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115 Cards in this Set
- Front
- Back
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What are the 7 characteristics of a eukaryote?
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1. 10-100 micrometer diameter (50-100 times the size of a prokaryote)
2. Flexible internal and outer membranes 3. Cytoskeleton 4. True Nuceleus enclosing DNA 5. Complex organelles including mitochondria, peroxisomes, and plastids (chloroplasts) 6. Divide by mitosis 7. Reproduce by meiosis |
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Eukaryotes are the sister group of what?
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Archea
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What theory explains how eucaryota share some features with both bacteria and archaea?
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The Endosymbiont Theory
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What is the Endosymbiont theory?
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A theory that posits that mitochondria, the Oxygen based energy centers of all eukaryotic cells, and chloroplasts, the sites of photosynthesis in all plants, orginated as prokaryotes that were incorporated into a pre-eukaryotic phagocyte. Their double membranes and self contained DNA strongly support this hypothesis.
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What is a mitochondria?
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They oxidise sugars and fats to produce energy in a process called repiration. A mitochondrion has two membranes, a smooth outer and a folded inner membrane. THey have their own DNA
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What is a chloroplast/plastid?
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The sites where photosynthesis occurs in green plants. The threadlike structures running the length of the chloroplast are grana, stacks of flattened membranes that contain chlorophyll. The faint white patches within the chloroplasts are called nucleoids, where the chloroplast DNA is stored.
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Did the endosymbiont occur once or repeatedly?
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Endosymbiosis happens repeatedly in different eukaryote lineages.
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What is the support for the endosymbiosis theory?
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1.independent DNA of mitochondria and chloroplasts
2. Double membrane - consistent with a cell within a vesicle 3. Not limited to prokaryotes |
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What is mitosis?
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The process by which a ukaryotic cell separates the chromosomes in its cell nucleus into two identical sets, in two separate nuclei, each of which is inherited by a daughter cell. (The major mechanism for reproducing DNA in an organism with a nucleus)
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What is Meiosis?
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A process in which DNA from the two copies produced by mitosis is mixed and the cell subsequently divides to produce four haploid cells (cells with only one copy of each gene). The haploid cells are gametes. (Cells that join with another gamete to produce a new diploid cell)
All this comes down to the invention of sex; recombination increaed rate at which variation was generated in populations and therefore accelerated evolution. |
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When did the crown group of eukaryotes diverge?
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1750 Ma
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When was the earliest single cell fossil?
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1450 Ma
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What was the earliest multicelluar fossil? When was it dated?
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Grypania around 1.87 Ma
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What is the oxygen holocaust?
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Oxygen reacts strongly with chemcially reduced materials like organic carbon molecules. With the rise of the free O2 in the atmosphere, it killed many anerobic microbial lineages.
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What is the Boring Billion?
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Between 1.8 and 0.8 Ga the Earth sytem appears to have been quite stable.
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What started occuring around 800 ma?
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Extreme negative carbon isotope excurisions. The bitter Springs Anomalay, the Stutian, Marinoan, Gaskiers, and Shuram anomalay. BIF reappeared and snowball conditions returened/
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What are the snowball earth glaciations?
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Sturtian, the Marinoan, and the Gaskiers. All occured showing very low carbon 13 on records.
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What are the 4 proofs that indicate ice ages?
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1) Strated surface overlain by the smalfjord diamicite
2) Faceted and multistraited stone 3) Dropstones in BIF 4) typical abrupt conformable contact between the upper dropstone unit and the cap dolostone |
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What are cap carbonates?
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They are distincitve carbonate rocks (mostly dolostones) that sharply overlie Neoproterozic glacial deposits.
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What are the cap carbonates characterizations?
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1) directly overlie glacial deposits
2) ususual cements indicating rapid carbonate precipitation from sea water 3) very light carbon 13 isotope values 4) shallowing upward facies |
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What is Ice-albedo feedback?
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Lifght is reflected back into space by ice which results in cooling, which makes more ice to send more light back into space making it even colder. It is a positive feedback loop. If ice gets closer than 30 degrees from the equator it will cause a runaway ice age.
