Term
| What is the law of original horizontality? |
|
Definition
| sediment layers are deposited horizontally because of gravity |
|
|
Term
| what do tilted layers of rock mean? |
|
Definition
| They have been move sometime after their disposition |
|
|
Term
| What is the law of original continuity? |
|
Definition
| All deposited originally as one continuous layer. even if there are disturbances (rifts or valleys) one can assume they were originally horizontal |
|
|
Term
| What is the law of superposition? |
|
Definition
| oldest on bottom, youngest on top |
|
|
Term
|
Definition
| When Sedimentary layers are completely parallel, and there is no missing time. |
|
|
Term
| What are proofs of missing time geologically? |
|
Definition
| discomformities (angular or ordinary). Th |
|
|
Term
| What is a sea level fall and how does it create a disconformity? |
|
Definition
| When rock is deposited on sea floor, and the floor rises (or sea level falls) rock becomes exposed to erosion. This create a non horizontal rock layer, which can then be deposited on. This is a non-conformity because you are losing time |
|
|
Term
| What is an angular conformity? how does it happen |
|
Definition
| Bc of mountain building, two sets of rocks appear at angles to each other. Mountains are formed at angles, erosion occurs and horizontal layers are deposited above |
|
|
Term
| What does evolution is unidirectional and extinction is forever mean? |
|
Definition
| You can't go back and recreate dinosaurs. They are dead for a reason, and their extinction is a factor of a changed environment |
|
|
Term
| What are fossils used for in biostratigraphy? |
|
Definition
| used to supplement insufficient information about the era's |
|
|
Term
| What is radioactive decay? why is it used in geological time scales? |
|
Definition
| the rate at which radioisotopes decay. Used to date rocks bc you can maeasure amount of radioactive decay in rock |
|
|
Term
| How do you measure fissils dont contain any U235, or U238? |
|
Definition
| measure volcanic ash zircon and compare the dates of layers of ash. The ash above them is younger than them and below them is older. So you can gain a relative geologic time period |
|
|
Term
| What does C-14 decay into? what is it's half life? |
|
Definition
|
|
Term
| What % of carbon in the world is c-14? why don't we measure C-13? |
|
Definition
| less than 1% of carbon is c-14, we don't measure c-13 or c-12 because those are stable and don't decay radioactively |
|
|
Term
| What is c-14 good for measuring? what is it not good for (what do we use instead) |
|
Definition
| good for dating recent things (6000 yr half life) but not good for much older things. instead we use uranium |
|
|
Term
| what is the half life for U-235, 238? |
|
Definition
| 235 - 713 Ma, and 238 -4.5Ga |
|
|
Term
| How do measure things that are very old but don't contain Uranium? |
|
Definition
| We measure age of lava flow or volcanic ash layer near fossil bed, both above and below and gain a range. |
|
|
Term
| How old is lucy? where was she found and what species is she? |
|
Definition
| 3 Ma, Hadar, ethiopia, australopithecus afarensis |
|
|
Term
|
Definition
| She is found below 2.95Ma ash, above 3.18Ma ash, so she is about 3Ma |
|
|
Term
| What is alpha, beta and gamma emission? When does radioactive decay in normal cellular processes? |
|
Definition
| alpha - lose two protons and two neutrons. Beta - loss of electron /positron, gamma decay- electron capture. Occurs during photosynthesis. |
|
|
Term
| When was the geologic time scale created? |
|
Definition
|
|
Term
| List All the eons and times |
|
Definition
| Archaen (4.5ga to 2.5ma), Proterozoic (2.5Ga to 540Ma), and Phanerozoic (540 to present) |
|
|
Term
| LIst all periods in the paleozoic (including late phanerozoic) and their times |
|
Definition
| Ediacaran (?) cambria (540-495) ordovician (495), silurian (440), devonian (417) carboniferous (354), permian (292) |
|
|
Term
| List all period and times of Mesozoic era |
|
Definition
| Triassic (250 -202), Jurassic (202 - 142) and Cretaceous (142 - 65) |
