Why a coelom?

1
Why a coelom?
2
Some functions of a coelom

• Function as a hydrostatic skeleton
• Facilitate movement of materials between organs
  and organ systems
• Function as a depository for excretory materials
• Function as a shock absorber
• Allow for changes in organ sizes with out
  negative effects on the organism

3
How could a coelom originate

• Gonocoel theory
• Excretory space

4
Origins of metamerism

• Metamerismserial repetition of body parts
• segmented

5
Advantages of segmentation

• Increases body size
• Loss of segments doesnt always imply loss of
  life
• Division of labor
• Nature of appendagesare segmental related
• More effective locomotion
• Saving energy

6
Original appendages

• Outgrowths of the body wall
• They can have independent muscularture
• Also have coelomic space

7
How did it happen

• Flatworms
• Outcomes
• New environment is available to the creatures
• Ecologically speaking, bioturbation. aeriation