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158 Cards in this Set
- Front
- Back
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Functional morphology
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structure-function matching, ex flat occlusional surfaces=herbivore, and sharp occlusional surfaces=carnivore
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Methods of Reconstruction: (3)
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1. Analogy
2. Modeling 3. Context |
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Method of Reconstruction: Analogy
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based on form-function relationships, useful with homologous structures
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Method of Reconstruction: Analogy
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uses real/mathematical models, build model and put in wind tunnel to see if possible to swim with this or that type of fin
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Method of Reconstruction: Context
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where was it found? uses associated with fossils and sediment, found in a packed bed, then swam at 30 ft, found in a gray bed, then swam in 100 ft.
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homologous structure
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same embryonic origin, can have different functions
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Use methods of reconstruction analogy to analyze the osteostracan fish. It is jawless, flattened bony head shield, field of bony platelets, paired pectoral fins
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1. Analysis: semicircular canals balance, detect pressure differences, moves up and down, resemble bottom dwelling fish, heavy head shield and bony armor, prevents active swimming, depressed head holds to bottom.
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Power:
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work needed to overcome drag (on test)
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Cost of transport:
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energy needed to move body 1 m (on test)
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How to find the optimal swim speed?
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look at a graph of swim speed vs power/cost of transport and see where the cost of transport is the lowest, see that it takes more to get going
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Using model of reconstruction: model to analyze the osteostracan fish
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Model: build/model .38 m long in wind tunnel 15x speed what is the LIFT and DRAG? is it possible as we have it designed, can find optimal speed by graphing cost of transport vs swim speed, then when we found swim speed we can approx muscle construction b/c red is slow and white is fast
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Using model of reconstruction: context, analyze the osteostracan fish
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found in mud stone, shallow water and weak current (more muddy, less current)
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Levels of reliability: (3)
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1. possible (not)
2. plausible 3. probable (very) |
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Fossils:
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any trace of an organisms body or behavior preserved in the rock record
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body fossils
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actual body parts of organisms
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trace fossils
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evidence of organismal activities, eg holes in clam shells
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geology: sedimentary
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composed of remains of preexisting rocks, record conditions of earth's surface, inhabited by living organisms, produced in sequential layers
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Fossilization environment: best and worst and why
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best in depositional environment, where it can be buried quickly. Worst in erosional environment because they are not going to get buried or they will fall all the way down to a depositional and get abraised before burial
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What produces high quality preservation? (4)
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1. rapid burial (so bac and scavengers can't hurt)
2. fine grained sediment (protect bacteria and will preserve fine details) 3. biologically benign: earthworms are bad, tree roots ect because oxygen will get in 4. physically benign: places with earthquakes and tornados tear up fossil record |
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Lagerstatten:
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very DETAILED fossils
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History of a fossil, 4 steps:
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1. biotic stage
2. interment stage 3. diagenetic stage 4. investigative stage |
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taphonomy:
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study of changes to organic material during fossilization, the four steps describe biotic, interment, diagenetic, investigative
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biotic
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birth-death
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interment:decay (4)
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death-final burial
1. decomposition: soft tissue 2. disassociation: hard parts separate 3. abrasion: surface details rubbed off 4. breakage: bacteria eats protein and breaks bone, minerals left only 5. winnowing: separate skeleton by size |
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diagenetic: decay (3)
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final burial-discovery
-this is where chemical changes occur 1. dissolution: hard parts are chemically altered to soluble compounds 2. compaction: remains crushed by overlaying sediment 3. crystal intrusion: dissolved minerals enter, crystalize and apply pressure to crack the artifact |
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investigative
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discovery-ultimate destruction
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biased in fossil record favoring:
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-animals with hard skeletons
-animals with thick skeletons -adults, bones more mineralized -infaunal animals (living inside another already buried) -in benign depositional environments -sizes -common species |
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fossilization processes in order: (7)
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1. freezing: rapid drop, water sublimes 40,000 years
2. desiccation: rapid removal of H20, arid 100,000 years 3. unaltered: shell dead, intact and cleaned 4. petrification: addition of new chemicals, 3 subsets 5. carbonization: degrade organic materials into carbon film 6. molds: cavity fills with opal ect 7. trace fossils: shows behavior or patterns or coprolite (poop) |
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Petrification: addition of new chemicals and a way to fossilize, name the three subsets
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1. permineralization: empty space is is filled and original remains
2. replacement: original material chemically replaced by another mineral, can not see body temp or crystal muscle structure 3. Recrystallization: original material modified into related crystalline form (aragonite to calcite) |
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Aragonite to calcite
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recrystallization, a process of petrifaction which is chemically altering adding new chemicals in fossilization
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name the four filters between creature and fossil:
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1. biotic
2. interment 3. diagenetic 4. investigative |
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Archean Era: When did life appear? What land form made this possible?
