Fossils and Ancient Life Hynerpeton bassetti (early tetrapod)

Transcription

1 Fossils and Ancient Life Hynerpeton bassetti (early tetrapod) Define paleontology. Identify and list the types of fossils that have been found. Identify and list the kinds of information that can be discovered from the fossil record. Is the fossil record complete? Explain! Will it ever be complete? Explain! Define extinct. Define extant. What percentage of species that have ever lived are now extinct? 1

2 Water carries small rock particles to lakes and seas. How Fossils Form The preserved remains may be later discovered and studied. Dead organisms are buried by layers of Identify the most common type of fossil. sediment, which Identify the kind of rock they are found in. forms new rock. Study the diagram and explain the process. Define strata. Explain how strata relate to time. Does every organism that dies become a fossil? What conditions make the difference? What parts of the organism are most often preserved? Are soft tissues ever preserved? What does it depend on? Is DNA ever preserved? What can it tell us or be used for? 2

3 Interpreting Fossil Evidence Relative Dating Ammonites & other Molluscs Foraminifera Trilobites Define relative dating. Explain how it is generally done. Define index fossil. Explain how they can be used in relative dating. What three criteria make a good index fossil? Provide three examples of index fossils. 3

4 Interpreting Fossil Evidence Absolute Dating Define absolute dating. Define radioactive isotope. Define radioactive decay. Define half-life. Define radiometric dating. Study the graph... Explain the process of radiometric dating using Potassium-40 as an example. Give one example of something Potassium-40 would be appropriate for determining the absolute age of. What does it depend on? What is the half-life of Carbon-14? What would Carbon-14 be appropriate for determining the absolute age of? 4

5 Geologic Time Scale Vendian Back 4.8bya The Vendian (kind of rock) or Ediacaran (Australian hills with fossils) period is when the earliest-known animals evolved. Vendian biota (Ediacara fauna ), included soft-bodied multi-cellular animals, like sponges and worms (This is just for the Vendian, not the Precambrian.) Define the geologic time scale. Who developed it and what is it primarily based on? Define geologic Era. Describe the Precambrian Era. Why is it called Precambrian? Approximately what percentage of Earth's history is Precambrian? Define geologic Period. In general, what designates the Vendian period? What event marks the end of the Precambrian Era and Vendian Period? 5

6 Geologic Time Scale List the three Eras that follow the Precambrian. Translate Paleozoic. What are periods generally named after? What major animal groups (Phyla) evolved during the Paleozoic Era? What major event marks the end of the Paleozoic Era? Permian Carboniferous Devonian Silurian Ordovician Cambrian

7 Geologic Time Scale Cretaceous Jurassic Triassic Translate Mesozoic. What major terrestrial animal group (Class) dominated the Mesozoic Era? What major event marks the end of the Mesozoic Era? 7

8 Geologic Time Scale Translate Cenozoic. What major terrestrial animal group (Class) dominates the Cenozoic? 8

9 Geologic Time Scale Clock Model of Earth s History Label the major events marked with a pointer line. Chose from the following: First humans First animals Radiation of mammals First plants Accumulation of atmospheric oxygen First prokaryotes First multicellular organisms First eukaryotes Cenozoic Era Mesozoic Era Paleozoic Era Precambrian Time 4.4 by 4.8 by 0.4 by 4.0 by 0.8 by 1.2 by 3.6 by 3.2 by 1.6 by 2.8 by 2.0 by 2.4 by From the perspective of geologic time, how long (generally) have humans been here? 9

10 Formation of Earth Do we know how the Earth formed for sure? Explain! Which formed first, the Earth or the solar system? Explain! Define nebula. Define and explain planetary accretion. Approximately how long did this take? Explain how our moon formed. What was the heavy bombardment and how long did it last? Describe the Earth during this time. 10

11 Formation of Earth Study the diagram above... Describe the structure of the Earth from inside out. What was the state of the Earth when it took on this layered structure? What determined where different elements ended up? Have we ever drilled all the way to the core? What layer have we drilled through? Study the diagram to the right... Explain how we know Earth's core is solid. What is the outermost layer not shown in the diagram? How did it form? 11