|
|
Term
| List all periods and times of cenozoic era |
|
Definition
| Paleogene (65-24), neogene (24 to present) |
|
|
Term
| List all era's and times of phanerozoic |
|
Definition
| paleozoic (540 to 250), mesozoic (250 to 65) and cenozoic (65 to present) |
|
|
Term
| List all epochs of paleogene and times |
|
Definition
| Paleocene (65 to 55), eocene (55 to 34), oligocene (34 to 24), Miocene (24 to 5.3), pliocene (5.3 to 1.8), Pleistocene (1.8 to 15,000 ya) and holocene ( 15,000 to present) |
|
|
Term
| List all epochs of paleogene and times |
|
Definition
| Paleocene (65 to 55), eocene (55 to 34), oligocene (34 to 24), Miocene (24 to 5.3), pliocene (5.3 to 1.8), Pleistocene (1.8 to 15,000 ya) and holocene ( 15,000 to present) |
|
|
Term
| What occured during paleozoic, mesozoic and cenozoic eras? p |
|
Definition
| first invertebrates with skeletons, first dinosuars, mammals and birds, acme of mammals and flowering plants |
|
|
Term
| What epoch does the first human family appear in? |
|
Definition
| In the pliocene epoch (5.3 MA to 1.8Ma) |
|
|
Term
|
Definition
| View that the world was fixed and immobile. |
|
|
Term
| What is the youngest feature on the planet? how old? |
|
Definition
| Oceans, have only been around for 250Ma |
|
|
Term
| How are oceans created and destroyed? how fast are they moving? |
|
Definition
| They are created and destroyed at fault lines, move at rate fingernails grow. |
|
|
Term
| Who suggested continental drift? |
|
Definition
|
|
Term
| What four pieces of evidence did wegner have? |
|
Definition
1) Fit of S. america and africa
2) fossil distribution - Mesosaurus found in east Sa and western africa (not in N.Amer or Asia - continental drift)
3) Distributions of glacial deposits - Scratching marks are radiating outwards, so they all radiate outwards to where gondwana would have been
4) Continuity of mountain belts across oceans - appalachian and atlas mountains is continuous but separated by oceans |
|
|
Term
| What are the three arguments for current plate tectonics? |
|
Definition
| 1) Ridge on bottom of atlantic ocean (right between Europe and N.A) - mid atlantic ridge 2) As you move towards continents, oceans are older (middle youngest) 3) Magnetic pole reversal --> Paleomagnetics recorded in rocks determine the latitude at which rocks where formed. (have been moving) |
|
|
Term
| What collision forms volcanic arcs? |
|
Definition
ocean plate to ocean plate - either one goes down or up - volcanic island arc
Ocean plate and continent - ocean goes down . OCean is more dense (has pressure of whole ocean on top of it). volcanic continental arc |
|
|
Term
| What is the result of continent to continent collision? |
|
Definition
| neither can go down, so they make a mountain belt by pushing upwards - exemplified by himalayas |
|
|
Term
| What did gonwana consist of? What was it considered? how long did it last for? |
|
Definition
| South America, africa, antartica, India, and Australia. Considered a mega continent , lasted for 3-350 my |
|
|
Term
| What is the combination of all continents called? when did it last happen? |
|
Definition
| Called a supercontinent, last time it happened was between 300Ma and 200Ma during carboniferous era --> called pangea |
|
|
Term
| When did pangea exist? What did it affect? |
|
Definition
| 200-300 Ma, affected evolution of life |
|
|
Term
| When did rodinia exist (what was it?) and what did it affect? |
|
Definition
supercontinent, 1200-800Ma
Allowed for all animal life to be possible by breaking up |
|
|
Term
| What was nuna, when did it exist? what did it's formation allow? |
|
Definition
| 2000 Ma, allowed for air to be breathable |
|
|
Term
| what were the supercontinents? |
|
Definition
|
|
Term
| how is a linear sea created? |
|
Definition
| The combination of plates bows up and created a high flat area. This is along a fault line, eventually fails and creates a huge volcano. The rift valley area increases to create a linear sea |
|
|
Term
| What forms from a linear sea? |
|
Definition
| A full ocean which contains a mid ocean ridge |
|
|
Term