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life appears 3.5 BYA and cratons form
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Proterozoic Era: What was the land forms like and what was made that indicated change to the environment? What other species came about?
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There were no continental shelves but there were stromatolites (2BYA) that has rings that showed the cyanobacteria photosynthesizing on it to create oxygen. (Prokaryotic) Later you see banded ironstone formation (2-1.5 BYA) that shows the Fe3O precipitating out of ocean before oxygen can even come into the air. Then 1.3 BYA the multicellular algae and worms and edicaran fauna, which were the first solid soft bodies fossils.
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Early Paleozoic: (Cambrian-Ordovician) What diversified then went away in each sub period?
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continental shelves appearing, with that the cambrian explosion: diversification of hard skeletons followed by mass extinction in cambrian then vertebrates and land plants in ordovician
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Middle Paleozoic Era: (Silurian-Devonian) What things evolved in each?
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Fish! More importantly, first animals invaded land (arthropods) in Silurian then in Devonian there were insects, 1st seed plants and trees. The amphibians that invaded land then went extinct in a huge extinction.
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Late Paleozoic Era: (Carbiniferous-Permian) How did the climate change? What did the food webs look like in response to the rise of certain animals.
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The land is low relief, all warm and similar temperatures. The Tethys sea swirls organisms around. In carboniferous, mississippi coal swamps show seed ferns, horsetails and club mosses. The first flying insects arose and terrestrial food webs linked to freshwater. The permian is when mountains built, it cooled and dried and therapsids (mammal precursor) and diapsids (archosaurs precursor) arose and led the first terrestrial food web. No herbivorous vertebrates, suddenly there are. There is a permian mass extinction.
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Mesozoic Era: What developed? How did this change the food chain?
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Mammals and cephalopods, archosaur radiation, modern food web. The Tethys sea is a major cause. Top carnivores 5% biomass, they are getting warmblooded. First shell breaking durophagus and angiosperms with insectis. Cretaceous extinction (dinos) with several earth shattering events.
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What animals fall under Archosaur?
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dinosaurs, birds, pterosaurs, crocodilians
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Take about durophagus:
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They arrived in the Mesozoic era (Jurrassic) and caused a minor extinction in the shells animals but then exploded with better defense. They, the shells things, appeared just before the Mesozoic era in the Permian.
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Cenozoic (63.4 MYA)
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modern continent, modern animals, sea went from himilayas to panama, e-w circulation, those currents caused glaciation and psychrosphere currents led to a diversification of climates (icehouse climate). Due to this, biotic modernization became as grazing animals spread
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Whats the order?
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Archean, Proterozoic, Early (cambrian-ordovician) Middle (silurian-devonian) Late Paleozoic (carboniferous-permian), mesozic, cenozoic
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On a grander scale, what was happening to climate over these eras?
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Archean: no oxygen-oxygen
Paleozoic: continental plates to late paleozoic mountains build and becomes cool and dry Mesozoic: tethyes sea, bolide impact Cenozoic: psychropsphere brings us to icehouse climate, e-w current, makes poles diversify |
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forn-function relationships: guild plans
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unrelated organisms have similar body plans because they have similar life styles and nature chooses the most efficient body plan
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When you are analyzing symmetry, what is the main thing it clues you into?
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different activity levels
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radial symmetry
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usually found in sessile or slow-moving animals, 360 sensory and diffuse nervous system, armored, limited mobility-may have a bit of muscle and for that they have low metabolic rates, they have incomplete gut or U-shaped, limits size:coloniality.modularity
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What is coloniality/modularity?
