CHAPTER 13 How Populations Evolve Figures 13 1 13 5 PowerPoint Lecture Slides for Essential Biology Second Edition Essential Biology with Physiology Neil Campbell Jane Reece and Eric Simon Presentation prepared by Chris C Romero Copyright 2003 Pearson Education Inc publishing as Benjamin Cummings All humans are connected by descent from African ancestors The same types of bones make up the forelimbs of humans cats whales and bats Copyright 2003 Pearson Education Inc publishing as Benjamin Cummings BIOLOGY AND SOCIETY PERSISTENT PESTS Mosquitoes and malaria In the 1960s the World Health Organization WHO began a campaign to eradicate the mosquitoes that transmit malaria It used DDT to which some mosquitoes have evolved resistance Copyright 2003 Pearson Education Inc publishing as Benjamin Cummings 1 Insecticide application Chromosome with gene conferring resistance to insecticide Survivors Additional applications of the same insecticide will be less effective and the frequency of resistant insects in the population will grow Figure 13 1 Copyright 2003 Pearson Education Inc publishing as Benjamin Cummings CHARLES DARWIN AND THE ORIGIN OF SPECIES Charles Darwin s On the Origin of Species by Means of Natural Selection Was published on November 24 1859 Focused biologists attention on the great diversity of organisms Copyright 2003 Pearson Education Inc publishing as Benjamin Cummings The basic idea of natural selection is that Organisms can change over generations Individuals with certain heritable traits leave more offspring than others Copyright 2003 Pearson Education Inc publishing as Benjamin Cummings 2 The result of natural selection is evolutionary adaptation b A Trinidad tree mantid that mimics dead leaves a A flower mantid in Malaysia c A leaf mantid in Costa Rica Figure 13 2 Copyright 2003 Pearson Education Inc publishing as Benjamin Cummings Darwin s Cultural and Scientific Context The Origin of Species Challenged the notion that the Earth was relatively young and populated by unrelated species Copyright 2003 Pearson Education Inc publishing as Benjamin Cummings The Idea of Fixed Species The Greek philosopher Aristotle held the belief that species are fixed and do not evolve The Judeo Christian culture fortified this idea and suggested that the Earth is only about 6 000 years old Copyright 2003 Pearson Education Inc publishing as Benjamin Cummings 3 Lamarck and Adaptive Evolution In the mid 1700s the study of fossils began to take form as a branch of science Naturalist Georges Buffon Suggested that the Earth might be older than 6 000 years Observed similarities between fossils and living species Copyright 2003 Pearson Education Inc publishing as Benjamin Cummings Jean Baptiste Lamarck Suggested that organisms evolved by the process of adaptation Also suggested some erroneous ideas such as the inheritance of acquired characteristics Copyright 2003 Pearson Education Inc publishing as Benjamin Cummings The Voyage of the Beagle In December 1831 Darwin left Great Britain on the HMS Beagle to explore the world Great Britain Europe North America ATLANTIC OCEAN PACIFIC OCEAN Africa Gal pagos Islands Equator South America Andes Australia Cape of Good Hope Tasmania Cape Horn Tierra del Fuego New Zealand Figure 13 3 Copyright 2003 Pearson Education Inc publishing as Benjamin Cummings 4 The Galapagos Islands are located about 900 Km off the west coast of Ecuador Copyright 2003 Pearson Education Inc publishing as Benjamin Cummings On his journey on the Beagle Darwin Collected thousands of specimens Observed various adaptations in organisms Copyright 2003 Pearson Education Inc publishing as Benjamin Cummings Darwin was intrigued by The distribution of organisms on the Gal pagos Islands The fact that Gal pagos organisms resembled those in South America Figure 13 4 Copyright 2003 Pearson Education Inc publishing as Benjamin Cummings 5 The New Geology Darwin was strongly influenced by the writings of geologist Charles Lyell Darwin reasoned that The Earth is very old and has been shaped by slow processes Subtle processes occurring over long periods of time can cause great change Copyright 2003 Pearson Education Inc publishing as Benjamin Cummings Descent with Modification Darwin made two main points in The Origin of Species Organisms inhabiting Earth today descended from ancestral species Natural selection was the mechanism for descent with modification Copyright 2003 Pearson Education Inc publishing as Benjamin Cummings Elephas maximus Asian elephant Today 10 000 years ago 2 million years ago Loxodonta africana Loxodonta cyclotis African savannah African forest elephant elephant Mammuthus mammoth Mammut mastodon Deinotherium 5 5 million years ago Stegodon Platybelodon 24 million years ago Moeritherium Barytherium 34 million years ago Figure 13 5 Copyright 2003 Pearson Education Inc publishing as Benjamin Cummings 6 EVIDENCE OF EVOLUTION Biological evolution has left marks of evidence Copyright 2003 Pearson Education Inc publishing as Benjamin Cummings The Fossil Record Fossils Are preserved remnants or impressions left by organisms that lived in the past Are often found in sedimentary rocks Copyright 2003 Pearson Education Inc publishing as Benjamin Cummings 1 Rivers bring sediment to the ocean Sedimentary rocks containing fossils form on the ocean floor 2 Over time additional strata are added containing fossils from each time period 3 As sea levels change and the seafloor is pushed upward sedimentary rocks are exposed Erosion by rivers reveals strata deeper strata contain older fossils Younger stratum with more recent fossils Older stratum with older fossils Figure 13 6 Copyright 2003 Pearson Education Inc publishing as Benjamin Cummings 7 The fossil record Is the chronology of fossil appearances in rock layers Testifies that organisms have appeared in a historical sequence Fits with other evidence of evolution Figure 13 7 Copyright 2003 Pearson Education Inc publishing as Benjamin Cummings Paleontologists Are scientists that study fossils Have discovered many transitional forms that link past and present Copyright 2003 Pearson Education Inc publishing as Benjamin Cummings Figure 13 8 Copyright 2003 Pearson Education Inc publishing as Benjamin Cummings 8 Biogeography Biogeography Is the study of the geographic distribution of species First suggested to Darwin that today s organisms evolved from ancestral forms Copyright 2003 Pearson Education Inc publishing as Benjamin Cummings Many