CH. 17 HISTORY OF LIFE

1. CH. 17 HISTORY OF LIFE

2. Figure 17-2 Formation of a Fossil The FOSSIL RECORD provides evidence about the history of life on Earth (and for evolution). Alone, it does not PROVE evolution. Why? Section 17-1 Water carries small rock particles to lakes and seas. Dead organisms are buried by layers of sediment, which forms new rock. The preserved remains may later be discovered and studied.

3. RELATIVE DATING

4. HOW FOSSILS FORM • REQUIRES PRECISE CONDITIONS! • EGGS, FOOTPRINTS, LEAVES, SHELLS, BONES, ANIMAL DROPPINGS, WOOD….. • MOST FORM IN SEDIMENTARY ROCK • SOMETIMES SMALL PARTICLES ENCASE REMAINS & PRESERVE ONLY IMPRINT • SOMETIMES HARD PARTS PRESERVED WHEN THEY ARE REPLACED BY LONG-LASTING MINERAL COMPOUNDS • SOMETIMES PERFECTLY PRESERVED WHEN BURIED QUICKLY BY FINE-GRAINED CLAY OR VOLCANIC ASH BEFORE THEY BEGIN TO DECAY

5. Pompeii

6. Age of fossil with respect to another rock or fossil (that is, older or younger) Age of a fossil in years Comparing depth of a fossil’s source stratum to the position of a reference fossil or rock Determining the relative amounts of a radioactive isotope and nonradioactive isotope in a specimen Imprecision and limitations of age data Difficulty of radioassay laboratory methods Compare/Contrast Table Section 17-1 Comparing Relative and Absolute Dating of Fossils Relative Dating Absolute Dating Can determine Is performed by Drawbacks

7. IN RADIOACTIVE DATING (THINK CARBON-14), SCIENTISTS CALCULATE THE AGE OF A SAMPLE BASED ON THE AMOUNT OF REMAINING RADIOACTIVE ISOTOPES IT CONTAINS. HALF-LIFE: THE AMOUNT OF TIME REQUIRED FOR HALF OF THE RADIOACTIVE ATOMS IN A SAMPLE TO DECAY. Practice: The half-life of carbon-14 is 5730 years. What is the age of a fossil containing 1/16 the amount of carbon-14 of living organisms? ABSOLUTE DATING (RADIOACTIVE)

8. Concept Map EARTH’S EARLY HISTORY Section 17-2 Evolution of Life Early Earth was hot; atmosphere contained poisonous gases. Earth cooled and oceans condensed. Simple organic molecules may have formed in the oceans.. Small sequences of RNA may have formed and replicated. First prokaryotes may have formed when RNA or DNA was enclosed in microspheres. Later prokaryotes were photosynthetic and produced oxygen. An oxygenated atmosphere capped by the ozone layer protected Earth. First eukaryotes may have been communities of prokaryotes. Multicellular eukaryotes evolved. Sexual reproduction increased genetic variability, hastening evolution.

9. Earth’s early atmosphere probably contained hydrogen cyanide, carbon dioxide, carbon monoxide, nitrogen, hydrogen sulfide, and water. Hot and no good for life!

10. Figure 17-8 Miller-Urey Experiment THE FIRST ORGANIC MOLECULES Section 17-2 Mixture of gases simulating atmospheres of early Earth Spark simulating lightning storms MILLER & UREY • FILLED A FLASK WITH HYDROGEN, METHANE, AMMONIA, AND WATER TO REPRESENT EARTH’S EARLY ATMOSPHERE. • PASSED ELECTRIC SPARKS THROUGH THE MIXTURE. • RESULT: SEVERAL AMINO ACIDS BEGAN TO ACCUMULATE. • SUGGESTED: HOW MIXTURES OF THE ORGANIC COMPOUNDS NECESSARY FOR LIFE COULD HAVE ARISEN FROM SIMPLER COMPOUNDS PRESENT ON A PRIMITIVE EARTH! Condensation chamber Cold water cools chamber, causing droplets to form Water vapor Liquid containing amino acids and other organic compounds

11. PHOTOSYNTHETIC BACTERIA ADDED OXYGEN TO EARTH’S ATMOSPHERE. RUST ON OCEAN FLOOR, OCEANS TURNED BLUE-GREEN, OXYGEN ACCUMULATED IN THE ATMOSPHERE, METHANE AND HYDROGEN SULFIDE DECREASED, AND THE OZONE LAYER FORMED. OXYGEN FOR???

12. THE FIRST CELL??? • DROPLETS • COACERVATES: tiny spherical droplets of assorted organic molecules (specifically, lipid molecules) which are held together by hydrophobic forces from a surrounding liquid. – form spontaneously in dilute organic solutions • MICROSPHERES – protocells – like coacervates • BUBBLES???

