2006-2007Regents Biology
Insect eaters
Bud eater
Seed eaters
Cactuseater
Warblerfinch
Tree
finc
hes Ground finches
Darwin & Evolution by
Natural Selection
Regents Biology
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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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?
Regents Biology
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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.
Regents Biology
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.
_____________________ _____________________
_____________________ _____________________ _____________________
_____________________ _____________________
_____________________ _____________________
_____________________ _____________________ _____________________
Regents Biology
Relationship between species (beaks) & food
Regents Biology
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
___________________________________
Regents Biology
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
Regents Biology
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!