The body's appendix has long been thought of as nothing more than a worthless evolutionary artifact, good for nothing save a potentially lethal case of inflammation.
Now researchers suggest the appendix is a lot more than a useless remnant. Not only was it recently proposed to actually possess a critical function, but scientists now find it appears in nature a lot more often than before thought. And it's possible some of this organ's ancient uses could be recruited by physicians to help the human body fight disease more effectively.
"Maybe it's time to correct the textbooks," said researcher William Parker, an immunologist at Duke University Medical Center in Durham, N.C. "Many biology texts today still refer to the appendix as a 'vestigial organ.'"
The vermiform appendix is a slimy dead-end sac that hangs between the small and large intestines. No less than Charles Darwin first suggested that the appendix was a vestigial organ from an ancestor that ate leaves, theorizing that it was the evolutionary remains of a larger structure, called a cecum, which once was used by now-extinct predecessors for digesting food.
However, Parker and his colleagues recently suggested that the appendix still served as a vital safehouse where good bacteria could lie in wait until they were needed to repopulate the gut after a nasty case of diarrhea. Past studies had also found the appendix can help make, direct and train white blood cells.
Now, in the first investigation of the appendix over the ages, Parker explained they discovered that it has been around much longer than anyone had suspected, hinting that it plays a critical function.
Several living species, including several lemurs, certain rodents and the scaly-tailed flying squirrel, still have an appendix attached to a large cecum, which is used in digestion. Darwin had thought appendices appeared in only a small handful of animals.
"We're not saying that Darwin's idea of evolution is wrong — that would be absurd, as we're using his ideas on evolution to do this work," Parker told LiveScience. "It's just that Darwin simply didn't have the information we have now."
He added, "If Darwin had been aware of the species that have an appendix attached to a large cecum, and if he had known about the widespread nature of the appendix, he probably would not have thought of the appendix as a vestige of evolution."
[TBC: It has long been pointed out that the “vestigial organ” list is constantly being pared down as more researchers discover that evolutionary assumptions are simply false. See also: http://www.answersingenesis.org/tj/v3/i1/appendix.asp.]