Born in Africa_ The Quest for the Origins of Human Life - Martin Meredith [90]
Oldowan: An Early Stone Age industry, first described from Olduvai Gorge, lasting from about 2.6 million to about 1 million years ago. It is characterised by scrapers made from flakes split by hammerstones and by crude choppers made from cobbles—hence the name ‘pebble tools’.
Palaeoanthropology: The study of the physical and behavioural aspects of humans in prehistory.
Palaeolithic Age: A prehistoric era in Eurasia divided into three main parts—Lower Palaeolithic, Middle Palaeolithic and Upper Palaeolithic—that are roughly contemporaneous with the three stages of Africa’s Stone Age.
Palaeomagnetic dating: A geological technique that dates rock based on the occurrence of polar reversals when the magnetic pole moves to the opposite end of the earth. Such reversals have occurred at regular intervals of hundreds of thousands of years throughout the history of the earth.
Palaeontology: The study of fossils and biology of extinct organisms.
Palynology: The study of contemporary and fossil palynomorphs, such as pollen.
Phyletic gradualism: A mode of evolution characterised by gradual change within a lineage.
Phylogeny: The reconstruction of evolutionary relationships between groups and species, primarily concerned with branching events, usually shown as a branching diagram or phylogenetic tree.
Plate tectonics: The study of the earth’s crustal structures, such as continental plates, and the forces that cause them to change shape and move relative to one another.
Pleistocene: The epoch from 1.64 million to about 10,000 years ago, a period which included the Ice Ages and the evolution of the first members of the genus Homo in Africa.
Pliocene: The epoch from 5.2 million to 1.64 million years ago when the first hominids evolved in Africa.
Pongidae: The family of great apes that includes chimpanzees, gorillas and orang-utans and their ancestors.
Potassium-argon dating: A radiometric dating method based on measurement of the product of the radioactive decay of an isotope of potassium into argon.
Primitive character: A character that was present in a common ancestor of a group and is therefore shared by all members of that group. (See Derived character.)
Proteins: Large molecules that consist of a long chain of amino acids.
Punctuated equilibrium: A mode of evolution characterised by periods of stasis interspersed with brief episodes of rapid change.
Radiometric dating: Clocklike dating methods based on the measurement of the constant rate of decay of naturally occurring radioactive materials.
Relative dating: Techniques that provide information about a site by referring to what is known at other sites or other sources of information, such as faunal correlation. (See Absolute dating.)
Saltation: A sudden event, resulting in a discontinuity, or gap, such as the sudden production of new species.
Speciation: The division of a single parent species into two or more descendant species.
Stasis: A period in the history of organisms during which evolution seemed to have been at a standstill.
Stratigraphy: A branch of geology concerned with the formation, constituents and sequence of stratified deposits.
Tuff: A layer of consolidated volcanic ash and related materials.
Notes on Sources
The material for this book is based largely on the work, writings and reminiscences of several generations of scientists. These chapter notes include references to books I found to be of particular interest and value. A more complete list is contained in the Selected Bibliography.
INTRODUCTION
Since Charles Darwin’s time, the study of human evolution has developed into a major industry. Two recent compendiums provide a wealth of information and analysis: The Complete World of Human Evolution by Chris Stringer and Peter Andrews (2005); and Human Evolution: An Illustrated Introduction by Roger Lewin (2005). In 2007, G. J. Sawyer and Viktor Deak published The Last Human: A Guide to Twenty-Two Species of Extinct Humans, which contains