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APES
Alec Humphries
Galapagos Islands Case Study
Study Questions
1. How did the Galapagos Islands come into existence?
Hydrothermal vents at the bottom of the Galapagos Rift released magma,
creating the islands.
2. Were plate tectonics involved?
Yes.
3. How old are the Galapagos Islands?
No more than 5 million years old.
4. What kinds of animals and plants are endemic to the islands?
Pioneer species of plants are endemic, and many reptiles are endemic to the
Galapagos.
5. How do species become endemic?
A species becomes endemic when it has evolved in such a manner that it can
only survive in a specific region or place.
6.
Where did the original colonists come from and how did they get to
the Galapagos?
The original colonists came from Spain, and they got to the Galapagos
through a lucrative shipping route along the pacific coast of Ecuador.
7. What kind of special adaptations do the animals and plants have?
How do adaptations evolve?
The adaptations seen were ones that helped them obtain food in the easiest
ways. Adaptations evolve through constant use of a resource until the animal
slowly changes its features to be able to acquire this resource easier.
8. How did these islands figure into Darwin’s ideas on evolution?
Darwin observed the differently evolved finches on each of the islands.
Study Questions
1. What is DNA fingerprinting and how is it done?
The process of identifying a species by its DNA sequence. This is done by
storing a record of a individual's DNA so it can be identified via DNA sample
later.
2. How can we measure evolution?As rates of evolution by a ratio of
dominant alleles and recessive alleles.
3. What is the difference between natural selection and evolution?
Evolution is usually the changing of an organism into something more complex
while natural selection is a process by which organisms that are well adapted
survive and reproduce while less adapted organisms do not.
APES
Alec Humphries
Galapagos Islands Case Study
4. What is genetic drift and how could it be involved in evolution?
Genetic drift is the change in frequency of an allele, and, like natural selection,
can affect the course of evolution. If more specimens survive that have a
specific allele, the more likely that allele is going to survive, even if it might not
be a good trait.
5. What is resource partitioning and character displacement?
Resource partitioning helps competing species share a resource and develop a
niche for themselves in an ecosystem. Character displacement is when similar
species habits overlap, and they are in direct competition for food and other
vital resources. Then one of the other species will evolve and thrive over the
other.
6. What is sexual selection?
Natural selection arising through preference by one sex for certain
characteristics in individuals of the other sex.
7. How might one test if beak size is due to genetic or environmental
factors?
Environmental factors usually affect the organisms behavior, while genetic
factors cause a physical change.
8. If hybridization occurs during good times, what does this suggest
about the degree of genetic differences between species?
The genetic difference is not substantial enough to make breeding impossible.
9. What are reproductive isolating mechanisms and how do they
evolve?
Reproductive isolating mechanisms are mechanisms that prevent two species
from having hybrid offspring, and these evolve by geographic, behavioral, or
physical differences in the populations.
10. Must populations of finches be separated in order to evolve into
different species?
No, because becoming separated only increases the chance to have a
behavioral barrier instead of other sorts of barriers.
11. What causes an El Niño?
Trade winds blow west towards the Pacific, normally and push warm surface
water away from the coast of South America moving towards Australia and The
Philippines. The water is cold and rich in nutrients. During El Nino trade winds
calm down in the central and west Pacific, which causes warm water to gather
in the surface. The number of nutrients caused by cold water decrease, which
ends up killing plankton and fish, seabirds then also die, from lack of food.
This causes major disorder of weather patterns worldwide.
APES
Alec Humphries
Galapagos Islands Case Study
Study Questions
1. Should Kate have chosen to work on a different species than the
tortoises that are being threatened? Her thesis work might be destroyed
by the politics of the islands.
No, her information collected could be vital to solving this problem.
2. Should Kate get involved in the politics of saving the islands, the way
Dian Fossey did in trying to save the Mountain Gorilla?
Yes.
3. Should fishing, tourism, or inhabitants be allowed in the islands?
No, these islands should be preserved for the sake that animals on these
islands are native to only this area, and human civilization could cause them to
get destroyed.
4. How should the Ecuadorian government deal with the conflicts over
the islands?
Sealing off the islands from travel and creating a preserve for the endangered
and almost extinct animals that reside only on these islands.
5. Extinction is a natural phenomenon. Why should we worry about
whether a few species on some remote islands in the Pacific survive or
not?
These species could have major impacts on their ecosystems that have not
been realized, and their disappearance could destroy the entire ecosystem.