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213 Cards in this Set
- Front
- Back
Relative dating |
Getting geological events in the right order. Looking at strata |
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Superposition |
Oldest strata will be at bottom, youngest on top |
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Law of horizontality |
Strata is deposited in layers that are parallel |
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Law of original continuity |
Law of horizontality continues over lateral distance, if not disturbed |
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Boundary |
Between geological units |
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Unconformity |
When a "time period is missing" between strata in a geological section. |
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Disconformity |
Type of unconformity. Erosion between sedimentary strata |
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Non-conformity |
Type of unconformity. Sedimentary rocks deposited on eroded metamorphic/igneous rock. |
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Angular unconformity |
Type of unconformity. Sedimentary strata is deposited on tilted and eroded layers |
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Absolute dating |
Measuring radiometric data. You measure radioisotopes in fossils to get an exact date. Compare radioisotopes with amount of gatherd decay. Volcanic ash beds are important, contains zircoins. |
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Continental drift |
How the continent moves. proposed by Alfred Wegener 1912 |
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Alfred Wegener |
Proposed continental drift on following "evidence" 1912 1. The fit - continents visually fit together 2. Distribution of fossils - Gondwana contains Mesosauros and Glossopteris 3. Ice flow FROM center of gondwana 4. Continuation of mountain belts across present oceans Rejected because he couldn't think of a mechanism. |
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Mesosaurus & Glossopteris |
Evidence for continental drift. Fossils found on different continents of animals that couldn't have moved over oceans |
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Geophysical evidence for continental drift |
Mid ocean ridges, paleomagnetics, No ocean crust older than 200 ma - older further away from mid ocean ridge |
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Mid ocean ridge |
Underwater mountain ridge, ocean spreading center, seafloor spreading, plate spread + mantle upwelling No ocean crust older than 200 ma - older further away from mid ocean ridge |
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Paleomagnetics |
How continental plates move |
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Continent - continent collision |
Continents collide and that produces mountains, ex south asia and india collided and formed himalayas |
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Subduction zone |
Where one plate is forced under another, ex pacific plate subducting western south america to form Andes |
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Nuna |
Supercontinent (all continents) 1800 MA to 1500 MA. Proterozoic |
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Rodinia |
Supercontinent (all continents) 1250 MA to 750 MA. Proterozoic. |
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Pangea |
Supercontinent (all continents) 300 MA - 200 MA. Between Paleozoic and Mesoic. |
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Gondwana |
Megacontinent (not all continents) 540 MA - 142 MA. Paleozoic and almost whole Mesozoic |
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Rift valley |
Low land between mountains, begins breakup of continent |
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Wilson Cycle |
How oceans are formed: Transitory features created when a mega/super continent breaks up. Dissapears when continents collide. Takes 100 ma years. Continents collide, then break a part forming oceans |
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Nucleotide |
Organic molecule, subunit in a nucleic acid |
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Nucleic acid |
"Biopolymers" essential for all life - RNA, DNA |
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DNA |
Molecule dontaining genetic instructions on Growth, development, functioning, reproduction |
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RNA |
Polymeric molecule essential for coding, decoding, redulation, expression of genes |
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Gene pool |
Total amount of genetic info coded on all individuals in a group. Species who reproduces sexually reshuffles gene pool - this is what keeps evolution going |
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Mutation |
Change in one or more nucleotides in DNA. Innovation: Most likely small and harmful. If beneficial -> enhanced by natural selection |
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Natural selection |
Survival of the fittest, individual best suited for hunt for food, living space, mating, avoidance of predators will survive and pass down their genes Pepper moth: speckled, 1880 industrial revolution, black, 1960 clean air act, 50/5 Darwin's finchers: one species to galapagos, evolved into 14 different ones DIRECTIONAL - eliminates bad genes and enhances beneficial |
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Anagenesis |
Mutation, Continued evolution until the species unconsciously becomes a new one, replacing the other |