12 Formation of Earth Methane Amonia Define atmospheric outgassing. Study the volcano diagram... Identify and list the gases that composed the first atmosphere. How do we know? Identify the gas and it's source that was NOT present in the early atmosphere. Because of this, what protective atmospheric layer was also missing? Consequence? How is the Earth's early atmosphere described chemically, due to the lack of oxygen? Approximately when did the heavy bombardment end? Approximately when did the Earth cool enough for liquid water? What is the significance of this? 12

13 1950s, Stanley Miller and Harold Urey The First Organic Molecules Mixture of gases simulating atmosphere of early Earth (hydrogen, methane & ammonia) Study the diagram... Identify the question Miller and Urey were investigating. What were they trying to simulate with this apparatus? Water vapor Write the null hypothesis. Describe the apparatus Liquid Water identifying the function & Liquid containing early Earth equivalent amino acids, fatty of each component. acids and other What were the results? organic compounds How long did it take? Review What are amino acids? What are fatty acids? Do these results support or refute the null hypothesis? What did Miller & Urey conclude? Is this the only experiment of this type ever performed? Where else have organic compounds been found to form? What is the significance of this? Spark simulating lightning storms Condensation chamber Cold water cools chamber, causing droplets to form. Trap Valve 13

14 ~200my After Liquid H2O (3.6 bya) Membrane? Define proteinoid microsphere. Define liposome. Describe how these form. What cellular component are these similar to? Review What two compounds make up most of the plasma membrane? Define protocell. Identify 2 cellular functions that have been demonstrated in protocells. 14

15 Genetic Material? Proteins build cell structures and catalyze chemical reactions RNA nucleotides Simple organic molecules Abiotic stew of inorganic matter Then Translation Now Transcription RNA able to replicate itself, synthesize proteins, and function in information storage DNA functions in information storage and retrieval Review What experiment showed the possible formation of simple organic compounds from inorganic matter? Describe the RNA world hypothesis. Study the diagram... Explain why RNA is hypothesized to be the first genetic material. Review What is something RNA does more frequently than DNA? What does the capacity for heredity, mutation & replication allow for?...and therefore? If RNA can do it all, why is there DNA? Is RNA alive? 15

16 Free Oxygen Study the figure & read the caption... Explain the significance of this fossil find in relation to atmospheric O2. Review: microfossils. prokaryotes, cyanobacteria, & photosynthesis. If these represent the earliest photosynthetic organisms, about how long ago did O2 generation begin? Where did the O2 build up first? What happened to it? Define free oxygen. Define saturation. Where was there free O2 about 2.2bya? Explain why O2 generation caused the extinction of many species. Explain the connection between O2 generation and the evolution of cellular respiration. Microfossils from the Apex Chert, North Pole, Australia. These organisms are Archean in age, approximately billion years old, and resemble filamentous cyanobacteria. 16

17 Ancient Prokaryotes Aerobic bacteria The Endosymbiotic Theory Chloroplast Photosynthetic bacteria Nuclear envelope evolving Mitochondrion Nucleus Algae and plants Nucleus Mitochondrion Primitive Aerobic Photosynthetic Eukaryote Protozoa, fungi and animals Archaeal Anaerobic Primitive Aerobic Prokaryote Eukaryote Review the significant environmental change that had taken place by about 2.2bya. Review the evolutionary events that followed this change. Study the diagram... What was the anaerobic archaeal prokaryote in danger of at this time? What was the aerobic bacteria able to handle and why? What advantages did the aerobe provide the anaerobe? What defines it as a eukaryote? What ecological term describes this partnership? Define endosymbiosis. Identify the photosynthetic bacteria. Define serial endosymbiosis. What advantage did the cyanobacteria provide the primitive aerobic eukaryote? What may be the origin of other internal membranes? Do you have endosymbionts? Note the major eukaryotic groups each of these lines were progenitors of. 17 Identify and explain the evidence for these events?

