The Father of EvolutionThe Father of Evolution

Charles DarwinCharles Darwin1809-18821809-1882

Charles Darwin

Born in 1809, Shrewsbury, England

Naturalist

Studied Medicine

Degree in Theology

Buried in Westminster Abbey

After Cambridge, After Cambridge, Charles was Charles was

recommended for a recommended for a surveying trip on thesurveying trip on the

HMS Beagle.HMS Beagle.

After Cambridge, After Cambridge, Charles was Charles was

recommended for a recommended for a surveying trip on thesurveying trip on the

HMS Beagle.HMS Beagle.

Darwin sailed aboard Darwin sailed aboard the the BeagleBeagle for 5 years, for 5 years, working as a naturalist.working as a naturalist.

Darwin sailed aboard Darwin sailed aboard the the BeagleBeagle for 5 years, for 5 years, working as a naturalist.working as a naturalist.

The mission of the The mission of the voyage was to chart voyage was to chart

stretches of the South stretches of the South American coast.American coast.

The mission of the The mission of the voyage was to chart voyage was to chart

stretches of the South stretches of the South American coast.American coast.

Row, row, row Row, row, row your boat!your boat!

• Voyage of H.M.S. BeagleVoyage of H.M.S. Beagle– 5 year unpaid voyage5 year unpaid voyage– Darwin studied Darwin studied plants, animals, plants, animals,

collected fossilscollected fossils– Found fossils of extinct animals Found fossils of extinct animals

that were that were similarsimilar to modern to modern species. On the species. On the Galapagos IslandsGalapagos Islands in the Pacific Ocean he noticed in the Pacific Ocean he noticed many variations among plants and many variations among plants and animals of the same general type as animals of the same general type as those in those in South AmericaSouth America. .

This voyage lasted fromThis voyage lasted from 1831 1831 toto 1836. 1836. This voyage lasted fromThis voyage lasted from 1831 1831 toto 1836. 1836.

The Galapagos The Galapagos Islands lie 500 miles Islands lie 500 miles west of Ecuador in west of Ecuador in the Pacific Ocean, the Pacific Ocean,

directly on the directly on the equator.equator.

The Galapagos The Galapagos Islands lie 500 miles Islands lie 500 miles west of Ecuador in west of Ecuador in the Pacific Ocean, the Pacific Ocean,

directly on the directly on the equator.equator.

Many of Darwin’s Many of Darwin’s conclusions were conclusions were

based on based on observations of observations of

wildlife in thewildlife in the Galapagos IslandsGalapagos Islands..

Many of Darwin’s Many of Darwin’s conclusions were conclusions were

based on based on observations of observations of

wildlife in thewildlife in the Galapagos IslandsGalapagos Islands..

“Galapagos” means turtle.

Darwin was influenced Darwin was influenced by :by :

•GeologistGeologist

•Contribution:Contribution:– Earth is very old Earth is very old

(much older than (much older than thought)thought)

– Earth has Earth has changed over changed over time (constantly time (constantly changing)changing)

Sir Charles Lyell 1797 - 1875

Another influential Another influential personperson

•EconomistEconomist•Contribution:Contribution:

– Populations Populations have the have the potential to potential to increase increase faster than faster than the available the available food supplyfood supply Thomas Malthus

1766-1834

Another influential Another influential scientistscientist

•BotanistBotanist•Contribution:Contribution:

– Essay described Essay described evolution by evolution by natural selectionnatural selection

Alfred Russel Wallace 1823 - 1913

Darwin noticed Darwin noticed there were several there were several types of finches on types of finches on

these islandsthese islands..

Darwin noticed Darwin noticed there were several there were several types of finches on types of finches on

these islandsthese islands..

In particular, In particular, Darwin observed Darwin observed something odd something odd

about the about the finches: they all finches: they all

looked like a looked like a bird he had seen bird he had seen

on theon the South South American American continent.continent.

In particular, In particular, Darwin observed Darwin observed something odd something odd

about the about the finches: they all finches: they all

looked like a looked like a bird he had seen bird he had seen

on theon the South South American American continent.continent.

In all, there wereIn all, there were 13 13 types of finches, some types of finches, some species being confined species being confined

to only one island.to only one island.

