history of natural theology classical greek philosophers had ideas about the natural evolution of...

History of Natural TheologyHistory of Natural Theology Classical Greek philosophers had ideas Classical Greek philosophers had ideas

about the natural evolution of lifeabout the natural evolution of life Plato (427-347 B.C.) believed there were Plato (427-347 B.C.) believed there were

two worlds. A real world which was perfect two worlds. A real world which was perfect and an illusionary world that was imperfect.and an illusionary world that was imperfect.

He did not believe in evolution.He did not believe in evolution. His student Aristotle (384 -322 B.C.) His student Aristotle (384 -322 B.C.)

believed that all forms could be arranged believed that all forms could be arranged on a ladder or scale called the “on a ladder or scale called the “scala scala naturae”naturae” Each form of life had an allotted Each form of life had an allotted rung on the ladder.rung on the ladder.

Belief prevailed for 200 years.Belief prevailed for 200 years.

Carolus Linnaeus(1707- 1778)Carolus Linnaeus(1707- 1778) Father of taxonomy.Father of taxonomy. Taxonomy is the branch of biology Taxonomy is the branch of biology

concerned with naming and concerned with naming and classifying organisms.classifying organisms. Came up with Kingdom, Phylum, Class, Came up with Kingdom, Phylum, Class,

Order, Genus, Species.Order, Genus, Species. However he believed there was no However he believed there was no

evolutionary kinship between them.evolutionary kinship between them.

Georges Cuvier(1769-1832)Georges Cuvier(1769-1832) Paleontologist.Paleontologist. Documented and recorded the succession Documented and recorded the succession

of fossils in sedimentary strata in the Paris of fossils in sedimentary strata in the Paris Basin.Basin.

Found deeper and older fossils to be Found deeper and older fossils to be dissimilar. New species appear and older dissimilar. New species appear and older species disappear.species disappear.

Advocated catastrophism. Species killed off Advocated catastrophism. Species killed off by catastrophes and recreated.by catastrophes and recreated.

James Hutton(1726-1797)James Hutton(1726-1797)

Scottish geologist.Scottish geologist. Proposed Proposed gradualism . gradualism . Profound changes are due to gradual Profound changes are due to gradual

changes over a long period of time due to changes over a long period of time due to natural processes occurring within the natural processes occurring within the Earth’s crust. Earth’s crust.

Charles Lyell (1997-1875)Charles Lyell (1997-1875) Proposed Proposed uniformitarianismuniformitarianism. The idea that . The idea that

geological processes have not changed geological processes have not changed over time and are at work.over time and are at work.

Suggested the earth was a lot older than the Suggested the earth was a lot older than the previously thought 6000 years.previously thought 6000 years.

Processes persisting over long periods of Processes persisting over long periods of time can accumulate to substantial change.time can accumulate to substantial change.

Charles Lyell

Jean Baptist Lamark Jean Baptist Lamark Was in charge of an invertebrate collection Was in charge of an invertebrate collection

at the Natural History Museum in Paris.at the Natural History Museum in Paris. Noticed that species changed over time.Noticed that species changed over time. Proposed that phenotype can change in Proposed that phenotype can change in

response to environment changes and those response to environment changes and those new characteristics were passed on to the new characteristics were passed on to the offspring.offspring.

First idea that adaptations occur in response First idea that adaptations occur in response to the environment.to the environment.

Jean Batist Lamark

The Darwinian RevolutionThe Darwinian Revolution Charles Darwin(1809 -1882) was born in Charles Darwin(1809 -1882) was born in

Shrewsbury England.Shrewsbury England. Wanted to be naturalist but was sent to medical Wanted to be naturalist but was sent to medical

school in Edinborough at 16.school in Edinborough at 16. He dropped out and went to Christ College at He dropped out and went to Christ College at

Cambridge University and became a clergyman. Cambridge University and became a clergyman. Back then most naturalist were clergyman.Back then most naturalist were clergyman.

Viewed the world as natural theologists.Viewed the world as natural theologists. The view that each species was newly designed The view that each species was newly designed

and non-evolving.and non-evolving.

