*The following in an excerpt from Katy Bowman’s book Move Your DNA: Restore Your Health Through Natural Movement

Diseases of Captivity

Have you ever been to an aquarium or sea-life theme park featuring an orca (also known as a “killer whale”)? Or maybe you’ve watched Free Willy. Either way, you might have noticed the collapsed dorsal fin of this breed when in captivity.

Marine biologists and sea-mammal veterinarians have dug deeper to find out why this Flaccid Fin Syndrome (FFS, although marine biologist Wende Alexandra Evans points out that the fin is in fact rigid, and “Folded Fin Syndrome” would be more accurate) occurs, asking what is it about captivity, specifically, that increases the chance of this happening. They have created a list of behaviors unique to captivity:

1. Orcas in captivity only swim in a counter-clockwise circle.
2. Orcas kept in shallow tanks miss out on moving through the higher static fluid pressure environment created by oceanic depths.
3. The diet of an orca in captivity is different—the food has lower water content—than in nature.
4. The amount of time an orca spends at the surface is greater when in captivity.

Marine scientists observed that fin deformities are also found in natural settings, only at a much lesser frequency and to a smaller degree. You might see a little fin curl, but not to the degree or in the direction that is found in most captive males. The ocean-dwelling whales that did have floppage also seemed to have some sort of trauma associated with the dorsal fin (as indicated by visible wounds), and some whales with the deformity demonstrated an improvement when spotted at later dates. There are no records of a captive orca’s FFS improving. There were other data points to consider:

1. A natural softening (increased wobbliness) occurs in the fin during growth spurts in pubescent orcas.
2. The males have longer dorsal fins than females.
3. The dorsal fin of an orca is made of a tissue similar to our ligaments. Mostly collagen fibers, the dorsal fin does not have any bones or contain muscle to hold itself, which makes it a passive tissue.

Putting all these data points together, scientists hypothesize that the most likely cause of FFS is the mechanical environment of captivity—in this case the missing loads to the fin that would have been created by a lot of forward swimming at depths that pushed the passive tissues of the fin into an upright position, and also the unnaturally high loads created by single-direction, tight-circle swimming, and the fin’s increased exposure to gravity (due to the fin being above the surface of the water). Whales that would be most susceptible to FFS would, then, be those whales with the tallest fins, whales that did their growing in captivity, and whales with a genetic precursor for wobbly collagen.

So now, my point. It seems like a dorsal fin, a structure necessary for stable swimming—an essential life task for a whale—should come with some sort of stabilizing mechanism (like that provided by a muscle) to prevent problems like fin floppage. But if we consider this problem from an evolutionary perspective, why would a whale, evolved to eons of swimming in a certain way, through an ocean environment, need a stabilizing mechanism if the simple act of swimming in that environment creates the necessary forces for function? A stabilizing mechanism would be unnecessary hardware for the whale, costing energy to use and maintain. The whale’s equipment is perfectly suited for swimming; it is only the captive whale’s environment that is the problem. Even for the whales with a genetically “weaker” fin, the genetics are only poor in the specific environment of captivity.

Human diseases are repeatedly explained to us in terms of their chemical or genetic makeup; meanwhile, we’ve completely ignored the load profile that the function of our body depends upon. As far-fetched as this may sound, we, like these floppy-finned orcas, are animals in captivity, and our tissues are not suited to the loads created through the way we move in our modern habitat.