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GEOG 235. Biogeography |
| What Darwin Never Saw: Video Assignment |
Note: This video is from The New Explorers series. A copy is in my office to be checked out for viewing for this assignment.
Introduction. This film documents the work of Peter and Rosemary Grant, who for over 20 years have been studying the Darwin finches on Daphne Major, a small island in the Galapagos archipelago. As they state in the video, they have been continuing work begun by Charles Darwin and are trying to answer three questions:
- Whether species compete;
- Why some populations are so phenotypically variable; and
- How species are formed.
By watching this video you will see what the Galapagos Islands are like; you will see the nature of field research; and you will be introduced to examples of natural selection and evolution in progress.
Questions:
- Describe the Galapagos Islands in terms of
- the physical environment, and
- island species and their characteristics
- Describe the Grants' evidence for evolution. Identify the natural selection events and the respective evolutionary responses of the "fortis" population. A sketch or diagram may be used to complement your writing.
- How are species formed? Again, a sketch or diagram may be used to complement your writing.
Please turn in well considered and well written responses to the above questions. Your paper should typed, double-spaced.
Glossary
- Darwin's finches:
- Thirteen species of small birds in the genus Geospiza, which is endemic to the Galapogas Islands. Those species which are mentioned on Daphne are:
- G. scandens, the cactus finch
- G. fortis, the medium ground finch
- G. magnirostris, the large ground finch.
- Tribulus sp.:
- caltrop or puncture vine, the species producing a large, spiny seed. This herb belongs to a genus widely distributed in the tropics and to the same family (Zygophyllaceae) as the creosotebush of the hot deserts of North America.
- El Nino:
- the name given to a recurring but as yet unpredictable flow of warm currents along the west coast of South America. The winds which cause cold water upwelling and aridity along that coast weaken and allow warm surface waters to dominate. Unusually high amounts of precipitation are associated with the El Nino phenomenon in coastal Peru and Ecuador and on the Galapagos. El Nino is associated with other weather anomalies worldwide.
| Biogeography Home Page | Geography Department | Radford University |
Created by Susan Woodward, March 1997. Last modified September 29, 1997 by slw.