The temporal sequence of events that have occurred.

Techniques used to determine the age of materials, based on the content and half-lives of the RADIOACTIVE ISOTOPES they contain.

The scientific study of past societies through artifacts, fossils, etc.

The distinctly human attributes and attainments of a particular society.

A plant genus of the family CUPRESSACEAE. The species are slow growing coniferous evergreen trees or shrubs.

The period of history before 500 of the common era.

The ash, dust, gases, and lava released by volcanic explosion. The gases are volatile matter composed principally of about 90% water vapor, and carbon dioxide, sulfur dioxide, hydrogen, carbon monoxide, and nitrogen. The ash or dust is pyroclastic ejecta and lava is molten extrusive material consisting mainly of magnesium silicate. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)

Remains, impressions, or traces of animals or plants of past geological times which have been preserved in the earth's crust.

Family of the suborder HAPLORHINI (Anthropoidea) comprising bipedal primate MAMMALS. It includes modern man (HOMO SAPIENS) and the great apes: gorillas (GORILLA GORILLA), chimpanzees (PAN PANISCUS and PAN TROGLODYTES), and orangutans (PONGO PYGMAEUS).

The longterm manifestations of WEATHER. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)

A product of hard secondary xylem composed of CELLULOSE, hemicellulose, and LIGNANS, that is under the bark of trees and shrubs. It is used in construction and as a source of CHARCOAL and many other products.

The study of early forms of life through fossil remains.

Time period from 1801 through 1900 of the common era.

Time period from 1901 through 2000 of the common era.

Woody, usually tall, perennial higher plants (Angiosperms, Gymnosperms, and some Pterophyta) having usually a main stem and numerous branches.

The science dealing with the earth and its life, especially the description of land, sea, and air and the distribution of plant and animal life, including humanity and human industries with reference to the mutual relations of these elements. (From Webster, 3d ed)

Elements of limited time intervals, contributing to particular results or situations.

A theorem in probability theory named for Thomas Bayes (1702-1761). In epidemiology, it is used to obtain the probability of disease in a group of people with some characteristic on the basis of the overall rate of that disease and of the likelihood of that characteristic in healthy and diseased individuals. The most familiar application is in clinical decision analysis where it is used for estimating the probability of a particular diagnosis given the appearance of some symptoms or test result.

The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.

The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.

The relationships of groups of organisms as reflected by their genetic makeup.