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60 Cards in this Set
- Front
- Back
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Life Originated how many yrs ago?
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3.5-4 billions yrs ago
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Earth was formed?
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4.6 billions yrs ago
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Stanley Miller:
(put hypothesis to the test) (elegent)what did he find? |
found a variety of amino acids found in orgamisms today, along with other organic compunds. But no produced organic molecules.
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How was the 1st atmosphere like?
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thick, with water vapor, along with various compounds released by volcanic eruptions, including, nitrogen, and its oxides, methane, ammonia, hydrogen, and hydrogen sulfide. As earth cooled the water vapor became oceans and hydrogen escaped into space.
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A.I Oparin and J.B.S Hamdane hypothesized?
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earth early atmosphere was a reducing (electron-adding)enviroment, in which organic compounds could have formed from simple molecules.
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Abiotic Synthesis of Macromolecules
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posible that polymers may have acted as weak catalysts for a variety of raction on earth. Evidences showed dripping solution of AA into a hot sand, clay or rock, research have been able to produce AA polymers. Formed spontaneously with out help of enzymes or ribosomes.
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Protobionts
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collections of abiotically produced molecules surrounded by a membrane-like structure. may exhibit some property of life.
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liposomes
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can produce and perform simple metabolic reactions
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ribozymes
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RNA catalysts (enzyme like catalysts. indicative that RNA molecules may have been self replicating in the prebiotic world.
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RNA 1st genetic material?
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once hypothesized what maintains the 1st genes were short strands of RNA (NOT DNA)
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Geological record divided into 3 eons:
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1. Archaean
2. Proterozoic * Paleozoic * Mesozoic(age of reptiles) * Cenozoic 3. |
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1st evidence of life(single cell organism) 3.5 billion yrs ago, comes from fossilized ...
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Stromatolites: are layered rocks that form when certain prokaryotes bind thin films of sediment together. (bacteria and sediment)
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self replicating RNA
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RNA catalysts, ribozymes, self replicate to make complementary pieces of RNA
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stromatolites: first single cell organism (3.5 billion years ago)
prokaryotes |
first single cell organism
3.5 billion years ago prokaryotes rocks that form when certain prokaryotes bind sediments |
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photosynthesis and O2
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atmospheric gas
O2 in water react with iron iron oxide became sediment find this by striated rocks |
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prokaryotes before O2
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some where able to survive on aerobic processing
bacteria gave off O2 some survived off photosynthesis |
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cyanobacteria
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bacteria gave off O2
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First Eukaryote: Endosymbiosis
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cell living within host
mitochon. and plastids (chloroplasts) small prokaryotes that evolved to living within large cells |
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origin of multicellularity
Earliest multicellular eukaryotes |
Edicarian Biota: assembly of fossils of diverse and soft bodied organisms
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Cambrian Explosion
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earliest fossils of many groups of animals
hox gene (adaptation of predator-prey limbs and other function and new adaptations) , atmospheric oxygen, and animal replication Cnidaria, Prolifera, Mollusca |
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Colonization of Land?
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multicellular eukaryotes evolved from water to land
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Continental Drift
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earth's crust made of plates that move over time
Pangea: one land mass formation of mountains and valleys |
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self replicating RNA
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RNA catalysts, ribozymes, self replicate to make complementary pieces of RNA
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stromatolites: first single cell organism (3.5 billion years ago)
prokaryotes |
first single cell organism
3.5 billion years ago prokaryotes rocks that form when certain prokaryotes bind sediments |
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photosynthesis and O2
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atmospheric gas
O2 in water react with iron iron oxide became sediment find this by striated rocks |
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prokaryotes before O2
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some where able to survive on aerobic processing
bacteria gave off O2 some survived off photosynthesis |
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cyanobacteria
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bacteria gave off O2
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First Eukaryote: Endosymbiosis
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cell living within host
mitochon. and plastids (chloroplasts) small prokaryotes that evolved to living within large cells |
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origin of multicellularity
Earliest multicellular eukaryotes |
Edicarian Biota: assembly of fossils of diverse and soft bodied organisms
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Cambrian Explosion
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earliest fossils of many groups of animals
hox gene (adaptation of predator-prey limbs and other function and new adaptations) , atmospheric oxygen, and animal replication Cnidaria, Prolifera, Mollusca |
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Colonization of Land?
