Darwin Evolution by Natural Selection ch he fin
Darwin & Evolution by Natural Selection ch he fin c ee Tr fin Insect eaters Regents Biology es Seed eaters Bud eater nd Cactus eater ou Gr s er Warbl finch 2006 -2007
Charles Darwin § ___________________ How did creatures change over time? u _________ u § ___________________ 1809 -1882 u British naturalist u Regents Biology
Voyage of the HMS Beagle § Invited to travel around the world 1831 -1836 (22 years old!) u makes many observations of nature u § main mission of the Beagle was to chart South American coastline Robert Fitzroy Regents Biology
Voyage of the HMS Beagle § Stopped in ___________ u 500 miles off coast of Ecuador Regents Biology
Galapagos Recently formed volcanic islands. Most of animals on the Galápagos live nowhere else in world, but they look like species living on South American mainland. Regents Biology 800 km west of Ecuador
Darwin found…many unique species Many of Darwin’s observations made him wonder… Why? Darwin asked: Why were these creatures found only on the Galapagos Islands? Regents Biology
Darwin found…clues in the fossils Darwin found: _____________________ present day Armadillos Darwin asked: ancient Armadillo Regents Biology Why should extinct armadillos & modern armadillos be found on same continent?
Darwin found… more fossils Darwin found: Evidence that creatures have changed over time present day Sloth (extinct) Giant ground sloth Regents Biology Darwin asked: Why should extinct sloths & modern sloths be found on the same continent?
Darwin found: Different shells on tortoises on different islands Darwin asked: Is there a relationship between the environment & what an animal looks like? Regents Biology
Darwin found… birds Darwin found: Many different birds on the Galapagos Islands. He thought he found Finch? very different kinds… Regents Biology Woodpecker? Sparrow? Warbler?
But Darwin found… a lot of finches Darwin was amazed to find out: All 14 species of birds were finches… But there is only one species of finch on the mainland! Large. Finch? ground finch Small. Sparrow? ground finch Darwin asked: If the Galapagos finches came from the mainland, why are they so different now? Regents Biology Warbler finch Woodpecker? Tree finch Warbler?
The finches cinched it! Darwin found: The differences Darwin said: between species of Darwin said: n __________ finches were associated with the Ahaaaa! n __________ different food they ate. Big Aeater flock of Small South Large seed ground Small ground seed eater finch Finch? Sparrow? __________ finch American finches n were __________ stranded on the Galapagos… n __________ n Regents Biology __________ Warbler Insect eater finch Woodpecker? Leaf Tree & bud finch eater Warbler?
Relationship between species (beak) & food ___________ Regents Biology radiate out to fill different niches
Darwin’s finches § Darwin’s conclusions u __________________ § differences in the original flock § adaptations to foods available on islands u __________________ § over many generations, the finches were selected for specific beaks & behaviors u __________________ § accumulation of winning traits: beaks & behaviors u __________________ Regents Biology
From 1 species to 14 species… Warbler finch Cactus finch Woodpecker finch Small insectivorous tree finch Large insectivorous tree finch Sharp-beaked finch Small ground finch ch he fin c ee Tr fin Regents Biology Bud eater selection es variation nd Insect eaters Seed eaters Vegetarian tree finch ou Cactus eater Gr s er Warbl finch Medium ground finch Large ground finch heredity
Earlier ideas on Evolution § La. Marck creatures developed traits during their lifetime u give those traits to their offspring u example u § in reaching higher leaves giraffes stretch their necks & give the acquired longer neck to offspring Regents Biology
Darwin’s view of Evolution § Darwin giraffes that already have long necks survive better u leave more offspring who inherit their long necks u § _______________ § ________ Regents Biology
Any Questions? ? Regents Biology 2006 -2007
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