"history of the development and behavior of living beings as affected by their environment," 1882, coined by English biologist St. George Jackson Mivart (1827-1900) from Greek hexis "a state or habit," from ekhein "to have, hold;" in intransitive use, "be in a given state or condition" (from PIE root *segh- "to hold").
Every living creature has also relations with other living creatures, which may tend to destroy it, or indirectly to aid it, and the various physical forces and conditions exercise their several influences upon it. The study of all these complex relations to time, space, physical forces, other organisms, and to surrounding conditions generally, constitutes the science of hexicology (hexiology?). [Mivart]
early 14c., "any sentient living creature" (including humans), from Latin animale "living being, being which breathes," noun use of neuter of animalis (adj.) "animate, living; of the air," from anima "breath, soul; a current of air" (from PIE root *ane- "to breathe;" compare deer). A rare word in English before c. 1600, and not in KJV (1611). Commonly only of non-human creatures. It drove out the older beast in common usage. Used derisively of brutish humans (in which the "animal," or non-rational, non-spiritual nature is ascendant) from 1580s.
Quid est homo? A dedlych best and resonable, animal racionale. ["Battlefield Grammar," c. 1450]