In all, there wereIn all, there were 13 13 types of finches, some types of finches, some species being confined species being confined

to only one island.to only one island.

The most distinct difference among finch The most distinct difference among finch species is theirspecies is their beaks, beaks, which are adapted for which are adapted for

the specific diets available on the islands.the specific diets available on the islands.

The most distinct difference among finch The most distinct difference among finch species is theirspecies is their beaks, beaks, which are adapted for which are adapted for

the specific diets available on the islands.the specific diets available on the islands.

Darwin wondered if the birds and other Darwin wondered if the birds and other animals had beenanimals had been created created to match their to match their

environment, why didn’t these birds look like environment, why didn’t these birds look like the birds of the African continent, since the the birds of the African continent, since the

environments of both the Galapagos and environments of both the Galapagos and Africa were similar.Africa were similar.

Darwin wondered if the birds and other Darwin wondered if the birds and other animals had beenanimals had been created created to match their to match their

environment, why didn’t these birds look like environment, why didn’t these birds look like the birds of the African continent, since the the birds of the African continent, since the

environments of both the Galapagos and environments of both the Galapagos and Africa were similar.Africa were similar.

Darwin guessed that Darwin guessed that some of the birds some of the birds

from South America from South America migrated to the migrated to the

Galapagos.Galapagos.

Darwin guessed that Darwin guessed that some of the birds some of the birds

from South America from South America migrated to the migrated to the

Galapagos.Galapagos.

Once on the islands, Once on the islands, the birds must have the birds must have

changed changed over the over the years.years.

Once on the islands, Once on the islands, the birds must have the birds must have

changed changed over the over the years.years.

This would explain the numerous species of This would explain the numerous species of birds present.birds present.

This would explain the numerous species of This would explain the numerous species of birds present.birds present.

woodpecker finch

cactus finch

large ground finch

Warbler Finch

Tree Finch

Ground Finch

Certhidea olivacea

& C. Fusca

Geospiza difficilisG. conirostris

G. scandens Cacts Finch(nectar,eeds, blood)

G. magnirostris

Seed-eating Finch

G. fuliginosa

G. fortis

Platyspiza crassitrostris

C. heliobates

Cactospiza pallida

Woodpecker-like Finch

Vegetarian Finch

Insect-eating Finch

Camarhynchus pauper

C. psittacula

C. pauper

(seeds & insects)

PHYLOGENIC TREE:

A diagram showing the evolutionary history of a species of an animal.

This tree has how many major branches?

TWO TYPES OF TWO TYPES OF EVOLUTION:EVOLUTION:

Convergent EvolutionConvergent Evolution: process by which : process by which unrelated species become similar as unrelated species become similar as they adapt to similar environments.they adapt to similar environments.

Divergent EvolutionDivergent Evolution: : formation of new formation of new species from an existing species species from an existing species adapting to new environments.adapting to new environments.

What type of evolution is a phylogenic What type of evolution is a phylogenic tree?tree?

After returning from After returning from the Galapagos and the Galapagos and studying all the studying all the different types of different types of plants & animals. plants & animals. Darwin concluded new Darwin concluded new concepts of change….concepts of change….

Darwin extended these Darwin extended these principles to biology, which principles to biology, which

helped him form his theory of…helped him form his theory of…

Darwin extended these Darwin extended these principles to biology, which principles to biology, which

helped him form his theory of…helped him form his theory of…

……oror Survival of the Fittest. Survival of the Fittest.……oror Survival of the Fittest. Survival of the Fittest.

Darwin called this…Darwin called this…which means (which means (change in species over timechange in species over time))

Five basic components ofFive basic components ofFive basic components ofFive basic components of

1. All species have genetic variation.1. All species have genetic variation.1. All species have genetic variation.1. All species have genetic variation.

Every species is different, Every species is different, even within itself.even within itself.

Every species is different, Every species is different, even within itself.even within itself.

Look around you…are Look around you…are you all the same?you all the same?

Look around you…are Look around you…are you all the same?you all the same?

