1. Interdependence and adaptation
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2. Overview
Organisms are well adapted to survive in their normal environment.
Population size depends on a variety of factors including competition, predation, disease and human influences.
Changes in the environment may affect the distribution and behaviour of organisms.
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3. Competition
All animals and plants require a supply of materials from their surroundings and from other organisms that live there.
For example, take a wild rabbit.
What does it need from its surroundings?
What is it competing with?
What limits the population of rabbits?
Vibe Images/Fotolia
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4. Plant competition Plants also compete with other organisms to live.
Take the example of a daisy on a lawn.
What is it competing for?
What is it competing with?
What will limit the population of the daisies?
Trancedrumer/Fotolia
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5. Competition summary Plants compete for Animals compete for Light Food
Space
Mates
Water
Territory
Nutrients from the soil
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6. Adaptation
Organisms, including microorganisms, have features and adaptations that enable them to get the materials they need from their habitat to survive.
What adaptations are needed for typical organisms to live in these environments?
Very cold places like the Arctic and Antarctic
Hot, dry deserts
The depths of the oceans
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7. Adaptations for cold environments
Some organisms need to cope with extreme cold, little light and snow. For example, polar bears have:
a thick layer of fat for energy and insulation
thick fur for insulation
white fur for camouflage
large canine teeth for killing
large paws for swimming
Ilana Vargulich/Fotolia
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8. Adaptations for hot, dry environments
Some organisms need to cope with extreme heat and lack of water. For example, camels have:
fat stored in a hump, as a supply of food and water
thick fur for insulation for cold nights and hot days
large feet for walking on soft sand
long eyelashes to keep sand out of their eyes
nostrils that close during sandstorms
Oleg Seleznev/Fotolia
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9. Plant adaptations
Plants can also be adapted to live in dry environments. For example, cacti have:
large root systems
small surface area of leaves to reduce water loss
waxy surfaces of leaves
water storage tissue
Lucy Cole
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10. Environmental changes
Environments are changing constantly due to both living and non-living factors. This affects the distribution of the organisms living there.
For example, populations of competitors or predators may change (these are living factors). Pollution, floods, droughts and temperature changes are examples of non-living factors.
What would happen to the population of rabbits if the fox population was wiped out by hunting?
How would an extended drought affect the wildlife in your area?
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11. Monitoring environmental changes 1
Changes to the environment can be measured using non-living indicators, such as oxygen levels, temperature and rainfall.
Living organisms also can be used as indicators of pollution:
Lichen populations can be used to determine levels of sulfur dioxide in the air.
Invertebrates living in ponds and streams indicate water pollution and the concentration of dissolved oxygen.
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12. Monitoring environmental changes 2
Christine Woodward