Geology 105 CofC Test 2 Colgan – Flashcards
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Acanthostega
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first amphibian; one of the first vertebrate animals to have recognizable limbs; lived almost entirely in fresh water
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Arthodires
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armored jaw fish that flourished in the Devonian period before their sudden extinction, surviving for 50 mill. years and penetrating most marine ecological niche
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Amino Acids
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proteins of life
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Lobefin Fishes
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immediate predecessor of tetrapods (most closely related to us); have a central appendage in their fins containing many bones and muscles
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Rayfin Fishes
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largest and most successful group of fishes and make up half of all living vertebrates; fish with true teeth, true bones, and a jaw bone
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Archaea
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any group of single celled prokaryotic organisms; best candidate for earliest life (can live in extreme environments)
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Isua, Greenland
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first chemical evidence of life; biologically produced carbon, shallow marine vent community
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Agnatha
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chordate jawless fish
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C. megalodon
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giant shark of South Carolina, fed on whales
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Deuterostome
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filter-feeders with floating larvae; include echinoderms and chordates
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Eryops
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most famous Paleozoic amphibian; evolved from lobe-finned fish, adapted many fish-like characteristics for land life
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BIF (Banded Iron Formations)
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sedimentary rocks found mainly in sequences older than 1800MYA; we find increasing accumulations of these from the beginning of the Archaean
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Ichtyostega
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one of the first tetrapods in the fossil record
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Lung Fishes
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used gills to breathe air into lungs; connected to the first land creatures; the side fins are the same bones that create arms and legs
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Pikaia
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a primitive chordate; worm; if Pikaia didn't survive, we wouldn't exist *historically contingent*
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Trace Fossils
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fossil of a footprint, trail, burrow, or other trace of an animal
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C. Lyell
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father of modern geology, created concept of uniformitarianism
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Lateral Line
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sensors under the shark's skin that monitors pressure and helps sharks find surrounding fish; only functional in water
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Eusthenopteron
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Devonian fish. "the fish with legs," similar limb and bone structure
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Hallucigenia
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Cambrian animal found in Burgess Shale; had 14 "tentacles" that seemed to have a mouth at each tip; only 3 cm long
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Labrythodont
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one of the first land animals/amphibians, the pectoral and pelvic fins were modified into short, powerful legs
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Placoderms
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jawed fish from the Silurian period with absent teeth; outside shell of its head and neck were made of bone while the remainder of its body was cartilage
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Tiktaalik
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has a neck for receiving oxygen and wrists (like us)
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Amphioxus
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chordate; intermediate form between invertebrates; has a notochord and gills, slender fish without eyes or definite head
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Coelacanths
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transition to land animals; used fins to waddle-gave rise to amphibians
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Stomatolites
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structures formed in shallow water by the accretion and cementation of sedimentary grains of microorganisms, especially cyanobacteria
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Prokaryotic cells
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no nucleus/internal structure
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Helicoprion
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shark-like fish
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Tommotian fauna
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diverse, early Cambrian shelly fauna provided diversity; secreted skeletons including mollusks, archeocyathids, etc..
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Opabinia
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small Cambrian critter, caught prey with grasping claws of its long, tube-like proboscis
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Tetrapods
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first four-limbed vertebrates
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Anomalocaris
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extinct shrimp-like life form closely related to arthropods; top predator that rules during Cambrian period
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Cooksonia
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world's oldest known plant, underwater, mushroom-shaped and had vascular characteristics
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DNA
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a nucleic acid that contains the genetic constructions used in the development and functioning of all known living organisms
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Fitz-Roy
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captain of the ship; he was depressed and needed a dinner companion; Darwin's partner and captain of HMS Beagle
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Henslow
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English clergyman, botanist and geologist; best remembered as a friend and mentor to pupil Charles Darwin
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Little Shelly Fauna
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first appearance of skeletonized taxa in the rock record
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Ostracoderms
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the armored jawless fishes of the Paleozoic
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Uniformitarianism
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assumes that the same natural laws and processes that operate in the universe now, have always operated in the past and apply everywhere in the universe
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What is the Big Bang and how long ago did it happen?
