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The Arthropod Story Table of Contents   

The laws of physics and inheritance

Arthropods inherited both an exoskeleton and jointed legs. These traits have opened up many opportunities in arthropod evolution, but they have also blocked other possibilities. In particular, you will explore three constraints on the size of terrestrial arthropods:
  • Molting: Molting is more hazardous for larger animals.
  • Exoskeleton strength: The exoskeleton may not be strong enough to support larger animals.
  • Respiration: Many arthropods can only get enough oxygen to support small bodies.

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