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living in groups
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bilateral symmetry: cephalization
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since organs concentrated in anterior, polarized sensory field meaning they can tell up down left and right which is essential for manuvering
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bilateral symmetry: mesoderm effects on body
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the mobility requires larger muscle volume and then mesoderm which produces muscles fast
-they interact with other embryonic tissue to form sense organs -large muscles then require more high metabolic rate, complex organs systems to get energy rapidly |
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bilateral symmetry: effects of high speed movement on body
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-complex brain and localization sense organs
-streamlined body -fluid filled body cavity -reduced armor -segmentation and tagmosis -every organ must perfom at its top to get energy and remove waste more quickly |
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"Tully monster" where was it found and what did it look like and what era was it from
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middle pennsylvanian (meaning permian), carbonized mold (iron) in siderite conceretions
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what are the characteristics of the tullimonstrum gregarium
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-oviod body wiht transverse markings
-anterior proboscis with teeth -posterior fin -bar organ wiht tips -swellings near bar -linear complete gut |
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what organism do they now compare the tully monster to?
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heteropod gastropod
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What were some of the problems with the logic behind the original reconstruction of the tully monster?
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-too dark of a color
-the "teeth" would have trouble bringing food in -no real gut -why is it segmented? -there is not actually symmetrical pectoral fins -eyes facing down means cant see predators |
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new tully monster reconstruction?
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-dorsal nervous system instead of the ventral nervous system
-imbedded eyes instead of eye stalks -probioscis with teeth in muscular bulb instead of in bifurcated tip -the posterior tail is vertical not horizontal -sequential muscle bands instead of segmentation |
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What do you do when context, analogy and modeling say different things? (EXAM)
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You realize that, for example, all cephalapsins are not alike, some are more simplified and can not make sharp turns with no pectoral fins, less active others are better with predators and not as fast because of large horns and more drag but lives in area with more predators, you can make analogies between extinct species THEMSELVES
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An animal with a mesoderm also has...
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a high meat to muscle content, they have bilateral symmetry, they have sense organs, they have very complex and quick nerves and organs. The speed and the large brain are energy suckers.
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How long does it take a human to circulate all blood?
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12 seconds
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Recipe for high speed functioning and moving in bilaterals:
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fluid filled body: fluid filled bicaveity allows transmit forces one part of the body to another
tagmosis: group together parts that do the same thing (insects in locomotion) |
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Other Problems with original Tullimonstum:
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-eye stalks look down and produces drag
-no direct evidence -bifurcated tip -tail asymtrical (not two lateral lobes but ventral and dorsal) -instead of segmented, there are segmented muscles analogies will tell if one is right over the other |
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Diversity vs. Disparity, what is the difference?
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diversity is how complex a community in terms of which species there are. disparity is more concerned with the range of body morphologies present and their abundance
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what does functional morphology often tell us?
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that a different shape means a different lifestyle
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who and when created the adaptive landscape?
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sewell wright (1932) which showed how different fitness levels from different gene combinations will cause selection to favor variants that are closer to adaptive peaks
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morphospaces
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each axis is a parameter, whole area possible but we find clusters of individuals that form species.
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theoretical morphology
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taking the parameters and tweaking them to get all sorts of shapes and sizes that could possibly exist, across a line defines an important feature
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what does a hole in the morphospace indicate?
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this body plan is not advantageous
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what is funny about molars?
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biomechanically backwards, molar 3 is smallest, then 2 and 1 is largest, look at a morphospace diagram and see the outliers and indicated what about their lifestyle makes them an outlier
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talk about the morphology of the ectoprots? why are there holes in the morphology?
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the ones that don't show up are inefficient in filter feeding; selective disadvantages
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what is finess ratio?
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height of bell to width, defines shape
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what is the process of morphospace?
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model predicts all possible shapes, which don't fit, which do and why? look at outliers and examine lifestyle
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which medusae is fastest? bell or umbrella
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bell, actually bullet but you can also look at what they eat to see what shape they are going to be. speed correlated with size, fast is large which proves form is function
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What are problems with theoretical morphospace?
