origins of life 1 patterns
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Origins of LifeOrigins of LifePatterns of EvolutionPatterns of Evolution
- Classification -- Classification -
Phyletic GradualismPhyletic Gradualism (Uniformitarianism) (Uniformitarianism)
Sedimentation rates we commonly see today are Sedimentation rates we commonly see today are very very slowslow (centimeters/year) (centimeters/year)• Assuming those rates have been constant throughout Earth’s Assuming those rates have been constant throughout Earth’s
history, it would take millions of years for the sedimentary history, it would take millions of years for the sedimentary layers we see at locations such as the Grand Canyon to formlayers we see at locations such as the Grand Canyon to form
Phyletic Discontinuity Phyletic Discontinuity (Catastrophism)(Catastrophism)
Catastrophic events (volcanoes, floods, etc.) cause Catastrophic events (volcanoes, floods, etc.) cause rapid, widespread sedimentation and dramatic changes rapid, widespread sedimentation and dramatic changes to the geologic recordto the geologic record• Mt. St. Helens displaced huge amounts of dirt, rock and snow, Mt. St. Helens displaced huge amounts of dirt, rock and snow,
carving a mini grand canyon and leaving over 50 feet of carving a mini grand canyon and leaving over 50 feet of sediment deposited across the valleysediment deposited across the valley within a matter of within a matter of minutesminutes
Punctuated Punctuated EquilibriumEquilibrium
Slow sedimentation rates and Slow sedimentation rates and evolutionary changes evolutionary changes "punctuated" (interrupted) by "punctuated" (interrupted) by events that facilitate rapid events that facilitate rapid bursts of evolutionbursts of evolution• Mass extinctionsMass extinctions• Explains "Cambrian Explosion"Explains "Cambrian Explosion"
Sudden appearance of new Sudden appearance of new species (fossils)species (fossils)
• Explains lack of transitional fossilsExplains lack of transitional fossils
Fossil Dating MethodsFossil Dating Methods
Radioisotope DatingRadioisotope Dating• Decay of unstable elements used to measure Decay of unstable elements used to measure
elapsed time (assumes known original amount, elapsed time (assumes known original amount, constant rate of decay, and lack of contamination)constant rate of decay, and lack of contamination)
Molecular ClocksMolecular Clocks• Measurable rates of mutation used Measurable rates of mutation used
to compare DNA of organisms and to compare DNA of organisms and estimate time between evolved estimate time between evolved ancestors ancestors
StratigraphyStratigraphy• Age of rock layers and the fossils within are Age of rock layers and the fossils within are
interpreted with the belief that younger fossils are interpreted with the belief that younger fossils are deposited on top of older fossils (deposited on top of older fossils (superpositionsuperposition))
Classification & PhylogenyClassification & Phylogeny
ClassificationClassification• the process of describing, the process of describing,
naming, and grouping things naming, and grouping things based on their similaritiesbased on their similarities
• grouped organisms are easier grouped organisms are easier to studyto study
TaxonomyTaxonomy• scientific study of how living scientific study of how living
things are classifiedthings are classified PhylogenyPhylogeny
• the evolutionary history of a the evolutionary history of a organisms as depicted in a organisms as depicted in a "family tree""family tree"
Systems of ClassificationSystems of Classification Carolus Linnaeus (1750s)Carolus Linnaeus (1750s)
• grouped organisms based on observable features (long grouped organisms based on observable features (long before evolution was proposed)before evolution was proposed)
• system used for over 250 yearssystem used for over 250 years• devised naming system for organismsdevised naming system for organisms
Binomial NomenclatureBinomial Nomenclature 2 part naming system using Latin words2 part naming system using Latin words Genus speciesGenus species (i.e. (i.e. Felis concolorFelis concolor))
Phylogenetic ClassificationPhylogenetic Classification• Retains Linnaean system for the most partRetains Linnaean system for the most part• Species with similar Species with similar hypothesizedhypothesized evolutionary histories evolutionary histories
are grouped more closely togetherare grouped more closely together• Based on DNA similarities more than physical appearanceBased on DNA similarities more than physical appearance• Evolution of species is presupposedEvolution of species is presupposed
1707-1778
Levels of ClassificationLevels of Classification There are There are 77 levels of classification. levels of classification.
