VocabVocab

PopulationPopulation- group of organisms of the SAME - group of organisms of the SAME species that occupies certain areaspecies that occupies certain area

SpeciesSpecies- organisms that can INTERBREED - organisms that can INTERBREED and produce FERTILE offspringand produce FERTILE offspring

Ex) Sauerman Woods Crown PointEx) Sauerman Woods Crown Point -whitetail rabbits-whitetail rabbits -deer-deer

-sparrows-sparrows -squirrels-squirrels

Liger (lion and tiger)-infertileLiger (lion and tiger)-infertile

Cama (camel and llama)-infertileCama (camel and llama)-infertile

Tigon (tiger and lion)--infertileTigon (tiger and lion)--infertile

History of Evolutionary ThoughtHistory of Evolutionary ThoughtBefore 1850, most people believed…Before 1850, most people believed…– Earth formed by supernatural events and never changed.Earth formed by supernatural events and never changed.– Earth only a few thousand years old.Earth only a few thousand years old.– Each species was made to fit its environment.Each species was made to fit its environment.– Species never changed and did not go extinct.Species never changed and did not go extinct.

History of Evolutionary ThoughtHistory of Evolutionary Thought

Jean Baptiste LamarckJean Baptiste LamarckProposed that species Proposed that species DO evolve DO evolve

***PROPOSED ***PROPOSED EVOLUTION EVOLUTION OCCURRED BY OCCURRED BY INHERITANCE OF INHERITANCE OF ACQUIRED ACQUIRED CHARACTERISTICSCHARACTERISTICS

LamarckLamarckLamarckLamarck’’s Hypothesis:s Hypothesis:

1. Desire causes change 1. Desire causes change

Ex.) ancestors of birds had a desire to fly, so they Ex.) ancestors of birds had a desire to fly, so they did.did.

2. Use and Disuse2. Use and Disuse

Ex.) If species used its arms to swim over and Ex.) If species used its arms to swim over and over, it would develop flippers. If not, flippers would over, it would develop flippers. If not, flippers would disappear.disappear.

3. Traits acquired during life can be passed 3. Traits acquired during life can be passed onon

Ex.) Tiger WoodsEx.) Tiger Woods’’ children will be great golfers. children will be great golfers.

WRONG!!!!WRONG!!!!

History of Evolutionary ThoughtHistory of Evolutionary Thought

Alfred WallaceAlfred WallaceEnglish teacher who English teacher who collected plants and collected plants and insects.insects.

Observed variations in Observed variations in organismsorganisms

Proposed that species Proposed that species DO evolveDO evolve

similar to Darwin’ssimilar to Darwin’s

Sent idea to DarwinSent idea to Darwin

Charles DarwinCharles Darwin

At 22, sailed on the At 22, sailed on the ““HMS HMS BeagleBeagle”” to the Galapagos to the Galapagos Islands.Islands.

Was going to school to be Was going to school to be a minister-believed God a minister-believed God created each species to created each species to match its habitat and they match its habitat and they never changed.never changed.

Thought Earth was about Thought Earth was about 6,000 years old and didn6,000 years old and didn’’t t change.change.

Charles Darwin cont.Charles Darwin cont.

During journey, he made During journey, he made observations and observations and recorded them in a recorded them in a journal.journal.

Darwin began to doubt Darwin began to doubt that species remained that species remained ““constant.constant.””

Charles Darwin cont.Charles Darwin cont.

In 1859, Darwin published In 1859, Darwin published The The Origin of Species.Origin of Species.His book stirred up controversy.His book stirred up controversy.Proposed **EVOLUTION Proposed **EVOLUTION OCCURRED BY NATURAL OCCURRED BY NATURAL SELECTIONSELECTION

Major points of DarwinMajor points of Darwin’’s book:s book:

Organisms have more offspring than can survive.Organisms have more offspring than can survive.

Certain individuals are more likely to survive than Certain individuals are more likely to survive than others (survival of the fittest.)others (survival of the fittest.)

Species DO change over time.Species DO change over time.

Gradual changes may cause members of one Gradual changes may cause members of one species to eventually evolve into new species.species to eventually evolve into new species.

African apes are African apes are close genetic relativesclose genetic relatives of modern of modern humans.humans.

Darwin Video

What We Know NowWhat We Know Now

Evolution is a Scientific Evolution is a Scientific TheoryTheory

Not a hypothesis, or an Not a hypothesis, or an educated guess, or a “theory” in educated guess, or a “theory” in layman’s terms.layman’s terms.

Unending amount of evidence to Unending amount of evidence to support itsupport it

Evolution is called “the unifying Evolution is called “the unifying principle of Biology”principle of Biology”

Isn't Evolution JUST a Theory?