18 Identify and list various forms of asexual reproduction. Identify and list the types of organisms which reproduce asexually. Define sexual reproduction. Identify and list the types of organisms that reproduce sexually. Compare and contrast the two forms of reproduction in terms of : -Number of parents -Reproductive rate -Production of gametes -Mutation rate -Opportunity for gene shuffling -Opportunity for variation -Genetic comparison of parents and offspring -Advantages -Disadvantages Why did sexual reproduction evolve? Sexual Reproduction 18

19 Multicellular Organisms Precambrian Time Study the images and read the captions. How common are animal fossils from this time? Explain why. Frog Embryo Shown are scanning electron photomicrographs of two fossil embryo specimens from the 600-millionyear-old Doushantuo Formation in South China. The soccer-ball-shaped specimen is interpreted as an early stage (blastula) embryo, and the baseballshaped specimen is interpreted as an intermediatestage helical embryo consisting of three clockwise coils. Embryos are about millimeter in diameter. Dickinsonia sp. a Vendian animal fossil thought related to annelid worms. 19

20 Paleozoic Era A) Cambrian B) Ordovician C) Silurian D) Devonian E) Carboniferous F) Permian Define the Cambrian explosion. Which units of geologic time are listed? Match each Period with its representative figure by labeling the figure with a letter. 20

21 Paleozoic Era: Cambrian Period Invent an improved term for the Cambrian explosion. What is a better word than explosion? In general, how many modern animal phyla appeared at this time? Although diverse, all of the fossils belong to which major general animal group? Identify the body parts that fossilized particularly well. Brachiopods (Mollusk) Trilobites (Arthropod) 21

22 Supercontinent Pannotia In the image above, trilobites (1) live among many species that are not normally preserved. A typical Cambrian outcrop might produce only trilobites, brachiopods (2), mollusks (3), and crinoids (4). That is a tiny fraction of the full Cambrian biota, better represented by the roster of the Burgess Shale. That community includes sponges Vauxia (5), Hazelia (6), and Eifellia (7); brachipods Nisusia (2); priapulid worms Ottoia (8); trilobites Olenoides (1); other arthropods such as Sidneyia (9), Leanchoilia (10), Marella (11), Canadaspis (12), Helmetia (13), Burgessia (14), Tegopelte (15), Naraoia (16), Waptia (17), Sanctacaris (18), and Odaraia (19); lobopods Hallucigenia (20) and Aysheaia (21); mollusks Scenella (3); echinoderms Echmatocrinus (4); and chordates Pikaia (22); among other oddities, including Haplophrentis (23) Opabinia (24), Dinomischus (25), Wiwaxia (26), 22 Amiskwia (27), and Anomalocaris (28). Can you identify the possible ancestor of vertebrates?

23 Paleozoic Era: Ordovician & Silurian Periods Study these 4 figures... Determine the events during these Periods that each figure represents. Oldest Land Animal Fossil (scorpion stinger, 350my) 23

24 Paleozoic Era: Devonian Period Laurasia and Gondwana The Devonian Period is also known as the age of? Identify the evolutionary advancement in Kingdom Plantae. How did this advancement raise the fitness of this group? Identify the evolutionary advancement in Phylum Arthropoda. 24

25 Paleozoic Era: Devonian Period Acanthostega gunnari Identify the evolutionary advancement in the vertebrate group. Translate and define tetrapod. Explain the current understanding of how tetrapods evolved. 25

26 Paleozoic Era: Carboniferous & Permian Periods Supercontinent Pangea Anteosaurus was a large carnivore and probably weighed around Kg. The Early Permian apex predator Dimetrodon. A synapsid, mammal-like reptile. Explain how the Carboniferous Period got it's name. How many different evolutionary lines of reptiles arose at this time? What distinguishes them in the fossil record? To which generalized group does each line lead? Then... 26

27 Paleozoic Era: Permian Period The end-permian event that occurred 250 million years ago triggered an abrupt shift to the current dominance of higher-metabolism, mobile organisms (such as snails, clams and crabs) that actually go out and find their own food, and the decreased diversity of older groups of low-metabolism, stationary organisms (such as lamp shells and sea lilies) that filter nutrients from the water. What was the end Permian event? How extensive was the extinction? Identify and list four possible causes. This not only ended the Permian Period, but also the? 27

