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 § Proposed a way how evolution works How did creatures change over time? u by natural selection u § Collected a lot of evidence to support his ideas 1809 -1882 u British naturalist u Regents Biology
Voyage of the HMS Beagle § Stopped in Galapagos Islands u 500 miles off coast of Ecuador Regents Biology
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: Evidence that creatures have changed over time present day Armadillos Darwin asked: ancient Armadillo Regents Biology Why should extinct armadillos & modern armadillos be found on 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 ground Finch? 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! different beaks are Darwin found: inherited variations The differences Darwin said: between species of n serve as adaptations that help. Ahaaaa! birds compete finches were A flock of South for food associated with the American finches n these birds survive & different food they ate. Big Large seed ground eater Smallground seed eater finch were stranded on the reproduce finch Galapagos… n pass on the genes for those more fit beaks n over time nature selected for different species with different beaks n Regents Biology Warbler Insect eater finch Leaf Tree & bud finch eater
Darwin’s finches § Darwin’s conclusions u variations in beaks § differences in beaks in the original flock § adaptations to foods available on islands u natural selection for most fit § over many generations, the finches were selected for specific beaks & behaviors u offspring inherit successful traits § accumulation of winning traits: both beaks & behaviors u separate into different species Regents Biology
From 1 species to 14 species… Warbler finch Cactus finch Woodpecker finch Small ground finch ch fin c ee Tr fin Insect eaters variation Regents Biology Bud eater es Seed eaters Vegetarian tree finch nd Cactus eater ou he s er Warbl finch Gr Small insectivorous tree finch Large insectivorous tree finch Sharp-beaked finch Medium ground finch Large ground finch natural selection for best survival & reproduction
Earlier ideas on Evolution § La. Marck u evolution by acquired traits § creatures developed traits during their lifetime § give those traits to their offspring u example § in reaching higher leaves giraffes stretch their necks & give the acquired longer neck to offspring u not accepted as valid 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 § variation § selection & u survival § reproduction & inheritance of Regents Biologymore fit traits
Asking Questions is a good adaptation! Regents Biology 2006 -2007
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