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Cladogenesis/divergence |
Splitting of on species in to two |
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Convergence |
Opposite of cladogenesis/divergence: Similar life, similar environment will evolve similar morphology even though they are not related |
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Analogous convergence |
Opposite of cladogenesis/divergence: Similar life, similar environment will evolve similar morphology even though they are not related Functionally similar traits, sabre tooth: for cutting chunks of flesh from prey leaving them to bleed to death. evolved separately 5 times. |
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Homologous convergence |
Opposite of cladogenesis/divergence: Similar life, similar environment will evolve similar morphology even though they are not related Common origin but not similar function |
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Co-evolution |
Evolution as a response to change in environment. arms race and mutualism |
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Arms-race |
Co-evolution: Race between predator and prey. Faster, hunting strategies, powerful, camouflage, poison and so on |
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Mutualism |
Co-evolution: Mutually beneficial, nectar - insects. berries/nuts - birds = polination and seeding |
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Red Queen Effect |
The world is changing around you, evolve or go extinct |
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Court jester effect |
Factors outside of the animals control also shape evolution |
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Species |
2 million species described. Animals 1 1 600 (insects 80%) Plants 270 000 Fungi 72 000 Algae 40 000 Bacteria/archae 4 000 Viruses 1500 |
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Phylogeny |
Mapping of organisms according to evolutionary relationsships. Shown in a Phylogeny Tree. Based on similariteis/differences in physical or genetic characters |
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Phylogeny tree |
Diagram that show a species phylogeny |
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Organelle |
Subunit in cell that has a specific funtion, tiny organ. Ex: Nucleus (cointains DNA) |
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Nucleus |
Organelle, contains DNA |
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Eukaryote |
Unicellular or multicellular. DNA in Nucleus, contains organelles |
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Prokaryote |
Unicellular, no nucleus or organelle, bacteria and Archaea |
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Linnean classification |
Carl Von Linne 1700, Organized organisms. Domain/Superkingdom Kingdom Phyla Classes Orders Families Genera Species |
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The three superkingdoms/domains |
A) Bacteria - normal prokaryotes B) Achae - extremophile prokaryote C) Eukaryotes - All eukaryotes |
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Eukaryote 4 kingdoms |
1. Protoctista - unicellular 2. Fungi - multicellular, non-motile 3. Plantae - nutrients, multicellural, non-motile, photosynthesis 4. Animalia - Multicellular, motile |
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Motile |
Organism moves and consumes energy in process |
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Cladistics |
How we know which animals to put where. Method in which you divide organisms into brances (clades) depending on evolutionary connections. |
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Will Henning |
First cladistics guy, 1950 |
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Clade |
Group of organisms who share same characters (morphological and molecular). Ancestor and all species descendant from that ancestor |
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The three sets or morphological characters |
1. Primitive - from ancestor 2. Derived - first appear in the clade 3. Convergent - similar features in unrelated organisms |
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Cladogram |
Tree that shows evolutionary appearance of derived characters |
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Strengths of cladistics |
1. Rigorous and testable 2. Can be used at any level of taxonomy 3. Can include fossil and living species in same cladogram 4. Shows sibling (not ancestor-decendant) relationships |
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Molecular phylogeny |
Measures genetic differences. Francis Crick. Measures degree of substitution in DNA, RNA and Protein |
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Molecular clocks |
Technique that uses the mutation rate of biomolecules to deduce the time in prehistory when two or more life forms diverged. Timing of these are controversial |
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Strengths and weaknesses of molecular phylogeny |
Str: 1. Rigorous and testable 2. Can be used at any level of taxonomy 3. Directly measure genetic differences Weakness: 1. Can only be used in modern fossils. except if fossil is preserved in amber |
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Molecular Phylogeny and Cladistics |
Poweful tool to unravel history of life |
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Fossils |
Remains of ancient organism. More than 5000 years old. Organisms remains or traces |