28 Mesozoic Era: Triassic Period Break-up of Pangaea starts. Following the Permian extinction, where did the species at the beginning of the Triassic Period come from? What pattern of evolution followed? Study the figure at left... Identify this line of descent. Identify the evolutionary advancement in Kingdom Plantae. How did this advancement raise the fitness of these species? 28

29 Mesozoic Era: Jurassic Period Explain why the Jurassic Period is considered the age of reptiles. Study the phylogenetic tree... Were they all dinosaurs? Explain! Study the bottom right figure... Find this species on the phylogenetic tree. What dinosaur-related group does it represent? What other major group was also here? (Hint: previous slide) Where were they? 29

30 Mesozoic Era: Cretaceous Period Identify the dominant terrestrial animals during the Cretaceous Period. Identify the animals in the lower left image... Are they dinosaurs? Identify the evolutionary advancement in Kingdom Plantae. How did this advancement raise the fitness of these species? (Not in Note Guide) What does evidence suggest happened to end the Cretaceous Period? This event also marked the end of what other geologic time? 30

31 Cenozoic Era Plesiadapis (60mya) is one of the oldest known primate-like mammal species Following the Cretaceous extinction, where did the species at the beginning of the Cenozoic Era come from? What pattern of evolution followed? Identify the dominant terrestrial animals during the Cenozoic Era. Note that the Periods of this Era are further defined by Epochs. What is the current Era, Period and Epoch? When will they end? 31

32 Cenozoic Era: Tertiary Period Australopithecus afarensis How did climate change during this period? What group of flowering plants evolved during this time? What was the significance of this? What evolutionary changes took place in the mammalian Orders represented here? Infer connections between environmental changes and mammalian evolution. 32

33 Cenozoic Era: Quaternary Period Doedicurus Identify the climatic changes that mark this period. What climatic period do we now enjoy? When did it start? Will it continue? Explain! Identify representative species of this time. What one word describes many of the North American species of this time? 33 What happened to them. Infer a possible cause.

34 Geologic Time You don't have this slide. I simply wanted you to view (and review) the geologic time scale as a whole. 34

35 Patterns of Macroevolution Extinction How many mass extinctions were there? Is extinction the exception, or the rule? Use the geologic time scale on the previous slide and/or the figure at right to label the geologic Period that corresponds to each extinction event. Do we know what caused all of these? Explain the effect extinction has had on biodiversity and the dominant species. (You don't have this.) 35

36 Adaptive Radiation Define adaptive radiation. Explain why each extinction event was followed by adaptive radiation. Be able to recognize and explain adaptive radiation using both the example of Darwin's finches on the Galapagos and Class Mammalia following the Cretaceous extinction. 36

37 Convergent Evolution Vertebrate (left) and Octopus (right). Define convergent evolution. Define analogous structure. Explain how each figure above is an example of convergent evolution. 37

38 Coevolution Some Central American Acacia species have hollow thorns and pores at the base of their leaves that secrete nectar. These hollow thorns are the exclusive nest-site of some species of ant that drink the nectar. But the ants are not just taking advantage of the plant they also defend their acacia plant against herbivores. Define coevolution. Explain how each figure above is an example of coevolution. Coevolution stems from what ecological relationship? 38

39 Punctuated Equilibrium Study the figure and read the captions... Compare and contrast these models that attempt to describe evolutionary rates. Evaluate each of these models... Explain which model you think is the most accurate. Time (a) Gradualism model. Species descended from a common ancestor gradually diverge more and more in their morphology as they acquire unique adaptations. (b) Punctuated equilibrium model. A new species changes most as it buds from a parent species and then changes little for the rest of its existence. 39

40 Developmental Genes and Body Plans Ancient Insect Two Types of Modern Insects Review homeobox (HOX) genes. Explain how a mutation in one HOX gene could explain the evolution shown in the example above. Describe how mutations effecting the location, timing and duration in the expression of single genes can result in profound physical changes. Apply this knowledge to explain how the difference between human and chimpanzee brains may have evolved. What experimental evidence would support this hypothesis? 40