13. Figure 17-12 Endosymbiotic Theory ORIGIN OF EUKARYOTIC CELLS: ENDOSYMBIOTIC THEORY (EUK CELLS AROSE FROM LIVING COMMUNITIES FORMED BY PROKARYOTIC ORGANISMS) Section 17-2 Chloroplast Plants and plantlike protists Aerobic bacteria Ancient Prokaryotes Photosynthetic bacteria Nuclear envelope evolving Mitochondrion Primitive Photosynthetic Eukaryote Animals, fungi, and non-plantlike protists Primitive Aerobic Eukaryote Ancient Anaerobic Prokaryote

14. Flowchart CH. 18 TAXONOMY Section 18-1 Linnaeus’s System of Classification Kingdom Phylum Class Order Family Genus Species

15. Figure 18-5 Classification of Ursus arctos BINOMIAL NOMENCLATURE: (SCIENTIFIC NAME) TWO-PART NAME (GENUS & SPECIES). ALWAYS WRITTEN IN ITALICS, GENUS CAPITALIZED, SPECIES LOWERCASED Section 18-1 Coral snake Abert squirrel Sea star Grizzly bear Black bear Giant panda Red fox KINGDOM Animalia PHYLUM Chordata CLASS Mammalia ORDER Carnivora FAMILY Ursidae GENUS Ursus SPECIES Ursus arctos

16. CLASSIFICATION OF MAN Kingdom: Animalia Phylum: Chordata (notochords) Class: Mammalia(hair, milk glands, diaphragm) Order: Primate (fingers, flat nails) Family: Hominidae (upright posture, flat face) Genus: Homo (double-curved spine, long youth, life span) Species: Sapiens (chin, high forehead, well-developed cerebrum) Scientific Name: Homo sapiens

17. Traditional Classification Versus Cladogram TRADITIONAL CLASSIFICATION VS CLADOGRAM (PHYLOGENETIC TREE) Section 18-2 Appendages Conical Shells Crustaceans Gastropod Crab Crab Limpet Limpet Barnacle Barnacle Molted exoskeleton Segmentation Tiny free-swimming larva CLASSIFICATION BASED ON VISIBLE SIMILARITIES CLADOGRAM

18. Traditional Classification Versus Cladogram TRADITIONAL CLASSIFICATION VS CLADOGRAM (PHYLOGENETIC TREE) Section 18-2 Appendages Conical Shells Crustaceans Gastropod Crab Crab Limpet Limpet Barnacle Barnacle Molted exoskeleton Segmentation Tiny free-swimming larva CLASSIFICATION BASED ON VISIBLE SIMILARITIES CLADOGRAM

19. Eukaryotic cells Prokaryotic cells Kingdom Plantae Kingdom Protista Domain Bacteria Domain Archaea Kingdom Fungi Kingdom Animalia Kingdom Eubacteria Kingdom Archaebacteria Concept Map Section 18-3 Living Things are characterized by Important characteristics which place them in and differing Domain Eukarya Cell wall structures such as which is subdivided into which place them in which coincides with which coincides with

20. Figure 18-12 Key Characteristics of Kingdoms and Domains CHARACTERISTICS OF KINGDOMS AND DOMAINS Section 18-3 Classification of Living Things DOMAIN KINGDOM CELL TYPE CELL STRUCTURES NUMBER OF CELLS MODE OF NUTRITION EXAMPLES Bacteria Eubacteria Prokaryote Cell walls with peptidoglycan Unicellular Autotroph or heterotroph Streptococcus, Escherichia coli Archaea Archaebacteria Prokaryote Cell walls without peptidoglycan Unicellular Autotroph or heterotroph Methanogens, halophiles Protista Eukaryote Cell walls of cellulose in some; some have chloroplasts Most unicellular; some colonial; some multicellular Autotroph or heterotroph Amoeba, Paramecium, slime molds, giant kelp Fungi Eukaryote Cell walls of chitin Most multicellular; some unicellular Heterotroph Mushrooms, yeasts Eukarya Plantae Eukaryote Cell walls of cellulose; chloroplasts Multicellular Autotroph Mosses, ferns, flowering plants Animalia Eukaryote No cell walls or chloroplasts Multicellular Heterotroph Sponges, worms, insects, fishes, mammals

21. CLADOGRAM

22. CLADOGRAM & PHYLOGENETIC TREE (TYPE OF CLADOGRAM)

23. GEL ELECTROPHORESIS AND CLADISTICS DESIGN A CLADOGRAM THAT ILLUSTRATES THE EVOLUTIONARY RELATIONSHIPS SHOWN BY THIS GEL.

24. Figure 18-13 Cladogram of Six Kingdoms and Three Domains CLADOGRAM OF 6 KINGDOMS AND 3 DOMAINS Section 18-3 DOMAIN ARCHAEA DOMAIN EUKARYA Kingdoms Eubacteria Archaebacteria Protista Plantae Fungi Animalia DOMAIN BACTERIA

25. MOLECULAR CLOCK • USES DNA COMPARISONS TO ESTIMATE THE LENGTH OF TIME THAT TWO SPECIES HAVE BEEN EVOLVING INDEPENDENTLY. The genetic equidistance phenomenon was first noted in 1963 by E. Margoliash, who wrote: "It appears that the number of residue differences between cytochrome C of any two species is mostly conditioned by the time elapsed since the lines of evolution leading to these two species originally diverged. If this is correct, the cytochrome c of all mammals should be equally different from the cytochrome c of all birds. Since fish diverges from the main stem of vertebrate evolution earlier than either birds or mammals, the cytochrome c of both mammals and birds should be equally different from the cytochrome c of fish. Similarly, all vertebrate cytochrome c should be equally different from the yeast protein."[2] For example, the difference between the cytochrome C of a carp and a frog, turtle, chicken, rabbit, and horse is a very constant 13% to 14%. Similarly, the difference between the cytochrome C of a bacterium and yeast, wheat, moth, tuna, pigeon, and horse ranges from 64% to 69%. Together with the work of Emile Zuckerkandl and Linus Pauling, the genetic equidistance result directly led to the formal postulation of the molecular clock hypothesis in the early 1960s.[3] Genetic equidistance has often been used to infer equal time of separation of different sister species from an outgroup.[4][5]