Applied Bio Unit 6

1
Applied Bio Unit 6

• Chapter 15 and 16

2
Evolution and Ecosystems

• Species change in order to survive better in
  their environments
• Co evolution is when 2 or more species change in
  response to each other
• Species interact with each other
• Flowering plants and organisms
• The plants need pollination to reproduce
• Insects need food (nectar)
• Plants use their color to attract, organisms use
  their body shape to gather the nectar

3
Defense

• Plants have thorns and spines to defend against
  predators
• They also use deadly or annoying chemicals
• Ex poison ivy
• Herbivores have learned of ways to overcome some
  plant defenses
• For example, the chemicals may not affect a
  certain species

4
3 types of close species interactions

• Symbiosis is when organisms live and interact
  with each other
• 1. Parasitism- one benefits while the other is
  harmed
• 2. Mutualism- both benefit
• 3. Commensalisms one benefits while the other is
  neither harmed nor benefited

5
Examples

• Parasitism- ticks and dogs
• Mutualism- sucker fish (remoras) and sharks
• Commensalisms hermit crabs using dead gastropods
  shells

6
Ecosystem Lifestyles

• Every organism is important within its habitat
• It has a niche or role
• Daily activities such as what they eat, where
  they hunt, where they sleep, how they reproduce
  are all their niche within the ecosystem

7
Competing organisms evolve

• Sometimes two or more organisms compete for the
  same resources
• Resources include food, water, shelter, space
• One organism may lose entirely and die or leave.
  This is called competitive exclusion.

8
Competition and ecosystem development

• Species better able to survive in a habitat move
  in and dominate over previous residents
• Eventually balance occurs and biodiversity
  increases
• Ex plant species change so that the environment
  goes from a simple field to a vibrant forest over
  time
• Succession is the progression of new species
  replacing old ones
• First inhabitant are called primary, newer
  inhabitant called secondary and so on

9
Ecosystem Stability

• Stability is the resistance to change and new
  inhabitant due to the presence of competitors
• More biodiversity exists the more stable the
  ecosystem
• A species whose niche affects many others is a
  keystone species. Losing it is devastating to
  the ecosystem

10
Some ecosystems are more diverse than others

• Two key factors for diversity
• 1. Size- more space, more opportunity for
  diversity because of different habitats
• 2. Latitude (distance from the equator)- closer
  to the equator (tropics) have more diversity
  because of a longer growing season (hotter and
  wetter) and more stable climate (less drastic
  seasons)

11
Human disruption

• Humans disrupt the physical habitat by burning,
  clearing, farming, cattle grazing, etc
• This decreases the species diversity
• Humans poach endangered animals which further
  decreases diversity
• Humans destroy species interaction by fragmenting
  habitat and over hunting of one species

12
The planet under stress

• Humans pollute water, air, soil, etc.
• Pollution is anything harmful added to the
  environment
• Some pollution causes cancer and is called a
  carcinogen

13
Pollutions Toll

• Humans endanger the water supply
• Ex Exxon Valdez oil spill, factory chemicals
  dumped into water supply, insecticide and
  pesticide run off
• Acid rain threatens forests and lakes. High
  sulfur coal is burned and releases sulfur into
  atmosphere. Sulfur combines with water in air
  making sulfuric acid. Rain, snow, etc falls
  containing the acid. Low pH (less than 7.0)

14
Destroying the Ozone Layer

• A hole exists over both poles
• CFCs (chlorofluorocarbons) destroy ozone
• It is a coolant in AC and fridges, aerosol cans,
  plastic foam
• Attack zone molecules which protect use from
  suns UV rays
• Health problems result skin cancer, cataracts
  because UV rays

Courtesy of NASA 2004
15
Global Warming

• See pics from Inconvenient Truth
• Increased carbon dioxide in air since industrial
  revolution
• Cause increase in global temp because rays not
  reflected back into space
• Melting polar ice caps
• Drought
• Floods
• Hurricanes and tornadoes

16
Meeting the Challenge

• Reducing pollution
• Laws on car emissions, CFCs, the Clean Air Act of
  1990 restricted factory emissions

17
Finding Enough Energy

• Nonrenewable resources do not replenish in our
  lifetime
• Fossil fuels- petroleum, coal, natural gas
• Renewable resources replenish easier and faster
• Trees, water, wind, solar
• Alternatives to fossil fuels include nuclear
  power when E is released by splitting atoms
• Concerns meltdowns, residual radioactivity

18
Using Energy more conservatively

• More efficient appliances
• Unplug when not in use
• Use fluorescent light bulbs
• Insulated homes
• UV windows
• Solar panels

19
Conserving nonrenewable resources

• Contour farming to reduce erosion
• Reduce use of ground water aquifers
• Conservation of rainforest
• Conservation of species endangerment
• Saving species is important because losing one
  disrupts ecosystems and we lose possible cures
  and medicines

20
Deeper problem Population Growth

• We are now exponentially growing p298
• 1650s and on we had better medical care and
  sanitation which caused lower death rate and
  maintained high birth rate
• We cannot grow indefinitely, we will reach
  Earths carrying capacity, resources will be used
  up, we must level out or we will have a drastic
  population decline

21
Environmental problems can be solved

• Commitment to truly solve problems
• Investigating alternatives
• Govt support
• How can you contribute
• Conserve E by using less hot water, fluorescent
  bulbs, less car and plane usage, use efficient
  car, recycle, save water

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