2006-2007Regents Biology

Insect eaters

Bud eater

Seed eaters

Cactuseater

Warblerfinch

Tree

finc

hes Ground finches

Darwin & Evolution by

Natural Selection

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Charles Darwin Proposed a way how

evolution worksHow did creatures

change over time? __________________

Collected a lot of evidence to support his ideas 1809-1882 British naturalist

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Robert Fitzroy

Voyage of the HMS Beagle Invited to travel around the world

1831-1836 (22 years old!) makes many observations of nature

main mission of the Beagle was to chart South American coastline

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Voyage of the HMS Beagle Stopped in _______________________

500 miles off coast of Ecuador

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GalapagosRecently formed volcanic islands. Most of animals on the Galápagos live nowhere else in world, but they look like species living on South American mainland.

800 km west of Ecuador

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Many of Darwin’s observations made him wonder… Why?

Darwin asked:Why were these creatures found only on the Galapagos Islands?

Darwin found…many unique species

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present day Armadillos

Darwin found:Darwin found:Evidence that creatures that creatures have changed over timehave changed over time

ancient Armadillo

Darwin asked:Darwin asked:Why should extinct Why should extinct armadillos & modern armadillos & modern armadillos be found on armadillos be found on same continent?same continent?

Darwin found…clues in the fossils

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Darwin found:Different shells on tortoises on different islands

Darwin asked:Darwin asked:Is there a relationship Is there a relationship

between the environment between the environment & what an animal & what an animal

looks like?looks like?

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QuickTime™ and aPhoto - JPEG decompressor

are needed to see this picture.

Finch? Sparrow?

Woodpecker? Warbler?

Darwin found… birds

Finch? Sparrow?

Woodpecker? Warbler?

Darwin found:Darwin found:Many different birds Many different birds on the Galapagos on the Galapagos Islands. Islands.

He thought he found He thought he found very different kinds…very different kinds…

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Darwin was amazed to find out: All 14 species of birds were finches…

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Finch? Sparrow?

Woodpecker? Warbler?

Finch? Sparrow?

Woodpecker? Warbler?

But Darwin found… a lot of finches

Large ground finch

Small ground finch

Warbler finch Tree finch

But there is only one species of finch on the mainland! Darwin asked:Darwin asked:

If the Galapagos If the Galapagos finches came from the finches came from the mainland, why are they mainland, why are they

so different now?so different now?

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QuickTime™ and aPhoto - JPEG decompressor

are needed to see this picture.

Finch? Sparrow?

Woodpecker? Warbler?

The finches cinched it!

Large ground finch

Small ground finch

Warbler finch Tree finch

Big seed eater Small seed eater

Insect eater Leaf & bud eater

Darwin said:Darwin said:Ahaaaa! Ahaaaa!

A flock of South A flock of South American finches American finches

were stranded on the were stranded on the Galapagos…Galapagos…

Darwin found: The differences between species of finches were associated with the different food they ate.

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QuickTime™ and aPhoto - JPEG decompressor

are needed to see this picture.

Finch? Sparrow?

Woodpecker? Warbler?

The finches cinched it!

Large ground finch

Small ground finch

Warbler finch Tree finch

Big seed eater Small seed eater

Insect eater Leaf & bud eater

Darwin said:Darwin said:Ahaaaa! Ahaaaa!

A flock of South A flock of South American finches American finches

were stranded on the were stranded on the Galapagos…Galapagos…

Darwin found: The differences between species of finches were associated with the different food they ate.

_____________________ _____________________

_____________________ _____________________ _____________________

_____________________ _____________________

_____________________ _____________________

_____________________ _____________________ _____________________

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Relationship between species (beaks) & food

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Darwin’s finches Darwin’s conclusions

___________________________________ differences in beaks in the original flock adaptations to foods available on islands

___________________________________ over many generations, the finches were

selected for specific beaks & behaviors ___________________________________

accumulation of winning traits:both beaks & behaviors

___________________________________

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Warbler finch

Woodpecker finch

Small insectivorous

tree finchLarge

insectivoroustree finch

Vegetariantree finch

Cactus finch

Sharp-beaked finch

Small groundfinch

Mediumground finch

Large groundfinch

Insect eaters

Bud eater

Seed eaters

Cactuseater

Warblerfinch

Tree

finc

hes Ground finches

_________ _____________________ _____________________

From 1 species to 14 species…

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LaMarck ____________________

____________________ creatures developed

traits during their lifetime give those traits to their

offspring example

in reaching higher leaves giraffes stretch their necks & give the acquired longer neck to offspring

____________________

Earlier ideas on Evolution

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Darwin’s view of Evolution Darwin

giraffes that already have long necks survive better

leave more offspring who inherit their long necks _______________ _______________

_______________ _______________

_______________ _______________

2006-2007Regents Biology

Asking Questionsis a good adaptation!