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5 categories of fossils |
1. Bones - phosphate much mor resiliant than soft bodies. 2. Shells - invertabrates, carbonate and silica 3. cellulose - plants, wood can become pertrified by silica (quartz). carbonized into coal 4. Trace - tacks, burrows 5. Soft tissue - harder to find coz bodies disapear easier than bones. lagerstätten fossil collections. Amber also |
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Fossilization |
Taphonomy. Quicker burial the better. |
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Archean World |
1. No continents, volcanic islands 2. Faint new sun - 80 % power 3. Volcanic atmosphere - No oxygen. co2 500x todays level 4. Stromatolites |
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Synthesesis of life |
1. Formation of simple organic compunds. Miller urey experiment 2. Simple organic compounds to complex. NOT SOLVED 3. Initiation of replication. Spiegelman Monster |
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Miller-Urey experiment |
chemical experiment that simulated the conditions thought at the time to be present on the early Earth - solved issue 1 in synthesesis of life |
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Spiegelman Monster |
is the name given to an RNA chain of only 218 nucleotides that is able to be reproduced by the RNA replication enzyme RNA-dependent RNA polymerase, also called RNA replicase. Solved issue 3 in synthesesis of life - initiation of reproduction |
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Where did life evolve |
Theory: Hydrothermal vents. 1. Not affected by bombardment of meteorites 3,8 ga 2. Wide range of temperatures needed(-1 to 100) for chemical reactions 3. Extremeophiles root of universal tree of life |
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Oldest life |
Pilbara Craton Western austrailia. more than 3 ga old Barberton south australia more than 3,4 ga 1. Stromatolites, greatest abundance proterozoic Oldest from Warrawoona in pilbara craton 2. Organic microfossils - unicellular organisms Pilbara craton microfossils formred in submarine hot water springs |
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Great oxidation event |
Oxygen increased 100x to 5% of todays levels ca 2300 ma - between 2400 and 1800 ma - Nuna around same time Why: Cyanobacteria produced o2 through photosynthesis Effect: 1. BIF dissapeared 2. Red soils appeared 3. co2 decreased - led to first ice ages 4. Ozone layer formed (o3) 5. First fully aerobic metabolism |
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Gunflint chert |
North shore of lake superior. Most important and famous early proterozoic fossil locality |
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BIF |
Banded Iron Formation. Units of sedimantary rock that indicates that iron was in a reduced form in the oceans (stage 1, 4600-2400 ma) |
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faint new sun paradox |
Archean world: sun at 80 % but temperatures still high. Explanation: co2 levels 500x todays levels - green house effect kept earth warm. |
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Early prokakryotes used what to "breath"? |
Nitrate, sulphate, carbon dioxide - did not utilize oxygen
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Anaerobic |
cannot tolerate oxygen |
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Amphiaerobic |
Used o2 if avalible, otherwise anaerobic |
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Aerobic |
Uses oxygen for metabolism, 18x more effective than anaerobic |
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Stages of oxygenation of earth |
1. 4,6-2,4 Iron ocean. reduced iron in oceans 2. 1,8-0,6 Canfield ocean. some free oxygen in shallow oceans, deep oceans still no oxygen. 3. 0,6 -> modern oceans. Atmosphere, shallow and deep oceans are all oxygenated |
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Endosymbiosis |
Theory of evolution of eukaryotes and prokaryotes. Eukaryotes evolved by prokaryotes joining together in symbiosis. Containing: 1. Fermenter cell - host 2. Purple bacterium - ancestral mithocondrium 3. cyanobacterium - ancestral plastids |
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Steranes |
Eukaryote biomarkers, signs of eukaryotes. Early 2,7 - controversial evidence of life: 1. Acritarcs 1600 ma eukaryote microfossil 2. Carbonaceous compressions: 2,1 ga MAYBE. 1,6 ga definitely. 3. Fossil red algae 1200 ma. green algae 4. testate Amoebans (first heterotrophic - predator/scavanger) |
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Greenville mountains |
Records the collision that produced Rodinia - Set up for Ediacaran Biota
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Biota |
The plant/animal life of a region |
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When life got big |
Neoproterozoic. around around 580 ma. After gaskiers glaciation |
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What happens when glacials melt |
Increased biological complexity |
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Oxygen events are connected to what |
ice ages |
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Describe end of proterozoic |
Tumultuous rodinia breaks up Severe global ice ages major change in sealevel and isotopes in water |
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The three massive episodes of Neoproterozoic glaciations: |
1. Sturtian Glaciation - 715 ma. Sponge biomarkers, simple, first to evolve 2. Marionoan Glaciaiton - 635 ma. Microscopic animals. 3. Gaskiers glaciation - 580 ma. Ediacara biota - first large eukaryotes - when life got big. |