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1. done have mathmatical model to predict types so you use a goodness of fit model which assumes complex shapes are defined by math
2. comparative morphology: compares living to extinct animals |
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analogy morphospace:
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it will have two factors and no mathmatical model between and just graph things that are alive and things that are extinct to compare them
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what does the decoupled head to body ratio tell us?
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the creodont may have been solitary, may take down big prey on own, shorter, bear like legs, slower
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decoupled scaling:
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body proportions different than expected, if the creodonts fell on the dog line, then they would have lived like dogs and their scaling is coupled, if decoupled, they do not live the same... how did they live?
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EXAM: creodonts, what is the problem with the picture?
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they are chasing pray and looks like they are moving too fast, they have short legs and are not likely a persuit predator, color speculative, they are in a full gallop here but morphologically would not have been a fast animal, it looks like they hunt in packs here but they likely do not
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which medusae is fastest? bell or umbrella
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bell, actually bullet but you can also look at what they eat to see what shape they are going to be. speed correlated with size, fast is large which proves form is function
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What are problems with theoretical morphospace?
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1. done have mathmatical model to predict types so you use a goodness of fit model which assumes complex shapes are defined by math
2. comparative morphology: compares living to extinct animals |
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analogy morphospace:
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it will have two factors and no mathmatical model between and just graph things that are alive and things that are extinct to compare them
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what does the decoupled head to body ratio tell us?
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the creodont may have been solitary, may take down big prey on own, shorter, bear like legs, slower
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decoupled scaling:
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body proportions different than expected, if the creodonts fell on the dog line, then they would have lived like dogs and their scaling is coupled, if decoupled, they do not live the same... how did they live?
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EXAM: creodonts, what is the problem with the picture?
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they are chasing pray and looks like they are moving too fast, they have short legs and are not likely a persuit predator, color speculative, they are in a full gallop here but morphologically would not have been a fast animal, it looks like they hunt in packs here but they likely do not
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What is a developmental time scale?
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changes in shape over the life of an individual, looking different in shape based on being a kid and adult
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What is the evolutionary time scale?
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change over a span of evolutionary time in a species, within this we can ask, does the change happen because the mechanics is better of because the lifestyle changes?
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What could be the two reasons why organisms structures are different shapes because they are different sizes?
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-physical constraints
-different functions |
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What is a nonadaptive explination:
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due to physical constraints, the femer must get thicker as it gets longer
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What is the adaptive fuction?
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the function changes as the animal changes, this is the reason for the shape change
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What is an allometric constraint?
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shape change due solely to change in size
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What is adaptational innovation?
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shape change due to change in life style
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EXAM: Have a raptorex, which is a mini t-rex. It is full adult but when you compare skulls to a T-rex what differences do you see?
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large: abrupt nose, large mandable, blunt snout
small: smooth nose, slender mandable, tapered snout |
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scaling body plans: you model organisms as cubes. Length=L, Cross-sectional area=L^2 and Volume=L^3 What does strength go by? What does mass go by?
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cross sectional area, L^2 and mass goes by volume L^3
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If you double the cross sectional area, what does that do to the strength?
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x4
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what is the mathmatics of scaling?
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y=ax^b
logy=loga+b(logx) b=slope, most informative |
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what would you expect the slope to be for a graph of log volumexlog area
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log volume=3
log area=2 2/3=y axis/x axis=.67 |
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what is isometry?
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the organismal shape exibits geometric similarity, they follow the expected slope
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geometric similarity:
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as size increases all your measurements stay the same, shape does not change as it gets bigger
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What is Leedsichthys?
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it is a fish made of a few fragmented bones, almost a complete tail was found, teh pectoral fins, the skull bones and gill rakers and we think a cartilaginous axial skeleton, but we don't have any idea how big it is
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How do you find the shape of Leedsichthys, a non-whole pachycormid?
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compare it with a whole pachycormid, assume isometric scaling and use:
bodylengthL/bodylengthP=partlengthL/partlengthP |
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What happens when you assume isometric scaling and then you use it and get two different predictions for the estimated number by using the same species?
