Download Adaptations worksheet

NAME ___________________________________________ DATE ______________________________
Adaptations and Natural Selection
PURPOSE:
To determine how the environment and the process of natural selection produces adaptations in a
population.
BACKGROUND INFORMATION
Natural selection is the powerful process by which certain inherited characteristics—those
that make it more likely for an organism to survive and successfully reproduce —become
more common in a population over many generations. It is a key mechanism of evolution
and has resulted in some amazing adaptations in the natural world, such as the thick body armor of the
armadillo. Adaptations are any physical or behavioral characteristic of an organism that increases its
chances of survival in an ever-changing environment.
The relationship between adaptations and the process of natural selection is often misunderstood, and
many students develop the misconception that natural selection gives organisms their unique traits for
enhanced survival. Rather, it is the chance appearance of the characteristic through mutations and gene
shuffling which sets the stage for the process of natural selection to occur. Organisms which by chance
possess a unique characteristic that increases the chances for survival in a particular environment will live
to pass on the characteristic to subsequent generations, while other organisms without the characteristic
will eventually die out. Thus, the favorable characteristic becomes an adaptation in the generations that
follow, thereby changing the genetic makeup of the population over time.
1) Where do adaptations come from? ____________________________________________________
2) How is natural selection connected to adaptations? _______________________________________
________________________________________________________________________________
3) What does the population’s environment have to do with a particular adaptation?
________________________________________________________________________________
4) How does an environmental change (ex. hurricane, drought, etc.) affect the organisms that are adapted
to the environment before the change?
PROCEDURE: Specific physical and behavioral adaptations are described in the tables below.
Some of the information has been removed. Fill in the blanks using the following information.
A.
B.
C.
D.
E.
F.
provides required nutrients
organism blends in with the environment
hibernation
gets rid of excess heat
temporary hot, dry conditions
leaves are spines
ORGANISM
PHYSICAL
CHARACTERISTIC
African
elephant
large, flat ears
leaf bug
body shaped
and colored liked
a leaf
prickly pear
cactus
Venus fly
trap plant
traps insects in
leaves
frogs and
toads
(hibernation by
burrowing)
Alaskan
brown bear
estivation
FUNCTION
ENVIRONMENTAL
STIMULUS
hot climate
avoid detection
predation
reduces water
loss and
provides
protection
hot, dry
environment
nutrient-poor
soil
keep body cool,
conserves
water
survival in long
winters
cold climate
ADAPTATION EXPLANATION
easy and efficient method for
keeping body cooled
structure allows for
conservation of water and
increases chances of survival
two methods for acquiring
food (nutrition) provides for
improved health
need for water reduced; body
temperature kept in
homeostasis while in the
ground
little need for food, water
since energy requirement is
low
ANALYSIS
1) The color and pattern of the viceroy butterfly’s wings mimics the monarch butterfly's
appearance except for a black horizontal stripe that crosses the bottom of the back
wings. Predators of the monarch butterfly quickly discover an important difference
between these two, however: the monarch butterfly is poisonous and tastes terrible!
How can the appearance of the viceroy butterfly’s wings be considered an adaptation?
2) The tails of many lizards, including the leopard gecko, is used as fat storage for times when there is not
much food available in their environment. When grabbed by a predator, the tail breaks off and
continues to flop around and wriggle long after it has dropped off the lizard's body.
How is this phenomenon related to adaptations and natural selection?