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Mistaken point |
In newfoundland. Contains oldest ediacaran fossils. 580 ma old. 2 ma after gaskiers. |
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Rangeomorphs |
Fractal formed creatures. extinct clade - the ediacaran experiment. Suspension fed - filtering chemicals from seawater (osmoptrophy) |
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Ediacara Australia |
younger assemblages of fossils 560-550 ma ediacara biota |
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Namibia and British columbia |
550 - 541 ma - first shelly fossils found |
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Ediacara biota - what was it? |
First animal eco-system! Major extinction at the end of proterozoic - led to beginning of cambrian explosion of animals Older theories "dawn of animal life" - the ediacaran animals had similarities with later life Dolf seilacher - proposed that ediacaran clades died out - failed experiment New: "Both right Extinct clades, most ediacaran fossils cannot be related to any modern animal Stem group - some may have been ancestral taxa that evolved into ex arthropods |
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Big bang of evolution |
Early cambiran, most profound & rapid diversification event |
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Crown - group |
Clade |
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Sponge |
Appeared early cambrian, Easy simple animals, just cells that attach to eachother |
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Sclerites |
Spines that armour body |
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Cambrian skeletons |
Sponges, small shelly fossils, Brachiopods, Trilobites, Echinoredmata and chordata |
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Cambrian brains |
Ediacaran burrows were simple horizontal Cambrian burrows shows evidence of complex patterns: - Comlpex patterns - Vertical dwelling burrows Systematic meandering burrows |
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Burgess shale |
Field British COlumbia One of the most important lagerstätten of all time Info: soft bodied and soft parts of skeletal animals preserved Stem group arthropods Predators! Opabina and anomalocaris |
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Anomalocaris |
Top cambrian carnivore. Misidentified as seperate fossils first, shrimp, jellyfish, some kind of teeth looking thing Was in fact one animal. Big compund eyes, brain |
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Cause of cambrian explosion |
1. Higher oxygen levels allows formation of collagen, exoskeleton, high oxygen, favours predatord 2. Ecological feedback - arms race |
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Agronomic revolution |
Part of cambrian explosion. From only on bottom to swimming, on bottom, under bottom. form 2d to 3d |
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First life: Collagen |
Protein molecules holding cells together. Sticky tape of life. Most comon protein in our body. Oxygen needed to produce. Oxygen event -> ability to produce |
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First life: Rangeomorphs |
Protoanimal - body built up by fractals. did not evolve Mistaken point |
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First life: What attributes does the 550 ma australian fossils have that the rangeomorphs didn't? |
They could move |
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First life: Sex, what evidence, why important? |
Colonies of animals were found. one colony one size, other colony other size. suggest that they reproduced and spread the same genes among them.
To evolve with changing environment you need to reshuffle the gene pool |
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First life: What caused carboniferous oxygen event? Effect? |
Forest with many plants - photosynthesis Enabled animals to grow very big |
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Supercontinent cycles and climate |
Supercontinent cycles coincide with glaciations Cycles seem to control climate BReaking up 0 ice age |
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Greenhouse - ice house - cycles |
HUndreds of millions of years, CO2 as driver Greenhouse: Warm conditions over much of earth, high sea Icehouse: Cold conditions, low sea levels, ice sheets, ice-covered poles |
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Three main ways of measuring global temperature change |
1. leaf analysis 2. Oxygen isotope analysis 3. Community analysis (look at animals/plants living at that time/area) |
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Al Fischer |
Greenhouse/icehouse cycles guy |
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Fossil Forest |
Axel heiberg island canadian arctic Mummified forests with trees and leaves perfectly preserved Aligators, turtles etc - indicates warm climat |
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Milankovits Cyclicity |
relates to changes in obliquity (tilting) precession (wobble, and eccentricity of earths orbit |
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Sepkoski |
Divided all Phanerozoic marine animals into three overlapping evolutionary faunas |
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Three Evolutionary Faunas |
1. Cambrian fauna no hard bodies, trilobites, archaic molluscs, echinoderms, brachiopods armoured mudgrubbers 2. Palleozoic fauna Armoured filter-feeders and pelagic predators (ordvician) ecological tiering Cephalopod top carnivore 3. Modern fauna Gastropods, bivalves, crustaceans, echinoids, bony fish. Less armored adn more mobile than their eqvuvalents in Paleozic fauna |
