Post on 29-Dec-2015
Key ConceptsKey Concepts
Origins of lifeOrigins of life
Evolution and evolutionary processesEvolution and evolutionary processes
Ecological nichesEcological niches
Species formationSpecies formation
Species extinctionSpecies extinction
How Did We Become Such a How Did We Become Such a Powerful Species So Quickly?Powerful Species So Quickly?
Adaptive traitsAdaptive traits
Human weaknessesHuman weaknesses
Opposable thumbsOpposable thumbs
Walk uprightWalk upright
IntelligenceIntelligence
Environmental impactsEnvironmental impacts
p. 67
Origins of LifeOrigins of Life
Chemical evolutionChemical evolution
Biological evolutionBiological evolution
How Do We Know Which How Do We Know Which Organisms Lived in the Past?Organisms Lived in the Past?
Fossil recordFossil record
Radiometric datingRadiometric dating
Ice coresIce cores
DNA studies DNA studies
Fig. 4-2, p. 65
Fig. 4-3, p. 66
Modern humans(Homo sapiens)appear about2 secondsbefore midnight
Recorded humanhistory begins1/4 secondbefore midnight
Origin of life(3.6–3.8 billionyears ago)
Biological Evolution of LifeBiological Evolution of Life
Biological EvolutionBiological Evolution
EvolutionEvolution
Theory of evolutionTheory of evolution
MicroevolutionMicroevolution
MacroevolutionMacroevolution
MicroevolutionMicroevolution
Gene poolGene pool
Genetic variabilityGenetic variability
MutationsMutations
MutagensMutagens
Natural selectionNatural selection
Fig. 2-5 p. 33
A human body contains trillionsof cells, each with an identicalset of genes.
There is a nucleus inside eachhuman cell (except red blood cells).
Each cell nucleus has an identicalset of chromosomes, which arefound in pairs.
A specific pair of chromosomescontains one chromosome fromeach parent.
Each chromosome contains a longDNA molecule in the form of a coileddouble helix.
Genes are segments of DNA onchromosomes that contain instructionsto make proteins—the building blocksof life.
The genes in each cell are codedby sequences of nucleotides intheir DNA molecules.
Genetic Genetic MaterialsMaterials
Natural SelectionNatural Selection
Differential reproductionDifferential reproduction
Adaptation (adaptive trait)Adaptation (adaptive trait)
CoevolutionCoevolution
Ecological Niches and Ecological Niches and AdaptationAdaptation
Ecological nicheEcological niche
HabitatsHabitats
Fundamental nicheFundamental niche
Realized nicheRealized niche
Specialized Feeding Niches for Specialized Feeding Niches for BirdsBirds
Black skimmerseizes small fishat water surface
Flamingofeeds on minuteorganismsin mud
Scaup and otherdiving ducks feed onmollusks, crustaceans,and aquatic vegetation
Brown pelican dives for fish,which it locates from the air
Avocet sweeps bill throughmud and surface water in search of small crustaceans,insects, and seeds
Louisiana heron wades intowater to seize small fish
Oystercatcher feeds onclams, mussels, and other shellfish into which it pries its narrow beak
Dowitcher probes deeplyinto mud in search ofsnails, marine worms,and small crustaceans
Knot (a sandpiper) picks upworms and small crustaceansleft by receding tide
Herring gull is atireless scavenger
Ruddy turnstone searchesunder shells and pebbles for small invertebrates
Piping plover feedson insects and tinycrustaceans on sandy beaches
Fig. 4-10, p. 72
Broad and Narrow Niches and Broad and Narrow Niches and Limits of AdaptationLimits of Adaptation
Generalist speciesGeneralist species
Specialist speciesSpecialist species
Limits of adaptationLimits of adaptation
Fig. 4-4, p. 68
Nicheseparation
Specialist specieswith a narrow niche
Generalist specieswith a broad niche
Nichebreadth
Region ofniche overlap
Niches of Specialist and Niches of Specialist and Generalist SpeciesGeneralist Species
Resource use
Nu
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Fig. 4-6, p. 70Unknown finch ancestor
Fruit and seed eaters Insect and nectar eaters
Greater Koa-finch
Kona Grosbeak
Akiapolaau
Maui Parrotbill
Kuai Akialaoa
Crested Honeycreeper
Apapane
Amakihi
Evolutionary Divergence of Evolutionary Divergence of HoneycreepersHoneycreepers
Misconceptions of EvolutionMisconceptions of Evolution
““Survival of the fittest”Survival of the fittest”
““Progress to perfection”Progress to perfection”
SpeciationSpeciation
What is speciation?What is speciation?