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What is Hysteresis?
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catastrophic shifts between alternative states - in the case of snowball conditions, the ice albedo positive feedback will drive ice sheets once they get within 30 degrees latitude of the equator; accumulation of CO2 when all the surface are covered by ice causes a reverse shift and catastrophic melting and warming.
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What causes cap carbonates?
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The reults of the very high CO2 immediately after melting, resulting in extreme warmth, weathering, and carbonate precipitation in the oceans
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When did O2 rise to modern levels?
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Right after the Marinoan Glaciation (Neoproterozoic). This is recorded by the shuran anomaly and coincides with the first appearance and rapid expansion of animal fossils in the rock record.
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What is the Doushantuo Formation the candidate for?
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The first fossil embryos from 570 Ma. They show palintomy but this is NOT unique to animal embryos
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What are the 6 characteristics of the Ediacaran Fauana?
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1) global distribtuion
2) soft bodied 3) large (up to >1m across) 4) Shallow and deep marine 5) variety of body plans 6) From 575-541 Ma |
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What are Rangeomoprhs?
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Rangeomorphs appear to be constructed of modular units repeated at different scles. This morphology greatly increases the surface area to volume ratio of these organisms. This is consisten with an osmotrophic mode of feeding (absorption of nutrients through diffusion from the surrounding environment.
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What do the Bilaterians indicate?
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That they were (Kimberella) were the first to leave trails and appears to have scraped the sediment for food. This shows that they have muscles and an through going gut.
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What is the coelom?
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a a fluid filled cavity that allowed movmenet.
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What is the substrate revolution?
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Ediacaran marine substrates were covered by microbial mats so trace fossils were limted to the sediment surface. However with the trepichnun pedum it started burrowing and destoryed the mats.
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What is the trepichnus pedum?
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The trace fossil that defins the base of the cambrian and burrowed. This caused the microbial mats to be lossed and then relased sequestered nutrients
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What is skeletonization?
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the evolution of armor teeth, structural support, and leverage
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What are the cambrian Small shelly fauna?
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Shells, spicules, sclerites (molluscs, brachiopods, and sponges, but also many mysterious sclerites) All of which were made out of CaCO3 or CaPO4
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What are the five major splits of fuana?
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Metazoa -> eumetazoa (diploblasty) -> bilateria (triploblasty) -> Beuterostomata & Protostomata -> Lophotrochozoa & Ecdysoza
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When did the major splits of cambrian life occur?
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In the Neoproterozoic
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What is Gondwana?
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The Southern Continents; Laurentia, Baltica, Sibera, Arbuckle, Aulacogen, Taconic Orogeny
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What is the Sauk Sequence?
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Expansion of the tropical eperic seas
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What is the Taconic Orogeny?
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Docking of Avalonia
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What is happening in the Sauk Sequence portion of the sea level changes?
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It is slowly lowering
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What is happening in the tippecanoe sequence of the sea level changes?
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It start to rise at the end of the age
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What do the SPICE and Hirnantian positive excursions indicate about the world from the carbon cycle at that time?
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That the climate was cooling
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The cambrian explosion and ordovician radiation did what for marine diversity?
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Made a huge rise in the marine diversity.
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What was established by the end of the cambrian for sea life?
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all major phyla and classes are established (body plans appear early and remain stable)
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What are the major marine ecosystems established in the Early paleozic (cambrian-ordovician)?
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Reef-building, predation, and burrowing
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What is a crown group?
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a clade that has all the traits of its modern descendants
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What is a stem group?
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organisms that do not yet have all the traits of their modern descendants
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What is the burgess Shale?
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A cambrian lagerstatten. It quickly buried everything and kept the soft parts from being dissolved/destroyed. This lead to a great find and information on animals of that time.
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What occurs in the ordovician as far as animals and plants?
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1) consolidation of paleozoic style organisms
2) first animal traces by early ordovician 3) first plant fragments and spores by middle ordovician |
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What are the five modern animal phylas?
