Naila :]

Naila :]

Wednesday, January 30, 2013

Natural Selection

Who is Charles Darwin and what did he study?
  Charles Darwin is the person that came up with the theory 'natural selection'. He studied medicine, theology, anatomy, geology, and classification.

What is natural selection?

  Natural selection is the process of when a species becomes more specialized to suit their environments.

Environmental pressures animals face:
Deforestation, Ice melting in the Arctic, Pollution, Disposal of household wastes, Storm water (often contaminated with sewage and gas/oil from roadways).

Examples of variations:
different skin color, skin pattern, height, fur color, feet/paws/hands size, nose shape, neck length, eyelashes length, thick or thin coats(of fur).

What does survival of the fittest mean?

   Natural selection conceived of as a struggle for life in which only those organisms best adapted to existing conditions are able to survive and reproduce.

1. Giraffe:

   a. environmental pressure- not long enough necks to reach the leaves from trees for food
   b. variation- skin patterns

2. Rabbit:

   a. environmental pressure- not being able to find food around them
   b. variation- fur colors

3. Cactus:

   a.environmental pressures- lack of water
   b. variation- thickness of thorns

4. Shark:
   a. environmental pressure- being hunted by the human race
   b. variation- different types of shark teeth
Describing 5 senses the chimpanzees have:
1. Sight- required to spot predators, to run away from being eaten
2. Hearing-  run away from well camouflaged predators
3. Smell- to distinguish foods from poisonous and safe foods 
4. Touch- to sense objects
5. Taste- touch and taste go together

Those chimpanzees who have better eye-sight will be able to notice faster whenever there are predators around. Those with better hearing will be able to run away from the well-camouflaged predators. Those with better smell ability, will be able to distinguish the good from the bad foods. Which these will end up to live longer, enough to reproduce, enough to pass on these traits.

Polar Bears:
Polar bears live along shores and on sea ice in the icy arctic. It's habitat is at a seal's breathing hole in the ice. They feed primarily on seals.
 Physical features that help them survive include- their white fur allows them to camouflage with the ice or the snow. Their ability to swim helps them catch prey that is underneath  the ice. Paw pads help prevent them from slipping on the ice. To swim, they use their large front paws to propel themselves through the water and their back legs to steer.

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