Download KEY Analysis Questions- Activity Part 1- Natural Selection

KEY Analysis Questions- Activity Part 1- Natural Selection
1. Which prey was most successful in avoiding capture? Why?
The prey that was closest to the color of the background (paper) makes it
camouflaged, and less easy to see in the short time period the predator has
to hunt.
2. Which prey was least successful at survival? Why?
The prey that is not the color of the background is easier
to see and catch in a short time period.
3. Was there a difference in the success of the predator? If so, why do you
think that happened?
Subject to the actions of the predators, but students may
report some were more aggressive in predation, or found it
easier to catch prey than others. There may be small
difference due to behavior or ability of the predators.
4. What does the steady reduction in foraging time represent?
Predators that get less to eat become weaker and have less chance
of competing for food. The reduced ability to obtain food
is represented by the reduced time allowed to get food.
This also shows that they are less competitive in foraging.
5. Were your predictions correct about which prey would be the most and
the least successful? Explain why you predicted the way you did.
Answers may vary depending on student’s predictions. Most probably the
students will recognize that camouflaged prey will have the best chance of
survival.
6. Explain why it is the phenotype not the genotype that natural selection is
acting upon.
Phenotype is the expression of the genotype. A predator reacts to the
appearance of a prey, which is the phenotype. In natural selection the most
“fit” has characteristics or traits that are expressed in some manner that can
be acted upon.
7. What do you think will happen to the population of beans over many
generations? Which traits (color) will survive in the population?
Students will predict that the colored beans “prey” who survived the foraging
will have the best chance to reproduced and pass on their genes to the next
generation. Those that were less able to reproduce due to being eaten, will
not be able to pass their genes to the next generation. Overtime the color that
helps in camouflage will increase in the population and the color that does not
help survival will be reduced in frequency.
8. Explain how the diversity of color in the prey population increased the
chance of that species’ survival.
A prey population of differing colors has a great chance of some of
its members surviving by blending in with foliage backgrounds.
The foliage backgrounds can be varied in color, and in seasons, so
a variety of color increases the probability that some of the species
will survive by camouflage.
9. Explain the following statement in terms of the prey data you obtained in
this activity. “Overtime, natural selection results in changes in the
inherited characteristics of a population. These changes increase a
species fitness in its environment. “
Students will use their data to confirm that a prey species that is more “fit” will
pass on its genes to the next generation. Data will also show that less “fit”
species are not as able to pass on their genes to the next generation. The
activity simulates the mechanism of natural selection (in the form of
predation) selects for the most “fit” species leading to changes in the inherited
characteristics or allele frequency in a population.
10. Let’s suppose a sudden mutation begins to show up in the predator
population. Some birds now have spoon and knife shape beaks instead of
fork shaped. Predict how this could change the survival success of some
of the predators.
Students will probably predict that a bird with a spoon beak has an increased
ability to forage for prey and as a result will survive to pass on it’s genes in a
higher rate than a fork beak, and most certainly a knife beak. The Knife beak
will most probably have difficulty foraging for prey and less chance of survival.
The mutation of a knife beak will not be an advantage in survival, but the
spoon mutation may.