Chapter 22 Flashcards
descent with modification; the idea that living species were descendants of ancestral species that were different from the present-day ones; also defined more narrowly as the change in the genetic composition of a population from generation to generation.
evolution
a preserved remnant or impression of an organism that lived in the past.
fossils
a rock layer formed when new layers of sediment cover older ones and compress them.
stratum (plural, strata)
the scientific study of fossils.
paleontology
the principle that events in the past occurred suddenly and were caused by different mechanisms than those operating today.
catastrophism
the principle stating that mechanisms of change are constant over time.
uniformitarianism
inherited characteristic of an organism that enhances its survival and reproduction in specific environments.
adaptations
a process in which organisms with certain inherited characteristics are more likely to survive and reproduce than are organisms with other characteristics.
natural selection
the selective breeding of domesticated plants and animals to encourage the occurrence of desirable traits.
artificial selection
structures in different species that are similar because of common ancestry.
homologous structures
similarity in characteristics resulting from a shared ancestry.
homology
a structure of marginal, if any, importance to an organism. They are often historical remnants that had important functions in ancestors.
vestigial structures
a branching diagram that reflects a hypothesis about evolutionary relationships among groups of organisms.
evolutionary tree
The evolution of similar features in independent evolutionary lineages.
convergent evolution
the study of the past and present distribution of species.
biogeography