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Why was the modern Fauna mor mobile and amored compared to the Paleozic Fauna? |
a) Predation - mobile svimmers, enhanced ability to drill, crush, break shells b) Biological bulldozing Depth and amount of burrowing increased, burrowed up to 1 m depth Not good for filter feeders |
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Classification of extinctions |
1. Major: More than 50 % familiy extinction; permian 2. Intermediate: 10-50 % familiy extinction; ordvician, Devonian, Triassic, cretaceous 3. Lesser: 3-10% family extinction; several |
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What followes a mass extinction? |
Burst of evolution (RADIATION) into unfilled niches Mass extinctions is probably equal to natural selection in controlling the evolution of life on earth |
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Paleobiography |
Biographic provinces are areas with distinct biotas. High temperature area = more species Low temperature area = less species Larger are = more speceis |
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Simpson Similarity Index |
Measures degree of similarity between two biographical provinces - increases as continental plates gets closer and decreases as they move a part. |
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Kingston in ordvician, 3 steps |
1. Tidal environment (oldest)
Lower part of rock section Broad supratidal and intratidal flats few modern organisms can stand these conditions abundant stromatolites 2. Tetradium Thicket Fringinf reef attached to shoreline Coral Tetradium filter feeders 3. Subtidal sea-floor Ideal environment for animal and algal life |
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Sea level in ordvician + warm shallow seas |
Extremely high. almost all north america covered in warm shallow seas - Epeiric seas
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From what "sea plant" was land plants probably derived from? |
Green Algea |
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Which plant dominates terrestrial life? |
Empryophytes (bryophytes + vascular plants) |
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Bryophytes |
Mosssa, thin walled, water dconduction cells - no xylem. Needs a lot of water. Waxy cuticle |
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Vascular plants |
more advanced than Bryophytes Xylem Phloem Intercellular gas transport tubes |
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Xylem |
elongate dead cells taht form upwardly-directed pipes for water flow |
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Phloem
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Elongate cells that transport sugars made in photosyntesesis to roots and stem |
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Intercellular gas transport tubes
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brings o2 to roots and co2 to leaves |
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When did first plants on earth? |
ordvician |
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Early paleophytic floras (devonian and earlier) |
1. Rhynophytes 2. Trimerophytes 3. Lycopods and PRogymnosperms |
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Rhyniphytes - where? |
Rhynie Chert in Scotland |
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Type of trimerophyte? |
Psilophyton |
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Lycopod |
Leaves present, small and narrow first appear in Devonian, dominate carboniferous trees up to 50 m, good roots |
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Progymnosperms |
Fern liek leaves, secondary xylem = wood) 10 m tall trees |
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Early Paleophytic forests - were? |
Gilboa in the Catskills of New York state Proymnosperms, lycopods, fern, horestail poor root system - floodplains with semi-permnantn water |
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Late Paleophytic floras
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Upper paleozoic and Triassic AGE O PLANTS Lycopods and fern |
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Fern |
spore bearing, feathery leaves |
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Seed fern
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First gymnosperm - plants bearing a naked seed Glossopteris |
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Effects of evolution of land plants: |
1. Binding loose sediment by plant roots permanentely changed pattersn of erosion and sedimentation on the continents
2. Firt appearance of a new type of river - meandering 3. First appearence of a new rock typ - coal 4. Altered carbon cycling - MASSIVE DRAWDOWN OF CO2 = end of greenhouse cycle 5. PErmanent rise in oxygen in atmosphere 6. Permitted origin of terrestrial animals |
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Osteichthyes |
bony fish, 95% of 19,500 living species of fish |
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Agnatha - origin of fish |
Jawless fish - earliest type of fish Early cambrian Craniated from Chengjian lagerstätten - imply that boneless fish arose early cambrian explosion Fish was uncomon throughout ordvician - major radiaiton in Silurian Slow, bottom grubbing fish - definitely not top carnivore YET |
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ORIGIN OF TETRAPOD |
