Re: intelligent design and rabbit poo

On May 23, 9:51 pm, r norman <r_s_norman@xxxxxxxxxxxx> wrote:
On Wed, 23 May 2007 18:49:48 -0600, Desertphile

<desertph...@xxxxxxxxxx> wrote:
From "Flock of Dodos"
http://www.youtube.com/watch?v=ba_932EhxoY

Rabbits, rabbit poop, and unintelligent design.

Coprophagy (the polite term for ***-eating) is a quite normal
phenomenon in many animals. We humans are the weird ones in thinking
there is something "wrong" in it. And I happen to think it is an
exceptionally clever trick of evolution -- intelligent adaptation, if
you will. The fact is that animals can't digest cellulose so many
animals have internal bacteria to do it for them. Ruminants like
cows have special fermentation chambers early enough in their
digestive system so they can cough up the bacteria processed stuff
(and the bacteria, themselves), chew it again (the cud) and then run
it through the digestive system to take advantage of the yummy result.
Most other mammals can't do that; they do the bacterial fermentation
in their caecum which is at the junction between the small and large
intestine. So the bacterial product is produced too far back for them
to be able to digest. That is why they run the stuff through twice.
The first time they produce soft, moist material fresh from the caecum
and filled with nutrients. The second time they produce the hard dry
pellets that are more familiar as rabbit or rodent droppings. That is
really an exceptionally efficient and practical way of doing things,
an excellent example of really clever "design" and one I used to use
frequently in teaching.

There was a really neat senior thesis project done at my alma mater on
this. Rabbits were equipped with those satellite collars- the ones you
put on dogs to prevent them from biting surgical incisions and such.
They were fed high-quality rabbit chow in unlimited amounts. The ones
with the collars invariably lost weight over the course of the
experiment. They were simply incapable of absorbing enough nutrients
with a single pass through the gut, even if the food was of higher
quality than typical forage. The ones without collars got nice and
plump and went on to fullfill their destinies at the annual end of
year banquet :)

If you ever read "Watership Down", the rabbits refer to this on a
number of occasions. They talk about "chewing pellets" as a social
activity. They also distinguished between "night pellets" and "day
pellets"- do wild rabbits eliminate the twice-through material at a
particular time?

Chris

.