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Porifera - Sponges
Deuterostomata - Echinodermata (sea urhcins, startfish, sea lily) Chordata (Horse, ray finned fish) Lophotrochozoa - (squird, clams, snails) Ecdysozoa - (insects, arthropods) Cnidaria - Corals, Jellyfish, Anemones |
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What are the 4 things that occured for the emergence of the modern marine ecosystems?
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1) multiple distinct lineages
2) body plans appear early and remain stable 3) skeletonization appears in multiple lineages 4) reef building, predation, sediment reworking were new ecological opportunities reflecting the evolutionary innovations of animal body organization |
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What is the Hirnantian Event?
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1.9 Ma year duration that started with sudden cooling, growth of ice sheets on gondwana, and extensive sea level drop. It ended with rapid warming, the loss of the ice sheets, and sea level rise.
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What is the End-Ordovician Mass Extinction?
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A two phase extinction. The start of the Hirnantian event and the end of hirnanatian events are the phases. 49% of genera are lost.
However the cool water hirnantian fauna are spread worldwide |
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What is the Acadian Orogeny?
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The collision with Baltica and main portion of Avalonia
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What is the Antler Orgogeny?
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The collision with Eastern Klamth Island Arc
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What is the Siluro-Devonian Evolution or North America?
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The Acadian Orogeny and the Antler Orogeny, with the Tippecanoe sequence regression and the kaskaskia sequence transgression.
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What happens in the tippecanoe regression?
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The water level rises
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What happens in the kaskasia transgression?
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Water level falls
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The end-Ordovician mass extinction has what effect on the ecologic communities in the Middle Paleozoic (silurian-Devonian)?
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Little, the basic structure of ecologic communities did not change much. They are very similar to the ordovician.
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The Middle Paleozoic (silurian-Devonian) is what kind of period for the paleozic fauna?
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A rapid recovery period, espcially for reefs
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Gnathostomes appeared when with what chacateristics?
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In the late silurian
1) Placoderms (armor-plated) 2) Jaw 3) Chondirchtyes 4) Swim-bladder/lung 5) Actinopterygii (ray-finned fish) 6) Sarcopterygii (lobe-finned fish) |
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What are the stem tetrapods?
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A group that stemed from saropterygians; they modified limbs and they are the origin of a flexible neck; EX (Tiktaalik, Acanthostega, Icthyostega)
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What is the oldest known plant to have a stem with vascular tissue?
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Cooksonia.
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What are stomata?
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pores on the surface of leaves and stems used for gas exchange.
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What are Tracheids?
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elongated cells that serve in the transport of water and mineral salts in vascular plants
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When does wood come around? What is it made of?
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In the devonian. It is composed of cellulose fibers embeeded in a matrix of ligning. Lignin made tall tress possible and is very hard to decompose.
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What were the parts of devonian forests?
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Canpoies, understories, and groundcover
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What are the three important trends in the evolution of seeds?
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1) heterospory (gametes of two different sizes)
2) integument (outer case) 3) pollen receiving structures. |
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When did seeds start being used and what did they allow?
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In the late devonian. It gave plants freedom from water for reproduction
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When did arthropods first come on land?
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Devonian. They were pre adapated with external waterproof skeleton and internal fertilization; spiracle adapted for breathing
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What are the characteristics of the Mass Extinction in the late devonian?
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50% of the marine genera are lost
End-Givetian, lower and upper keejllwasser, and hangenberg carbon isotope excursions - each associated with sea level drops followed by flooding of anoxic waters on shallow marine shelves and epicontenetal seas; low latitude alpine glaciation in Appalachians |
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What were the last two steps for the assembly of Pangaea?
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Alleghenian Orogeny
Ouachita Orogeny |
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What is the Alleghenian Orogeny?
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The collision with Gondwana
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What is the Ouachita Orogeny?
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The regional expression of the Alleghenian Orogeny.
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What Separates the Mississippian from the Pennsylvanian?
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a mid carboniferous unconformity
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What is the lowest point of global sea level in the Phanerozoic?
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The End Permian
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What were the charactertics of the late Paleozoic Ice Age?
