1. C HAPTER 16: D ARWIN ’ S T HEORY OF E VOLUTION Section 16-1: Darwin’s Voyage of Discovery

2. D ARWIN ’ S E PIC J OURNEY Charles Darwin – born February 12, 1809 in England Scientific view of natural world dramatically changing Geologists – Earth ancient, changed over time Biologists – life changed Evolution = change over time Darwin developed a scientific theory of biological evolution that explains how modern organisms evolved over long periods of time through descent from common ancestors.

3. O BSERVATIONS A BOARD THE B EAGLE Darwin traveled on the HMS Beagle as naturalist for 5 years, collecting specimens of plants and animals from around the world

4. O BSERVATIONS A BOARD THE B EAGLE Amazed by the variety/number of living things Filled notebooks with observations of characteristics/habitats Noticed three patterns of biological diversity : Species vary globally Species vary locally Species vary over time

5. S PECIES V ARY G LOBALLY Different, yet ecologically similar, animal species inhabited separated, but ecologically similar, habitats around the globe Rheas of South America look/act like ostriches of Africa, emus of Australia Live in grasslands – not ALL species the same

6. S PECIES V ARY L OCALLY Different, yet related, animal species often occupied different habitats within a local area Galapagos Islands – very close, but very different conditions Tortoises vary in a predictable way BIRDS

7. S PECIES V ARY O VER T IME Collected fossils – the preserved remains/traces of ancient organisms Noticed that some fossils of extinct animals were similar to living species

8. P UTTING THE P IECES T OGETHER Darwin analyzed patterns he observed on the voyage home Sent plant/animal specimens to be identified Galapagos animals unique, but similar to South American species Evidence suggested species were not fixed – changed by some natural process