Geographic isolationGeographic isolation
Reproduction isolationReproduction isolation
Fig. 4-9, p. 70
Spreads northwardand southwardand separates
Arctic Fox
Gray Fox
Adapted to cold through heavier fur, short ears, short legs, short nose. White fur matches snow for camouflage.
Adapted to heat through lightweight fur and long ears, legs, and nose, which give off more heat.
Different environmentalconditions lead to differentselective pressures and evolutioninto two different species.
Northernpopulation
Southernpopulation
Early foxpopulation
Geographic Isolation can Lead to Geographic Isolation can Lead to Speciation Speciation
Factors Leading to ExtinctionFactors Leading to Extinction
Plate tectonicsPlate tectonics
Climatic changes over timeClimatic changes over time
Natural catastrophesNatural catastrophes
Human impactsHuman impacts
ExtinctionsExtinctions
Background extinctionsBackground extinctions
Mass extinctionsMass extinctions
Mass depletionsMass depletions
Human impactsHuman impacts
PANGAEA
GONDWANALAND
LAURASIA
NORTH AMERICA
ANTARTICAAUSTRALIA
AFRICA
EURASIA
SO
UTH
AM
ER
ICA
INDIAMADAGASCAR
225 million years ago 135 million years ago
65 million years ago Present
Fig. 4-8, 4-9 p. 69
““Continental Drift” (Plate Tectonics): The Continental Drift” (Plate Tectonics): The Breakup of PangaeaBreakup of Pangaea
Fig. 4-10, p. 74
Terrestrialorganisms
Marineorganisms
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Ter
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Jura
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Tri
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Per
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Dev
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Silu
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Ord
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1.8 0651452052502903554104405005453500
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1200
800
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Nu
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Millions of years ago
Changes in Biodiversity over Changes in Biodiversity over Geologic TimeGeologic Time
Future of EvolutionFuture of Evolution
Artificial selectionArtificial selection
Genetic engineering (gene splicing)Genetic engineering (gene splicing)
Genetic modified organisms (GMOs)Genetic modified organisms (GMOs)
CloningCloning
Ethical concernsEthical concerns
Fig. 4-11, p. 75
Phase 1Make Modified Gene
Identify and extractgene with desired trait
Identify and removeportion of DNAwith desired trait
Remove plasmidfrom DNA of E. coli
Insert extracted DNA(step 2) into plasmid(step3)
Insert modifiedplasmid into E. coli
Grow in tissueculture to
make copies
Cell
plasmid
E. coli
DNA
Geneticallymodifiedplasmid
Extract plasmid
Genetic EngineeringGenetic Engineering
Gene of interest
Extract DNA
Fig. 4-11, p. 75
Phase 2Make Transgenic Cell
Transfer plasmid copies to a carrier agrobacterium Agrobacterium inserts foreign
DNA into plant cell to yield transgenic cell
Transfer plasmidto surfacemicroscopic metalparticle
Use gene gunto inject DNAinto plant cell
A. tumefaciens(agrobacterium) Host DNA
Foreign DNA
Genetic EngineeringGenetic Engineering
E. coli
Nucleus
Fig. 4-11, p. 75
Phase 3Grow Genetically Engineered Plant
Transgenic cellfrom Phase 2
Cell division oftransgenic cells
Culture cellsto form plantlets
Transgenic plantswith new traits
Transfer to soil
Genetic EngineeringGenetic Engineering