| What always occurs during continental break up? |
|
Definition
|
|
Term
| what is an example of a linear sea? t |
|
Definition
| between the red sea and gulf of aden |
|
|
Term
| what is the rift valley an example of? |
|
Definition
| a failed attempt of africa to break into two parts |
|
|
Term
| What is the wilson/supercontinent cycle? |
|
Definition
| The theory that oceans are transitory features, only form when continents break up and disperse. They then are destroyed on the other side of the world when contients collide |
|
|
Term
| When was flat limestone in kingston deposited? |
|
Definition
| in the ordovician era, around 460Ma |
|
|
Term
| What period was pangea in? |
|
Definition
|
|
Term
| In what period did laurasia split from gondwana? |
|
Definition
|
|
Term
| When is gondwana officially broken apart? |
|
Definition
| by 94 MA (late cretaceous) |
|
|
Term
| When does europe split from asia and north america (laurasia split)? |
|
Definition
|
|
Term
| How and when are himalayas created? |
|
Definition
| In the late oligocene when India crashed into asia |
|
|
Term
| What allows for evolution in terms of genetic code? |
|
Definition
| mutations, allow for code to be changed |
|
|
Term
|
Definition
| The total amount of genetic information encoded on all individuals in population |
|
|
Term
| How is the pepper moth an example of survival of the fittest? |
|
Definition
| When conditions where clean, pre 1880, 99% of moths were speckled. During industrial revolution, 99% became black variety. Now it's back to 50/50. Moths naturally select and those best to camoflauge can survive |
|
|
Term
| In what way is natural selection directional? |
|
Definition
| It only moves in one direction, better. It enhances beneficial genes and elimates harmful ones. |
|
|
Term
|
Definition
| Evolution of species invloving entire population rather than individual species |
|
|
Term
| What is cladogenesis? why does it happen? |
|
Definition
| When one species forms two distinct two different species. There is no replacement of ancestral species, rather just a branching out. Happens in response to environmental pressures |
|
|
Term
| What is convergence? what causes it? |
|
Definition
| When two species that are very different become more similar due to living in similar environments. |
|
|
Term
| What morphological features of bats are consistent with convergent evolution? |
|
Definition
| Their wings, as they are similar to insects, but have no lineage or connection to them |
|
|
Term
| how is the sabre-tooth an example of convergent evolution? Why was it a useful tool? |
|
Definition
| It developed independantly in other species at least 5 other times (replictles, placental mammals, etc...). Was useful because they could kill prey by ambushing them from behind and then run away. It's quick and slashing, minimum risk to attacker |
|
|
Term
|
Definition
| When organisms evolve as response to changes in both their environment and in response to evolutionary changes in other organisms |
|
|
Term
| What are two opposing types of co-evolution? |
|
Definition
Arms race (predator and prey) --> where adaptions on part of the predator lead to adaptions on part of the prey. If zebras get faster, lions don't eat. Lions have to adapt to be better hunter. If lions get better at hunting, zebras will die.
The other type is mutualism, where co-evolution is for the purpose of helping both species , like the co-evolution of flowering plants and mammals. |
|
|
Term
| What way does mutualism work, how does it benefit both parties (example of vector seed dispersal)? |
|
Definition
| Works that nuts are produced in order to be eaten by squirrels, but squirrels first bury nuts away from tree and then come back and eat them. If squirrels just forget, then the nut will be implanted and it's beneficial for everyone. |
|
|
Term
| What is the Red Queen effect? who proposed it? |
|
Definition
Every creature is evolving and this affects the evolution of every other creature. Any evolutionary advance by one species forces the rapid evolution of all species that are dependent on it.
