The appendix does have a use - re-booting the gut

For generations medical orthodoxy has maintained that the appendix is useless, warranting attention only for its tendency to become painfully inflamed and requiring swift removal. But now the reputation of this cul-de-sac in the human gut has been rehabilitated by a theory from a team of immunologists .

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 system after the host has contracted diseases such as amoebic dysentery or cholera, which kill off helpful germs and purge the gut.

This function has been made obsolete by modern, industrialised society; populations are now so dense that people pick up essential bacteria from each other, allowing gut organisms to regrow without help from the appendix, the researchers said.

But in earlier centuries, when vast tracts of land were more sparsely populated and whole regions could be wiped out by an epidemic of cholera, the appendix provided survivors with a vital individual stockpile of suitable bacteria.

"The function of the appendix seems related to the massive amount of bacteria that populates the human digestive system," said Bill Parker, a professor of surgery and one of the scientists responsible for establishing its status as a useful organ. "The location of the appendix, just below the normal one-way flow of food and germs in the large intestine, helps support the theory."

Other studies had shown that, in less-developed countries where the appendix may still be useful, the rate of appendicitis was lower than in the US, he said.

The theory, developed by a team from Duke University Medical School, North Carolina, and published in the Journal of Theoretical Biology, has sent ripples through the scientific community. It "seems by far the most likely" explanation for the function of the appendix and "makes evolutionary sense", said Douglas Theobald, a professor of biochemistry at Brandeis University in Boston.

"I'll bet we'll eventually find the same sort of thing with the tonsils," said Gary Huffnagle, a professor of internal medicine and microbiology at the University of Michigan.

The appendix is a worm-like tube between two and four inches long protruding from the start of the large intestine. Doctors routinely remove it should it become infected and inflamed – a burst appendix can cause peritonitis, which can kill.

In the UK, one in six people will have their appendix out at some point in their lives, although appendicitis is most common between the ages of eight and 14. NHS surgeons perform about 39,000 appendectomies a year.

And other 'spare parts'

* Male nipples

Men have nipples and mammary tissue which can be stimulated to produce milk. They can also get breast cancer.

* Wisdom teeth

Early humans had an extra row of molars to help with the vast quantity of vegetation they had to chew .

* Coccyx

The remains of a tail lost long before man began to walk upright six million years ago.

* Spare ribs

Humans have 12 ribs but about eight per cent of people have an extra pair, as do chimps and gorillas.

Life and Style
ebookNow available in paperback
ebooks
ebookA delicious collection of 50 meaty main courses
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
SPONSORED FEATURES

ES Rentals

    Independent Dating
    and  

    By clicking 'Search' you
    are agreeing to our
    Terms of Use.

    iJobs Job Widget
    iJobs General

    Recruitment Genius: UX Consultant

    £35000 - £45000 per annum: Recruitment Genius: You will be working with a 8 st...

    Recruitment Genius: Part-time Editor

    £8000 - £12000 per annum: Recruitment Genius: A unique opportunity has arisen ...

    Recruitment Genius: Field Sales Executive

    Negotiable: Recruitment Genius: An exceptional opportunity has arisen for a pa...

    Recruitment Genius: Kitchen and Bathroom Installers

    £18000 - £20000 per annum: Recruitment Genius: This provider of designer kitch...

    Day In a Page

    Orthorexia nervosa: How becoming obsessed with healthy eating can lead to malnutrition

    Orthorexia nervosa

    How becoming obsessed with healthy eating can lead to malnutrition
    Lady Chatterley is not obscene, says TV director

    Lady Chatterley’s Lover

    Director Jed Mercurio on why DH Lawrence's novel 'is not an obscene story'
    Farmers in tropical forests are training ants to kill off bigger pests

    Set a pest to catch a pest

    Farmers in tropical forests are training ants to kill off bigger pests
    Mexico: A culture that celebrates darkness as an essential part of life

    The dark side of Mexico

    A culture that celebrates darkness as an essential part of life
    Being sexually assaulted was not your fault, Chrissie Hynde. Don't tell other victims it was theirs

    Being sexually assaulted was not your fault, Chrissie Hynde

    Please don't tell other victims it was theirs
    A nap a day could save your life - and here's why

    A nap a day could save your life

    A midday nap is 'associated with reduced blood pressure'
    If men are so obsessed by sex, why do they clam up when confronted with the grisly realities?

    If men are so obsessed by sex...

    ...why do they clam up when confronted with the grisly realities?
    The comedy titans of Avalon on their attempt to save BBC3

    Jon Thoday and Richard Allen-Turner

    The comedy titans of Avalon on their attempt to save BBC3
    The bathing machine is back... but with a difference

    Rolling in the deep

    The bathing machine is back but with a difference
    Part-privatised tests, new age limits, driverless cars: Tories plot motoring revolution

    Conservatives plot a motoring revolution

    Draft report reveals biggest reform to regulations since driving test introduced in 1935
    The Silk Roads that trace civilisation: Long before the West rose to power, Asian pathways were connecting peoples and places

    The Silk Roads that trace civilisation

    Long before the West rose to power, Asian pathways were connecting peoples and places
    House of Lords: Outcry as donors, fixers and MPs caught up in expenses scandal are ennobled

    The honours that shame Britain

    Outcry as donors, fixers and MPs caught up in expenses scandal are ennobled
    When it comes to street harassment, we need to talk about race

    'When it comes to street harassment, we need to talk about race'

    Why are black men living the stereotypes and why are we letting them get away with it?
    International Tap Festival: Forget Fred Astaire and Ginger Rogers - this dancing is improvised, spontaneous and rhythmic

    International Tap Festival comes to the UK

    Forget Fred Astaire and Ginger Rogers - this dancing is improvised, spontaneous and rhythmic
    War with Isis: Is Turkey's buffer zone in Syria a matter of self-defence – or just anti-Kurd?

    Turkey's buffer zone in Syria: self-defence – or just anti-Kurd?

    Ankara accused of exacerbating racial division by allowing Turkmen minority to cross the border