Adaptations of Species

Adaptations of Species
Organisms and Environments
Adaptations of Species
Background
Scientists have found and named at least 1.3 million different
species of organisms. Some scientists believe not all organisms
have been discovered and think there are possibly as many as
8.7 million different types of organisms on Earth. Amazing as this
is, even more amazing is that each species has its own set of
unique traits that allow the organism to survive. A trait is a
characteristic or quality of an organism that is genetically inherited
from one generation to the next. Traits can be behavioral such as
migration or hibernation; physiological, such as gills to breathe
under water or hollow bones to be lighter for flight; or external
features, such as feathers, four legs or scales. Over generations,
traits that enhance survival of a species are selected over those
that do not.
The finches have adapted
different shapes of beaks to be
able to compete for the available
food supply.
Habitats change so the survival needs of organisms change as well. Adaptation is the process by
which a population becomes better suited to its habitat. One example is the gradual lengthening of
the giraffe’s neck to allow for grazing in tall trees above the grazing line of animals with a shorter
reach. Such an adaptation is a genetic variation that provides an advantage to the survival of a
giraffe. Over time giraffes with longer necks survive to breed with other giraffes with longer necks
and pass the long neck trait along to the next generation.
Migration is a behavioral trait of some organisms. Animals migrate by traveling long distances in
search of new habitats. This may be due to seasonal climate changes or availability of food. Many
species of birds fly south for the winter. They migrate from the cold snowy northern states of the
U.S. to spend the winter in the warmer climate of the southern states where food is more plentiful.
Hibernation is a way that animals adapt to the climate and their surrounding environment. Certain
animals must be able to survive through extreme cold conditions. Hibernating animals store food
as body fat during the end of the fall season. Physiological changes occur in the animal to help it
survive long periods of time during these conditions. The animal’s body temperature, heartbeat,
and breathing rate drops to save energy. The stored fat is able to last longer when the body’s
metabolism slows down.
Please continue to the next page.
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Adaptations of Species
Organisms and Environments
Background, continued
The internal structures of many organisms have adaptations that allow specific functions. Gills
make it possible for fish to breathe under water. When a fish breathes, it takes in water and forces
it through the gill openings so that it passes over the gills. Gases are exchanged through the thin
walls in gills allowing blood to carry oxygen to other parts of the body. Carbon dioxide passes from
the blood through the thin gill tissue into the water.
Hollow bones in birds make their bodies lighter and allow them to fly long distances without
carrying a lot of weight. The hollow bones have the same hard exterior found in bones of most
other organisms, however, bird bones are filled with air rather than marrow. Some of the bones
also have extensions of the air sacs from the bird’s lungs. These air sacs help the bird get the
oxygen it needs to fly quickly and easily. Bird bones have added strength from structures inside the
bone called struts. The struts give the bones added strength so that they can withstand the
movements of birds taking off, flying, and landing.
Plants also have adaptations to help them survive in different areas. The xylem is an important
structure because it transports water and other nutrients from the root system to the rest of the
plant. The hollow structure and lignin in the lining of the xylem make it ideal for water and nutrient
transportation. The hollow structure allows the liquid to be drawn up into the plant through capillary
action, much like sucking water through a straw. The lignin allows the water to move easily into
the plant cells.
Some plants have structures that store energy (carbohydrates) or water. An example of a plant
structure that helps a plant survive in unfavorable conditions is a storage bulb. Plant bulbs typically
grow underground. Plants are able to use the energy or water stored in the bulb to help it survive
during conditions such as extreme cold or heat, lack of available light, or during a drought.
Answer the Background questions in your Student Journal.
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Adaptations of Species
Organisms and Environments
Part I: Survival
Use the information in the background to practice matching how a trait can provide a survival
advantage.
1.  First match each trait from the list provided in Part 1 of your Student Journal to the related
survival advantage provided by the trait. Record your answers on the table titled: Survivor
Match Up.
2.  Pair with another student to compare your answers. Discuss any differences to agree upon the
best answer.
3.  Choose one of the eleven listed traits and corresponding survival advantages to complete the
chart titled: Thinking about Survivors. Pair with another student to discuss completion of this
chart and provide detailed responses.
4.  The internal structures of organisms also have adaptations that give organisms a survival
advantage. Choose two of the organisms below and research the indicated internal structure to
identify the specific function of the structure and how it gives the organism a survival
advantage.
Example: The hollow bones in birds give birds structural support that weighs less, which helps
birds to fly long distances. This allows birds to migrate to a warmer climate with more plentiful
food during winter.
Plants:
Venus Fly Trap – the ability to digest insects
Cacti – thick stems to store water
Phototropism in plants
Animals:
Ruminants (cows, deer, sheep) – stomachs
Fish – air bladders
Birds - crops
Complete Part I of your Student Journal.
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Adaptations of Species
Organisms and Environments
Part II: Daphne Island
For the last 20 years, scientists have been researching a 100-acre island called, Daphne. These
studies noted that the local plants yield two major types of seeds. One type of seed is small and
soft, while the other is large and hard. About 10 years ago, scientists observed a bird species
adaptable to eating the small seed types, but were unable to crack open the larger seed types with
their beaks. More recently, scientists watched individuals from a larger beak species group eating
the large seed types. Scientists concluded natural selection had occurred when a genetic mutation
of the small seed eating species resulted in producing the variation of the larger-sized beaks in an
individual bird, which then bred successfully with others. This led to the spread of this adaptive
trait, creating a subpopulation able to take advantage of the larger sized seed resource.
As a scientist, you are assigned to complete a 10-year study to record annual rainfall conditions,
observe annual seed yield, and estimate bird population numbers. Record and analyze your data
comparing how annual precipitation affects the two bird populations, which have adapted differently
to the available food resources.
What You Know:
•  Bird Population A has small beaks and only eats
the small seed type.
•  Bird Population B has large beaks and only eats
the large seed type.
•  Annual precipitation varies.
•  The annual yield of both seed types is directly
dependent on annual precipitation.
•  Dry conditions reduce the small seed yield, while
wet conditions reduce the large seed yield.
•  Other environmental factors limit the number of
individuals to 300 for each subpopulation.
Small Beak
Population A
Large Beak
Population B
Complete the Part II Background questions in your Student Journal.
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Adaptations of Species
Organisms and Environments
Part III: Plan Your Investigation
You will develop an investigation to record observations about changes in the habitat of two
subpopulations of bird species. You will record the area’s annual precipitation, annual seed yields,
and estimated numbers of the two subpopulations of birds. The two populations vary in beak size.
Population A has a small beak, and these birds eat the small seed types in the study area.
Population B has a large beak, and these birds eat the large seed type. You will observe, record,
and analyze the data for 10 cycles (“Study Years”).
Question of Inquiry: With your class and teacher, discuss the Question of Inquiry and list the
materials that you will need to conduct your investigation.
Safety Precautions: Additional safety precautions are not required in a simulated investigation.
Procedure: Follow the instructions in Part IV: Implement Your Investigation.
Part IV: Implement Your Investigation
Procedure:
1.  Cut out the 8 Observation Cards from the Teacher Printout: Observation Cards.
2.  Place the cards in a brown paper bag or another non-see-through container.
3.  Randomly pull out one card at a time for each “Study Year.” Each card represents a “Study
Year”, record the information from each “Study Year” in the data table titled Ten Year Study
Data.
4.  Return the Observation Card to the bag, mixing up the card set, and then pull out a card for the
next “Study Year.”
5.  Repeat the observation procedure for a total of 10 times to complete a 10-year study.
Complete Part III of your Student Journal.
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