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13.7 billion years ago The cataclysmic explosion of a small volume of matter at extremely high density and temperature
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How long after the Big Band did our solar system form?
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Long period of darkness, cooling, first stats were 1 billion years ago
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What elements were produced during the Big Bang? And were do all the other elements found on our earth come from?
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Hydrogen and helium Inside stars
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What is a supernova an why should it be important to you when you examine your history?
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-death of a star and release of elements into space -elements that make up our solar system come from supernovas
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How were the planets formed?
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-a star exploded and created a cloud of dust, gravity pulled the dust together -solar nebula/supernova
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Why are rocky (terrestrial) planets located near the sun?
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-They're heavier planets -Heavier planets are closer to the Sun and lighter planets are further away
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Describe Haden Crust
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-oldest rocks on earth--origin of the earth -4.6-3.8 BYA -very hot--heat release -segregation fo core, mantle, and crust -incandescent magma ocean
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What is the solar nebular theory?
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Big Bang (Supernova)- accumulating star dust keeps spinning until planets are formed
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When and how did the Moon originate?
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Mars-sized planet collided into earth and threw out a large amount of debris
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What is the Goldilocks (Habitable) zone and why is it important to us?
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-Zone that is not too hot, not too cold for water (Earth) -Where life/liquid water is able to exist
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The outgassing of volcanoes released what gases into the atmosphere? How did these gases set the stage for chemical and biological evolution?
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-water vapor, carbon monoxide, carbon dioxide, hydrochloric acid, methane -they will form amino acids, which are needed for life extreme environments caused Achaea to form -it set the stage for the atmosphere to fully form- thus allowing oxygen and life on Earth to exist
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What is the faint Sun Paradox? Why didn't the early Earth freeze?
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-baby sun -didn't emit much heat, but methane made it not freeze
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What are some greenhouse gases and what is the greenhouse effect?
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-carbon dioxide, nitrogen, water vapor -thermal radiation is absorbed in the atmosphere (Sun's heat is trapped)
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What was the source of water for the oceans? How did oceans form?
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-All the water today came from the atmosphere; water vapor from volcanoes -started as a gas, but as the Earth cooled below 100 degrees Celsius, it began to rain -salt in the ocean came from the weathering of rocks -Rivers->ocean
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When did the Earth form? How do we know?
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-4.6 billion years ago -we can date materials
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What is life? How do we know that Robin is alive?
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-organisms that undergo evolution and take in energy from their environment -requirements for life: free energy, organic molecules, liquid water
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What do you share in common with the first life form on Earth?
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-All life is made of the same organic compound -All life uses the same 20 amino acids -All life uses the same genetic code
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When did life first appear on Earth? How do we know? Remember there are no fossils associated with the first life forms.
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-3.8 billion year-old rock made of Isua sediments (Archaean eon) -Peculiar chemical signature of living organisms -biologically produced carbon -shallow marine vent community
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Why is Archaea considered the best candidate as the prototype for the first microbe to appear on Earth?
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-It's single-celled, most basic form of life -can survive in extreme environments -deep sea vents, anoxic conditions, hot springs, ice, acid sulfur springs
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Early Archaea bacteria produced methane gas as a byproduct of respiration. What was the impact of this methane on the Earth?
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-Warm planet -greenhouse gas -orange colored sky
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What is abiogenesis? How would you describe the environment and the type of microbes that are the best candidates for first life forms?
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-life arises from inorganic matter, anaerobic environment (need no oxygen) -anaerobic, heterotrophic, prokaryotic cells
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Where did life first start on Earth? Discuss two locations where life could have originated. Are there fossils of the earliest forms of life?
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-Deep, marine hydrothermal setting -early shallow, warm tidal pools
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Why are vent communities considered the location where life originated?
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-internal heat, Archaea and bacteria abundant -amino acids found and can be formed -safe from meteorite bombardment
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What were the oldest fossils? how were these fossils formed?
