Name
Tanner Adams
Section #
28
Exercise 1
Voyage to the Galapagos: Worksheet
Introduction
This week’s laboratory exercise is centered on the Scientific American Frontiers
production,“Voyage To The Galapagos.” Following the movie, students should use laboratory
time to explore and discuss, with their classmates and lab instructor, the questions
presented on the following worksheet:
1.
Some of the Galapagos Islands, a chain of volcanic islands off the western coast
of South America are only a few hundreds of thousands of years old, while other
islands are much older. In the space provided, discuss how plants and land animals
arrived in the Galapagos Islands. (2 pts)
Came on floating ramps of vegetation or chunks of land that might even have standing
trees on them. These chunks of land can bring several species at once.
2.
Provide two examples of natural selection on the Galapagos Islands and EXPLAIN
the process of natural selection for each example.
(4 pts)
Sea Lions have gotten much smaller in the Galapagos than the ones in California. Sea
lions in the galapagos do not need to be as large as the ones in california because of
food supply, and the area they are in.
Lizards in the Galapagos eat along the shoreline and are expert swimmers, also have a
bacteria that helps them digest all their greens. Other land lizards will only swim when
they have to and cannot digest these greens. They are even smaller on different islands
of the Galapagos depending on the supply of food they have available.
3.
Explain how beak sizes of ground finches on the island of Daphne Major change
over short periods of time.
How is this a good example of Natural Selection? (2 pts)
Thick heavy beak opens hard large seeds, and a sharp beak eats small seeds. This is a
good example of natural selection because when small seeds are plentiful, the beaks the
next year are smaller, but during drier years the beaks will be larger. Each generation has
a different beak size. Small beaked birds have a larger population.
4.
Describe/discuss two examples of non-native plants or animals that were
introduced by humans and that are now causing serious problems in the Galapagos
Islands.
(4 pts)
Dogs and pigs have made iguanas extinct by going into their burrows and eating their
eggs. As well as goats harming tortoises by competing for resources, which brought
their numbers down significantly for a while.
