adapting to the environment

Adapting to the Environment

Section 3.2

Adaptations of Organisms

• We have just finished studying 8 areas in the biosphere that have different climates and environmental conditions.

• We called these areas biomes.

• Today we will focus on the adaptations that organisms must have in order to survive the environments that these biomes provide.


• What is an adaptation?– Any trait that an organism has that improves its

chances of survival.– There are adaptations that affect and/or are

influenced by both the biotic and abiotic environments of the organisms.


• Examples:– Turtles• Abiotic adaptations: (help with life in water)–Eyes/nostrils high on head–Paddle shaped feet and skin between toes

• Biotic adaptations: (help escape predators)–Swims with most of its body under water–Hard shell for protection


• Examples:– Arctic Fox:• Abiotic adaptations: (for the cold temperatures)–Thick coat of fur

• Biotic adaptations: (to help escape predators)–White coat to blend in with environment


• Examples:– Hawk:• Abiotic adaptations: (to help fly)–Light, hollow bones–Wide wing span for soaring

• Biotic adaptations: (to catch prey)–Keen eyesight to spot prey–Sharp beak and claws–Fast movement to catch escaping prey

The Process of Natural Selection

• When you think of Natural Selection there is one phrase that you need to remember:

“Survival of the fittest.”


• This means that:– Nature selects only the best adapted organisms to

survive and reproduce while the least fit are eliminated.


• Nature selects only the best adapted organisms to survive and produce offspring.

• How do these organisms acquire these important adaptations?


• These traits are passed down from generations to generation through genes that are inherited from parents.

• They are not acquired by the organism in order to survive.

“Adaptation happens by chance, not by choice.”

Natural Selection & Predation

• Natural Selection will favour the best adapted predators as well as the best adapted prey.

• There are a few common mechanisms that have been observed…


• Camouflage:– This is an adaptation that allows the organism to

hide from predators, or to increase the chance of finding prey.

Natural Selection & Predation• Warning Coloration:– Organisms develop a colour that warns potential

predators that they might be poisonous.– A.K.A. aposematic coloring


• Mimicry:– When one species has evolved a resemblance to

another poisonous/dangerous/distasteful organism.


• Coevolution:– Predator and prey evolve structures in response to

each other’s adaptations.– As one organism changes (evolves), so does the

other.

Biodiversity

• Biodiversity:– The wide variety of living organisms and the

variation among organisms.

– The higher the primary productivity (productivity of producers) the more biodiversity there will be.

Biodiversity

• Ecosystems with low primary productivity tend to be the fragile ecosystems.

• This is because there are few species to begin with, so the removal of any species can be devastating to the ecosystem.

Keystone Species

• A keystone species is any species whose removal from an ecosystem can result in the collapse of the entire ecosystem.

• The sea otters that liveoff the west coast ofVancouver Island are agood example, see page65 in your book.

Keystone Species

• This is their food chain:Kelp

Sea Urchin

Sea Otter

Crab

Keystone Species

• For the rest, we need to know two definitions:– Extinction:• When a species is completely gone from the

Earth– Extirpation:• When a species is removed from one area

Keystone Species

• What happened to the food chain when the otter population was nearly extirpated?

Keystone Species

• Explain how the problem was solved in the late 60’s and early 70’s.

adapting to the environment

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