Darwin 1875

Reverend Robert HenslowReverend Robert Henslow Botany professor at Cambridge.Botany professor at Cambridge. Darwin was his protégéDarwin was his protégé At age 22 he was recommended to At age 22 he was recommended to

join Captain Robert Fitzroy on the join Captain Robert Fitzroy on the H.M.S. Beagle to sail around the world.H.M.S. Beagle to sail around the world.

The primary mission was to chart the The primary mission was to chart the South American coastline.South American coastline.

Darwin collected and observed the Darwin collected and observed the flora and fauna.flora and fauna.

H.M.S. Beagle Voyage

Descent With Modification

A Darwinian View of Life

The GalapagosThe Galapagos

Species unique although they most closely Species unique although they most closely resembled South American species.resembled South American species.

Darwin’s finches possessed different beaks to Darwin’s finches possessed different beaks to accommodate different modes of eating.accommodate different modes of eating.

Darwin read Darwin read Principles of GeologyPrinciples of Geology by Lyell by Lyell and surmised that “old Earth” was inhabited and surmised that “old Earth” was inhabited by evolving species.by evolving species.

Darwin’s Finches

The Origin of SpeciesThe Origin of Species Lyell and a collegue presented Darwin’s work Lyell and a collegue presented Darwin’s work

Along with another Bristish scientist by the Along with another Bristish scientist by the name of Alfred Wallace.name of Alfred Wallace.

The paper was on the theory of “The paper was on the theory of “Natural Natural SelectionSelection” which Wallace and Darwin came up ” which Wallace and Darwin came up with simultaneously.with simultaneously.

Darwin published Darwin published “The Origin of Species” a “The Origin of Species” a year later.year later.

Alfred Wallace

Darwin’s ObservationsDarwin’s Observations Species had distinct South American Species had distinct South American

characteristics.characteristics. South American species that lived in the South American species that lived in the

temperate regions more closely resembled temperate regions more closely resembled the tropical species on the same continent the tropical species on the same continent than species that resided in the temperate than species that resided in the temperate regions on a different continent.regions on a different continent.

South American fossils resembled south South American fossils resembled south American species.American species.

Observations That Lead Darwin to the Observations That Lead Darwin to the Theory of Natural SelectionTheory of Natural Selection

OBSERVATIONSOBSERVATIONS All species have the potential to All species have the potential to

reproduce the maximum number of reproduce the maximum number of offspring.offspring.

Populations remain a stable (except for Populations remain a stable (except for seasonal fulgurations.seasonal fulgurations.

Resources are limitedResources are limited CONCLUSIONCONCLUSION Organisms compete for food.Organisms compete for food.

Other ObservationsOther Observations

Organisms varyOrganisms vary Organism with suitable traits survive Organism with suitable traits survive

to reproduce.to reproduce. Gradual changes in a population Gradual changes in a population

occur and the population occur and the population accumulates favorable accumulates favorable characteristics.characteristics.

Additional Evidence for Natural SelectionAdditional Evidence for Natural Selection Homology similarities in characteristics due to a Homology similarities in characteristics due to a

common ancestor.common ancestor.– Anatomical homologiesAnatomical homologies

similar structures, different function.similar structures, different function.

– Embryological homologiesEmbryological homologies Similar structural development.Similar structural development.

– Molecular homologiesMolecular homologies Basic machinery of RNA and DNA are similar.Basic machinery of RNA and DNA are similar.

– Biogiographic homologiesBiogiographic homologies

Convergent evolutionConvergent evolution

HomologiesHomologies– Biogeographic homologiesBiogeographic homologies

Endemic species.Endemic species. Convergent evolutionConvergent evolution - species that look similar but - species that look similar but

have no common ancestry.have no common ancestry. Divergent evolutionDivergent evolution – species that have common – species that have common

ancestry but evolve disparate characteristics.ancestry but evolve disparate characteristics.

– Fossil Record – the appearance of certain Fossil Record – the appearance of certain classes of vertebrates in the fossil record.classes of vertebrates in the fossil record. Fish before amphibiansFish before amphibians

Homologous Structures

Convergent Evolution

Natural SelectionNatural Selection Differential success in reproduction.Differential success in reproduction. Variation in populations and how they Variation in populations and how they

respond to the environment.respond to the environment. The product of adaptation to their The product of adaptation to their

environment.environment.

Descent With Modification

Cartoon of Darwin