bird, that range can be represented as an interval on a number line. If two associated traits are measured, such as heart rate and breathing rate, they can be plotted on a two-dimensional graph where they would form a sort of patch, representing all existing combinations of the two. Three traits could be represented, using some skill, in a three-dimensional plot, and would form a three-dimensional solid, a “space.” (n traits, if n is a number more than three, could not be represented together visually in a single plot; they would form a hyperspace.)

Neotropics The tropical regions of the Americas, the “New World.”

nitrogen fixing The conversion of nitrogen gas from the atmosphere into essential nutrients that are usable by organisms.

overexploitation Wasteful killing of a species, usually by hunting or poaching, to well beyond the point at which population levels can be sustained.

ozone layer The layer of the upper atmosphere, approximately twenty-five kilometers in altitude, that contains maximum concentrations of ozone (O3).

paleontology The study of fossils.

passerine A perching bird or songbird.

pathogen Any disease-producing agent; such as, viruses, bacteria, or other microorganisms.

period, geologic An interval of geologic time, a subdivision of a geologic era.

pharmacopoeia A collection of medicines.

phylum A major grouping of species with similar special characteristics. An example is the arthropods, a phylum that includes insects, spiders, scorpions, millipedes, crabs, and other jointed-leg animals.

Pleistocene The geologic epoch lasting from 25,000 years ago to 10,000 years ago, coinciding with the last Ice Age.

pollution Contamination of air, water, or soil by the discharge of harmful, toxic substances.

population A group of organisms of one species, occupying a defined area and usually isolated from similar groups of the same species.

quantitative Using numbers, as opposed to verbal descriptions.

Quaternary The geologic period lasting from 2 million years ago to the present.

radiocarbon (radiometric) dating An estimate of age in a fossil based on the ratio of the transformed radioactive carbon isotope to the original radioactive carbon isotope. The higher the ratio the older the age of the object. Because the radioactive carbon changes relatively fast, this method is only accurate for ages on the scale of thousands, rather than millions, of years. Dating more ancient objects requires use of radioactive uranium, lead, or other elements.

rain forest A dense evergreen forest with an annual rainfall of at least 254 cm.; may be tropical (e.g., Amazon), or temperate (e.g., Pacific Northwest).

range The area naturally occupied by an individual, population, or species.

recycling, nutrient The movement of chemical elements essential for life from the environment into plants, up the food chain, and back into the environment, where they can be used again.

reintroduction To place members of a species in their original habitat.

reserve An area of land set aside for the use or protection of a species and its habitat.

services, ecosystem Benefits obtained from intact ecosystems, such as freshwater collection, waste breakdown, or oxygen production.

species A group of individuals, usually identifiable by a set of distinctive features, with a unique evolutionary history. Classically, the members of a species can interbreed only with each other to produce fertile offspring.

Species Survival Plan Captive-breeding programs administered by the American Zoological Association.

stratosphere The layer of the atmosphere that extends from approximately ten to fifty kilometers in altitude from the Earth’s surface.

stratum (pl. strata) Layer, usually in reference to geology.

subspecies A population of a species distinguished from other such populations by certain characteristics.

sustainable Meeting current needs without losing the ability to meet future needs.

systematics The science of identifying, describing, naming, and classifying groups of organisms and studying their genealogical histories.

taxon (pl. taxa) Any group in the classification of life, such as a family, phylum, or species.

temperate Having a climate neither extremely hot nor extremely cold; generally found in the zones between 23° and 66° north or south of the equator.

threatened Populations or species likely to become endangered in the near future.

tropical Existing between 23° north and 23° south of the equator, generally having a hot climate.

understory The plants in a forest growing under the trees.

ungulate A hoofed mammal; for example, horse, rhinoceros, pig, hippopotamus, camel.

U.S. Fish and Wildlife Services Federal agency that oversees the implementation of the Endangered Species Act.

viable Capable of living, developing, or germinating.

vulnerable A species is vulnerable when it satisfies some risk criteria, but not at a level that warrants its identification as endangered.

watershed The area of land that collects all the rainwater that flows into a given river or stream.

wetland A permanently moist lowland area such as a swamp or marsh.

This is an excerpt from THE BIODIVERSITY CRISIS: LOSING WHAT COUNTS, edited by Michael J. Novacek, a publication of the New Press. © 2000 American Museum of Natural History. To order the book, call 1-800-233-4830, or go to

American Museum of Natural History

Central Park West at 79th Street
New York, NY 10024-5192
Phone: 212-769-5100

Open daily from 10 am - 5:45 pm
except on Thanksgiving and Christmas
Maps and Directions

Enlighten Your Inbox

Stay informed about Museum news and research, events, and more!