There is a constant There is a constant struggle for survival. struggle for survival. Examples are:Examples are:

DroughtDrought

FiresFires

FloodsFloods

SnowstormsSnowstorms

HurricanesHurricanes

TornadoesTornadoes

Other natural disastersOther natural disasters

There is a constant There is a constant struggle for survival. struggle for survival. Examples are:Examples are:

DroughtDrought

FiresFires

FloodsFloods

SnowstormsSnowstorms

HurricanesHurricanes

TornadoesTornadoes

Other natural disastersOther natural disasters

2. The environment presents challenges to 2. The environment presents challenges to survival.survival.

2. The environment presents challenges to 2. The environment presents challenges to survival.survival.

3. Organisms produce more offspring than can 3. Organisms produce more offspring than can survive. Competition exists WITHIN and AMONG survive. Competition exists WITHIN and AMONG species.species.

3. Organisms produce more offspring than can 3. Organisms produce more offspring than can survive. Competition exists WITHIN and AMONG survive. Competition exists WITHIN and AMONG species.species.

foodfoodfoodfood

Within a Species Among a Species

spacespacespacespace

matesmatesmatesmates

foodfoodfoodfood

spacespacespacespace

4. Individuals that are fit to their environment 4. Individuals that are fit to their environment leave more offspring than those who aren’t.leave more offspring than those who aren’t.

4. Individuals that are fit to their environment 4. Individuals that are fit to their environment leave more offspring than those who aren’t.leave more offspring than those who aren’t.

Darwin’s definition of fitness:

an organism which has successfully an organism which has successfully adapted to its environmentadapted to its environment

an organism which has successfully an organism which has successfully adapted to its environmentadapted to its environment

Organisms who possess favorable traits will leave more offspring.

In other words, he who spreads the In other words, he who spreads the most genes wins!most genes wins!

In other words, he who spreads the In other words, he who spreads the most genes wins!most genes wins!

1st1st

5. Characteristics of fit individuals increase in a 5. Characteristics of fit individuals increase in a population over time.population over time.

5. Characteristics of fit individuals increase in a 5. Characteristics of fit individuals increase in a population over time.population over time.

Over time, genes for less favored Over time, genes for less favored characteristics will be eliminated from the characteristics will be eliminated from the gene pool.gene pool.

Over time, genes for less favored Over time, genes for less favored characteristics will be eliminated from the characteristics will be eliminated from the gene pool.gene pool.

Example: giraffes and their long necks.Example: giraffes and their long necks.Example: giraffes and their long necks.Example: giraffes and their long necks.

Therefore Darwin’s contributions: Provided evidence that species evolve In 1859, he proposed the Theory of Natural

Selection to explain evolution (Survival of the fittest)

Over time, change within species leads to the replacement of old species by new species as less successful species become extinct.

Some evidence from fossils may prove that species on Earth have evolved from ancestral forms that are extinct. (species that have disappeared permanently.)

What is a species?What is a species?One or more populations of individuals One or more populations of individuals that can that can interbreedinterbreed, producing fertile , producing fertile offspring.offspring.

SpeciationSpeciation is the process by which new is the process by which new species are formed over time.species are formed over time.

Equus, the modern horse, evolved from the dog-sized Hyracotherium. Notice it evolved from a four-toed front foot to the one-toed front foot of the modern horse.

Scientific Evidence of Evolution includes: Fossil Record Comparative Anatomy Embryology DNA & Proteins (Biochemical

Evidence)

Fossil RecordIn order for fossils to form: Calcium must be

replaced Burial must occur by

sediment Usually occurs in

swamps, mud, ocean floors, tar pits, etc.

. COMPARATIVE ANATOMY:Homologous structures are characteristics which are shared by related species because they have been inherited in some way from a common ancestor.

For example, the bones on the front fins of a whale are homologous to the bones in a human arm and both are homologous to the bones in a chimpanzee arm.

TurtleAlligator

BirdMammal

Analogous Structures

In convergent evolution, organisms evolve similar features independently, often because they live in similar habitats.

similar in function but not in origin and structure

VESTIGIAL STRUCTURES:structures that serve no useful purposeorgans so reduced in size that they are nonfunctioning remnants of similar organs in other species ex: human tailbone, appendix, whale pelvis

EMBRYOLOGY Embryos of different species may appear

similar in early stages of development

ex: vertebrate development

3 COMPARATIVE ANATOMY

Comparison of similarities in embryos can show:

Relationship to a common ancestor