The comparative physiology of seemingly disparate organisms often serves
as a surprising pathway to biological enlightenment. How appropriate,
then, that Robert Elsner sheds new light on the remarkable physiology of
diving seals through comparison with members of our own species on
quests toward enlightenment: meditating yogis.
As Elsner reveals, survival in extreme conditions such as those faced by
seals is often not about running for cover or coming up for air, but
rather about working within the confines of an environment and
suppressing normal bodily function. Animals in this withdrawn state
display reduced resting metabolic rates and are temporarily less
dependent upon customary levels of oxygen. For diving seals--creatures
especially well-adapted to prolonged submergence in the ocean's cold
depths--such periods of rest lengthen dive endurance. But while human
divers share modest, brief adjustments of suppressed metabolism with
diving seals, it is the practiced response achieved during deep
meditation that is characterized by metabolic rates well below normal
levels, sometimes even approaching those of non-exercising diving seals.
And the comparison does not end here: hibernating animals, infants
during birth, near-drowning victims, and clams at low tide all also
display similarly reduced metabolisms.
By investigating these states--and the regulatory functions that help
maintain them--across a range of species, Elsner offers suggestive
insight into the linked biology of survival and well-being.
