1. Section 19-2: Patterns and Processes of Evolution

2.  Fossil record shows that 99% of species that have ever existed have gone extinct  Macroevolutionary patterns are grand transformations in anatomy, phylogeny, ecology, and behavior, usually taking place in clades not individual species  Includes speciation, extinction, emergence of larger clades

3.  Paleontologists study fossils, put them into clades based on derived characters  Learn history of life

4.  As environments have changed, species either adapt or go extinct  Rates at which species appear, adapt, and become extinct vary  Emergence of new species in a clade impacts macroevolution of the clade  If “birth” of species is equal to “death” of species, clade will survive  Sometimes the more varied the clade more likely it will continue

5.  Background extinction – species goes extinct because of slow, steady natural selection  Mass extinction – many species go extinct over a short period of time  Entire ecosystems/food webs collapse  Change is too quick  Caused by asteroids, volcanoes, changing sea levels  Severely decreases biodiversity – some may survive then flourish  Eventually recover in 5 to 10 million years

7.  Gradualism – slow, steady change in a line of descent

8.  Punctuated equilibrium – equilibrium interrupted by brief periods of rapid change  New species created

9.  Small population becomes isolated from main population, and can evolve faster  Small group of organisms migrates (finches)  Organisms survive mass extinction

10.  Evolutionary process by which a single species or a small group of species evolves over a relatively short time into several different forms that live in different ways  Diversification of a clade

11.  Migration  Mass extinction  New adaptation  Examples in fossil record after extinction of dinosaurs  Finches

12.  Process of evolution that produces similar structures and characteristics in distantly- related organisms  Similar environments and selection pressures  Body parts with similar functions, may look similar (analogous)

13.  Two species evolving in response to changes in each other over time  Flowers and pollinators  Plants and herbivorous insects