Darwin Evolution by Natural Selection ch he fin

Darwin & Evolution by Natural Selection ch he fin c ee Tr fin Insect eaters 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

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

Voyage of the HMS Beagle § Stopped in Galapagos Islands u 500 miles off coast of Ecuador

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. 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?

Darwin found…clues in the fossils Darwin found: Evidence that creatures have changed over time present day Armadillos Darwin asked: ancient Armadillo 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?

Darwin found… birds Darwin found: Many different birds on the Galapagos Islands. He thought he found very different kinds… Sparrow? Finch? Woodpecker? 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? Warbler? Woodpecker? Warbler finch Woodpecker? Tree finch Warbler?

The finches cinched it! Darwin found: The differences between species of finches were associated with the different food they ate. Darwin said: Ahaaaa! Finch? Sparrow? Aeater flock of Small South Big Large seed ground Small ground seed eater finch American finches were stranded on the Galapagos… Woodpecker? Warbler Insect eater finch Warbler? Leaf Tree & bud finch eater

Relationship between species (beaks) & food

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

From 1 species to 14 species… Warbler finch Cactus finch Woodpecker finch Small ground finch ch fin c ee Tr fin Insect eaters variation 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

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 more fit traits

Asking Questions is a good adaptation! 2006 -2007

Darwin found… more fossils Darwin found: Evidence that creatures have changed over time present day Sloth (extinct) Giant ground sloth Darwin asked: Why should extinct sloths & modern sloths be found on the same continent?

§ “If I have seen further, it is by standing on the shoulders of giants. ” -Sir Isaac Newton What do you think this means?

Scientists of Evolution 4 Square Divide your paper into 4 squares Title your paper “Influences on Darwin's Evolutionary Theory” In each of the four squares write a scientist who helped Darwin to propose theory of Evolution: James Hutton, Charles Lyell, Jean-Baptiste-Lamarck, and Thomas Malthus. For Each Scientist: (use pages 373 -377) 1. Write each scientists hypothesis(es) or principles 2. Explain how these↑ influenced Darwin's thinking. 3. Draw a picture of something that will remind you of that scientist and their contribution to Evolution