So why do you think we have an appendix?

October 8, 2007 6:48 AM

Theories about the appendix abound. (scroll down) But a new one is outlined in an interesting article in today’s Independent (UK) referencing the work of Duke Medical School researchers in the Journal of Theoretical Biology.

A more cynical view might be
"Its major importance would appear to be financial support of the surgical profession." Alfred Sherwood Romer and Thomas S. Parsons
The Vertebrate Body (1986), p. 389.
“The US scientists found that the appendix acted as a “good safe house” for bacteria essential for healthy digestion, in effect re-booting the digestive tract after the host has contracted diseases such as amoebic dysentery, or cholera….”

See also some discussions about other “spare parts”. Male nipples, wisdom teeth, coccyx (warning: Creationist view!), and spare ribs.

posted by Wilder (37 comments total)

Someday, the poor, starving people of the world will have bacteria injected into their appendices to enable them to digest cellulose. You heard it here first.
posted by Citizen Premier at 7:01 AM on October 8, 2007 [3 favorites]

Interesting.

My roommate was trying to discuss this with me a couple days ago, but I couldn't stop giggling when he said "amoebic dysentery," because it reminded me of Oregon Trail.
posted by dismas at 7:02 AM on October 8, 2007

Someday, the poor, starving people of the world will have bacteria injected into their appendices to enable them to digest cellulose. You heard it here first.

Well, the problem isn't a lack of food, it's inefficient delivery methods. And uh, Isn't the human gut to short to effectively process cellulose? Of course, these might be super bacteria, I suppose.
posted by delmoi at 7:10 AM on October 8, 2007

Famous cases of appendicitis: Houdini, Sergeant Floyd (the only fatality on the Lewis and Clark expedition), Madeline (the doll has Madeline's appendix scar embroidered on.)
posted by StickyCarpet at 7:13 AM on October 8, 2007

Someday, the poor, starving people of the world will have bacteria injected into their appendices to enable them to digest cellulose.

Let them eat grass.
posted by grouse at 7:16 AM on October 8, 2007

Someday, the poor, starving people of the world will have bacteria injected into their appendices to enable them to digest cellulose.

For some reason, I read that as "cellulite." I wondered how on earth we'd make a market out of poor starving people processing our chubby thighs for us.
posted by generichuman at 7:20 AM on October 8, 2007

Ask the Soylent corporation.
posted by dismas at 7:30 AM on October 8, 2007

Someday, the poor, starving people of the world will have bacteria injected into their appendices to enable them to digest cellulose.

This will instantly be followed by the appearance of packaged, brand-name, $18.99/lb cellulose, ensuring that the poor folks in question either won't be able to afford it, or will turn their nose up at the readily-available kind they can afford, and take out a payday loan to buy some status-elevating, blinged-out, you know, wood chips.
posted by Wolfdog at 7:38 AM on October 8, 2007

My son, when he was young, came up with the theory of why boys have nipples: so they can tell how deep out into the lake they can go (since we told him he could only go out as far as that at the time).
posted by wfitzgerald at 7:38 AM on October 8, 2007 [2 favorites]

Where else could we put our data tables?
posted by goatdog at 7:51 AM on October 8, 2007 [2 favorites]

Well, whatever it is, I don't miss it much.
posted by T.D. Strange at 8:00 AM on October 8, 2007

Hold the phone. Men can lactate? This is up there with that video of a Russian dude with a tail from last week.
posted by sy at 8:20 AM on October 8, 2007

As a mild-to-moderate hypochondriac, I have to say that my appendix freaks me out. It's like walking around with a bomb in my gut that could, at any moment, blow up and kill me.
posted by Rangeboy at 8:29 AM on October 8, 2007

I think the biggest argument against the appendix being vestigial is that so many people die from appendicitis. I'm sure evolution would quickly make a useless organ harmless.
posted by bhnyc at 8:31 AM on October 8, 2007

The appendix is hypogastric, not hypochondriac.
posted by betaray at 8:43 AM on October 8, 2007

It is long established in anthropological circles that the human appendix is activate in cannibals. The appendix is the only part of the digestive tract that can absorb the nutritious fleshamins found in choicer cuts of people. Recent studies of zombies have found engorged appendicies as well, suggesting that the cerebellum may also be rich source of fleshamin.
posted by Pastabagel at 8:48 AM on October 8, 2007 [2 favorites]

I should be murdered for all the atrocious typos I made in that short comment. "is activate"? Really? Kill me.
posted by Pastabagel at 8:50 AM on October 8, 2007

Does anyone have a link to the article that works?
posted by agregoli at 9:42 AM on October 8, 2007

Nevermind, it mysteriously worked on the second click.
posted by agregoli at 9:43 AM on October 8, 2007

bhnyc - I think the biggest argument against the appendix being vestigial is that so many people die from appendicitis. I'm sure evolution would quickly make a useless organ harmless.