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multicellular eukaryotes evolved from water to land
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Continental Drift
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earth's crust made of plates that move over time
Pangea: one land mass formation of mountains and valleys |
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Consequences of Continental Drift; Mass extinction
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mass extinction: 50% species became extinct
Adaptive Radiation: other animals evolved from common ancestor sixth human caused? Crestaceous: 10 ton large asteroid landed in gulf of mexico |
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Changes in spacial pattern
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as organisms adapted to new environments, homeotic genes(master regulatory geenes) determined basic features or parts are arranged
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Hox gene
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a class of homeotic genes that provide body plan of animals
limbs, wings, arms, etc. |
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Evolution is not goal oriented
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Novels
natural selection can only improve a structure (why humans came first); descent with modifications--gradual modification of early ancestors Trends: |
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Linneaus: classification system
"Damn King Phillip Came Over For Good Sex"!!! |
Domain
Kingdom Phylum Class Order Family Genus Species |
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Phylogeny
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the evolutionary history of a group of species
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Binomial Nomenclature
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Genus name/ Species Name
-homosapien- |
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Linking phylogeny and classification
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phylogeny represented in a branching diagram: phylogenetic tree
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Phylogenetic tree
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at the branch point divergence of 2 species
shows pattern of descent doesn't show where they evolve can't assume they related because they look alike ancestral lineage or similar features |
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Morphological and Molecular Homology
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Homologous ancestors: shared ancestry
Analogous: convergence evolution/may share similar features but don't share common ancestor |
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Evaluating Molecular Homologies
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genes that code for homologous structures may be similar
Organisms with similar morphologies/DNA sequences likely closely related than organisms with different structures/sequences |
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Evaluating Molecular Homologies (cont)
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Molecular homology: using computerized alignment sequences, look at DNA sequences of similar animals and compare them
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Shared Characters are used to construct phylogenetic trees
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method of distinguishing homologous from analogous features/ phylogeny with homology: Cladistics
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Cladistics
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groups organisms by common descent
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Clade
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place species into gropus that includes an ancestral species and all its descendents
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Cladistics: Shared ancestral and derived characters
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Shared Ancestral: descent with modification; originated in an ancestor of the taxon (ie: all vertebrates have backbones)
Shared Derived: evolutionary novelty unique to a particular clade (hair shared by all mammals but not found in ancestors) |
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Cladistics: Inferring phylogenies using derived characters
Outgroup vs. Ingroup |
determine clade where shared derived character first appeared and to infer evolutionary relationships
homologies shared by the outgroup and ingroup are ancestral characters that predate the divergence of both groups from a common ancestor |
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Outgroup
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species closely related to ingroup; evoliutionary lineage diverged from before the ingroup
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Ingroup
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species of interest
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Phylogenetic trees as Hypothesis
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hypothesis about how organisms in the tree are related to one another
Maximum parsimony (looking at similar things to explore changes) and Maximum Likelihood (best fit and simplest solution) Tree with the fewest evolutionary events is more likely Likelihood: how DNA changes over time; tree that reflects the most likely sequence over time |
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organism's evolutionary history is documented in its genome
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different genes evolve at different rates in lineage
(DNA that codes for rRNA changes slow so so can see relationships between taxa that diverged a long time ago) also, mitochondrial DNA can help link evolutionary relationship in people (asians, africans, indians share similar mtDNA--more recent study) |
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Molecular clocks help track evolutionary time
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Molecular Clock: over time genetic change happens constant rates of evolution
some genes to estimate the absolute time of evolutionary change |
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Molecular clock (mammals)
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number of accululated mutations in proteins increased over time in a consistent manner for most mammals
based on fossil evidence same genes may evolve at different rates in different groups of organisms |
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New information continues to revise our understanding of the tree of life
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used to classify all species into two kingdoms:plants/animals
some microorganisms that were photosynthetic and move (euglenids) showed up in both kindoms Then went to five kingdoms -some prokaryotes differed from each other as eukaryotes did 3 Domains: Bacteria, Archaea, and Eukarya: higher taxonomy than kingdom bacteria and archaea: single celled eukarya: multicellular |
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Protists
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recently discovered diverse unicellular groups of eukaryotes
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Most eukaryotes are single-celled organisms
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have nucleus + membrane bound organelles (ie mito and golgi)
more complex than prokar's |
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Structural and functional diversity in protists
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more nutritionally diverse
more complex than prokar's 1. heterotrophs: absorb organic molecules 2. photoautotrophs: contain chloroplasts 3. mixotrophs: combine photosynthesis and heterotrophic nutrition can be sexual or asexual |
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Endosymbiosis in Euk's
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*process where certain organisms engulf other cells to become host cells
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