User:Jtwsaddress42/Projects/Project 4/Sections/Chapter 4/The innovations and challenges of the jawless vertebrates



The agnata represent the primitive state.


 * the development of a new adaptive immunity division of the immune system enhances innate immunity via the emergence of variable lymphocyte receptors.
 * the somatic and visceral divisions of the body are only connected at the pharyngeal-hindbrain region and the sacral end.
 * for the autonomic nervous systemn, there is no sympathetic division - only, an un-myelinated division of the para-sympathetic radiating out from the pharyngeal-hindbrain complex and sacral end of the organism.
 * there are no jaws or fins, no myelin.
 * due to lack of a sympathetic fight or flight system, the primary mode of response in the face of uncertainty is catatonic freezing or "feigning death".