Originally posted by npetreley
And I'll bet you are as confident of your understanding of that gene as you were about the function of the appendix. At least this explains why you participate on boards -- your mouth is too full most of the time to talk.
Function of the appendix? I must have missed something. A very morphologically similar organ called the caecum aids in digestion in other animals like rabbits, --intestine with digestive function. Can't get any more logical than that.
Now let's look at the appendix. Does it have any digestive function? Whoops.
Does it have any demonstrated use? Not really;
like all other human intestinal tissue, it's lined with GALT cells which are used by the immune system. However, some rare individuals are born without one and no worse off, and removing it has no demonstrated ill effects.
There was a study that correlated it with increased intestinal infections,
but it remains unclear whether people without an appendix are more prone to infection or
whether people prone to infection are more likely to lose their appendix.
In other words, correlation without causation--this can be cleared up with more studies but I'm currently unaware of any.
So, the appendix is useless as a digestive organ and quite possibly useless as anything else. Yet it's an extra piece of intestine, right there, which has a proven, specific, unambiguous use in other mammals.
In other words, it's about as good an example of a vestigial organ as you can find. The Manatee's toenails, as well as snake pelvic bones and the vomeronasal organ in humans and apes, which is either present, present and broken or wired incorrectly, still beat the crap out of it, though.
