Section Outline Section 17 4 17 4 Patterns

Section Outline Section 17 -4 17– 4 Patterns of Evolution A. Extinction B. Adaptive Radiation C. Convergent Evolution D. Coevolution E. Punctuated Equilibrium Go to Section:

PATTERNS OF EVOLUTION Chapter 17 -4 http: //www. baystatereplicas. com/images/repro_dino_pecksrex 3. jpg

Large scale evolutionary patterns and processes that occur over long periods of Macroevolution time = ____________ 1. 2. 3. 4. 5. ____________ Mass extinction Adaptive radiation (Divergent evolution) ________________________ Convergent evolution ____________ Coevolution ____________ Punctuated equilibrium

Mass Extinctions At several times in Earth’s history large numbers of species became extinct at the same time Caused by several factors: • erupting volcanoes • Plate tectonics (continents were moving) • Sea levels were changing • Asteroids hitting the Earth • Global climate change

Example: At the end of the _________ MESOZOIC Era. More than HALF of all plants and animals were wiped out… including the dinosaurs http: //www. changbi. com/file_img/webzine/dinosaur 02_02. jpg

Effects of mass extinctions: _______ Opens habitats and provides opportunities for _______species remaining After mass extinctions there is often a __________ burst of evolution that produces many _________ new species EX: Cenozoic era that followed = “________” Age of Mammals species increased dramatically Image from: BIOLOGY by Miller and Levine; Prentice Hall Publishing© 2006

When a single species or small group of species has evolved through __________ natural selection into diverse forms that live in different ways = __________________ adaptive radiation OR divergent evolution Ex: Galápagos finches More than a dozen species evolved from one species http: //www. pbs. org/wgbh/evolution/library/01/6/image_pop/l_016_02. html

Sometimes different organisms evolution in different places or at different times but in _____________ ecologically similar environments…and end up looking very similar. Process by which unrelated organisms come to resemble each other = ____________ convergent evolution

Example: Sharks, penguins, dolphins have all developed ________ streamlined bodies and appendages to move through water.

See more examples of __________ CONVERGENT __________ EVOLUTION http: //cas. bellarmine. edu/tietjen/Evolution /convergent_evolution_examples. htm

http: //www. painetworks. com/photos/ii/ii 1971. JPG The process by which two species evolve in response to changes in each other over time = _________ coevolution See many examples of coevolution http: //biology. clc. uc. edu/courses/bio 303/coevolution. htm

How fast does evolution operate? Darwin believed evolution happened slowly over a long time If biological change is at a slow pace, it is called _______. gradualism http: //animals. timduru. org/dirlist/dino/Flying. Dinosaurus-Pterodon-fossil. jpg

Fossil record shows evolution happens more in _____. bursts Pattern of a long stable period interrupted by a brief period of more rapid change Punctuated =______ Equilibrium

Rapid evolution after long periods of equilibrium can occur for several reasons: 1) Happens when a small population is ISOLATED from the main population OR ______ MIGRATES 2) A small group ________to a new environment (like Galápagos finches) http: //www. pbs. org/wgbh/evolution/library/01/6/image_pop/l_016_02. html http: //tolweb. org/tree/To. Limages/blank_map. 250 a. gif

Flowchart Section 17 -4 Species that are Unrelated form Related in under in in Interrelationshiops Similar environments Intense environmental pressure Small populations Different environments can undergo can undergo Coevolution Convergent evolution Extinction Punctuated equilibrium Adaptive radiation Go to Section:

SOUTH DAKOTA CORE SCIENCE STANDARDS LIFE SCIENCE: Indicator 2: Analyze various patterns and products of natural and induced biological change. 9 -12. L. 2. 2. Students are able to describe how genetic recombination, mutations, and natural selection lead to adaptations, evolution, extinction, or the emergence of new species. (SYNTHESIS)