DarwinDarwin’’s Natural Selection is the s Natural Selection is the Driving Force Behind Evolution Driving Force Behind Evolution

Natural selection-Natural selection- organisms best suited to organisms best suited to their environment survive and reproduce.their environment survive and reproduce.

– Darwin’s proposed mechanism of evolution Darwin’s proposed mechanism of evolution – Survival depends on the particular environmental Survival depends on the particular environmental

conditions a species finds itself in—nature!conditions a species finds itself in—nature!– If the environment changes, so do the populations If the environment changes, so do the populations

that live there.that live there.

Adaptation- Adaptation- using inherited genetic using inherited genetic characteristics to increase chance of survival characteristics to increase chance of survival in new environment.in new environment.Natural Selection and SalamandersNatural Selection and Salamanders

Whose idea for evolution is this?

Natural SelectionNatural SelectionThree conditions necessary for natural selection to Three conditions necessary for natural selection to

occur:occur:1.1. Genetic variation:Genetic variation: Individuals within a population must be Individuals within a population must be

genetically different. This is due to mutation.genetically different. This is due to mutation.

****Random mutations are the raw material for evolution to ****Random mutations are the raw material for evolution to occur!!!!!!!occur!!!!!!!

2.2. Overproduction of offspring:Overproduction of offspring: More organisms are born than More organisms are born than can survive.can survive.

3.3. Differential reproduction:Differential reproduction: Certain traits enable individuals to Certain traits enable individuals to survive and have more offspring than others.—SURVIVAL OF survive and have more offspring than others.—SURVIVAL OF THE FITTESTTHE FITTEST

Natural SelectionNatural Selection

Result of Natural SelectionResult of Natural Selection: : - Genes that help a species survive stay in the Genes that help a species survive stay in the

gene pool. gene pool. - ““UnfavorableUnfavorable”” genes gradually decrease. genes gradually decrease. - This causes changes in the genetics of This causes changes in the genetics of

populationspopulations EVOLUTION!!!!!EVOLUTION!!!!!- Over a long time, the new populations no longer Over a long time, the new populations no longer

can mate with the original they started as. New can mate with the original they started as. New species have formed. species have formed.

Natural Selection ExampleNatural Selection ExampleThe industrial revolutionThe industrial revolution– In England in the early 1800’s industry boomedIn England in the early 1800’s industry boomed– Factories, trains, smoke and smogFactories, trains, smoke and smog– Peppered moths were dark or light colored, and Peppered moths were dark or light colored, and

the dark ones that were once rare became more the dark ones that were once rare became more common.common.

– Hypothesis?Hypothesis?

The Peppered MothThe Peppered Moth– Kettlewell tested this hypothesisKettlewell tested this hypothesis

Released equal numbers of moths in polluted Released equal numbers of moths in polluted AND clean forests.AND clean forests.

In industrialized areas, dark gray moth was In industrialized areas, dark gray moth was better camouflaged.better camouflaged.

They survived, had more offspringThey survived, had more offspring – The population *The population *as a wholeas a whole** evolved to be evolved to be

better suited to the environmentbetter suited to the environment more gray more gray and camouflagedand camouflagedADAPTATION!ADAPTATION!

– This is an example of microevolutionThis is an example of microevolution

The Peppered MothThe Peppered Moth

Peppered Moth Peppered Moth SimulationSimulation

Types of EvolutionTypes of EvolutionEvolutionEvolution - - geneticgenetic change of a change of a populationpopulation of of organisms over time- organisms over time- descent with modificationdescent with modification

MicroMicroevolution: evolution: Small genetic changes of a populationSmall genetic changes of a populationShorter amount of time Shorter amount of time Bengal tiger simulation was microevolutionBengal tiger simulation was microevolution

Types of EvolutionTypes of Evolution

MACROMACROevolution:evolution:– When new species are When new species are

formed over long periods formed over long periods of time.of time.

– Due to tremendous Due to tremendous amounts of accumulated amounts of accumulated genetic changes in a genetic changes in a populationpopulation

– Speciation-Speciation- formation of formation of new species due to new species due to accumulated accumulated microevolution and microevolution and mutations.mutations.

SpeciationSpeciationGeographical isolationGeographical isolation-- members of a population members of a population are separated geographicallyare separated geographically– Major step that leads to speciation.Major step that leads to speciation.– Due to volcanoes, earthquakes, flooding, etc.Due to volcanoes, earthquakes, flooding, etc.– Can lead to divergence and then speciation.Can lead to divergence and then speciation.

