I could add perhaps another dozen or so argumentative points to support
the idea that ferrets adhere to the same physiological rules regarding
dietary restriction, but to the open minded person, the point has been
made.  Occam's razor, the rule of parsimony, works here as well: is it
simpler for ferrets to have the same physiology as all the other animals,
or have they somehow changed, becoming unique among the animal kingdom?
 
As an evolutionist, I have to find some type of historic explanation
for the observed phenomenon- -the life-extending benefits of dietary
restriction.  It has to make some sort of evolutionary sense, or I cannot
easily accept it.  So I ask myself, "Why would it make sense for animals
that are living in a food-restricted environment to live longer?" The
answer lies in one of the major effects of DR, one I have yet to mention.
In every animal species studied, restrict access to food by 30-40%, and
tumor incidence is greatly diminished, disease is minimized, autoimmunity
is reduced, lifespan is extended, and reproduction is greatly diminished.
Now, the phenomenon makes perfect evolutionary sense: when food is
scarce, the primary need is not reproduction, but survival.
 
After all, if food were scarce, reproduction would be a waste of energy
and resources anyway.  Suppose a ferret requires 100 units of food per
day too survive and successfully reproduce.  A pregnant jill might have
an additional food requirement of 30-50 units, bringing the total daily
requirement to 130 units, minimally.  The presence of kits might increase
that requirement by 10-15 units apiece, so a litter of six would raise
the daily requirement to 190 units, minimally.  So, what happens if the
environment, for whatever reason, only supplies 70 units of food per day?
All the kits would starve (in the real world, the mother would eat or
abandon them).  A pregnant jill would starve to death.  The only animals
that would survive would be those that shut down reproduction, and
somehow shifted their core physiology to one that would allow survival
until conditions got better.
 
While the mechanisms of dietary restriction are still being investigated
and tested, the observable effects are clear-cut.  They are universal
among mammals, suggesting it is a very important adaptation, made for
very important reasons.  It shuts down reproduction, suggesting the
reason is one that promotes basic survival.  It extends life by reducing
or delaying end-of-life diseases (cancers, organ deterioration, etc.),
suggesting the goal is to survive bad conditions, so that reproduction
can take place when things get better.  It is a simple answer that makes
evolutionary sense.
 
If true, then you would expect the positive effects of dietary
restriction to be more pronounced in small animals with short life spans,
those most sensitive to short-term environmental conditions.  That is, in
fact, what has been discovered.  The positive effects of DR were first
noticed in rats and other rodents, exactly the types of animals where the
effects would be most pronounced.  It also explains the universal nature
of the phenomenon in animals; it probably was an early evolutionary
adaptation conserved through time.  As small-bodied, short lived mammals
extremely sensitive to food fluctuations, it is EXTREMELY unlikely
ferrets would be exempt from the positive effects of dietary restriction.
 
In the next series of posts (the Ad Libitum E series), I will discuss
specific ferret illnesses and how the current kibble diet impacts them,
either triggering, exacerbating, or actually causing them.  Obviously,
little or no research has been done in ferrets in these areas, so I will
have few direct studies that can be cited and will have to use other
species as examples.  I urge people to READ the words I say, rather than
react to them.  For example, if I show dietary restriction impacts the
pancreas and cite how heavy carbohydrates cause pancreatic pathologies in
other animals, I am NOT trying to imply identical changes would be seen
in ferrets.  ALL I will be showing is that the potential exists, that it
can impact the organ system, and any differences are probably due to the
ferret's unique evolutionary history.  Also, try to read the entire
sentence.  If I say "only a single series of experiments was performed"
or, "neither study has been independently verified by other researchers,"
be careful with your response, or I could make you look rather insipid.
"Independently verified" means other scientists NOT associated with the
first study has independently run the same experiment to test the
observed results.  "A single series of experiments" doesn't mean a
single experiment, but a SERIES of related experiments.  It means that a
different type of experiment investigating the question from a different
perspective that results in the same answer has not been done.  I'm not
trying to intimidate anyone here, but if you want a positive response
from me, don't make an obtuse, aggressive series of remarks.  LOL.  My
resulting response could be mistaken as intimidating.  LOL.  Even if the
remarks were untrue and not misunderstood, the objection did NOT change
the basic point that the positive effects of dietary restriction have
been independently verified numerous times in dozens of species, by
researchers throughout the world looking at the question from varied
disciplines and viewpoints.  The ignored point was that if these limited
studies (ECE, Rabies) should be accepted, why not consider the HUNDREDS
of studies that have confirmed the effects of dietary restriction as
having some validity.  The trouble with nitpicking is that so much effort
is spent looking for nits that the point is missed.  The point was never
the nit, but the leopard lurking in the tree.  LOL.
 
Bob C
[Posted in FML issue 3963]