Why do endoparasites have simple sensory systems?
Answer Dear Abbey – “Why” queastions are better suited to philosophy rather than scientific discussions. That aside, because of the environment in which they live, namely the body of a host, their sensory input requirements usually are far less than those of free-living organisms, that must be able to distinguish friend from foe, locate often scattered/diffuse food sources, attract mates, etc. Nature basically is conservative, with evolutionary forces usually resulting in organisms suited for their environment. In some instances, endoparasites may have evolved from free-living ancestors, losing unnecessary details (such as limbs, eyes, etc.) in the process.