Van Valen |
|
|
Term
| What are two reasons evolution occurs/ |
|
Definition
| Changing environmental conditions, or ecological feedback |
|
|
Term
| How many species have been classified? How many species likely exist? |
|
Definition
| 2 mill classified, 10 mil likely exist. |
|
|
Term
|
Definition
| unicellular, no cell nucleus or organelles |
|
|
Term
|
Definition
| Unicellular or multicellular organisms, have nucleus bound DNA and contain organelles |
|
|
Term
| What is the linean classification system? when was it created? |
|
Definition
| It consists of dividing all entities into three main domains: bacteria (normal prokaryotes), archea (extremophile prokaryotes) and eukaryotes. created in 1735-58 |
|
|
Term
| how is something classified into a domain? |
|
Definition
| based on differences in RNA and protein |
|
|
Term
| What are the kingdoms of eukarya in the linnean system? what did they used to be encompassed in? |
|
Definition
| Fungi (non-motile, absord mutrients from other organisms), Plantae (non mobile photosynthesizers) and Animalia. They used to in the grou PROTOCTISTA but this was an artificial grouping with far too many differences in RNA |
|
|
Term
| Name the hierachy from domains to species? |
|
Definition
| domain, kingdom, phyla (divisions), classes, orders, families, genera and species |
|
|
Term
| Name the entire biologicial classification of humans? |
|
Definition
| domain - eukaryo, kingdom - animalia, phyla - chordata, subphyla - vertebrate, class- mammalia, order - primata, family - hominidae, genera - homo, species - sapiens. |
|
|
Term
| Name the entire biologicial classification of humans? |
|
Definition
| domain - eukaryo, kingdom - animalia, phyla - chordata, subphyla - vertebrate, class- mammalia, order - primata, family - hominidae, genera - homo, species - sapiens. |
|
|
Term
| What is phylogeny and what must it reflect? |
|
Definition
| The evolutionary history of animals, must be reflected in classification mechanisms. |
|
|
Term
| What is cladistics, when was it proposed? |
|
Definition
| method of classifying species of organism into groups called clades that consists only of its ancestor and all it's descendants. Proposed in 1958 |
|
|
Term
|
Definition
| classification/group of species that only contain it's descendants and ancestor organism |
|
|
Term
| What is a monophyletic group? |
|
Definition
| a group that contains a common ancestor and all its descendants. The presence of shared derived characteristics is the important trait when creating clades. |
|
|
Term
| What are polyphyletic and paraphyletic groups? |
|
Definition
| polyphyltics groups are things that have more than one ancestor, paraphyletic are things that have a common ancestor but don't include all of it's descendants. |
|
|
Term
| What three sets of morphological characters are considered when creating clades? |
|
Definition
| Primitive characters --> those relating to original ancestoral features, dervied characters --> characters that first appear in the clade, and convergent/analgous charcters - similar features in unrelated organisms |
|
|
Term
| what are pleisiomorphies? |
|
Definition
| characters of the descendant that are shared with the ancestor (like hair on humans) |
|
|
Term
|
Definition
| characteristics of descendants that differ from their ancestry (bipedal motion for humans) |
|
|
Term
| What does clade nesting mean? |
|
Definition
| They can be organized within another clade, thus sharing certain features that may be primitive in a small clade, but derived in the larger clade that clade nest is included in. |
|
|
Term
|
Definition
| an image that shows the order of evolutionary appearance of derived characteristics. |
|
|
Term
| how are cladograms used in combination with fossils? |
|
Definition
| to create phylogram that shows evolutionary relationships over time. |
|
|
Term
| What are 3 strengths and a weakness of cladistics? |
|
Definition
strengths are its rigorous and testable (mathematically analyzable), can be used at all levels of taxonomy (kingdoms and species can all be examined), can also include fossils and living species within the same cladogram.
A weakness is that is can only show relative level of relationship, not absolute degree of relationship between species |
|
|
Term
| What is molecular phylogeny? who proposed it and when? |
|
Definition
| It measures degree of substitution of DNA, RNA or proteins to examine the differences between organisms. Proposed by francis crick in the late 60s. |
|
|
Term
| why is mutation important to molecular phylogeny? |
|
Definition
| different molecules mutate at different rate - so we can examine based on molecules that rate of substitution and thus the amount of differences |
|
|
Term
| What is a molecular clock, how is it made? |
|
Definition
| a ruler to measure the time of origin of different clades (like animals vs plants). you can associate the amount of substitution between species and see how far before they diverged (i.e. 7% substitution means the species diverged 225 ma) |
|
|
Term
| What molecules are good to use for dating older things and which for newer organisms in molecular phylogeny? |
|
Definition
| New - fibrinpeptides (substitute at rapid rate), and cytochrome C is good for old things (substitutes very slowly, can show separation of animals and plants) |
|
|
Term
| What are the strengths and weakness of molecular phylogeny? |
|
Definition
| Strengths - rigorous and mathematically testable, used at any level of taxonomy, direct measurer of genetic differces (better than cladisitcs because it shows degree of association between organisms). A weakness is that is can only be used on living and recently dead material. |
|
|
Term
| why does amber fossils provide a solution to issues to molecular phylogeny? |
|
Definition