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-Stomatolites- still alive today -trapped layers of sediments with blue-green algae (cyanobacteria) -Pilbara Hills, Australia- found stomatolites in shallow marine community -Prokaryote cells
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Explain the set-up and purpose of Miller-Urey experiments. Why is it important? What was the problem with the experiments?
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-An experiment that simulated the conditions of the early Earth, testing the occurrence of chemical origins of life -Used water, methane, ammonia, hydrogen -Found organic compounds necessary for life
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What is the Last Universal Common Ancestor (LUCA)? What is the evidence for LUCA?
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-common ancestor of all life -we all share something with LUCA -same organic compounds, genetic code coiling structure, and amino acids
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What are fossils?
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-The preserved remains of animals, plants, and other organisms from the remote past -tangible remains or signs of ancient organisms- most found in sedimentary rocks
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The fossil record is strongly biased towards what type of organism?
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marine organisms (no oxygen, hard animals)
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What is the difference between absolute and relative time?
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-absolute time- concrete date -relative time- sequence of events
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What is the difference between body and trace fossils?
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-body fossils- reveal anatomy -trace fossils- reveal behavior
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What characteristics and environments favor the preservation of an animal in the fossil record?
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-hard organisms with fast burial rate -anoxic environments (oxygen causes decay) -best record: marine animals with shells
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Why is the fossil record a biased repository of evolutionary information?
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-unequal preservation -best record- marine animals with shells -poor record- terrestrial animals with bones -almost no record- terrestrial animals without bones
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How is uniformitarianism used in the study o fossil organisms?
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Assuming that the living conditions of the fossilized organisms were the same as the living conditions of their present-day relatives
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Describe the first metazoan
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-sponge- 780 million years old -small- grain of sand, microscopic
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Explain how a symbiotic relationship among Proterozoic prokaryotes may have given rise to eukaryotes.
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-prokaryotes absorbed bacteria and became more complex -eventually developed into eukaryotes -"According to Dr. Lynn Margulis, eukaryotic cells originate by endosymbiosis of prokaryotic cells (bacteria) with larger ones" - in class question
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How did the evolution of life alter the Earth's physical environment? Hint: think oceans, atmosphere, land...
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-gases escaping through -volcanoes made an envelope of atmosphere
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How did the retreat of glaciers during the snowball earth influence the development of metazoans?
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-Releases nutrients into the ocean -sharp increase in phosphorus -oxygen and nutrients stimulate growth of phytoplankton->evolution of metazoans
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Name the metabolic process in which carbon dioxide and water combine into organic molecules, and oxygen is released as a waste product. What is its importance?
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-photosynthesis -oxygen leads to nutrients = life and diversity
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What are Banded Iron Formations, and how were those structures formed?
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-Stomatolites produce oxygen gas in the ocean -abundant dissolved iron captures any free oxygen -oxidized iron deposited producing banded iron formations
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What are continental red beds and what do they indicate about condition of the atmosphere?
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-sandstone and shales of red color -they indicate a transition to a warmer atmosphere
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What are Hox genes and why are these genes so important in the evolution of metazoans?
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-found within all metazoans -master (regulatory) genes- control structural genes -determine form, number, and structure -Metazoans with the same characteristics can be traced back
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What are stomatolites and how do they forms? Why were they important?
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-single-celled prokaryotes -formed by malt-like masses of microbes-photosynthetic bacteria
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What evidence indicates that eukaryotic cells evolved over 2 billion years ago?
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fossils are big and you can see them without a microscope
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What indicates that free oxygen was present in the Proterozoic atmosphere 1.8 billion years ago?
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Red beds
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What is Snowball Earth?
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-a severe ice age that occurred 716-630 MYA -Frozen from poles to equator -2-3 cycles of freezing -ocean becomes anoxic
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What is the great oxygenation event? What was the importance of that event?
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-a rapid increase of oxygen -Evolution of Metazoans
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What is the Red Queen Hypothesis and how does this hypothesis help to explain the importance of sexual reproduction?
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-must constantly evolve to survive -sexual reproduction make evolving faster due to crossing over, random assortment, and random gamete fusion -introduce new genes, making offspring more variable
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What is the relationship between sexual reproduction and evolution?
