Animal Physiology’s Legacy in Our Human Experience


Animals are organisms which move. Movement is perhaps the single largest evolutionary leap and required the development of specialized tissues for both movement (muscle tissue/Mesoderm) and tissues to figure out the how/where/why of action (nerve tissue/Ectoderm). These tissues overlay and are supported by the core endoderm, and in turn, support the endoderm by enabling access to nutrients and opportunities to reproduce.

Originally movement was extension and contraction(e.g.: how a snail moves), but rather quickly developed into a free-swimming movement, which can be considered movement along a line. Jellies are an example of early experiments in movement. Fish, amphibians, and reptiles are much more advanced vertebrates that continue to operate within this constraint of linear movement.

Here is a fun article from Science Magazine that talks about what it was like for our ancestors at the beginning of the era of animals:



Discussion of the emergence of animal form at the line dimension. Time not sensed.


For organisms limited to a fixed point in space, protective responses are based largely of sensing vibration or sudden changes in light. The point archetypical response to a sensed threat is a contraction. We usually label this protective response as freeze, which we experience as either a locking of our physiology or as panic. The most efficient means to sense vibration is using hairs (cat whiskers are an excellent example). Humans still have a direct neurological connection to and from our hair follicles to the deepest layers of our core neurophysiology (Enteric Nervous System). If you have experienced your hair standing on end when frightened, you have experienced this neurophysiological response both perceiving a threat and priming to become more sensitive (a notable quality of this response is its immediacy – it unfolds much more quickly than our conscious awareness can track). This connection between our skin and our core neurophysiology is why tactile protocols often can help us to down-regulate our protective responses effectively aiding in the treatment of a post-traumatic stress response.