evolution biology riverdell high school ms. c. militano

EvolutionEvolution

BiologyBiology

RiverDell High SchoolRiverDell High School

Ms. C. MilitanoMs. C. Militano

I. Evidence of EvolutionI. Evidence of EvolutionA. FossilsA. Fossils

1. definition - trace or remains of 1. definition - trace or remains of

organisms that are preservedorganisms that are preserved

2. types2. types

a. a. moldmold (rock imprint) (rock imprint)

b. b. castcast (mold that is filled) (mold that is filled)

c. c. petrifiedpetrified

d. preserved in d. preserved in amberamber or or tar pitstar pits

Mold Fossil Cast FossilMold Fossil Cast Fossil

Fossil in AmberFossil in Amber Petrified WoodPetrified Wood

Dinosaur Fossils Toe of a DinosaurDinosaur Fossils Toe of a Dinosaur

Plant FossilsPlant Fossils Flower Fossil Cone Flower Fossil Cone Fossil Fossil

I. I. Evidence of EvolutionEvidence of EvolutionA. FossilsA. Fossils

3. location3. location

a. sedimentary rocka. sedimentary rock

b. amber or tar pitsb. amber or tar pits

4. distribution4. distribution

aa..Law of SuperpositionLaw of Superposition(Steno 1638-1686)(Steno 1638-1686)

1) 1) relative agerelative age

2) 2) absolute ageabsolute age

b. b. biogeographybiogeography

Fossils Are Found in Tar PitsFossils Are Found in Tar Pits

Sedimentary Rock Showing LayersSedimentary Rock Showing Layers

Law of SuperpositionLaw of Superposition – younger fossils are – younger fossils are closer to the surface – older fossils are deepercloser to the surface – older fossils are deeper

I. Evidence of EvolutionI. Evidence of EvolutionB. Comparative AnatomyB. Comparative Anatomy

1. 1. homologous structureshomologous structures a. similar structure, evolution, a. similar structure, evolution, developmentdevelopment b. wing, arm, flipper)b. wing, arm, flipper) 2. 2. analogous structuresanalogous structures a. similar functiona. similar function b. wing of a bird and an insectb. wing of a bird and an insect

Homologous vs Analogous StructuresHomologous vs Analogous Structures

I. Evidence of EvolutionI. Evidence of EvolutionB. Comparative AnatomyB. Comparative Anatomy

3. 3. vestigial structuresvestigial structures

a. useful in past organisms but not a. useful in past organisms but not

nownow

b. appendix, tail vertebrae, b. appendix, tail vertebrae,

ear musclesear muscles

Vestigial StructuresVestigial Structures Appendix in Humans Leg Bones in a Whale Appendix in Humans Leg Bones in a Whale

I. Evidence of EvolutionI. Evidence of EvolutionC. Embryology SimilaritiesC. Embryology Similarities

1. 1. Haeckel(1834-1919) [German]Haeckel(1834-1919) [German]

a. “ontogeny recapitulate phylogeny”a. “ontogeny recapitulate phylogeny”

1) embryo undergoes changes 1) embryo undergoes changes

that repeat evolutionary that repeat evolutionary

developmentdevelopment

Diagram Showing Similarities in Early Diagram Showing Similarities in Early Stages of Embryo DevelopmentStages of Embryo Development

I.I. Evidence of EvolutionEvidence of EvolutionD. BiochemistryD. Biochemistry

1. similarity in amino acids in specific 1. similarity in amino acids in specific

proteinsproteins

2. similarity in RNA and DNA base 2. similarity in RNA and DNA base

sequencessequences

Comparing Amino Acid Differences of Comparing Amino Acid Differences of Several Organisms to HumansSeveral Organisms to Humans

II. Theories of EvolutionII. Theories of EvolutionA. Lamark (1744-1829)A. Lamark (1744-1829)

1.1. Acquired traits – Acquired traits – traits that traits that develop during one generation develop during one generation can be passed to the next can be passed to the next generationgeneration 2. 2. Law of Use and DisuseLaw of Use and Disuse – if a trait – if a trait is not used it will be lostis not used it will be lost

