Chapter 16 Flashcards
Naturalists
People who observe life from a scientific perspective
Biogeography
The study of patterns in the observation of species
Comparative morphologists
Study body plans and structures among groups of organisms
Vestigial structure
A structure in an organism that has lost all or most of its original structure in the course of evolution
Catastrophism
Georges Cuvier: many species became extinct due to catastrophic geological events
Gradualism
Jean-baptiste Lamarck: individuals changed in response to their environmental and passed those changes on to their descendants
Theory of uniformity
Lylells theory proposed that gradual, repetitive geological processes shaped the earth over great spans of time
Natural selection
Differential survival and reproduction among individuals of a population that vary in details of shared, inherited traits
Adaptive traits
Any trait that enhances and individuals fitness (ability to survive and reproduce in a particular environment)
Trace fossils
Nests trails footprints burrows bore holes eggshells
Lineages
Lines of descent
Radiometric dating
Reveals the age of material by determining its radioisotope and daughter element content
Radioisotope
A form of an element with an unstable nucleus
Half-life
The time it takes for half of a radioisotopes Aton to decay into a daughter element
Geological time scale
The chronology of earths history
Gondwana
Ancient supercontinent older that Pangea
