Darwin’s Theory of Evolution

1. Darwin’s Theory of Evolution Chapter 16

2. Darwin’s observations from this trip lead to the theory of _____________. • Evolution: • _________________________________ • Process by which today’s organisms have _____________ from ancient organisms.

3. During his 5 year journey: • Collected __________ and ____________ specimens • Took detailed notes of new plants and animals he observed • Darwin noticed specifically the different types of tortoises and finches that he found on different islands. • The strange plants and animals of the Galápagos Islands puzzled Darwin. • Many birds, plants, insects, and reptiles on the Galápagos _____________ South American species, but were____________ _____________.

4. Tortoises • Darwin saw that each tortoise inhabited a ____________ island. • The townspeople could tell which island a tortoise came from by the _________ of its ___________. • On islands with humid highlands, the tortoises are: • ____________________ • ____________________ • ____________________ • On islands with dry lowlands, the tortoises are: • ____________________ • ____________________ • ____________________

5. Finches • As Darwin traveled from island to island in the Galapagos Islands, he noticed that the birds that lived on each island looked ____________ but had ___________________________________. • Darwin began to wonder if species from the mainland had reached the Galápagos, and then __________ —as they ___________to this new ________________.

6. He discovered 3 patterns of biological diversity: • Species vary around the world • Species vary locally • Species vary over time.

8. _____________ The evidence that Darwin had gathered during his trip suggested that species _______ over ________ by some natural process.

9. Jean-Baptiste Lamarck • Suggested that all organisms want to improve themselves. (acquired traits) • Giraffes could stretch everyday to acquire a longer neck. • The acquired traits of the parents are passed on to the children • A giraffe’s longer neck could be passed to offspring. • This was the reason species changed and improved over time.

10. Jean-Baptiste Lamarck • Suggested that all organisms want to improve themselves. (_________________) • Giraffes could stretch everyday to acquire a longer neck. • The acquired traits of the parents are _________ on to the __________ • A giraffe’s longer neck could be passed to offspring. • This was the reason species changed and improved over time.

11. 16.3 Darwin’s theory of Evolution by natural selection Darwin published his first book on evolution -______________________________ • In this book, he explained the 3 parts to evolution. • ______________ for existence • ________________________ • ________________________

12. Organisms produce ______offspring than can ____________. • Organisms must compete for: • ___________ • Water • living space • ____________ • Those that ________, will _________ survive. Struggle for Existence

13. Finches • They have __________to allow for specialized ____________most finches. • crushing beaks • grasping beaks • probing beaks • The specialization developed allowing the birds to ___________during the dry season and drought when little food is available. • These specialized tools allow the birds to better compete for food sources with other birds and animals.