1. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Chapter 26: The Tree of Life An Introduction to Biological Diversity

2. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Figure 26.1 An artist’s conception of Earth 3 billion years ago

3. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Figure 26.2 Can organic molecules form in a reducing atmosphere? RESULTS As material circulated through the apparatus, Miller and Urey periodically collected samples for analysis. They identified a variety of organic molecules, including amino acids such as alanine and glutamic acid that are common in the proteins of organisms. They also found many other amino acids and complex, oily hydrocarbons. EXPERIMENT Miller and Urey set up a closed system in their laboratory to simulate conditions thought to have existed on early Earth. A warmed flask of water simulated the primeval sea. The strongly reducing “atmosphere” in the system consisted of H 2, methane (CH 4 ), ammonia (NH 3 ), and water vapor. Sparks were discharged in the synthetic atmosphere to mimic lightning. A condenser cooled the atmosphere, raining water and any dissolved compounds into the miniature sea. Electrode Condenser Cooled water containing organic molecules H2OH2O Sample for chemical analysis Cold water Water vapor CH 4 H2H2 NH 3 CONCLUSION Organic molecules, a first step in the origin of life, can form in a strongly reducing atmosphere.

4. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 26.3 Hydro Thermal Vent

5. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Figure 26.4 Laboratory versions of protobionts 20  m (a) Simple reproduction. This lipo- some is “giving birth” to smaller liposomes (LM). (b) Simple metabolism. If enzymes—in this case, phosphorylase and amylase—are included in the solution from which the droplets self-assemble, some liposomes can carry out simple metabolic reactions and export the products. Glucose-phosphate Phosphorylase Starch Amylase Maltose Phosphate

6. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Figure 26.7 Radiometric dating 1 234 Accumulating “daughter” isotope Ratio of parent isotope to daughter isotope Remaining “parent” isotope 1 1 1 1 Time (half-lives) 2 4 8 16

7. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Figure 26.8 Diversity of life and periods of mass extinction Cambrian Proterozoic eon Ordovician Silurian Devonian Carboniferous Permian Triassic Jurassic Cretaceous Paleogene Neogene Number of families ( ) Number of taxonomic families Extinction rate Cretaceous mass extinction Permian mass extinction Millions of years ago Extinction rate ( ) PaleozoicMesozoic 0 20 60 40 80 100 600 500 400300200 1000 2,500 1,500 1,000 500 0 2,000 Ceno- zoic

8. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Table 26.1 The Geologic Record

9. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Figure 26.10 Clock analogy for some key events in Earth’s history Land plants Animals Multicellular eukaryotes Single-celled eukaryotes Atmospheric oxygen Prokaryotes Origin of solar system and Earth Humans Ceno- zoic Meso- zoic Paleozoic Archaean Eon Billions of years ago Proterozoic Eon 1 2 3 4

10. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Figure 26.13 A model of the origin of eukaryotes through serial endosymbiosis Cytoplasm DNA Plasma membrane Ancestral prokaryote Infolding of plasma membrane Endoplasmic reticulum Nuclear envelope Nucleus Engulfing of aerobic heterotrophic prokaryote Cell with nucleus and endomembrane system Mitochondrion Ancestral heterotrophic eukaryote Plastid Mitochondrion Engulfing of photosynthetic prokaryote in some cells Ancestral Photosynthetic eukaryote

11. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Figure 26.18 Earth’s major crustal plates North American Plate Caribbean Plate Juan de Fuca Plate Cocos Plate Pacific Plate Nazca Plate South American Plate African Plate Scotia Plate Antarctic Plate Arabian Plate Eurasian Plate Philippine Plate Indian Plate Australian Plate

12. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Figure 26.19 Events at plate boundaries Volcanoes and volcanic islands Trench Oceanic ridge Oceanic crust Seafloor spreading Subduction zone

13. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 26.19 Lava Flow

14. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings 26.19 Volcanic Eruption

15. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Figure 26.20 The history of continental drift during the Phanerozoic India collided with Eurasia just 10 million years ago, forming the Himalayas, the tallest and youngest of Earth’s major mountain ranges. The continents continue to drift. By the end of the Mesozoic, Laurasia and Gondwana separated into the present-day continents. By the mid-Mesozoic, Pangaea split into northern (Laurasia) and southern (Gondwana) landmasses. Cenozoic North America Eurasia Africa South America India Madagascar Antarctica Australia Laurasia Mesozoic Gondwana At the end of the Paleozoic, all of Earth’s landmasses were joined in the supercontinent Pangaea. Pangaea Paleozoic 251 135 65.5 0 Millions of years ago

16. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Figure 26.22 One current view of biological diversity Proteobacteria Chlamydias Spirochetes Cyanobacteria Gram-positive bacteria Korarchaeotes Euryarchaeotes, crenarchaeotes, nanoarchaeotes Diplomonads, parabasalids Euglenozoans Alveolates (dinoflagellates, apicomplexans, ciliates) Stramenopiles (water molds, diatoms, golden algae, brown algae) Cercozoans, radiolarians Red algae Chlorophytes Charophyceans Domain Archaea Domain Eukarya Universal ancestor Domain Bacteria Chapter 27 Chapter 28

17. Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Bryophytes (mosses, liverworts, hornworts) Plants Fungi Animals Seedless vascular plants (ferns) Gymnosperms Angiosperms Amoebozoans (amoebas, slime molds) Chytrids Zygote fungi Arbuscular mycorrhizal fungi Sac fungi Club fungi Choanoflagellates Sponges Cnidarians (jellies, coral) Bilaterally symmetrical animals (annelis, arthropods, molluscs, echinoderms, vertebrate) Chapter 29 Chapter 30 Chapter 28Chapter 31Chapter 32Chapters 33, 34