patterns of evolution. macroevolution/microevolution allele gene both involve changes in allele...
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Patterns of EvolutionPatterns of Evolution
Macroevolution/MicroevolutionMacroevolution/Microevolution
Both involve changes in alleleallele frequencies in genegene pools
Both work through the same basicsame basic processes
The differencedifference is largely one of approach approach and scalescale
Each offers offers different insightsinsights into the evolutionevolution process
Macroevolution/MicroevolutionMacroevolution/Microevolution
Macroevolution- One genus or familyfamily evolves into another….due to largelarge scale changes that take place over longlong periods of time.
Microevolution- SmallSmall scale changes within a species to produce new varieties or speciesspecies in a relatively shortshort amount of time.
Macroevolution/MicroevolutionMacroevolution/Microevolution
Macroevolution1. Large-scaleLarge-scale changes
in gene frequencies 2. Occurs over a longer longer
(geological) time time period period
3. Occurs at or above the level of specieslevel of species in separatedseparated gene pools
4. Consists of extendedextended
microevolutionmicroevolution
Microevolution1. Small-scaleSmall-scale changes
in gene frequencies
2. Occurs over a few few generationsgenerations
3. Occurs within a within a speciesspecies or population in samesame gene pool
4. Refers to smallersmaller
evolutionaryevolutionary changes
Macroevolution/MicroevolutionMacroevolution/Microevolution
Macroevolution5. Has notnot been
directly observedobserved
6. Evidence based on
remnants remnants of the past past
7. More More controversial 8. Example: Birds from
reptiles
Microevolution5. ObservableObservable
6. Evidence produced
by experimentationexperimentation
7. Less Less controversial 8. Example: Bacterial
resistance to
antibiotics
Macroevolution/MicroevolutionMacroevolution/Microevolution
Dog Variability When bred for certain traits, dogs become different and distinctive. This is a common example of microevolution—changes in size, shape, and color—or minor genetic alterations. It is not macroevolution: an upward, beneficial increase in complexity.
Macroevolution/MicroevolutionMacroevolution/Microevolution
Patterns of MacroevolutionPatterns of Macroevolution
A. Mass Extinctions
B. Adaptive Radiation
C. Convergent Evolution
D. Coevolution
E. Gradualism
F. Punctuated Equilibrium
These are theories/models of evolution
Mass ExtinctionsMass Extinctions
Event in which manymany types of living things became extinct at the same timeat the same time.
Period in which huge numbers of speciesspecies disappeareddisappeared.
Whole ecosystemsecosystems were wiped outwiped out Left habitatshabitats/niches openopen Resulted in burst of evolutionburst of evolution of new
species in new habitat Disrupted energy flowenergy flow throughout the
biosphere and caused food websfood webs to collapsecollapse
Mass ExtinctionsMass Extinctions
Possible causes– AsteroidsAsteroids hitting earth– VolcanicVolcanic eruptions– Continental driftdrift– Sea levelsSea levels changing
Mass Mass ExtinctionsExtinctions
Is an on-going process
Adaptive RadiationAdaptive Radiation
The evolution of an ancestral speciesancestral species, which was adaptedadapted to a particular way of life, into many diversemany diverse species, each adapted to a different habitatdifferent habitat
Many new speciesspecies diversify from a common ancestorcommon ancestor .
The branching outbranching out of a population through variationvariation.
The new species livelive in differentdifferent ways thanthan the original original species did.
Adaptive RadiationAdaptive Radiation
Adaptive RadiationAdaptive Radiation
Adaptive RadiationAdaptive Radiation
Diversity in anoles
is most strikingin the
Caribbean islands
Adaptive RadiationAdaptive Radiation
Hawaiian honeycreepers
Variation in color and bill shape is related to their habitat and diet
Convergent EvolutionConvergent Evolution
OppositeOpposite of divergent evolutiondivergent evolution (adaptive radiation)
UnrelatedUnrelated organismsorganisms independently evolve evolve similaritiessimilarities when adapting to similarsimilar environments, or ecological nichesniches
Analogous structuresAnalogous structures are a result of this process Example: penguin limb/whale flipperflipper/fish finfin The wings of insects, birds, pterosaurs, and bats
all serve the same functionsame function and are similar in similar in structurestructure, but each evolved independently independently
Convergent EvolutionConvergent Evolution
Convergent EvolutionConvergent Evolution
ConvergentConvergent Evolution Evolution
Convergent EvolutionConvergent Evolution
ocotillo (left) from the American Southwest, and in the allauidia (right) from Madagascar
Convergent EvolutionConvergent Evolution
Hummingbird Hawkmoth
Convergent EvolutionConvergent Evolution
Similar body shapes and structures
have evolved in the North
American cacti...and in
the euphorbias in Southern
Africa
CoevolutionCoevolution
The mutual mutual evolutionary influenceinfluence between two speciesspecies
When twotwo species evolveevolve in responseresponse to changes in each othereach other
They are closely connected to one another by ecological interactionsecological interactions (have a symbiotic relationship) including:– Predator/prey prey – ParasiteParasite/host – PlantPlant/pollinator
EachEach party exerts selective pressurespressures on the otherother, thereby affecting each others' evolution
CoevolutionCoevolution
CoevolutionCoevolution
A fly and an orchid--can influence each other's evolution
CoevolutionCoevolution
Bumblebees and the flowers the they pollinate have co-evolved so that both have become
dependent on each other for survival.
CoevolutionCoevolution
Coevolution between the yucca moth and the yucca plant. (right) A female yucca moth pushing pollen into the stigma tube of the yucca flower while visiting the flower to deposit her eggs. Yucca moth larvae (left) feeding on seeds in the yucca fruit.
CoevolutionCoevolution
Clown Fish and Sea anemone
CoevolutionCoevolution
Praying Mantis simulates plant to protect itself from predators and eats pests that are attracted to and feed on the plant, so it protects the plant.
CoevolutionCoevolution
Shrimp cleaningTitan triggerfish in Pacific Ocean
GradualismGradualism
The evolution of new species by gradual accumulation of small genetic changessmall genetic changes over long periodslong periods of time
Emphasizing slowslow and steady changesteady change in an organism
Occurs at a slow but constant rateconstant rate Over a short period of time it is hard to hard to
noticenotice
GradualismGradualism
GradualismGradualism Current living zebras (top), extinct quaggas (bottom)
GradualismGradualism
GradualismGradualism
Punctuated EquilibriumPunctuated Equilibrium
Stable periodsStable periods of no change (genetic equilibrium) interruptedinterrupted by rapid changesrapid changes involving many different lines of descent
Opposite of gradualismgradualism It is rare, rapid events of branching branching
speciationspeciation Characterized by long periods of virtual virtual
standstillstandstill ("equilibrium"), "punctuated""punctuated" by episodes of very fast developmentfast development of new forms
Punctuated EquilibriumPunctuated Equilibrium
Horseshoe crabs have change little since their first appearance in the fossil record.
They are in a state of equilibrium
Punctuated EquilibriumPunctuated Equilibrium
Punctuated EquilibriumPunctuated Equilibrium
Gradualism orGradualism orPunctuated EquilibriumPunctuated Equilibrium
Patterns of MacroevolutionPatterns of Macroevolution
that are
can undergo can undergo can undergo can undergo can undergo
in underunderform inin
Species
Unrelated Related
Inter-relationships
Similar environments
Intense environmental
pressure
Smallpopulations
Different environments
Coevolution Convergent evolution Extinction
Punctuated equilibrium
Adaptive radiation
Flow ChartFlow Chart