This story illustrates the power of standing back from the mechanistic details of an animal (chemistry, physiology, cellular anatomy) to see the whole animal and understand how it relates to the surrounding world. Animal responses reflect their life force, which is called vitality. Vitality is something we all sense and know, have difficulty measuring, and cannot capture and put into a bottle for study or consumption. Vitality is not a substance that can be reduced to a mechanistic explanation. It is a feeling of well-being and responsiveness that is diminished when we are stressed or sick. Stress is something that we are all concerned with because it is associated with disease and mortality. Stress effects can be measured by internal changes in blood or brain chemistry, heart rate, or metabolism. But these changes are not directly seen and responded to by other animals, which can be food or threats to survival. Eventually we all die when our vitality is gone.
Perhaps vitality can be measured using whole-animal responses. These responses are called behavior. When animals are stressed or sick, they respond with impaired behavior. Voluntary behavior is adaptive and changes in response to internal motivation and state (fear, hunger, avoidance, attraction, stress, disease) and to external factors (light, temperature, hypoxia, food, threat). Because voluntary behavior responds simultaneously to so many types of factors, some of which are not associated with stress, it is not expected to predict disease or mortality. Involuntary behaviors are reflex actions (orientation, gag, startle) and these are fixed. They either respond or not to a stimulus and this response is modified by the level of vitality that an animal has. Reflex actions can be used to measure and predict stress, disease, and eventual mortality. Anyone can measure reflex actions and these measurements are a simple and cheap way to understand vitality and our impact on other animals.
In my life as a scientist, I studied fish stress and mortality. There are many ways to research this subject. They involve developing hypotheses about the effects of stressors. Examples of stressors are temperature, hypoxia, and wounding from capture. Then experiments are designed to test for these effects by exposing fish to stressors and measuring resulting changes in markers for stress. If you want to understand how these changes affect fish disease and mortality, then fish must be held for days after stress induction to monitor their condition. These results are then used to test the original hypotheses and try to understand and predict future stress and mortality in fish.
Through the course of this research, it became clear that there was not a 1:1 correspondence between stressors and their effects. We could not reliably predict disease and mortality by measuring physiology or volitional behavior. One day after many experiments, I was standing beside a tank of fish that had been stressed from exposure to higher temperature, similar to their exposure after capture in cold water and being brought to the surface in warm water. I noticed that the fish were lethargic, disoriented, and did not have a startle response. Later I wanted to measure body core temperature of fish exposed to warm water. I didn’t have any fancy instruments so I simply inserted a thermometer through the mouth and throat, into the gut. When I did this for fish that were not stressed, they quickly responded by gagging and I noted that this method would not be a good one to use. I also wondered how a fish that had been exposed to warm water would react. I placed a thermometer in the throat of a fish stressed by warm water and discovered two things. First, they had warmed and second, they did not gag in response to the thermometer.
The observations of diminished reflex actions; lack of orientation, startle response, and gag response seemed important for understanding stress and mortality. Suddenly I had a compelling thought and hypothesis. Could it be that involuntary reflex responses had a 1:1 correspondence with stress and mortality in fish? The short answer is yes, stress and mortality can be predicted by measuring reflex impairment. There are many reasons that this is true and you can read the research paper for those details.
By looking at the whole animal instead of it’s internal details, “seeing the forest for the trees”, I was able to see vitality. Sometimes the details of a subject obscure the understanding of that subject. It is refreshing to stand back and take in the view, the big picture. This is the power of wildness. When we experience nature, we directly see the nature of ourselves, others, and surrounding space without the bias of thought and interpretation. We have an involuntary response (reflex) to nature that supports our vitality and well-being.
Posted by michael
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