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Diamictities, dropstones, and striations on souther continents
cyclothemic sea level changes in low latitude (tropical seas) |
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What are the characteristics of marine life in the late paleozoic (carboniferious-permian)?
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There is stable diversity, no reefs in the early part, but extensive reefs in the Permian (made up of sponges, bryozoans, and algea)
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With the exception of angiosperms, all major plant lineages were established by when?
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The devonian-carboniferous tranition.
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What is Amniota?
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(340 MA)A vertebrate evolution that has claws or nails at ends of digits
Complete loss of water breathing larvae Internal fertilization. There are two clades: synapsida (310 MA) and sauropsida (320 MA) |
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What evidence is there for a large amount of plants in the Late Paleozoic?
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The expansion of plant life consumed CO2 from the atmosphere by making wood and increased weathering rates as root systems evolved. They left behind 02 as waste produce in the atmosphere. The low amount of CO2 levels show that there were many plants
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What allowed large insects to grow in the Late Paleozic?
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The high levels of O2
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What are the characteristics of the End Permian Mass extinction?
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79% of marine genera are killed
it hit calcified animals with poor ability to adjust to high CO2 levels harder It was preceded by end capitanian extinction 9.5 Ma earlier Widespread shallow oceanic euxinia (high sulfer anoxic condition) Extinction pluse was less than 200 ka but Earth carbon cycle remained distrubed for millions of years. Conincided with beginning of Siberian Traps (Release of CO2 and So2 caused weathering and acidfification) |
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What is the Sonoma Orogeny?
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The end of westward dipping subduction on Pacific margin
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What is the Nevadan Orogeny?
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The sierra Nevada Batholith on the Pacific Margin
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What created rift valleys along the east coast?
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opening of the north atlantic
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What is disaster faunas?
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low diversity ecological communities characterized by wide geographic and environmental distribution
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What did the Synapsid Evolution change?
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They went from Therapsids to Mammal life animals
Secondary Palate - the roof of the mouth separating the nasal cavity from the mouth. Having a secondary palate allows mammals to eat and breath at the same time Specialized teeth Jaw bone Whiskers |
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What did the Sauropsid Evolution change?
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extensive diversification including marine and flying forms; archosaurs develop an erect limb orientation (crocdilians and dinosaurs); dinosaurs appear by late triassic
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How did the marine realm change in the Early Meosozoic?
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Reefs re-evolved based on modern corals (scleractinian corals and photosymbionts)
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What is the Mesozoic Marine Revolution?
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Appearance of numerous groups of predators that puncture or crush shells (fish, crabs/lobsters/snails/starfish) starts an arms race with prey times evolving strong and more elaborate shells than in the Paleozoic or burrowing deeper rather than living on the surface of the sea floor
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What are the characteristics of the end-triassic mass extinction?
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55% of marine genara gone ( mostly paleozic leftovers that never really did wel lduring the triassic
a sharp negative carbon isotope excursion that coincides with the beginning of Central Atlantic Magmatic Province. |
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What is CAMP?
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Central Atlantic Magmatic Province: flood basalts and volcanism associated with opening of atlantic ocean
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What is present day climate like?
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warm peak in between ice ages that are cyclic and controlled by earths orbital parameters
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What is the Pliocene climate like?
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The final cooling to current icehouse climate
Thought to be tied to rise of the Isthmus of Panma This isolate atlantic from pacific and changed devliery of moisture and heat from equator to poles - with more moisture being transported to North Atlantic. More snow could accumulate leading to an ice albedo feedback exchange of mammal faunas between the americas (2.5-3MA) |
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What was the Miocene climate like?
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CO2 had dropped close to present atmospheric level
Expansion of grasslands (now with root growning instead of tip growning for grazers) evidence for expansion of grasslands is phytoliths (silica grains in grass cells) and hyposdonty index (high crowned teeth with enamel that extends past the gum to deal with the abrasiveness of phytoliths |
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What was the Eocene-Oligocene climate like?