Lamarck and Law of Use and DisuseLamarck and Law of Use and Disuse

According to According to Lamarck the Lamarck the giraffes pictured giraffes pictured grew longer necks grew longer necks in order to reach in order to reach the leaves in taller the leaves in taller treestrees

The longer necks The longer necks were then passed were then passed to the next to the next generationgeneration

II. Theories of EvolutionII. Theories of EvolutionB. Charles Darwin(1809-1882)B. Charles Darwin(1809-1882)

1. Biography1. Biography a. Darwin attended medical schoola. Darwin attended medical school b. studied to be a clergymanb. studied to be a clergyman c. 22 years old - signed on c. 22 years old - signed on HMS BeagleHMS Beagle 1) collect specimens as a naturalist1) collect specimens as a naturalist 2) refined data for 21 years2) refined data for 21 years

Charles Darwin Darwin’s HomeCharles Darwin Darwin’s Home

HMS BeagleHMS Beagle in Sydney Australia Harbor in Sydney Australia Harbor

Darwin’s VoyageDarwin’s Voyage


2. 2. The Origin of SpeciesThe Origin of Species (1859) (1859)

a.a. Descent with modificationDescent with modification

1) all species descend from a 1) all species descend from a

small number of original typessmall number of original types

2) there is variation among 2) there is variation among

organismsorganisms


b. b. Modification by SelectionModification by Selection

1) environment limits growth of populations1) environment limits growth of populations

-competition for life’s necessities-competition for life’s necessities

-specific traits are selected-specific traits are selected

2) 2) adaptive advantageadaptive advantage

- trait favorable for a given environment- trait favorable for a given environment

- adaptations make some organisms - adaptations make some organisms

more likely to survive than othersmore likely to survive than others


3) 3) fitnessfitness - ability of an organism to - ability of an organism to

make a genetic contribution to themake a genetic contribution to the

next generationnext generation

4) 4) natural selectionnatural selection allows individuals allows individuals

with survival adaptations to pass with survival adaptations to pass

traits to offspringtraits to offspring


5) 5) speciationspeciation - formation of new - formation of new species as favorable adaptations species as favorable adaptations accumulateaccumulate

6) 6) “survival of the fittest”“survival of the fittest” - those - those organisms with favorable traits organisms with favorable traits reproduce and pass their traits to reproduce and pass their traits to future generationsfuture generations

III. Patterns of EvolutionIII. Patterns of EvolutionA. A. CoevolutionCoevolution

1. changes in two or more species 1. changes in two or more species

closely associatedclosely associated

2. examples2. examples

a. predator and preya. predator and prey

b. parasite and hostb. parasite and host

c. plants and plant pollinatorsc. plants and plant pollinators

III. Patterns of Evolution III. Patterns of Evolution B. Convergent EvolutionB. Convergent Evolution

1. similar phenotypes are selected but1. similar phenotypes are selected but

ancestors are very differentancestors are very different

a. natural selection of analogous a. natural selection of analogous

structuresstructures

2. examples2. examples

a. wings in insects and birdsa. wings in insects and birds

b.fins & shape of sharks, fish, porpoiseb.fins & shape of sharks, fish, porpoise

Examples of Convergent EvolutionExamples of Convergent Evolution

III. Patterns of EvolutionIII. Patterns of EvolutionC. Divergent EvolutionC. Divergent Evolution

1. two or more related populations or 1. two or more related populations or

species become more dissimilarspecies become more dissimilar

a. a. speciationspeciation - new species may form - new species may form

2. example 2. example geographic isolationgeographic isolation

a. brown bear a. brown bear polar bear polar bear

III. Patterns of EvolutionIII. Patterns of EvolutionC. Divergent EvolutionC. Divergent Evolution

3. 3. adaptive radiationadaptive radiation

a. many species evolve from same a. many species evolve from same

ancestorancestor

1) ancestor migrates to different 1) ancestor migrates to different

environments (example) -environments (example) -

Galapagos finchesGalapagos finches

Adaptive Radiation – Darwin’s FinchesAdaptive Radiation – Darwin’s Finches

Beak shape Depends Upon Food SourceBeak shape Depends Upon Food Source

Adaptive Radiation – Hawaiian HoneycreepersAdaptive Radiation – Hawaiian Honeycreepers