| You can extract DNA from fossils in amber and use it to measure substitution of something that is no longer alive (can only do m. phylogeny on live things, so cant change old things like dinosaurs) |
|
|
Term
| What are the single most important source of information of the history of life and why? |
|
Definition
| fossils, because they are the remains of ancient organisms. Fossils are restricted to things taht are older than 5000 years old |
|
|
Term
| What are the five categories of fossils? |
|
Definition
| Bones, shells, plants (cellulose), Trace fosssils and soft tissue |
|
|
Term
| What are bone fossils made up of? why is this important? |
|
Definition
| Made up of phosphate, which is resistant to weathering much more than soft tissues, allows use to see them |
|
|
Term
| what is taphonomy? why is it important? |
|
Definition
| The conditions of fossilization, important because it shows us how bones are preserved, or if they are preserved at all |
|
|
Term
| What specific conditions are required for complete fossils? |
|
Definition
| Only if animal if buried rapidly during or immediately after death. IF animal is left on surface, weathering, waves and scavengers will even destroy large bones |
|
|
Term
| What are shell fossils made up of? how resistant is this material to weather problems? |
|
Definition
| carbonate (calcite or aragonite), and sometimes silica. Not as resistant as phosphoate, but much more than soft tissue. |
|
|
Term
| how are shells typically fossilized? |
|
Definition
| After concentration by waves or currents, shells typically leave molds in rock . |
|
|
Term
| How are plants preserved as fossils? what is wood petrification? |
|
Definition
| The cellulose inside plants can be preserved as is if plants are dried out or oxygen is exluded and plants aren't deeply buried. wood can be preserved by being petrified through filling all wood pores with silica quartx . |
|
|
Term
| what happens to cellulose buried a few hundred metres deep? |
|
Definition
| It will become carbonized, turned into coal by heat and pressure |
|
|
Term
|
Definition
| tracks, trails, burrows and boring of animals |
|
|
Term
| why are trace fossils important? |
|
Definition
| they describe the ethology (behavior) of the animal that made them. Can tell you what animal made them, what activity it was doing and what speed animal was travelling |
|
|
Term
| What are fossil lagerstatten? |
|
Definition
| deposits of fossils with preserved soft tissues, extremely important to recreating the history of life. Have contributed to at least 50% of known information about fossils. |
|
|
Term
| Give three examples of fossil lagerstatten? |
|
Definition
| frozen mammoths 100,000 yr old in siberian permafrost, paleozoic invertebrates with soft tissues preserved by carbonization or mineralization by pyrite. Amber --> oldest animals we see, sometime can show actions of animals as well |
|
|
Term
|
Definition
| There are plenty of animals with soft tissues or mixures of soft and bone, but we only find those which are boned vertebrates. so our perspective of old world is that of plenty hard creatures and no soft ones, when really it's quite the opposite |
|
|
Term
| When was the earth created? First supernova? |
|
Definition
|
|
Term
| How long after supernova were there planetary nebulae, crusts of the planetS? |
|
Definition
|
|
Term
| When was the hadean world? Where was the moon? |
|
Definition
| 4.5Ga, moon was very close, just collided |
|
|
Term
| What are the three main steps in the synthesis of life? |
|
Definition
| Formation of simple organic molecules, combination of simple organic molecules into complex molecules and initiation of replication. |
|
|
Term
| What is the Miller - Urey experiment? what did it prove? what prevented the experiment from working? |
|
Definition
| Took a bunch of gases, ran it through an electrode and condensor. He converted hydrogen cyanide to nitrogen, after shocking the experiment (with heat, sound) and it proved that the first step of synthesis (formation of simple molecules) is very easy. Oxygen prevented the machine from working |
|
|
Term
| Do we know how simple molecules become complex molecules? |
|
Definition
| Not really, but we think that RNA was the first to evolve. |
|
|
Term
| What was the spiegelman monster? what did it show? |
|
Definition
| Took a live virus, provided it with nucleotides and built an RNA with 220 nucleotide. But it didnt create a coat. Showed little bc it was creating life from something that already existed. |
|
|
Term
| What was Eigen experiments? proved? |
|
Definition
| He had a stream of nucleotides and a replicase but nothing live. Still created RNA organisms with 120 nucleotides - shows that replication could occur by itself and couldnt be stopped |
|
|
Term
| Where did life originate? three reasons why |
|
Definition
| Life originated in mid ocean ridges, where magma comes up. 1) Meterorite bombardment here sterilized upper oceans 2) Prebiotic chemical reactions could occur when you rapidly changed temperatures 3) Thermolithophiles are the only species that we have found that could live in extremes |
|
|
Term
| What are forms of evidence for the meteorites landing on earth prior to 3.8Ga? |
|
Definition
| Lunar craterings, with diameters of 100km or more. This would vaporize the oceans it hit |
|
|
Term
| Why were conditions on early earth ideal for formation of life? |
|
Definition
| Sterilized by meteorite, hydrothermal vents were nearby. Life evolved in the first billion years. |
|
|
Term
| What are stromatolites? When did they exist? |
|
Definition
| Layers of stromatolites that reflect the presence of mats of unicellular organisms. Oldest exist 3.5Ga from warrawoona in western australia |
|
|
Term
| What is the world oldest stromatolite dated to? where? |
|
Definition
| Warrawoona, Australia - 3.5Ga |
|
|
Term
| What can be said about cyanobacteria evolutionary tactics? |