Remember: Remember: KKing ing PPhilip hilip CCame ame OOver ver FFor or GGood ood SSoupoup
KKingdom ingdom broadest levelbroadest level
PPhylumhylumCClasslassOOrderrderFFamilyamilyGGenus enus SSpeciespecies most specificmost specific
Binomial NomenclatureBinomial Nomenclature two-name system of namingtwo-name system of naming
• GenusGenus is 1 is 1stst name (upper case); name (upper case); speciesspecies is 2 is 2ndnd name (lower case name (lower case
Phylogenetic TreePhylogenetic Tree
Classification Classification based on :based on :• Morphology (similar Morphology (similar
physical structures)physical structures)• Fossil recordFossil record• Embryological Embryological
patterns of patterns of developmentdevelopment
• Genetic similarities Genetic similarities (DNA) (DNA)
CladogramsCladograms A phylogenetic tree is based on a grouping/sorting similar organisms A phylogenetic tree is based on a grouping/sorting similar organisms
into groups called clades. into groups called clades. This is a relatively new system of grouping incorporating the same This is a relatively new system of grouping incorporating the same
derivedderived characteristics to represent evolutionary relationships. characteristics to represent evolutionary relationships. • Organisms within Organisms within a group are a group are descended from a descended from a common ancestorcommon ancestor• There is a There is a branching pattern branching pattern (splits in two where(splits in two where changes occur)changes occur)• Change in Change in characteristics characteristics occur in lineagesoccur in lineages over timeover time
Homologous CharacteristicsHomologous Characteristics A structure found in different species, but derived from a A structure found in different species, but derived from a
common ancestral structure.common ancestral structure.• The structure may or may not be used for the same function in the The structure may or may not be used for the same function in the
species in which it occurs. species in which it occurs.
Examples:Examples:• skeletal skeletal
structure of structure of vertebrate vertebrate limbslimbs
• embryonic embryonic similaritiessimilarities
• similarities in similarities in DNA, RNA, & DNA, RNA, & their proteinstheir proteins
Embryonic Embryonic Homologues Homologues
Structures that have different Structures that have different mature forms but develop mature forms but develop from the same embryonic from the same embryonic tissuestissues
Limbs are structurally similar Limbs are structurally similar but have different functionsbut have different functions
Recent developments in Recent developments in biochemistry show "similarity biochemistry show "similarity does not imply a genetic does not imply a genetic relationship" relationship"
Alligator
Turtle
Primitive Fish
Mammal
Comparative EmbryologyComparative Embryology
Analogous StructuresAnalogous Structures
Similar in function, but NOT derived from a common ancestral Similar in function, but NOT derived from a common ancestral structure structure
Examples:Examples:• wings of birds wings of birds
& bats& bats• walking limbs walking limbs
of insects & of insects & vertebratesvertebrates
• eyes of a eyes of a horse and an horse and an octopusoctopus
• human skull human skull and beetle's and beetle's head shield head shield exoskeletonexoskeleton
Bones are homologous structures, but wings Bones are homologous structures, but wings are only analogous.are only analogous.