IV. Variation in PopulationsIV. Variation in PopulationsA. Distribution of variationsA. Distribution of variations 1. graph is a bell curve 1. graph is a bell curve B. Natural Selection and Changes in B. Natural Selection and Changes in PopulationsPopulations 1. 1. Stabilizing SelectionStabilizing Selection – favors average– favors average formform 2. 2. Directional SelectionDirectional Selection – average shifts– average shifts to one extreme or the otherto one extreme or the other 3. 3. Disruptive Selection Disruptive Selection – extreme forms – extreme forms are favored- number of individuals are favored- number of individuals withwith thethe average form is reducedaverage form is reduced

Stabilizing SelectionStabilizing Selection

Directional SelectionDirectional Selection

Disruptive SelectionDisruptive Selection

Comparing Types of SelectionComparing Types of Selection

Comparing Three Types of SelectionComparing Three Types of Selection

IV. Variation in PopulationsIV. Variation in PopulationsC. Genetic Sources of VariationC. Genetic Sources of Variation

1. 1. MutationsMutations

a) a specific gene mutates in a) a specific gene mutates in

1/10,0000 gametes1/10,0000 gametes

b) thousands of genes in each gameteb) thousands of genes in each gamete

c) some mutations in every zygotec) some mutations in every zygote

d) most mutations are recessived) most mutations are recessive


2. 2. Genetic RecombinationGenetic Recombination a) random meeting of sperm and egga) random meeting of sperm and egg b) crossing overb) crossing over c) independent assortment c) independent assortment 3. 3. Genetic DriftGenetic Drift a) occurs in small populationsa) occurs in small populations b) elimination of some genes by chanceb) elimination of some genes by chance c) may decrease variationc) may decrease variation


4. 4. Non-random MatingNon-random Mating

5. 5. MigrationMigration

a) a) immigrationimmigration- movement into an - movement into an

area or population area or population

b) b) emigrationemigration – movement out of an – movement out of an

area or populationarea or population

IV. Variation in PopulationsIV. Variation in PopulationsD. Genetic EquilibriumD. Genetic Equilibrium

1. 1. Hardy-Weinberg PrincipleHardy-Weinberg Principle a) a) allele frequenciesallele frequencies are stable across are stable across generations generations b) sexual reproduction alone does notb) sexual reproduction alone does not affect genetic equilibriumaffect genetic equilibrium2. Conditions Necessary 2. Conditions Necessary a) no immigration b) no mutations a) no immigration b) no mutations c) no natural selection d)large populationsc) no natural selection d)large populations e) random matinge) random mating

IV. Variation in PopulationsIV. Variation in PopulationsE. Mathematics/Hardy WeinbergE. Mathematics/Hardy Weinberg

1. 1. gene poolgene pool - all the genes in a population - all the genes in a population

2. 2. allele frequencyallele frequency - % occurrence of a - % occurrence of a

specific allele in a populationspecific allele in a population

3. 3. phenotype frequencyphenotype frequency - % occurrence of - % occurrence of an individual in a population with a traitan individual in a population with a trait