|
Definition
| They are incredibly conservative, modern entophysalis is nearly identical to eoentophysalis from 2ga |
|
|
Term
| Describe the faint young sun paradox. How is it resolved? |
|
Definition
| Actual T on earth today is 21c, but 4.5Ga the sun was only giving off 70% of present light. The T should have been -18 back then and we should have seen ice. The paradox is that there is no evidence of ice in first 2ga. It's resolved because the old atmosphere had tons of greenhouse gases, 20% carbond dioxide. The surface was much warmer. |
|
|
Term
| With regards to faint young sun paradox, why did we not get a runaway greenhouse when solar luminosity increased? |
|
Definition
| Carbon dioxide was converted to oxygen by photosynthetic organisms which lowered T and increased oxygen |
|
|
Term
| What were oxygen levels in relation to present oxygen 2 Ga? |
|
Definition
|
|
Term
| When were the oceans considered iron oceans? what did that mean? |
|
Definition
| 4.6 to 2.4Ga, ocean contained abundant iron, with minimal oxygen near layers of stromatolites |
|
|
Term
| What were the results of the GEO? |
|
Definition
| The first free oxygen in the atmosphere existed |
|
|
Term
| When and what was the canfield ocean? |
|
Definition
| 1.8 to 0.8Ga atmosphere and surface ocean has measurable oxygen, but deep ocean was oxygen deprived (mainly hydrogen sulfide, not iron) |
|
|
Term
| When did the ocean increase it's oxygen level up to modern levels? |
|
Definition
|
|
Term
| Describe the four steps of the GEO? |
|
Definition
1) Dissapearance of BIF - iron could no longer be dissolved in oceans because of increasing oxygen levels, precipitated out.
2) High levels of oxygen pulled out so much Co2 that we got ice (first glaciations at 1ga)
3) The production of ozone layer
4) Permitted fully aerobic metabolism and eukaryotes |
|
|
Term
| What was the benefit of the ozone layer? |
|
Definition
| Shielded earth from UV radiation but also plant organisms modulated earth climate (too hot, more plants, too cold less plants and more CO2) |
|
|
Term
| What ultimately caused the GEO? |
|
Definition
| stromatolites - ultimately when there was no more dissolved iron, free oxygen could exist. |
|
|
Term
| What % of modern continents existed at beginning and end of the last part of the archean? |
|
Definition
|
|
Term
| what was a direct offshoot of the new amount of continents? |
|
Definition
| The new continents that were formed were covered with shallow seas, stromatolites grew, liberated oxygen. |
|
|
Term
| With more stromatolites at the end of the archean, what happened (3 things)? |
|
Definition
| Set up the organisms, climate feedback loop, created ozone, and produced free oxygen for organisms on earth |
|
|
Term
| How much more effective are aerobic organisms than anaerobic? |
|
Definition
|
|
Term
| Describe eukaryotes in terms of differences from prokaryotes? |
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Definition
| Eukaryotes have DNA enclosed in nucleus, organelles, complex morphology, ability to form multicellular organisms, Mostly sexual reproduction and aerobic respiration |
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Term
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Definition
| Mitochondria and chlrooplasts have different DNA, must have evolved from different prokaryotes. Purple bacteria - mitochondria, cyanobacteria - chloroplasts. |
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Term
| how many times has photosynthesis independanty evolved during evolution, what does this prove? |
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Definition
| 5x, shows that it is likely due to endosymbiosis. |
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Term
| What are five proofs for early eukaryotic existence? |
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Definition
1) Hammersley ranges, australia (biomarkers found for cyanobacteria and cell wall in eukaryote - precursor to eukaryotes found 2.7Ga)
2) Acritarchs (small rounded fossils definitely eukaryotic around 1.8ga)
3) Algal compressions (2.3Ga - too big and well constructed to be prokaryotes)
4) Crown group algae - red algae crow group found around 1.2Ga, green crown group found 850MA
5) Testate Amoeba - 750 MA crown group fossil of eukaryotes |
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Term
| When did we get multicellular eukaryotes and what were they? |
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Definition
| Likely around 1.2Ga with red algae |
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Term
| What caused multicellular eukaryotes to evolve? |
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Definition
| Movements of earth's plates... |
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Term
| When was rodinia aggregated and when did it break up? |
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Definition
| aggregated around 1ga, broke up multiple times between 800 and 500 Ma. |
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Term
| What did rodinia's break up cause? |
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Definition
| Caused a series of global glaciations, associated with changes in composition of oceans. |
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Term
| What 3 distinct period exist during the snowball earth glacials? |
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Definition
| The sturtian era (715), the marinoan (600) and the Gaskieres tillite (580) |
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Term
| What did the sturtian glaciation show? |
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Definition
| The first evidence for sponges (sponge fossils) |
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Term
| What did we find because of the Marinoan glaciation? |
