5-2 Notes – Adaptation & Extinction
Adaptations
• Humans can change their _____________________ to meet their needs.
• Organisms have evolved ___________________ to their environment by the
process of natural selection.
• Adaptations are inherited traits that increase an organism’s chance of
_______________________ and ________________________ in a particular
environment.
• Not all ____________________ are adaptations.
• Sometimes undesirable traits can be passed down because they are
•
•
____________________________ linked with other beneficial traits.
Adaptations are the final products of the long process of _____________________ ______________________ .
Adaptations are ____________________ selected for, not intentional .
Structural Adaptations
• _________________ adaptations are aspects of the physical body that help organisms survive and reproduce.
• ____________________ is coloring that blends with the environment, and makes organisms difficult to see.
• ___________ is when one species (the _________) looks like another species (the __________) in order to deceive
a third species.
• ___________________ mimicry is when the model organism is dangerous or venomous, but the mimic is not
•
•
dangerous.
___________________ mimicry is when both the model organism and the mimic are dangerous or distasteful.
_________ mimicry is when a species fools its prey by looking inviting or familiar OR to scare off a predator.
Batesian Mimicry
Coral Snake (model)
venomous
King Snake (mimic)
harmless
Mullerian Mimicry
Monarch Butterfly (model)
tastes bad
Viceroy Butterfly (mimic)
tatstes bad
Behavioral Adaptations
• _____________________ adaptations are ___________ or behaviors that help organisms survive and reproduce.
• The ______________ instinct is seen in cows , and they know a large group is less likely to be attacked than when
alone.
p. 21
Extinction
• A species becomes ____________ when all the individuals of a particular species die off.
•
There have been ____________________ major extinction events in history.
Extinction Causes
1. Loss of _________________________
 As humans develop and occupy more space, and use more _________________ , habitats are destroyed.
2. Loss of __________________ diversity
 Species NEED genetic _________________ to make it more likely to survive.
 A species is considered to be _______________________ if they are likely to become endangered due to
low __________________ variation.
 Cheetahs are threatened because they had to ___________________ and now have low genetic variation.
3. Competition with _______________ species
 Humans often introduce a new __________________ to an area because it is unique or pretty.
 If it has no known ___________________________ , it will take over and kill native species.
4. Inability to __________________
 This is involved in _______________ environmental changes, and can cause rapid extinction.
 If the ______________________ changes suddenly, and a species doesn’t have any individuals with
genetic traits that allow them to adapt, the entire species will go extinct.
Review
____ 1. What is not an example of an adaptation?
A. inbreeding
B. camouflage
C. mimicry
D. behavior
____ 2. Why do some non-desirable traits remain in a population?
A. selective breeding
B. mutation
C. they are genetically linked to more beneficial traits
D. they may be useful in the future
____ 3. What cause for extinction would most likely be involved in rapid environmental changes such as climate
change?
A. loss of habitat
C. loss of genetic diversity
B. inability to adapt
D. competition with exotic species
____ 4. Which of the causes of extinction is not influenced by human actions?
A. inability to adapt
C. loss of habitat
B. loss of genetic diversity
D. competition with exotic species
____ 5. Why do desert rabbits have mottled fur?
A. behavioral adaptations
B. mimicry
C. camouflage
D. incomplete dominance
____ 6. When do we designate a species as threatened or endangered?
A. when there is one population left
B. when the number of individuals falls below a certain level
C. when population numbers are declining
D. when genetic variation is low
5-2 Notes – Adaptation & Extinction
Adaptations
•
•
•
•
•
•
•
Humans can change their environment to meet their needs.
Organisms have evolved adaptations to their environment by the process of
natural selection.
Adaptations are inherited traits that increase an organism’s chance of surviving
and reproducing in a particular environment.
Not all traits are adaptations.
Sometimes undesirable traits can be passed down because they are genetically
linked with other beneficial traits.
Adaptations are the final products of the long process of natural selection.
Adaptations are naturally selected for, not intentional.
Structural Adaptations
• Structural adaptations are aspects of the physical body that help organisms survive and reproduce.
• Camouflage is coloring that blends with the environment, and makes organisms difficult to see.
• Mimicry is when one species (the mimic) looks like another species (the model) in order to deceive a third species.
• Batesian mimicry is when the model organism is dangerous or venomous, but the mimic is not dangerous.
• Mullerian mimicry is when both the model organism and the mimic are dangerous or distasteful.
• Self mimicry is when a species fools its prey by looking inviting or familiar OR to scare off a predator.
Batesian Mimicry
Coral Snake (model)
venomous
King Snake (mimic)
harmless
Mullerian Mimicry
Monarch Butterfly (model)
tastes bad
Viceroy Butterfly (mimic)
tatstes bad
Behavioral Adaptations
•
•
Behavioral adaptations are actions or behaviors that help organisms survive and reproduce.
The herding instinct is seen in cows, and they know a large group is less likely to be attacked than when alone.
Extinction
•
•
A species becomes extinct when all the individuals of a particular species die off.
There have been several major extinction events in history.
Extinction Causes
1. Loss of habitat

As humans develop and occupy more space, and use more resources, habitats are destroyed.
2. Loss of genetic diversity

Species NEED genetic variety to make it more likely to survive.

A species is considered to be threatened if they are likely to become endangered due to low genetic
variation.

Cheetahs are threatened because they had to inbreed and now have low genetic variation.
3. Competition with exotic species

Humans often introduce a new species to an area because it is unique or pretty.

If it has no known consumer, it will take over and kill native species.
4. Inability to adapt

This is involved in rapid environmental changes, and can cause rapid extinction.

If the climate changes suddenly, and a species doesn’t have any individuals with genetic traits that
allow them to adapt, the entire species will go extinct.
Review (Answers: 1-A, 2-C, 3-B, 4-A, 5-C, 6-D)
____ 1. What is not an example of an adaptation?
A. inbreeding
B. camouflage
____ 2. Why do some non-desirable traits remain in a population?
A. selective breeding
B. mutation
C. mimicry
D. behavior
C. they are genetically linked to more
beneficial traits
D. they may be useful in the future
____ 3. What cause for extinction would most likely be involved in rapid environmental changes such as climate
change?
A. loss of habitat
C. loss of genetic diversity
B. inability to adapt
D. competition with exotic species
____ 4. Which of the causes of extinction is not influenced by human actions?
A. inability to adapt
C. loss of habitat
B. loss of genetic diversity
D. competition with exotic species
____ 5. Why do desert rabbits have mottled fur?
A. behavioral adaptations
B. mimicry
C. camouflage
D. incomplete dominance
____ 6. When do we designate a species as threatened or endangered?
A. when there is one population left
B. when the number of individuals falls below a certain level
C. when population numbers are declining
D. when genetic variation is low