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you know the species you are trying to estimate is not isometric and identify it as very decoupled. you must say this animal that is unknown has a different lifestyle than the existing one
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all the biggest fish we find are filter feeders? t or f
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t
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Are the antlers too big for the Irish Elk?
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nope, its a big deer
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What time era is the Irish Elk?
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Cenozoic, Late
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How do we find out if the Irish Elk's antlers are too big for it?
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-Gould did research of height of shoulder and length of antlers for many deer
-1:1 prediction, but got 1.68 meaning the antlers increase in size faster than you think -the meglasaurus is not abnormal |
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Why do moose antlers make sense and these make sense?
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moose live in woods and run in there, want small
-the meglasaurus lived in open planes and was a runner |
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What clues about Meglasaurus give you idea of its lifestyle?
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1. slender legs with scapulae (shoulder blades) for supporting shoulder muscle, they allow for a big leg muscle- long distance running
2. large thoracic cavity: shows they can run in long distances 3. lived in herds and ran and ran in trouble 4. tines pointed backwards to make intimidation the key thing |
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What is Cope's Rule?
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within a lineage, body size increases through time, the mean size goes up
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Why does the body size increase over time and start small as according to Cope's Rule?
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1. the small individual can have a more varied body plan, as get bigger, more limited, specialized
2. the large species has several logical advantages, less food, locomotion, less vulnerable, get more stuff |
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Why is big an advantage? (4)
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1. M food= m body^3/4 you have a lower food demand
2. Bigger animals can get more resources 3. Locomotion, your cost of transport is less for the larger body per kg 4. Less vulnerable to predators |
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Why are big animals more likely to go extinct than the small?
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they have a more specialized body plan and can't adapt to change as much due to physical constraints
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What is fractal geometry:
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technique for analyzing shape
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M=ns^d
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n=number
s=units d=dimensions |
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Why are animals not orthogonal?
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you can make complex shapes with non-integer dimensions, a folded area that assumes volume like properties
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What do lungs, metabolic rate, oxygen consumption, food consumption scale to? that allows us to get big
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3/4 power
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Because we are not orthogonal... we use...
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complex systems to function that can't be explained by Euclidian geometry, so we escape physical 1:1 and we take less fuel per kg than a small thing does per kg!
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If you double the size of the tooth you must add how many more capillaries?
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23x
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What are some of the advantages of being warm-blooded?
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process information faster, more successful in attack, think and perform higher rate
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What is thermoregulation?
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the different life histories that have to do with the body temperature of the animal
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advantages to cold blooded
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they need less food because they have a lower metabolic rate
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disadvantage to warm blooded
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needs 3^10 times more food per kg than cold blooded
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What is the advantage to elevated temerature: when in normal ranges, every 10 degrees that you raise...what is this called
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the power output doubles, so all physiological processes double, called the Q10 rule
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What are some benefits of having a constant temperature?
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you can have more efficient enzyme activity because you can specialize enzymes to work at a certain temp, when you have the flu they are out of their range and don't work
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What environments do you find warm blooded/ cold blooded organisms in?
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Warm blooded: must be in place where food is abundant and a constant food supply year round (mammals and birds) Cold blooded: small or unpredictable food supplies, can go long periods of time with no food so they may be on islands
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What are the two strategies for elevating body temperatures:
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etothermy: absorb energy from environment by behavioral mechanisms
endothermy: temperature is elevated by physiological mechanisms |
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Strategies for keeping a constant body temperature?
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Poikliothermy: temperature fluctuates with environmental temperature
Homeothermy: temperature held constant |
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What two strategies for thermoregulation do cold blooded animals use?
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extothermy+ poikliothermy: snakes
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what two strategies of thermoregulation do warm blooded animals use?
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endothermy and homeothermy:
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small birds and mammals exhibit a thermoregulation lifestyle of ....
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heterothermy= endothermy + partial poikliothermy (controls how much it fluctuates with environment)
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What is daily heterothermy?
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torpor occurs at night, you can see based on oxygen consumption if it is in torpor
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What is seasonal heterothermy?
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torpor occurs in winter
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What is regional heterothermy?
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some body parts operate at reduced temperatures, in the paw of an animal that can walk on ice, teh warm and cold blood have countercurrent exchange that allows the core to maintain a high temperature and the legs cold
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What are the three types of heterothermy?