four limbed vertabrates - descendants are amphibians, birds, reptiles, mammals COllision of europe and NA in devonian produces mountain belts, complec mountains, lowlands, rivers etc Earliest evolution of terrestrial vertabrated occured in this interface bewtween fresh water, the land and the sea Earleist tetrapods were primitive amphibians |
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Age of fishes |
Devonian |
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Vertabrate origins |
Chordate closely related to echinoderms 2 chordate like phyla on the way to fish: Urochordata and Cephalochordata |
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Gnathostomes - jawed fish four main groups |
Achanthodians - first jawed fish, agile filter feeders, few predators
Chondrithyes - sharks, first appear devonian Placoderms, heavy external armor, devonian, some gigantic (6m) Osteichytehs jawed bony fish, devonian, dominant of modern seas, lakes , rivers Lobefins very important in devonian Rhipidistians an extinct griup that evolved into tetrapods |
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Paleozoic amphibians (leaving the water) |
Earliest tetrapods primitive amphibians late devonian Carniverous |
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Early reptiles - one important change that made colonizing land possible |
Development of cleidoic egg (closed) permitted true colonization of land |
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Amniotes |
Reptile, mammals and birds |
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Threemain groupings of amniotes based on number and position of fenestrae (holesother than orbits and nostrils) temporal fenestrae (fenestrae means window) |
Anapsid: No fenestrae (earliest reptiles) Synapsid - one fenestrae (mammal like reptiles and mammals) Diapsid - 2 fenestrae (most modern reptiles, dinosaurs, birds) |
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How was synapsid and diapsid conditions derived? |
from anapsid reptiles in the late carboniferous |
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earliest stem group repitiles, what and where? |
350 ma from sctoland, "Lizzie" - anapsid Earliest true reptile from joggings Nova Scotia Hylanomus |
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"Sail" on pelycosaurids
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Dimetrodon, early Permian Reptile used sai for heat regulation by facing it into or against the sun - sail filled ith blood vessels |
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Pelycosaurs replaces by what? |
Therapdis, mammal like |
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What are therapdids thought to had evolved? |
Thermoregulation (ability to produce their own hear and control their body temperature) Evidence suggest that they atleast were partial endotherms (creating own heat - ex when we eat) 1. Pits for insertion of bristles whow that they had hair 2. Therapdids lived in cold places - no modern cold blodded reptiels are able to live in these climates |
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The great dying what, when and why
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Late Permian MAJOR mass extinction End of Paleozoic Eon 57 % families 95 % Species Filter feeders got hit the worst Corals extinct for 20 million years Trilobites, several bryozans, cephalopods extinct Terrestrial vertebrates - 75 % families Less effect on terrestrial vegetation WHY? Extreme oceanic anoxia followed by sudden release of CO2 Same age as SIberian Traps (big volcanic deposit) |
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How did the ecosystem recover after the Permian Extinction_
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low biomass, low numbers, low diversity Distaster biotas (abundant marine stromatolites and terrestrial weeds common) Simple community structure 2. Middle Triassic Rebound Phase 15 ma years Increas biomass and dieversity Lazarus taxa (taxa same as pre-extinction) Elvis taxa (convergent with pre-extinction) 3. Upper Triassic Expansion phase New evolutionary innovation on land - dinosaurs and mammals, sea and air |
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The Triassic Takeover
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2. Marine Reptiles turtles, pleisiosaurs, ichthyosaurs 3. Terrestrial Diapsid Reptiels Archosaurus in middle-late Triassic SPRAWLING POSTURE |
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Carrier's Constraint
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Short burts of speed, ambush tactics |
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What freed the archosaurs form carriers constraint? |
evolution of semi-erect and erect posture |
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Theodonts and posture
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Parasuchids Crocodiles Other bramch led to 3 groups woth erect posuter INCLUDING DINOSAURS |
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Oldest dinosaurs, when?
|
early, late Triassic EORAPTOR - chicken to osrich size, theropods
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End Triassic extinction |
Massive volcanism, elimitad ornitosuchian diapdis and most synapids marks the beginning of age of dinosaurs |
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Dinosaur
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Largest land animals ever lived |
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How do we investigate how dinosaurs were so big yet could still move? and how fast?
