Chapter 14 Vocabulary - Evidence for Evolution Flashcards
Evolution
the cumulative genetic change in a population of organisms from generation to generation; leads to differences among populations and explains the origin of all of the organisms that exist today or have ever existed
Macroevolution
evolutionary patterns and trends on a larger scale than microevolution; e.g., adaptive radiation, coevolution
Microevolution
changes in allele frequencies that occur within a population over successive generations
Fossil
the physical evidence of an organism that lived in the ancient past
Gradualism
in biology, the idea that evolutionary change of a species is because of a slow, steady accumulation of changes over time; in geology, the principle that geologic changes result from slow processes rather than sudden events
Half-life
the characteristic time it takes for half of a quantity of a radioisotope to decay
Index Fossil
a fossil that dates the layers where it is found because it came from an organism that is abundantly preserved in rocks, was widespread geographically, and existed as a species or genus for only a relatively short time
Radiometric Dating
a method of estimating the age of a rock or fossil by measuring the content and proportions of a radioisotope and its daughter elements
Trace Fossil
the physical evidence from the ancient past of an organism’s activities
Uniformitarianism
a geologic principle that states geologic processes operate consistently throughout time
Analogous structure
a body structure that is similar in function or appearance to another in a different lineage but not similar in origin or development
Homologous structure
a body structure similar to another in a different lineage because the structure evolved in a common ancestor
Vestigial structure
an evolutionary remnant of a formerly functional structure