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-genetically unique offspring -crossing over increases variability->descent with modification
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What was the cause of the Huronian Glacial Event?
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-first of 5 major events -an increase in photosynthesis with eventually decreased the greenhouse effect -silicate weathering slowed- decreased CO2
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Why does sexual reproduction lead to the death of the parents?
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parents have made the new version of themselves
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What are metazoans and what characteristics do all metazoans have in common?
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-multicellular animals that pass through embryonic stages of development -all have in common: cell structure, type of metabolism, reproductions, pattern of embryonic development, locomotion, genetics
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What types of symmetry are found within metazoans?
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-asymmetrical-sponges -radial-corals -bilateral-animals
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Why do some think there are only three kinds of metazoans?
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Three kinds of symmetry: sponges, corals, animals
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Discuss the benefits of skeletonization
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-served as an adaptive breakthrough -allowing preferential survival and niche exploitation -protection from predators -storage of mineral nutrients -movement-muscles can attach -support increase in size
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Discuss the possible causes for the increase of diversity of life during the Cambrian
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-increased geologic activity -increased food supply -increased oxygen level -evolution of the Hox genes -evolution of the eyes -new predator prey relationships
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How did an increase in geological activity at the start of the Cambrian contribute to an increase in species diversity?
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-more volcanic eruptions -increase in CO2 -warmer temperature -Sea level rise -more shallow water environments
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Why does the fossil record become richer during the Cambrian?
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-more diversity and complexity -good environment for fossilization
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What are trilobites?
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-first abundant recognizable fossils -most common and diverse invertebrates
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What is the Burgess Shale fauna?
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-rare Cambrian fossils- 100,000 fossils; more than 130 animal species -complex community- high diversity of early life -many experimental body plans- now extinct -arthropods and chordates
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What is the evidence that glaciers were widespread during late Proterozoic Snowball Earth?
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-glacial striations -explosion of life
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What is the importance of the Ediacaran fauna?
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-first large fossils -soft body group of sea floor organisms, no predators around to eat them -Metazoan animals related to modern forms
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What is the importance of the Tommotion (Little Shelly) fauna?
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first appearance of skeletonized taxa in the rock record
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What is the importance of the Mistaken Point fauna? What are they?
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-reveal complex, organized creatures -preserved in volcanic ash (communities of charnia with patterns of branching)
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What phylum is best represented ini the Burgess Shale fauna?
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anthropods
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What predators were in the Burgess Shale fauna? Why are predators an important factor for increasing species diversity? (Red Queen Hypothesis)
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-Anomalocaris Canadensis -evidence of predators-bite scars -prey adapts to survive and reproduce -predation becomes an arms race
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What was Pikaia and what is its importance today?
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-primitive chordate -survives the major extinction of Burgess Shale fauna -we came from Pikaia- if it didn't survive, we wouldn't exist -historical contingency
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Describe and draw a very early fish. Label its features.
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-jawless, toothless, boneless -no skeleton or internal structure -notochord and gills
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What are examples of living and fossil jawless fishes?
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-ostracoderms -lampreys -hagfishes
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Discuss the evolution of shark teeth
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-Shark skin- small, jagged overlapping scaled for low resistance and turbidity -teeth become outgrowth/modified portions of skin
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What is a lobefin as opposed to a ray-fin? (Draw or describe)
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-lobe fins are more powerful than ray fins -lobefin fishes have internal systems of bones and muscles that gel swim more efficiently
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Today, Lungfishes live in South America, Africa, and Australia. Explain the distribution of Lungfishes.