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Comparative anatonomy and dinosaur footprints |
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Undertracks
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impressions of footprint preserved some distance below actual track |
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Relative stride length
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length of stride / length of leg |
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How fast were dinosaurs travelling?
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Faste speeds are shown in dinosaur stampede at Winton Queensland small dinos race at 11-20 kmh Some show speeds up to 43 kmh |
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Homeotherms
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are able to maintain a constant body temperature. Most homeotherms area endotherms and/or gigantotherms |
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Heterotherms
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allow their body temperature to vary widely depending on external factors. Heterotherms are ectothermic |
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Ectotherms |
invertabrates, fish, amphibians, reptiles. recive their body heat from an external source. Hiding in the shade or basking in the sun are their main methods of decreasing or increasing their internal temperature. Ectorherms are favoured in warm climates |
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Endothersm |
placental mamals, birds - produce heat to regulate their internal temperature. endothermy has a high energy cost but permits sustained exterion and function even in cold conditions. Favoured in temperate and especiall cold climates
|
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Partial endotherms |
monoremes, produce their own body heat. but are not able to fully overcome the effects of external temperature changes |
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Internal homeotherms (= gigantotherms) |
large animals who maintain a constant high body temperature simply by the virtue of teir large size. Note that mass (=heat production) rises as the cube diameter, but the surface area (=heat loss) only rise as the square. therefore any animal in excess of one tonne will experience giganothermy (eg adult tuna, great white, some turtles) |
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Dinos warm or cold blooded: Bakkers evidence
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Says dinos were endotherms because: 1 Predator/prey footprints 2. Gigantotherms and partia lendotherms requires far less energy - t rex 5 good feees/year 3. Upright posture 4. Running speeds 5. Polar dinosaurs |
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Dinos warm or cold blooded: Modern evidence |
1. plates and frills 2. Oxygen isotopes 3. Bone microstructure 4 Nasal rubinates 5 feathers - almostcertain that the origin of feathers was for insulation, implying that thesedinosaurs were at least partly endothermic |
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which three vertabrate groups evolved powered flight? |
Pterosaurus, Birds, Bats |
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What flora dominated carboniferous and Permian landscapes? |
Paleophytic flora, ferns lycopods |
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What flora dominated triassic and rest of mesozoic |
Mesophytic flora |
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The mesophytic flora |
DOminated by gymnosperms, trees 60m high early conifers (pine osv) Cycads (palm like leaves) Ginkgo important gymnosperm |
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What flora dominated middle cretaceous to present? |
Cenophytic flora |
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The Cenophytic flora |
Dominated by angiosperms strong reliance on vector pollination and seed dispersal - attract insets to carry pollen COEVOLUTION ANGIOSPERMS AND ANIMAL VECTORS |
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Angiosperm |
Dominant plant group today, floweringplants, seeed enclosed in tough outer coat, changed dinosaurs story, grass, magnolia |
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Traits of the Mesozoic marine life |
Filter feeders replaced by modern fauna: gastropods, bivalves, corals, bony fish Rudist reef builders Ammonites - coiled cephalopod Belemnites OCEANS DOMINATEd BY LARGE MARINE REPTILES |
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Sauropterigians |
Jurassic and Cretaceous, large marine reptiles that solved carriers constraing in water 1. Ichtysaurs 2. mososaurs 3. pleidosaurs |
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Cynodont |
Most advanced therapsid mammal ancestor |
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Evolving mammalian characters in the skeleton included MAMMALIAN INNOVATIONS: |
1. increasingly complex teeth and tooth replacement 2. reduction in the bumber of bones in lower jaw 3. simultaneous increase in the number of bones in the inner ear 4.fully uppright stance 5. increase brain size 6. full thermoregulation 7. live birth 8. milk production |
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Morganucodontids |
early stem-grou of mammaliformes, late triassic shrew to mouse sized |
