Transcript Chapter 3 Section 4 Adaptation and Survival

10/8 Bellwork
• Adaptation: Fur turns white during
the cold snowy winter months
• Purpose of fur:
_________________
• Animal:__________________
• Habitat: _______________
Chapter 3 Section 4
Adaptation and
Survival
• An adaptation is a
characteristic that improves an
individual’s ability to survive
and reproduce in a particular
environment.
• Objective
• Identify three kinds of
adaptations that help
organisms survive.
• 1. Obtaining Food
• Almost all organisms have
adaptations to help them
obtain food.
• Examples: Chameleon – long
tongue Woodpecker –
pointed beak Human –
hands and fingers
• 2. Predator-Prey
• Many organisms have adaptations
that serve as a defense against
predators. One common adaptation
that helps predators and prey is
called camouflage. An organism
that is camouflaged is disguised so
that it is hard to see even when the
organism is in view.
• 3. Interactions
• Two species can acquire
adaptations because of their
interaction with one another.
Interactions take place between
organisms that live close
together. We call these
interactions symbiosis.
• Natural selection
• The process by which
individuals that are better
adapted to their environment
survive and reproduce more
successfully than less well
adapted individuals do.
• Objective
• Describe the four parts of
natural selection. (Survival of
the Fittest)
• 1. Overproduction
• more offspring are born than
will live to become adults.
• 2. Genetic Variation
• Individuals in a population
differ from one another.
Some characteristics
improve chances while
others lower chances for
survival.
• 3. Struggle to Survive
• Many individuals die from
lack of resources. Others are
killed by predators or cannot
find mates to reproduce. The
ones who find resources,
survive!
• 4. Successful Reproduction
• This is the key to natural
selection. The strong
survive, while the weak die
early or have few strong
offspring.
• Objective
• Explain how genetic
variations occur and why
variation within a
population is important.
• Genetic Variation
• In natural selection, individuals within
the population must be different.
Over time, the population will be
made up of more individuals with
characteristics that help them
survive.
• If a population decreases rapidly, the
characteristics of the individuals are
reduced. This is called a genetic
bottleneck.
• Many characteristics may be
lost entirely because the
individuals with those
characteristics died. As the
population recovers,
organisms are genetically
similar causing genetic
diseases to occur.