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1. daily
2. seasonal 3. regional |
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What is gigantothermy?
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a type of homeothermy= partial endothermy and partial homeothermy
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What type of thermoregulation does a turtle have?
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Homeothermy (poikeothermy) and then endothermy as the physiological mechanism of their shell help them remain heated as their body temp falls with environment
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What is the thermoregulation of a myotragus (mouse goat)
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born as warm blooded then as they get older they become cold blooded, the bone which is dense layers near the lags shows cold bloodedness
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What type of thermoregulation do pelycosaurs have?
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had sails that acted as radiators, shed blood to sails to dump excess heat, used to intimidate,
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What are phylogenies?
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representative relationships between organisms, allows us to ask, what makes this or that innovation happen?
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What are the three types of similarities that can be made?
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primitive, convergent, derived
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What is primitive similarity
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single origin in distant ancestor, not implying a close relationship, homologous structures evident
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convergent similarity?
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independent origin, does not imply a close relationship, analogous rather than homologous, really tells us nothing about evolution
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what are the differences between bird and bats?
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really the only similarity is they have wings but they were convergently evolved and the feathers put a cap on how big the bird can get
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Derived similarity:
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most helpful in evolution, single origin and relatively recent ancestor, implies close relationship, you can look at homologous structures (mammals: milk,ect) you can ask what strong forces drive this animal this way?
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What are the derived similarities in mammals?
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hair, milk, 3 middle ear bones, single pair of lower jaw bones, diaphragm, occlusion of teeth
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What are the two different ways you can compare two species when trying to gain knowledge about species and evolution?
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1. use timing of divergence
2. use degree of divergence (the more dissimilar, less common ancestor) |
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What are the three types of comparing species?
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1. evolutionary taxonomy
2. phonetics 3. cladistics |
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what is evolutionary taxonomy?
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way of coming up with phylogenies that uses timing and degree of divergence
-subjective problem because you have to choose between the two |
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what is phonetics:
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way of coming up with phylogenies that uses only degree of divergence, how dissimilar or similar organisms appear to be, uses homologies and analogies, must look at a huge number of traits
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what is cladistics?
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a method of creating a phylogeny that uses only timing of divergence, by looking at two types of homologous traits (pleisomorphic and apomorphic) to show how closely related
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plesiomorphic:
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this is a homologous trait that is identified in cladistics and attributes the common trait to the primative ancestor many years ago, its ignored
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what is apomorphic:
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it is a type of homologous trait that is based on derived similarities, which looks at the more recently derived synapomorphies to make phylogentic relationships
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What is the goal in clade?
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always trying to construct the clade, a group of species that are united by a synapomorphy that is a derived trait, the more synapomorphies, the more closely related and the least time passed since the common ancestor
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What are the (3) different phylogenetic groupings?
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1. momphyletic: recent unique common ancestor and all its descendents, this is of interest in cladistics
2. paraphyletic 3. polyphyletic |
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how do you determine timing for cladistics?
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you look and see what the oputgroup can be, not related but similar and then know that ontogeny shows that things similar early in development are ancient and things later and more derived and recent
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Type One Phylogenetic Inferences:
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you have strong positive evidence for the soft tissue
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Type Two Phylogenetic Inferences:
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you have ambiguous evidence for the presence of the tissue
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Type Three Phylogenetic Inference:
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you have strong negative evidence that the structure was not present
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what is an archosaurs?
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the diapsid who led to birds, crocs and pterosaurs
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what is the problem with making soft tissue inferences based on homologies? so instead we use...?
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-no correlation with skeletal material we have
-lacks direct evidence in fossils -ignores form-function relationships -so instead we use phylogenetic brackets: correlations between soft and hard tissues, strengthen inferences about soft tissues in reconstruction |
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When looking at the ungual, what could that groove be?
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-the channel for nerves, blood vessels, tendons, gland ducts
-remnants of earlier developmental events (were present and functional in fetus but no influence to loose in adult even though useless) |
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if the ungual is the hard skeleton, what is the soft structure?
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the keratinized sheath, you can do the clade analysis with the actual hard part and make inferences about the soft part
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