Download Rat island activity

Coronado High School
Biology
RAT ISLAND ACTIVITY
Each student will be assigned an
island. Your job will be to design a rat
which has adapted to the conditions
of that particular island. Then each
person must submit a drawing of their
rat and an explanation of how each
adaptation helps their rat survive on
the island. Answer the questions as
well.
ISLAND A:
The island is fairly flat, with an
occasional hill. The ground consists of
soft dirt. Several species of shrubs grow
toward the center of the island. There is
no animal life on land, but the water is
full of friendly fish that swim around the
island. The island is also surrounded by a
coral reef which keeps predators out.
The shore is sandy with no algal growth.
Fresh water is available.
ISLAND B:
The island has a rocky shoreline.
Numerous tide pools dot the island along
the shore where the wave action is
somewhat sheltered by rock outcrops.
The tide pools host barnacles, chitons,
abalone, sea urchins and crabs. Algae
grows all around the island; however it is
quite sparse in the tide pools where the
various animals feed. The current is quite
strong along the rocky outcrops where
the algae grows best. Freshwater is
available.
Name:
Period:
My rat lives on island _________
My rat’s name is _________________
ISLAND C:
The island is somewhat barren. A few
species of cactus thrive on the bare
rocks. A large cactus-eating tortoise
inhabits the island. A species of very
large bird nests on the island annually.
They build their nests in the rocks, and
protect their eggs from the sun by
standing over the nests with outspread
wings. The nests are always found on the
windy side of the island which is
somewhat cooled by offshore breezes.
ISLAND D:
The island is an inactive volcano.
Vegetation in the island changes with the
altitude moving up the volcano. Grasses
grow at the base. Further up the slope
the grasses give way to low shrubs. Half
way up, the island becomes quite lush.;
tropical plants and trees dominate the
landscape. At this altitude, the island
experiences frequent rain showers. There
are two species of birds that inhabit the
island. One raptor and the other is a small
finch. The raptor enjoys eating small
rats.
1. Before rats came to Islands A, B. C, and D, there was a high population of
ancestral rats on Island Jackson, half a mile away. Island Jackson is made of
volcanic rock. The center part of the island has rolling grasslands and many shallow
lakes. Hidden within the caves near the grasslands are the ferocious cougars that
prey on the island rats. In the box below draw a picture of your rat's ancestor.
2. Explain how evolution occurs in terms of natural selection.
3. Variation within a species allows different phenotypes to be selected. Explain
how this is important for evolution to occur.
4. Speciation involves the creation of a new species from a common ancestor. How
might your new rat be different from the rat you drew above?
5. What is an adaptation?
6. Recall that fitness is the ability of an organism to survive and pass along it’s
genes to the next generation. How do adaptations affect the fitness of an
organism?
7. List some factors that your rat has to deal with on their island. Include possible food
options, predators they have to avoid, and any other environmental problems that they may
have to adapt to.
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8-12. In the table below, list 5 specific adaptations that your rat must have in
order to be successful in survival and reproduction on your island. Then briefly
explain why this adaptation will be beneficial. Use information about the island to
support your decisions in the reasons column. The adaptations must be believable.
Your rat probably didn’t grow wings or gills, for example.
Adaptation:
Reason:
1.
2.
3.
4.
5.
13. What type of selection puts pressure on a population to adapt to their
environment? What’s another name for this?
14. In the box below draw a picture of your rat and then label your rat with the 5
adaptations you have chosen for it.
15. How does your rat compete for natural resources on the island (discussed in
part 2 of Darwin's Theory)?
16. According to Darwin, what size litter would be most beneficial for your rat in
order to ensure survival and why (discussed in part 3 of Darwin's Theory)?
17. If your rats third toe on their front left foot gets stuck between 2 boulders
and torn off, will this trait be passed on to their offspring? Explain.
18. Describe Lamarck's theory of evolution (check your notes)?
19. How would Lamarck explain the differences between your rat and the ancestral
rat from Island Jackson?
20. How would Darwin explain the differences between your rat and the ancestral
rat from Island Jackson?