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Monotremes |
"protherians" fur covered partial endotherms, originated from Gondwana and has been restriceed to gondwana ever since |
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THerian mammals |
Marsupials(pouch) and placentals (delivers fully operational offspring) |
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Most common mesozoic mammals |
Multituberculates similar to modern rodents, extinct early tertiary |
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THerians |
marsupial and placentals originated in northern continents in the Jurassic or Cretaceous |
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Where was the largest mammal of the Mesozoic found? how big was it? |
inside dinosaurs stomach, racoon sized |
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Cynodonts - traits |
poor offaction and vision insensitive hearing lack of fine motor coordination |
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Stem-group mammals - traits |
brain 50-100% larger than cynodonts larger olfactory bulbs and vertebral hemispheres better smell and feel because burrowing |
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Crown group mammals - traits |
further brains size than stemgroup |
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The terminal cretaceous event: |
End of mesosoic 65 ma 17 % familiy extinction (fifth largest) DInosaurs, Pterosaurs and marine reptiles went extinct 1. Volcanism - Deccan Traps shows huge volcanic movement at same time 2. bolide impact - meteor: crater 80 km, dust cloud bloc ksunlight, heatblast then cold winter Walter Alvarez reported iridium anomaly Yucatan in mecixo crater |
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Factors that control susceptibility (mottaglighet) to mass exinctions |
1. size no animal över 25 kg has sruvived 2. Climate tropical and reef highly vulnerable, polar biotas less affected 3. Evolutionary niche - specialized = vulnerable. generalists and burrowers are less effected |
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Dinosaur reign |
Appeared in late Triassic, dominated through rest of mesozoic and went extinct in cretaceous 165 ma years. |
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What dominated the permian world |
Synapsids, especially therapids - first animal to achieve partial thermoregulation |
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When did mammals increase in size and by how much |
1000 fold in early cenozoic when dinosaurs went extinct |
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Eocene life - which fossil forrest exemplifies? |
sea mammals evolved, and most modern orders of mammals MESSEL fossil forest in germany |
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Mammalian top carnivores |
1. Mesonychids bizarre ungulates (andrewsaurchus) - largestcarnivours land mammal ever analogous to grizzly 2. Creodonts, small ferret-cat-dog sized 3. true carnivore evovle in eocene |
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The Miocene Savannah |
Kept in check by grazing and browsing organisms eat top parts of foliage encourages sideways growth Grazers:Thesize and diversity of the grazers were both similar to those of today, but inthe Miocene consisted almost entirely of early horses (modern grazers areantelope and zeras)- Browsers:most ecological roles filled by similar but mostly unrelated species (eglong-necked camel filled the role of modern giraffe as top browser)- MixedFeeders: A similar array of different sized mixedfeeders, but dominanted by camels rather than antelope in the Miocene.- Carnivores: Asimilar array of stabbing (sabre-tooth “cats” vs lions, leopards, and othertrue cats) and bone-crunching (bear-dogs vs hyenas) predators. Onlyswift-running pack hunters (wild dogs) seem to have been absent from theMiocene Svanna. |
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Evolution of horses |
To orders of hoofed mammals (ungulate) in eocen 1. Artiodactyls (sheep, deer, cows) 2. Perissodactyls (horses, rhinos, tapirs) Miocene age of horses |
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Ungulate |
hoofed mammal |
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Afrotheria |
early clde of mammals, evolved in africa and includes all modern elephants ,sea cows, hyraxed and aardvarks |
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Xenarthra |
Early clade of mammals, evolved in south america includes sloth, armadillos, anteaters |
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Early hominins |
In africa, 1. Sahelantropus 6,5ma single skull that exhibits chimplike and human like features 2. Ardipithecus Complete female skeleton "ardi" was a faculative biped, who was equally adept on the ground or in thetrees palmigrade climbing was later modified into "knuckle walking" and "tree swining" |
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EARLY HUMANS Australopithecines |
Taung Child found by Raymond Dart south africa 2,5 ma old subdivide into gracile and robust G: |
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EARLY HUMANS HOMO and their tools |
1. homo habilis 2.3-1.6 ma Oldowan tools 2. Homo erectus 1.8-0.3 ma Acheulean tools 3. Neanderthal 150.000 - 30.000 bp Mousterian tools 4. early homo sapiens 140-100.00 bp. Aurignacian tools |