1. The Galápagos Islands: Part 1 - Environmental Setting
BIO 53
Fall 2007

2. Geography 13 large islands (>10 km2), 6 smaller islands of 1-2 km2
Many islets, rocks
Total land area:
~8,000 km2
(SC: ~77,700 km2)
Mainland Ecuador ~960 km to east
Costa Rica ~1100 km away

3. Geology http://alpha.dickinson.edu/departments/geol/gal_2003.htm
Fernandina

4. Cocos Plate Galápagos Pacific Plate Nazca Plate

5. The Galápagos Platform

6. Hot Spots and Volcanic Island Formation

8. Lava flows (basalt)

9. Eroding tuff formation

10. Uplifted areas may include fossil-bearing (calcareous) rocks
Baltra Island

11. Climate of the Galápagos

12. Climate patterns

13. Climate patterns

14. Climate patterns

15. The Galápagos Islands: Part 2 – Darwin’s visit
Darwin’s voyage on the H.M.S. Beagle ( )

16. Charles Darwin (1809 - 1882) Darwin at age 31
(1840 portrait by Richmond)

17. Jean Baptist de Lamarck :
( )
Belief in gradual changes in organisms over long time periods
Recognized the environment as an important influence on evolution: Inheritance of acquired characters
Published theory in 1809

18. Charles Lyell: author of Principles of Geology (1830)
Proponent of uniformitarianism
Slow, steady, gradual changes have shaped earth surface
Earth at least millions (not thousands) of years old

19. Figure 23.1 Darwin and the Voyage of the Beagle (Part 2)

21. Sep. 17: Chatham (San Cristobal)

22. Arid lowlands and tortoises

23. Sep. 23: Charles (Floreana)

24. Moist Uplands

25. Sep. 29: Albemarle (Isabela)

26. Iguanas

27. Oct. 8: James (Santiago/San Salvador)

28. Moist Uplands

29. Other observations Galapagos Dove
25 of 26 land bird species unique to the islands
Galapagos Dove

30. Finches

31. Mockingbirds http://oikos.villanova.edu/Nesomimus/melanotis.html
San Cristóbal Mockingbird
Nesomimus melanotis

32. Tortoises
Saddleback
Dome-shaped

33. Plants: number of species confined to the islands
James: 38 of 71
Albemarle: 26 of 46
Chatham: 16 of 32
Charles: 29 of 68
in modern terms: high levels of endemism