Chapter 7-8 Flashcards
Fossil record
A historical sequence of life indicated by fossils found in layers of the Earths crust
Trait
A genetically determined characteristic
Selective breeding
The human practice of breeding animals or plants that have certain desired traits
Natural selection
The process by which individuals that are better adapted to their environment survive and reproduce more successfully than less well adapted individuals do; a theory to explain the mechanism of evolution.
Generation time
The period between the birth of one generation and the Brithish of the next generation
Speciation
The formation of new species as a result of evolution
Relative dating
Any method of determining whether an event or object is older or younger than other events or objects
Absolute dating
Any method of measuring th age of an object or event in years
Geologic time scale
The standard method used to divide the Earths long natural history into manageable parts
Extinct
Describes a species that has died out completely
Plate tectonics
The theory that explains how large pieces of the Earth outermost layer, called tectioic plates, move and change shape
Precambrian time
The period in the geologic time scale from th formation of the Earth to th beginning of the Paleozoic era, from about 4.6 billion to 542 million years ago
Paleozoic era
The geologic era that followed Precambrain time and that lasted from 542 millions years ago to 251 millions years ago
Mesozoic era
The geologic era that lasted from 251 million to 65.5 million years ago; also called the age of reptiles
Fossil
The trace or remains of an organism that lived long ago, most commonly preserved in sedimentary rock.