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Cooling trend through late Eocene until a major drop in deep ocean temps at Eocene-Oligocene boundary; associated with first ice sheet on Antarctica - due to opening of oceanic passages around Antartica
Cooling resulted in change from forest to parkland Savannah in North America |
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What was the Paleocene-Eocene climate like?
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very warm climate ( tropical forests in North America and subtropical forests above the arctic circle)
mammals begin to radiate (starting from lineages that had already split in the cretaceous), but mostly archaic forms present Paleocene-Eocene Thermal Maximum is a brief <.2 MA rise in temperature (5-8C) that allowed organisms to redistibute their geolgraphic ranges around the world overall maximum warmth in early eocene |
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What was the cenozoic climate like?
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not much action in carbon cycle, but general cooling trend (based on deep ocean water temperature)
cooling from paleocene through olgiocene associated with decreasing CO2, but not much change CO2 since beginning of Miocene |
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Explain the Subduction of Farallon Plate in Pacific Ocean
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It was the start of San Andreas strik slip fault;
coincides with beginning of Rio Grande Rift and further extension of the basin and Range of western North America |
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What did the Final Closure of Tethys Ocean cuase?
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the rise of the himalayas, causcases, carpathians, and alps;
collision of india and asia starts 50 MA closure of eastern Mediterranean around 15 Ma closer of western Mediterranean around 6.5 Ma leads to messinian Salinty Crisis trapping black sea and caspian sea within Asian Land Mass |
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What is the Sevier Orogeny?
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Continued subduction on Pacific Margin led to "thin skinned" thrust belt centered in Utah in the Middle Creataceous
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What is the Laramide Orogeny?
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"Thick-skinned" thrusting starts further east, centered on montana, wyoming, and colorado in the late cretaceous paleogene
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When was the highest sea level in the Phanerozoic?
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Cretaceous
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What was occuring in the Marine realm during the Jurassic-Cretaceous?
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Continued arms race between predators and prey
reefs taken over by rudist bivalves The jurassic saw the origin and radition of many marine planktonic groups which resulted in chalk seas |
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What are chalk seas?
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a new habitat that inclued inoceramids, large flat clams that floated on the sea floor and provided hard substrate for diversity communities of encrusters. The seas themselves were like mud
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What are dinosaurs
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Dominat large terrestrial vertebrates (herbivores and carnivores)
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What are the two main kinds of dinosaurs?
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The lineagesaurischia (lizard hipped) and ornthischia (bird hipped)
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What are Birds in the late jurassic?
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Archaeopteryx is the first bird;
decended from saurischia, they have feathers, but no beak or fused breastbone and still have a long tail |
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What are Mammals like in the late jurassic?
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Juramaia in late jurassic is earliest undisputed mammal
simple stronger jaw, tooth replacement, prismatic enamel |
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What are the three living lineages of mammals
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Monotremata (milk but still lay eggs)
metatheria (marsupials) eutheria (placental mammals); both therian groups have live birth |
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What plants evolved in the Early Cretaceous? What are the traits?
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Archaefructus in early creatceous is the earliest angiosperm
Traits: flowers, endosperm within seeds, fruit |
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What are the the sister groups of gymnosperms (conifers, cycad, ginkgos)
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angiosperms
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What is the cretaceous terrestrial revolution?
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dinosauras and gymnosperms dominated large organisms, but warm blooded mammals and birds and flower bearing angiosperms were all diversifying as small organisms
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What is the End Cretaceous impact?
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10km asteroid at chicxulb impact in the Yucatan peninsuala; iridium layer, shocked quartz and microspherules as evidence
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What are the characteristics of the End cretaceous mass extinction?
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60% of marine species include marine reptile, ammonoids, ruids, inoceramids, and plankton
deep oceanic benthos unscathed on land dinosaurs are lost, but oganisms that lived in water or burrow appear to have fared better immediate consequences of impact include tsunami, ejecta blanket and termal pluse and appear to have affect Norht America longer term consequences include acid rain fro mCO2 and So2 released from vaporized carbonate platform as well as dust and soot; no oceanic anoxia and no strong global warming signal |
