Chapter 16 Flashcards
Radiometric Dating
the use of radioactive isotopes as a measure for determining the age of a rock or fossil
Radioactive Isotope
an unstable form of an element that decays into another element by radiation - that is, by emitting energetic particles
Half-life
the time it takes for one-half of a sample of a radioactive isotope to decay
Sedimentary Rock
rock formed from the compression of layers of particles eroded from other rocks
Ingenious rock
Rock formed by the cooling and hardening of molten lava
Extinction
elimination of all individuals in a species; may occur over time or in a sudden mass die-off
Adaptive Radiation
spreading and diversification of organisms that occur when the organisms colonize a new habitat
Mass Extinction
extinction between 50% + 90% of all living species that occur relatively rapidly
Biogeography
the study of distribution of organisms in geographic space
Continental Drift
movement of the continents relative to one another over time
Plate Tectonics
theory that the continents are part of large sections that sit atop the Earth’s mantle and that move around and collide due to heart convection currents in the underlying mantle
Convergent Evolution
process by which organisms that are not closely related evolve similar adaptations as a result of independent episodes of natural selection
Taxonomy
the identification, naming, and classification of organisms on the basis of shared traits
9 Categories of Taxonomy
domain, supergroup, kingdom, phylum, class, order, family, genus, species
Vertebrates
animals with a rigid backbone
Mammals
members of the class Mammalia; all members of this class have mammary glands and a body covered with hair
Phylogeny
evolutionary history of a group of organisms
Phylogenetic Tree
a branching diagram of relationships showing common ancestry
Domain
Highest (most inclusive) category in the modern system of classification
3 Domains of Classification
Bacteria, Archaea, and Eukarya
