Early Ideas Early Ideas about about

EvolutionEvolution

James UssherJames UssherArchbishop of Ireland in the 17th centuryArchbishop of Ireland in the 17th century

►Used generations in the bible to fix the Used generations in the bible to fix the date of creation to 4004 B.C.date of creation to 4004 B.C.

►Life was about 6000 years oldLife was about 6000 years old►CreationistCreationist►God created an infinite & continuous God created an infinite & continuous

series of life formsseries of life forms►All have remained unchanged since All have remained unchanged since

creationcreation

Before Darwin, two ideas about life on Earth prevailed…

1.Species are fixed, or permanent. In other words, they do not change.

2.Earth itself is less than 10,000 years old and also relatively unchanging.

These ideas were challenged as people became aware of the incredible diversity of organisms, past and present, and the nature of Earth's geologic processes.

Beliefs in the 18Beliefs in the 18thth century… century…

Karl LinneausKarl LinneausSwedish botanist in the 18th centurySwedish botanist in the 18th century

► Precise descriptions of naturePrecise descriptions of nature► Purpose – to reveal the unchanging order of Purpose – to reveal the unchanging order of

life created by Godlife created by God► Problem: Noticed that hybrids could be Problem: Noticed that hybrids could be

createdcreated► Designed a logical classification systemDesigned a logical classification system

George LeclercGeorge LeclercFrench zoologist in the late 18th centuryFrench zoologist in the late 18th century

►Living things change through timeLiving things change through time►Earth must be at least 75,000 years Earth must be at least 75,000 years

oldold►Species could NOT evolve into other Species could NOT evolve into other

speciesspecies

Erasmus DarwinErasmus DarwinEnglish physician / amateur scientist in the late 18th centuryEnglish physician / amateur scientist in the late 18th century

►Evolution has occurred in living thingsEvolution has occurred in living things►Humans evolvedHumans evolved

Jean LamarckJean Lamarck

►New idea on how evolution occurs.New idea on how evolution occurs.►Simple organisms spontaneously arise and Simple organisms spontaneously arise and

inevitably develop into more complex formsinevitably develop into more complex forms►Evolution due to the inheritance of acquired Evolution due to the inheritance of acquired

characteristics… individuals acquire traits in characteristics… individuals acquire traits in their lifetimes as a result of experience or their lifetimes as a result of experience or behavior, then pass on these traits.behavior, then pass on these traits.

French biologist in the 19th centuryFrench biologist in the 19th century

Jean LamarckJean Lamarck

►Create your own example of Create your own example of Lamarkian evolution.Lamarkian evolution.

George CuvierGeorge CuvierFrench anatomist in the early 19th centuryFrench anatomist in the early 19th century

Reconstructed the appearance of unique Reconstructed the appearance of unique organisms from fossil bones.organisms from fossil bones.

1.1. Some organisms from the past different Some organisms from the past different greatly from any living speciesgreatly from any living species

2.2. Fossils in deeper layers of rock were Fossils in deeper layers of rock were increasing different from living speciesincreasing different from living species

3.3. Some organisms had become extinctSome organisms had become extinct

George CuvierGeorge CuvierFrench anatomist in the early 19th centuryFrench anatomist in the early 19th century

Idea of CATASTROPHISM >> sudden Idea of CATASTROPHISM >> sudden geologic catastrophes caused the geologic catastrophes caused the extinction of large groups of organisms extinction of large groups of organisms at certain points in the past.at certain points in the past.

Contributed to scientific acceptance that Contributed to scientific acceptance that geologic change and extinction had geologic change and extinction had occurred.occurred.

Charles LyellCharles LyellEnglish geologist in the 19th centuryEnglish geologist in the 19th century

►Uniformintarianism = slower, Uniformintarianism = slower, progressive changesprogressive changes

►Geologic processes that have changed Geologic processes that have changed the shape of Earth’s surface in the past the shape of Earth’s surface in the past continue to work in the same wayscontinue to work in the same ways

►Evidence from geology would contribute Evidence from geology would contribute to Darwin’s conclusionsto Darwin’s conclusions

Charles DarwinCharles DarwinNaturalist in the 19th centuryNaturalist in the 19th century

►Voyage to collect plants and animalsVoyage to collect plants and animals►Came up with evolution through Came up with evolution through

natural selection based on his natural selection based on his observationsobservations