See also: non sequitur
posted by kcds at 10:11 AM on October 8, 2007 [3 favorites]

I'm sure evolution would quickly make a useless organ harmless.

Nope.
posted by grouse at 10:19 AM on October 8, 2007 [2 favorites]

grouse, yes how could i have missed that point!

kcds- brilliant!

i'm willing to defend/expand my idea if someone counters. basically i'm saying evolution = survival of fittest, so if something is dangerous AND we don't need it then evolution is quickly going to select a non-dangerous adaptation. if we need it, then the risk may be worth it.
posted by bhnyc at 10:52 AM on October 8, 2007

There's nothing even vaguely "quick" about evolution (unless you believe Stephen Jay Gould, but even then such quickness only happens after loooooong psuedo-stagnant periods).

I always felt that the surest proof that God hates us is the appendix- what kind of loving creator would create us with an organ that serves no purpose other than to occasionally get massively infected and cause us to die in excruciating agony?
posted by Pope Guilty at 11:07 AM on October 8, 2007 [1 favorite]

i think in the context it was obvious, but i meant quick by evolutionary terms- like thousands of years instead of millions. and by "need it" i meant "need it" any time in the past few thousand years.
posted by bhnyc at 11:24 AM on October 8, 2007

Pastabagel. Just another difference between Homo Romerus and the rest of us.
posted by Gungho at 11:31 AM on October 8, 2007

Maladaptive traits do not necessarily get bred out of a population. Especially if the trait in question is only minimally lethal, and doesn't reliably kill people prior to their having reproduced.
posted by aramaic at 11:31 AM on October 8, 2007 [1 favorite]

grouse, yes how could i have missed that point!

Hmmm, I'm guessing because you are making things up based on misunderstandings of what evolution is. It's not "survival of the fittest," which is a poor way of describing natural selection, which itself is just one aspect of evolution. The other aspects of evolution can and do preserve deleterious traits, even over millions of years.
posted by grouse at 11:50 AM on October 8, 2007

grouse- which aspect of evolution preserves deleterious traits?
posted by bhnyc at 11:59 AM on October 8, 2007

Well, genetic drift and linkage for starters. Also the fact that development is extremely complicated and it's unlikely that you could genetically eliminate the appendix without affecting anything else.
posted by grouse at 12:11 PM on October 8, 2007

I should add that if you want to learn more about evolution, Berkeley has a fantastic resource on it.
posted by grouse at 12:15 PM on October 8, 2007

Shorthand for discussing evolution: Things will happen when the benefits outweigh the costs. (Where benefit means increasing the chance of producing viable offspring).

Many times people are mystified with biological curiosities because the cost or the benefit are non obvious. This article could mean that the benefit has finally been found. Now they just have to test their predictions.

A completely speculative example: Maybe a mutation that would create an appendix-less person will also make that person's intestine shorter or malformed, resulting in a malnourished kid that will either die before reproducing, or grow to be a skinny wimp that never gets tail.
posted by Dr. Curare at 12:52 PM on October 8, 2007 [2 favorites]

Besides, acute appendicitis is rather uncommon. Hardly the selective pressure necessary to stimulate its disappearance.
posted by randomstriker at 1:53 PM on October 8, 2007

Appendix (n): A part of a book that nobody has discovered the purpose of yet.
posted by UbuRoivas at 2:27 PM on October 8, 2007

I had mine out on Christmas day when I was 12 years old. I still remember the pain. Sheesh.
posted by vronsky at 4:50 PM on October 8, 2007

basically i'm saying evolution = survival of fittest, so if something is dangerous AND we don't need it then evolution is quickly going to select a non-dangerous adaptation. if we need it, then the risk may be worth it.

Please, stop doing this. See what aramaic said a little later. The mechanism of evolution is very, very simple. As a result, it can be described as both "really clever" or "really stupid," though neither is actually true. Here's the only thing you need to know about evolution:

Offspring differ slightly from parents.
Parents that successfully reproduce cause their genetic information to survive one more generation.

AND THAT'S ALL THERE IS!
posted by odinsdream at 6:18 PM on October 8, 2007

Redundancy: Redundancy!
posted by Smedleyman at 7:41 PM on October 8, 2007

Offspring differ slightly from parents.
Parents that successfully reproduce cause their genetic information to survive one more generation.

And the first point shows why the appendix could continue to persist even if it provides no benefit (and is thus a net negative, since it sometimes causes harm). The mutations upon which natural selection operates are essentially random (of course, natural selection itself is far from random). If no people happen to be born without an appendix, or with a smaller appendix, then natural selection can't select for that trait. Evolution doesn't somehow make useful traits more likely to arise.
posted by klausness at 1:59 PM on October 9, 2007