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Definition
| After 600, we found mammals embryo, the earliest animals and the first macroscopic algae seaweed |
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Term
| What did learn because of the Gaskiers Tillite? |
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Definition
| Appearance of large, complex life. We found ediacaran prawn 2m near mistaken point, Newfoundland |
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Term
| What did learn because of the Gaskiers Tillite? |
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Definition
| Appearance of large, complex life. We found ediacaran prawn 2m near mistaken point, Newfoundland |
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Term
| Why did glaciations have such a profound effect? |
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Definition
| Each glacier changed the composition of the ocean (from euxinic to oxygenated) and ice even marched towards the equator |
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Term
| What specifically happened to the ocean after the gaskiers glaciation? |
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Definition
| The deep oceans became oxygenated -within 3Ma years of this massive oxygenation, we have 2m prawns. |
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Term
| What 3 main assemblages represent the ediacaran era? |
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Definition
| Avalaon, white sea and Nama |
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Term
| What creatures are typical of the avalon assemblage? |
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Definition
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Term
| Describe the structure of rangeomorphs? |
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Definition
| Fractile creatures where each fundamental building block is multiplied, each branch mimicks the larger branch. this allows for bigger growth through modular assembly |
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Term
| how did rangeomorphs feed? |
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Definition
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Term
| What two new clades were found in the white sea shallow water assemblage? |
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Definition
| Erniettomorphs (560-542) and stem group bilaterians |
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Term
| Describe the structure of erniettomorphs |
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Definition
| Soda like stacks - packed tightly (not fractal) |
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Term
| Springinna and Kimbrella are bilaterians found in this era - were they stem group or crown group? What were their feeding patterns? |
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Definition
| stem group bilaterials (had bilateral symmetry) and fed like gastropods. Not a modern snail, but ancestor |
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Term
| What feeding pattern did most ediacaran animals have? |
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Definition
| suspension feeders and osmotrophs (extracted nutrition from sea water) |
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Term
| What type of animal did not exist in the ediacaran biota |
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Definition
| No macrophagous predators or scavengers |
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Term
| What is the NAMA era - where is it based? |
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Definition
| The end of the ediacaran, based from fossils in Namibia. |
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Term
| Name two fossils typical of the NAMA era? |
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Definition
| Oldest shelly fossils and Swarpuntia |
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Term
| What is so special about NAMA site? |
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Definition
| Has ash from cambrian era and ediacaran biota below it - can exactly date fossils and show when one era ended and another began. |
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Term
| Ediacaran biota are simpler than simplest modern phyla - corals - T/F |
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Definition
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Term
| There are two main aspects to the cambrian explosion - what are they? |
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Definition
| Evolution of armored sponges, small shelly fossils, complex trail fossils. 2) Brachiopods, trilobites, echinoderms and early cambrian chordates |
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Term
| What is the proper name for archaeocyathan? |
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Definition
| heavily armoured sponges - important as first skeletal reef builders |
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Term
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Definition
| shelly animals that contained spines that armoured their body |
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Term
| What type of fossils reflect evolution of brains? when do they arise? |
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Definition
| trace fossils - complex feeding burrows, burrows of increasing size. Found in cambrian explosion |
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Term
| When do trilobites appear? |
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Definition
| At end of the cambrian explosion (530-525) |
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Term
| What was the dominant group of the cambrian? |
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Definition