Inherited TraitsInherited Traits
Neo-Darwinism incorporates the Neo-Darwinism incorporates the similarities of genetics between similarities of genetics between species as evidence of evolutionspecies as evidence of evolution
Other scientists look at genetic Other scientists look at genetic code and see the complexity and code and see the complexity and efficiency of information transfer efficiency of information transfer as evidence for an intelligent as evidence for an intelligent “designer”“designer”
Six Six KingdoKingdo
msms ArchaebacteriaArchaebacteria EubacteriaEubacteria ProtistsProtists FungiFungi PlantsPlants AnimalsAnimals
First true cells are thought to have First true cells are thought to have arisen from aquatic, anaerobic, arisen from aquatic, anaerobic, "protocells""protocells"
6
EUBACTERIAARCHAEBACTERIA
Tree of Life VideoTree of Life Video
Domain (or Kingdom) ArchaeaDomain (or Kingdom) Archaea
Formerly part of the Formerly part of the Monera kingdomMonera kingdom
Bacteria that live in Bacteria that live in extreme conditions:extreme conditions:• hothot• acidicacidic• sulfuricsulfuric• deepdeep• coldcold
Domain (or Kingdom) Domain (or Kingdom) EubacteriaEubacteria
Formerly part of the Monera Formerly part of the Monera kingdomkingdom
"True Bacteria" "True Bacteria" • make us sickmake us sick• live in our intestineslive in our intestines• make cheesemake cheese
Different shapesDifferent shapes• Bacilli (rod-shape)Bacilli (rod-shape)• Strep/StaphyloStrep/Staphylococcuscoccus (round (round
chains/clusters)chains/clusters)• Spirilla (stringy spirals)Spirilla (stringy spirals)
Domain EukaryotaDomain Eukaryota
Includes all eukaryotic Includes all eukaryotic organismsorganisms
Includes 4 kingdoms:Includes 4 kingdoms:• ProtistaProtista• FungiFungi• PlantsPlants• AnimalsAnimals
Kingdom ProtistaKingdom Protista
Amoeba Paramecium Giardia
Water Mold Slime Mold
Euglena Dinoflagellates DiatomBrown AlgaeGreen Algae
Fungus-
Like
Plant-
Like
Eukaryotic (have Eukaryotic (have nucleus)nucleus)
Single-celledSingle-celled
Animal-Like
(protozoans)
Kingdom FungiKingdom Fungi
EukaryoticEukaryotic Multi-cellularMulti-cellular HeterotrophicHeterotrophic Sessile organismsSessile organisms Molds, mushrooms, Molds, mushrooms,
lichenslichens
Kingdom PlantaeKingdom Plantae
Bryophyte (Moss)
Pteridophytes (Ferns)
Conifers (cone-bearing plants)
Angiosperms (flowering plants)
EukaryoticEukaryotic Multi-cellularMulti-cellular Autotrophic (produce own Autotrophic (produce own
food)food) Sessile (don't move)Sessile (don't move)
Kingdom AnimaliaKingdom Animalia
Eukaryotic, multi-cellular, heterotrophic, motile Eukaryotic, multi-cellular, heterotrophic, motile Common Phyla:Common Phyla:
• Porifera (sponges, corral) Porifera (sponges, corral) • Cnidaria (jellyfish and similar animals)Cnidaria (jellyfish and similar animals)• Platyhelmenthes (flat worms, tapeworms) Platyhelmenthes (flat worms, tapeworms) • Nematoda (small unsegmented worms)Nematoda (small unsegmented worms)• Mollusca (inc. clams, oysters, etc..)Mollusca (inc. clams, oysters, etc..)• Annelida (segmented worms)Annelida (segmented worms)• Echinodermata (starfish and anemones)Echinodermata (starfish and anemones)• Arthropoda (crustaceans, insects, spiders)Arthropoda (crustaceans, insects, spiders)• Chordata (those with spinal chords: birds, mammals, Chordata (those with spinal chords: birds, mammals,
amphibians, bony fish, etc.)amphibians, bony fish, etc.)
Dichotomous KeysDichotomous Keys
1a. Organism has 4 legs Go to # 2
1b. Organism has more than 4 legs Go to # 20
2a. Organism has a tail Go to # 3
2b. Organism has no tail Go to # 35
3a. Organism has stripes Bengal Tiger
3b. Organism has no stripes African Lion
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