4. 4. genotype frequencygenotype frequency - % occurrence of - % occurrence of

individuals in a population with a specific individuals in a population with a specific

genotype genotype


5. applying mathematics5. applying mathematics

a) a) pp = frequency of the dominant allele = frequency of the dominant allele qq = frequency of the recessive allele = frequency of the recessive allele

b) b) p + q = 1p + q = 1c) c) pp22 + 2pq + q + 2pq + q22 = 1 = 1


d) d) qq22 = recessive phenotype/genotype = recessive phenotype/genotype

frequencyfrequency

pp22 +2pq+2pq = dominant phenotype = dominant phenotype

frequencyfrequency

pp22 = pure dominant genotype frequency = pure dominant genotype frequency

2pq2pq= heterozygous genotype frequency= heterozygous genotype frequency

V. Speciation and Rate of EvolutionV. Speciation and Rate of Evolution

A. A. SpeciesSpecies - organisms that are - organisms that are

morphologically similar and can morphologically similar and can interbreed to produce fertile offspringinterbreed to produce fertile offspring

1. 1. SpeciationSpeciation - process of forming - process of forming

speciesspecies

V. Speciation and Rate of EvolutionV. Speciation and Rate of EvolutionA. Species and SpeciationA. Species and Speciation

2. 2. Isolating mechanismsIsolating mechanisms that result in that result in

speciationspeciation

a) a) geographic barriersgeographic barriers separate populations separate populations

1) 1) gene flowgene flow stops and natural selection stops and natural selection

and genetic drift result in divergenceand genetic drift result in divergence

b) b) reproductive barriersreproductive barriers - prevent breeding - prevent breeding

of organisms in the same geographic areaof organisms in the same geographic area

V. Speciation and Rate of EvolutionV. Speciation and Rate of EvolutionB. Rate of EvolutionB. Rate of Evolution

1. 1. evolutionevolution may be defined as may be defined as

a) change in a) change in genetic materialgenetic material in a in a

populationpopulation

b) change in b) change in allele frequencyallele frequency in a in a

population population

c) change in c) change in genotype/phenotype ratiogenotype/phenotype ratio

d) d) speciationspeciation

V. Speciation and Rate of EvolutionV. Speciation and Rate of EvolutionB. Rate of EvolutionB. Rate of Evolution

2. 2. GradualismGradualism (Darwin) - new species arise (Darwin) - new species arise slowly and continuously through small, slowly and continuously through small, gradual changesgradual changes

3. 3. Punctuated EquilibriumPunctuated Equilibrium (Steven Gould (Steven Gould and Niles Eldredge) - there are long and Niles Eldredge) - there are long periods (up to millions of years) with little periods (up to millions of years) with little or no change - then there is a short period or no change - then there is a short period of rapid change of rapid change

VI. Evolution in ActionVI. Evolution in ActionCaribbean Anole LizardsCaribbean Anole Lizards

Live on Tree TrunksLive on Tree Trunks

Stocky bodyStocky body

Long legsLong legs

Live on Slender twigsLive on Slender twigs

Thin body and large toe padsThin body and large toe pads

Short legs and tailsShort legs and tails

Caribbean Anole LizardsCaribbean Anole Lizards

Live in grassLive in grass

Slender bodySlender body

Very long tailsVery long tails

* at least six anole body types - and * at least six anole body types - and distinct species with same body type distinct species with same body type on different islandson different islands


HypothesisHypothesis

Specialized twig dwellers lived on one Specialized twig dwellers lived on one islands and migrated to other islandsislands and migrated to other islands

Twig-dwellers evolved independently on Twig-dwellers evolved independently on each island from a distinct ancestor (DNA each island from a distinct ancestor (DNA evidence) – exampleevidence) – example

of convergent evolutionof convergent evolution


Divergent Evolution and RadiationDivergent Evolution and Radiation

Divergent evolutionDivergent evolution on each island on each island

Descendants from a single ancestor Descendants from a single ancestor diversify into species adapted for a diversify into species adapted for a specific environment – if populations specific environment – if populations fill many parts of the environment it is fill many parts of the environment it is called called adaptive radiationadaptive radiation


trunktrunk twig twig grassgrass

dwellerdweller dwellerdweller dwellerdweller

COMMON ANCESTORCOMMON ANCESTOR

Arrives on each islandArrives on each island

evolution biology riverdell high school ms. c. militano

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