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Term
| A fossil with 3 parts is likely a..., with 5 parts ... |
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Definition
| 3 parts is a trilobites, 5 an echinoderm |
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Term
| When do echinoderms and chordates first appear? what significance do chordates have? |
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Definition
| First appear at end of cambrian explosion, chordates are the phylum of humans, so it represents the earliest human ancestors per our phyla |
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Term
| What are three reasons why we see a rise in skeletons at beginning of cambrian? |
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Definition
1) Threshold oxygen factors
2) Empty ecosystem - end of ediacaran had spike of anoxic conditions leads to a clean slate for cambrian biota
3) Ecological feedback - First predators in ecosystems to the cambrian arms race where prey began to burrow and hide in places where skeletons are needed (skeletons for protection), while predators developed better attacking mechanisms like horns as part of their skeleton |
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Term
| When did all of the coelomic phyla develop? |
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Definition
| except byrozoan, all developed in period of 20-25 Mya in cambrian explosion. |
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Term
| What was the main effect of the cambrian explosion in terms of morphology? |
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Definition
| Evolution of skeletons and brain due to cambrian arms race |
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Term
| name six functions for skeletons? |
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Definition
| attachment for muscles, protection from environment, protection from predators, weapons, storehouse of nutrients, elevation above seafloor |
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Term
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Definition
| Hav einternal fluid filled cavity - developed mostly during cambrian |
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Term
| What is the burgess shale lagerstatte? |
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Definition
| The most important fossil assemblage in the world, records the cambrian explosion and has hundreds of thousands of fossils that preserve soft parts |
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Term
| What caused the soft bodied organisms in the burgess shale to be covered quickly and fossilized? |
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Definition
| Periods of anoxiac lead to organism preservation, carbon impressions as some where pyritized, rapid burials, no tectonics |
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Term
| Where did lobopods normally live, and where in burgess shale? what are they? |
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Definition
| normally live in forest, lived in marine in burgess shale. They are like catepillars |
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Term
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Definition
| The top predator/carnivore of the burgess shale. IT was made up of different supposed individual parts, such as shrimp claws, large arthropods (thorax) and jellyfishes (mouth) |
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Term
| What is the lace crab marella? What did it's discovery tell us about modern artropods |
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Definition
| simplest artropod ever found. found to moult - so because it's the simplest arthropod, we can infer that moulting is innate to all arthropods as even the simplest arthropods had ecdyses - was a synapomorphy |
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Term
| what different parts "made up" anomalcaris? |
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Definition
| The Peytoia shrimp, the aggarian thorax and the jellyfish mouth |
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Term
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Definition
| 8 eyes with long neck, related to anomalcaris |
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Term
| What was pikaia? what does it's physiology prove? |
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Definition
| A proto(pre)chordate. It is similar to modern ampioxus. contains muscles, nerves, gills. shows that the origin of chordates is filter feeders. |
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Term
| What was gould's 1st take home concept? |
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Definition
| Geology is like a bush of evolution, not tree. You see some things that are not of the same height because they failed in the evolution process. The burgess shale is an example of that as most of them died out very shortly aftewards |
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Term
| What was gould's 2nd take home concept? |
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Definition
| The idea that small differences lead to huge evolutionary changes - something that morphological looks tiny or genetically small could differentiate one thing dying out or becoming a crown group |
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Term
| What was gould 3rd take home concept of the burgess shale? |
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Definition
| Though the burgess shale is a bizarre ecosystem with strange experiments in animal evolution, it is quite familiar. It has top predators, herbivored, fauna. It had every major ecological interaction compared to modern oceans |
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