How does macroevolution work?How does macroevolution work?dibosirdsaurdibosirdsaur

GEOGRAPHIC ISOLATIONGEOGRAPHIC ISOLATIONdibosirdsaur dibosirdsaurdibosirdsaur dibosirdsaur

10 million years of accumulated mutations 10 million years of accumulated mutations diosirdsaur ibosirdsaurdiosirdsaur ibosirdsaur

10 million years of accumulated mutations10 million years of accumulated mutationsdiosirdsaur iboirdsaur diosirdsaur iboirdsaur

10 million years of accumulated mutations10 million years of accumulated mutationsdinoirdsaur boirdsaurdinoirdsaur boirdsaur

10 million years of accumulated mutations10 million years of accumulated mutationsdinordsaur boirdsur dinordsaur boirdsur

10 million years of accumulated mutations10 million years of accumulated mutationsdinodsaur boirdsudinodsaur boirdsu

10 million years of accumulated mutations10 million years of accumulated mutationsdinodsaurs boirdsdinodsaurs boirds

10 million years of accumulated mutations10 million years of accumulated mutationsDINOSAURS DINOSAURS BIRDS BIRDS

Darwin and the FinchesDarwin and the Finches

When Darwin traveled to the Galapagos he When Darwin traveled to the Galapagos he took interest in the finches.took interest in the finches.

He noticed the finch species on the islands He noticed the finch species on the islands were different, but all resembled one from S. were different, but all resembled one from S. America.America.

Darwin thought some migrated and new Darwin thought some migrated and new species evolved. This is what he proposed:species evolved. This is what he proposed:

DarwinDarwin’’s Finchess Finches

Finches migrated from Finches migrated from South America to the South America to the islandsislands– Populations on different Populations on different

islands adapted to islands adapted to different environments and different environments and food sources they found. food sources they found.

DarwinDarwin’’s Finchess Finches

Different mutations Different mutations accumulated in the accumulated in the different populations on different populations on the different islands the different islands and they became more and they became more and more different from and more different from each other.each other.

DivergenceDivergence- - the the accumulation accumulation of differences between of differences between species species or populations.or populations.

DarwinDarwin’’s Finchess FinchesOver time the populations on the islands became so Over time the populations on the islands became so different they no longer mated->speciationdifferent they no longer mated->speciation

Several new finch species evolved from a common Several new finch species evolved from a common ancestor from S. Americaancestor from S. America

This is an example of macroevolution This is an example of macroevolution

Recent finch research

EVOLUTIONby natural selection

MACROevolutionMicroevolution

Changes in gene frequencies

in a population

Shorter timesExamples:

Peppered moth and Bengal tiger

Accumulated microevolution and mutations to form whole new species

Longer timesExamples:

Darwin’s finches and geographical isolation

Artificial SelectionArtificial SelectionArtificial selectionArtificial selection-- human intervention in animal or human intervention in animal or plant reproduction to ensure that certain desirable plant reproduction to ensure that certain desirable traits are passed on.traits are passed on.

Instead of NATURE selecting which traits are Instead of NATURE selecting which traits are favorable, HUMANS selectively breed those animals favorable, HUMANS selectively breed those animals with favorable traits.with favorable traits.

Ex. dogs or racehorsesEx. dogs or racehorses

In 50 years, will the allele In 50 years, will the allele frequencies be the same?frequencies be the same?

Hardy-Weinberg Equilibrium PrincipleHardy-Weinberg Equilibrium Principle – –

““UnderUnder certain conditionscertain conditions, the frequencies of the, the frequencies of the

dominant and recessive alleles will remain the samedominant and recessive alleles will remain the same

generation after generation.generation after generation.””

Genetics of the Population…Genetics of the Population…

Gene Pool-Gene Pool- all of the all of the genes of every individual genes of every individual in population samplein population sampleFrequency-Frequency- how often how often something occurssomething occursPopulation genetics Population genetics involves studying the involves studying the frequencyfrequency with which with which certain certain allelesalleles occur in a occur in a populationpopulation’’s s gene poolgene pool..

HARDY WEINBERG HARDY WEINBERG 5 CONDITIONS5 CONDITIONS

To keep H-W equilibrium there must be:To keep H-W equilibrium there must be:

No mutationsNo mutations

Large population Large population

Population size remains same (no migration)Population size remains same (no migration)

Random matingRandom mating

No No ““survival of fittestsurvival of fittest”” (evolution) (evolution)

***These conditions are NEVER all met, so populations are ***These conditions are NEVER all met, so populations are always changing and NOT in always changing and NOT in

H-W equilibrium.H-W equilibrium.