Chapter 14 - The origin of species. This chapter define and discuss the limitations of the four species concepts, describe and provide examples of prezygotic and postzygotic reproductive barriers, distinguish between and provide examples of allopatric and sympatric speciation, explain how polyploidy can cause reproductive isolation, define the term hybrid zone and describe three outcomes for hybrid zones over time. | Chapter 14 The Origin of Species PowerPoint Lectures for Biology: Concepts & Connections, Sixth Edition Campbell, Reece, Taylor, Simon, and Dickey Lecture by Joan Sharp Copyright © 2009 Pearson Education, Inc. Introduction: The Rise and Fall of Cichlids Until recently, over 500 species of cichlid fishes lived in East Africa’s Lake Victoria – Where did these species come from? – Why are they disappearing? Copyright © 2009 Pearson Education, Inc. Africa Uganda Kenya Lake Victoria Lake Tanganyika Tanzania Lake Malawi Introduction: The Rise and Fall of Cichlids Lake Victoria’s cichlids diversified 100,000 years ago – Different species of cichlid have specialized mouthparts that allow them to specialize on different food sources – The bright colors of the males vary with species, as females chose males with specific colors Groups isolated by diet or female mate choice may have lost the ability to interbreed Copyright © 2009 Pearson Education, .