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-Had a widespread freshwater distribution -current distribution reflects extinction of many lineages following the breakup of Pangea
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Jawless fish
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ostracoderms- no jaw, open mouth, vertebral column, "plated skin" (aid in swimming, lack body skeleton), no fins, multiple gills
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Jawed fish
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Placoderms- first animal with a jaw, from gill arches, true teeth absent Arthodires- no true teeth, just bony plates part of the skull
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Teeth
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Cartilaginous Fishes/Chondrichthyes- sharkes; placoderms + teeth; no bone- cartilaginous skeleton, has true teeth- regular pattern of tooth replacement, shark skin becomes teeth, lateral line -Helicoprion- crazy spiral teeth -C. Megalodon- South Carolina
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Bone
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Rayfin fishes- jawed, true teeth, paired fins, bony (calcium phosphate) -Actinopterygii Lobefin fishes- same as above, fleshy fin, successful in shallow and inland waters -Coelacanths- bottom dwellers, used fins to "waddle"; gave rise to amphibians -Euthenophteron- the fish with legs, similar limb and skull structure as tetrapods -Panderrichthys- ecternal nostrils, same position as early tetrapods; started to leave the water -Lungfishes
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How did jaws evolve? What is the importance of jaws?
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-modification of gill arches -remodeling of existing structures- descent with modification
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Describe the first land community. When did it appear?
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-Appeared 385 MYA -consisted of a fish with limbs- no gills or neck -shared similar skull pattern as the animals in the mater
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Why did fishes start breathing air?
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high temperatures and anoxic waters
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Did limbs and air breathing occur before or after tetrapods emerged to live on land. Please explain.
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Before land-->limbs came from lobefins and air breathing evolved from gill arches
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Why did the first amphibians make excursions out of the water and onto land?
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-the development of limbs and loss of gills made the anoxic water no longer a suitable environment -had to be on land to take in oxygen
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Discuss the change needed to the skeleton of Acanthostega to enable an animal to move on land.
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-connection between the pelvis and hind limbs -extremely useful for terrestrial organisms to walk around on land- terrestrial locomotion
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What characteristics link lobefin fishes and the earliest amphibians? Which lobefin fish gave rise to amphibians?
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-skull and spine -braincase, ears, nostrils, and teeth -development of limbs- 4 legs -neck -the Coelecanth gave rise to amphibian- used fins to waddle
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Discuss the transition from Lobefin fishes to Amphibians. Place the following in correct order of appearance(Acanthostega, Eusthenopteron, Panderichthys, Ichthyostega, and Tiktaalik). For each animal, discuss the characteristics that were important during this transition.
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-Eustheropteron- tetrapod-like skull and spine -Panderichthys- tetrapod-like braincase and teeth, pelvic gurdle & fins -Tiktaalik- first neck, wrists ears (still in water) -Acanthostega- fish with 8 fingers- 4 legs -Ichthyostega- reduced to 5 toes, shoulders
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How does the transition from Lobefin fish to Amphibian support Darwin's theory of Descent with Modification? (IMPORTANT- you will see this)
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-development of existing structures -jaw from gill arch supports -teeth from shark skin -dermal skull- developed nostrils and neck (loss of gill cover) -evolution of limbs- movement
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Were the first tetrapods good swimmers or good walkers? Explain.
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-Acanthostega had 4 legs, but the first tetrapods were better at crawling the bottom of the water -Tail adapted for propulsion through water, still had gills
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What are some of the characteristics that you share with Tiktaalik?
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-neck -wrists -nose
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What is the importance of Tiktaalik and Panderichthys?
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-Tiktaalik- still water dweller, but had the first neck -Panderichthys- tetrapod-like braincase and teeth
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What were the first vertebrates to live their whole lives on land?
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amphibians
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When is a fish not a fish but an amphibian?
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A fish is an amphibian when it develops 4 feet and loses gills
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What characteristics are common to all chordates?
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-notochord -gills -single dorsal nerve chord -four limbs -back bone
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What characteristics do you share with lobefin fishes?
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-arms (limbs) -skull
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What characteristics link echinoderms to chordates?
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We share the same type of cell division during our embryonic state
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What is the fate of the gill arches in fishes?
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It becomes a jaw and ear bone
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How could such a complex structure like an eye evolve?
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Descent with modification
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In lobefin fishes, when do nostrils appear?
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When the mouth appears because their nostrils are connected to their mouth on the inside
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What do teeth, breasts, feathers, and hair have in common?
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-They all start as lower layers of skin folded inward -From these folds, each structure emerges
