Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings Darwin found convincing evidence for his ideas in the results of artificial selection –The selective breeding of domesticated plants and animals Figure 13.2A Hundreds to thousands of years of breeding (artificial selection) Ancestral dog (wolf) Figure 13.2B
Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings Darwin proposed that living species –Are descended from earlier life forms and that natural selection is the mechanism of evolution Thousands to millions of years of natural selection Ancestral canine African wild dogCoyote Wolf Fox Jackal Figure 13.2C
Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings Evidence for Evolution How can we show that species have changed through time? How can we observe natural selection? Fossil Record Biogeography Comparative Anatomy- Homologous Structures & Analogous Structure Comparative Embryology
Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings Fossil Record has strong evidence for evolution
Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings Many fossils link early extinct species with current species Figure 13.3I Fossil Record
Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings Biogeography Biogeography, the geographic distribution of species –Suggested to Darwin that organisms evolve from common ancestors Darwin noted that Galápagos animals –Resembled species of the South American mainland more than animals on similar but distant islands
Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings Comparative Anatomy Analogous & Homologous Structures Comparative anatomy –Is the comparison of body structures in different species –May show common ancestry despite different morphology (arm & fin) Homology –Is the similarity in characteristics that result from common ancestry
Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings Homologous structures –Are features that often have different functions but are structurally similar because of common ancestry Human CatWhale Bat Figure 13.4A
Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings Comparative Embryology Comparative embryology –Is the comparison of early stages of development among different organisms
Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings Comparative Embryology Many vertebrates –Have common embryonic structures Post-anal tail Pharyngeal pouches Chick embryo Human embryo Figure 13.4B
Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings Molecular Biology as Evidence for Evolution Comparisons of DNA and amino acid sequences between different organisms Reveal evolutionary relationships (common ancestry) homology has come to mean any similarity between characters that is due to their shared ancestry (DNA seq., Protein seq.,etc.) Table 13.4 malwmrllpl lallalwgpd paaafvnqhl cgshlvealy lvcgergffy tpktrreaed lqvgqvelgg gpgagslqpl alegslqkrg iveqcctsic slyqlenycn Amino Acid Sequence for Human Insulin NCBI link
Copyright © 2005 Pearson Education, Inc. Publishing as Benjamin Cummings Development of pesticide resistance in insects Pesticide application Survivor Chromosome with gene conferring resistance to pesticide Additional applications of the same pesticide will be less effective, and the frequency of resistant insects in the population will grow Figure 13.5B