Chapter 26: The Tree of Life An Introduction to Biological Diversity

1. Chapter 26: The Tree of LifeAn Introduction to Biological Diversity

2. Figure 26.1 An artist’s conception of Earth 3 billion years ago

3. 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 H2, methane (CH4), ammonia (NH3), 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. CH4 Electrode Water vapor H2 NH3 Condenser 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. Cold water Cooled water containing organic molecules H2O CONCLUSION Organic molecules, a first step in the origin of life, can form in a strongly reducing atmosphere. Sample for chemical analysis Figure 26.2 Can organic molecules form in a reducing atmosphere?

4. 26.3 Hydro Thermal Vent

5. Glucose-phosphate 20 m Glucose-phosphate Phosphorylase Starch Amylase Phosphate Maltose Maltose (a) Simple reproduction. This lipo-some is “giving birth” to smallerliposomes (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. Figure 26.4 Laboratory versions of protobionts

6. Accumulating “daughter” isotope 1 2 Ratio of parent isotope to daughter isotope 1 4 Remaining “parent” isotope 1 8 1 16 1 2 3 4 Time (half-lives) Figure 26.7 Radiometric dating

7. Millions of years ago 600 400 300 200 500 100 0 2,500 100 Number of taxonomic families 80 2,000 Permian mass extinction Extinction rate 60 1,500 Number of families ( ) Extinction rate ( ) 40 1,000 Cretaceous mass extinction 500 20 0 0 Carboniferous Neogene Cretaceous Ordovician Paleogene Cambrian Devonian Jurassic Permian Triassic Proterozoic eon Silurian Ceno- zoic Paleozoic Mesozoic Figure 26.8 Diversity of life and periods of mass extinction

8. Table 26.1 The Geologic Record

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

10. Cytoplasm DNA Plasma membrane Ancestral prokaryote Infolding of plasma membrane Nucleus Endoplasmic reticulum Nuclear envelope Engulfing of aerobic heterotrophic prokaryote Cell with nucleus and endomembrane system Mitochondrion Mitochondrion Engulfing of photosynthetic prokaryote in some cells Ancestral heterotrophic eukaryote Plastid Ancestral Photosynthetic eukaryote Figure 26.13 A model of the origin of eukaryotes through serial endosymbiosis

11. Eurasian Plate North American Plate Caribbean Plate Philippine Plate Juan de Fuca Plate Arabian Plate Indian Plate Cocos Plate South American Plate Pacific Plate Nazca Plate African Plate Australian Plate Scotia Plate Antarctic Plate Figure 26.18 Earth’s major crustal plates

12. Volcanoes and volcanic islands Oceanic ridge Trench Subduction zone Oceanic crust Seafloor spreading Figure 26.19 Events at plate boundaries

13. 26.19 Lava Flow

14. 26.19 Volcanic Eruption

15. 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. 0 Cenozoic North America Eurasia By the end of the Mesozoic, Laurasia and Gondwana separated into the present-day continents. 65.5 Africa India South America Madagascar Australia Antarctica By the mid-Mesozoic, Pangaea split into northern (Laurasia) and southern (Gondwana) landmasses. Laurasia Millions of years ago 135 Gondwana Mesozoic At the end of the Paleozoic, all of Earth’s landmasses were joined in the supercontinent Pangaea. 251 Pangaea Paleozoic Figure 26.20 The history of continental drift during the Phanerozoic

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

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