Name:
Class:
Date:
Video: The Making of the Fittest: Natural Selection and Adaptation
DURING THE VIDEO:
1.) Tbe rock pocket mouse blends in perfectly on desert sand, and its light
colored fur conceals it from___predators , but on dark lava rock this same
fur makes it stand out.
2.) What will happen when the rock pocket mice find themselves on the new
terrain?
The rock pocket mouse will adapt to its environment. Before the volcanic
eruption, the light colored mice blended in with the desert sand and hid them
from predators. After the eruptions, mice in the new terrain will undergo
natural selection, and mice best suited to their environment (darker colored
mice that are better hidden from predators) will be more likely to survive
and reproduce. Therefore, there will be more and more darker mice
populating the dark lava rock over time.
3.) Will he find more dark or light mice on the darker lava rock?
He will find more dark mice for the reasons explained above.
4.) Why is it significant that the underbellies of the mice haven’t evolved to be
darker too?
These mice still have white under bellies because there is no selection for the
underbelly to be darker since predators are coming from above.
5.) In this video, what is the driving force for natural selection?
The predator is the driving force that makes the difference in the change in
color.
6.) What is a mutation?
A mutation is a change in chemical letters that make up genes. It’s a copying
error of DNA when cells divide. In simpler terms, its what causes one mouse
to randomly be black (how the adaptation starts).
7.) How does one mutation spread throughout other mice so quickly?
While only 1 new mouse born in 100,000 may be black, hundreds of
thousands of mice are born a year, and black mice have advantage. This
advantage (blending in with the environment so they’re less visible to
predators) allows black mouse babies do better (they’re more likely to
survive and reproduce) and the same goes for their offspring and so on. Thus,
the advantage can quickly turn whole population black.
8.) Is evolution random? Mutation? Natural selection?
Mutations occur randomly, but natural selection isn’t random because it
sorts out winners and losers (who’s better fit for their environment) which
drives evolution. Proof: natural selection produces same result under same
conditions.
9.) “As environments transform so must the species that inhabit them:
adapting and readapting in the great and complex battle of life”
AFTER THE VIDEO:
1.) Using the knowledge you gathered from the video and your discussion with
your classmates, define natural selection:
The process by which forms of life having traits that better enable them to
adapt to specific environmental pressures, as predators, changes in climate,
or competition for food or mates, will tend to survive and reproduce in
greater numbers than others of their kind, thus ensuring the perpetuation of
those favorable traits in succeeding generations.
2.) Predict how a population of insects might change over time if farmers started
using pesticides to prevent the insects from eating their crops.
The insects will gradually become resistant to the pesticides due to natural
selection. The insects that contain a mutation that allows them to survive
despite pesticide presence will be selected for. These insects will survive and
reproduce until eventually all of the insects in the population will be
pesticide resistant.
3.) Explain the role of mutation in natural selection and give an example.
Mutation, which is random, is necessary for natural selection and evolution
to occur. Natural selection selects the genetic mutations that make the
organism most suited to its environment and therefore more likely to survive
and reproduce.
4.) Using what you know about natural selection, what do you think “artificial
selection” is? Hint: think about selective breeding of dogs.
Artificial selection is the process in which humans consciously select for or
against particular features in organisms. For example, the human may allow
only organisms with the desired feature to reproduce or may provide more
resources to the organisms with the desired feature. This process causes
evolutionary change in the organism and is similar to natural selection, only
with humans, not nature, doing the selecting
Bonus Question:
Now you know what natural selection is, but there are actually a few different kinds
of natural selection, some of which are listed below. Try your best to use what you
learned in class today to define these:
Directional Selection: directional selection is a mode of natural selection in which
one extreme trait is favored.
Disruptive Selection: describes changes in a population in which extreme values are
favored
Standardizing Selection: the opposite of disruptive selection, genetic diversity
decreases and the mean stabilizes on a particular trait in the middle, not the
extremes