State Standard

SB5A. Trace the history of the theory.

History of the Theory (15.1)

15.1 Darwin’s Theory of Natural Selection

Before Darwin

Evolution

__________ – 385-322 BC

Revered __________ philosopher & scientist Believed organisms were created in a

__________ form that could not __________ over time

His ideas were highly influential for __________

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15.1 Darwin’s Theory of Natural Selection

Before Darwin

Evolution

Jean Baptiste de __________ – 1800s French __________ Believed inheritance of

__________ traits were the driving force of evolution.

Believed traits were acquired through __________ __________.

Ex: A giraffe had to stretch its neck in order to reach food – so the neck got longer during the giraffe’s lifetime and was passed to the next generation.

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15.1 Darwin’s Theory of Natural Selection

Before Darwin – cont’d

Evolution

Geologists were discovering ancient __________, __________, & fossilized __________ in England in the 1800s.

These items were being found in hillsides & riverbeds & gave new __________ about diversity of organisms.

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15.1 Darwin’s Theory of Natural Selection

Other Names Who Influenced Darwin

Evolution

James __________ & Charles __________ – Gradualism

Earth had changed over very __________ periods of time.

Thomas __________ – Struggle for __________

Populations outgrew resources & had to __________.

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15.1 Darwin’s Theory of Natural Selection

Darwin’s Voyage

Evolution

In 1831, Darwin set sail on the HMS __________

Darwin’s role on the ship was as ____________ and companion to the captain.

His job was to ____________ biological and geological specimens during the ship’s travel.

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The Galápagos Islands

Evolution

Off the ________ coast of South America Each island had a unique ____________ &

geographical features. Darwin began to collect mockingbirds,

____________, and other animals on the four islands.

He noticed that the different islands seemed to have their own, slightly ____________ varieties of animals.

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Evolution

Darwin theorized that the island populations came from the __________ ancestral populations on the ____________.

Populations from the mainland ____________ after reaching the Galápagos.

15.1 Darwin’s Theory of Natural Selection

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The Galapagos Islands – cont’d

Concepts That Emerged from Darwin’s Work…

Evolution

________________ – inherited traits that may give an individual survival & reproductive ____________ over other individuals.

Darwin hypothesized that new species could appear gradually through small changes in ancestral species.

Darwin inferred that if humans could change species by artificial selection, then perhaps the same process could work in nature (__________ __________).

15.1 Darwin’s Theory of Natural Selection

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Concepts That Emerged from Darwin’s Work…cont’d

Evolution

____________ ____________ – populations that get geographically separated may give rise to adaptations specifically ____________ to each environment.

15.1 Darwin’s Theory of Natural Selection

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Principles of Natural Selection

Evolution

Individuals in a population show ____________.

Variations can be ____________.

Organisms have more offspring than can ____________ on available resources (overproduction).

Variations that increase reproductive ____________ will have a greater chance of being ____________ on.

15.1 Darwin’s Theory of Natural Selection

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Darwin & Wallace

Evolution

Darwin published On the Origin of __________ by Means of __________ Selection in 1859.

Natural Selection was a means of explaining how evolution __________.

Wallace also studied & wrote about evolution, emphasizing ____________ of resources, while Darwin focused on ____________ success.

Darwin’s amount of data & thorough explanations caused his theories to be become ____________.

15.1 Darwin’s Theory of Natural Selection

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