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What are Adaptations?
Every organism has a variety of adaptations that
are suited to its specific living conditions
An adaptation is a trait that an organism has
inherited that helps it survive and reproduce in
their habitat
Ex. Sharks sense of smell, shape of a bird’s beak, dogs
can hear well, flowers have bright colors
Physical Adaptations
Physical adaptations do not develop during
one lifetime, but over many generations
Genes that help determine survival are passed from
parent to offspring
Adaptations Over Time
Natural selection is the process by which
individuals who are better adapted to their
environment are more likely to survive and
reproduce than other members of the
same species.
Charles Darwin/Finches
Galapagos Islands
Charles Darwin- English
scientist who proposed the
theory of natural selection in
1859.
Sailed on the Beagle to South
America for research
Studied tortoises, finches,
lizards, and other animals on the
islands.
Animals of Galapagos Islands
Finches- beaks are adapted for different
feeding behaviors
Ex: insects, seeds, fruit
Iguanas- able to dive underwater to eat
algae, sharp claws to cling to rocks, expel
salt by sneezing
Tortoises- shell shape depends on island
environment
What Causes Adaptations Among
Species?
Inheriting traits/variations that
have advantages for survival or
reproduction
Overpopulation/competition
Environment/Climate
What Are Variations?
Variations are different ways that a trait can express itself
Some variations make individuals better fit for survival from predators allowing them to reproduce and pass the favorable trait to their offspring
Ex. Variations among turtles make some of them better able to survive. Turtles that survive to become adults will be able to reproduce.
Natural Selection by Environment Variations can also allow organisms to
become better adapted to survive in a
particular climate.
Organisms expressing traits that allow
them to survive & reproduce in a
particular environment will become the
dominant life within the environment.
Example of inherited traits for
survival
Camouflage Snake
Mimicry Mexican Milk Snake
Bright colors/poisonous Skunk and Poison Arrow
Frog
“Hair” projections Hedgehog quills
Deer Antlers
Courtship behaviors Male birds dance & have
colors to attract mates
How Do Organisms Become
Endangered or Extinct?
Organisms that are not able to adapt to
their environment could become
endangered or extinct.
Threatened- could become endangered
in near future
Endangered- at risk of extinction
Extinct- a species with no surviving
members
Reasons for Extinctions
Pollution
Overhunting
Habitat loss
Introduced species- compete with native
species
Diseases
Climate change- global warming
Biomes Biomes are Large geographic areas
characterized by a distinct climate and
specific types of plant & animal life.
Climate is the weather a place has over a
long period of time (50 years).
Taiga/Boreal Forest Biomes Winters are cold and very snowy
Summers are warm and rainy enough to melt all the snow Dominant plants adapt with needle-shaped leaves to
reduce water loss by having less surface area Ex. evergreens
Animal have adapted by camouflage, hibernating or migrating, & thick fur
Rain Forest Biomes
Wet, warm biomes that contain the greatest variety of life
on earth
Plant & animal life adapts in a variety of ways
Camouflage
Poisonous
Mimicry
Desert Biomes Receive less than 25 cm of rain per year.
Hottest temperature on Earth
The plants have many adaptations for getting and
conserving water. (deep roots, needles)
Some animals have adapted by being nocturnal,
burrowing under ground, & being hairless