Was Charles Darwin wrong? Doctors say there are no 'useless' organs

In 1893, Robert Wiedersheim added to the list of human vestigial organs published in Charles Darwin's The Descent of Man. In The Structure of Man, the German anatomist catalogued 86 'vestiges'. His was a list that led zoologist Horatio Newman to famously declare "sufficient to make of a man a veritable walking museum of antiquities."

Darwin's count had comprised wisdom teeth, body hair, the appendix, nictitating membrane (which develops as the 'third eyelid' in reptiles), coccyx (tail bone) and ear muscles. Wiedersheim went miles ahead, including several ribs, the phalanges (bones) of the fifth toe and the pituitary, thymus and pineal glands.

It took less than a century to find a majority of these essential to life.

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On May 27, a 26-year-old woman in Cameroon underwent an appendectomy. The cause: a swallowed condom, which had been sitting pretty in the organ for two weeks, causing fluid build-up and immense pain. But, surgeons noted, they've found the darnedest of things in the appendix – stones, coins, even bullets.

The beleaguered, caricatured appendage – that most famous of all 'useless' organs – got some respite in a landmark 2007 study by Dr William Parker and his team at Duke University Medical Center. The narrow pouch, they found, is a safehouse for good bacteria that can repopulate the gut post-diarrhoea and other infectious bouts.

"Whether removing the appendix has any impact on gut flora is yet to be proven. But I believe every organ is important, however vestigial," says Dr Prajesh Bhuta, consulting colorectal surgeon at Jaslok Hospital. "(Science) is yet to fully understand the function of every organ."

The same treatment was once meted out to the gall bladder and spleen, he points out. The latter has been found to store 10 times as many monocytes as the blood; monocytes are integral to heart health.

In another study, Dr William Parker had pointed to a possible link between appendix removal and increased risk of Crohn's (a type of inflammatory bowel disease).

Though such findings aren't set in stone, they raise an important question: does the ability to live without an appendix mean it's better not to have one?

"In the Indian context, increased risk of Crohn's can be due to the fact that people weren't as aware of the condition as they are today," says Dr Bhuta, when asked about an appendectomy-Crohn's disease link. "What could be Crohn's may have been misdiagnosed as appendicitis since symptoms are similar and the pain even originates in the same area (lower right abdomen). In some cases, Crohn's was also misdiagnosed as tuberculosis!"

The general population's understanding of appendicitis is still in the twilight zone. The fear of a ruptured appendix led some to consider preventative surgery – which Bhuta warns against. "Never be operated upon just on the basis of doubt. There are other misconceptions people have, such as constipation putting pressure on the appendix and eventually making it burst. While this can't be ruled out, it's still a relative myth."

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Debates rage about whether the male nipple is vestigial or not. But there seems to be more clarity about the other end of the reproductive spectrum – specifically, about the Gartner's duct.

This remnant of the embryonic stage, housed between the vagina wall and broad uterus ligament, has no known function. Fluid accumulation here can lead to cysts, says Dr Bandita Sinha, consultant gynaecologist at Fortis Hospital, Navi Mumbai.

"Gartner's duct or Bartholin cysts can also surface due to blockage or infection, in which case abscesses may form. Many women with such cysts complain of pain or swelling in the perineal region."

Surgery is recommended if complications arise. Removing the entire duct wall during the procedure is of prime importance so that cysts don't recur.

"Most vaginal conditions are traced to hygiene, which is why it's the best preventative measure," outlines Dr Sinha. "But I've had women come to me saying they use Dettol to clean themselves. That's the worst possible thing you can do to your vagina."

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No vestigial body part is as despised as the wisdom tooth. Its emergence is akin to a bulldozer in the mouth, its point of existence seemingly limited to testing thresholds of pain and discomfort.

There's no question that these teeth are best disposed of in the event of misalignment, corrosion and infections. Once crucial to early man for the breakdown of food, evolution rendered wisdom teeth useless when human diets changed and jaws got smaller over time.

But Bandra-based dental surgeon Dr Rajesh Shetty doesn't view the wisdom tooth in stark light. "Sixty per cent of our chewing load is borne by the first molar; the rest, by the posterior teeth. If one or more of these are lost, the wisdom tooth serves a purpose in filling this gap," he says.

"Wisdom teeth are now being used in stem cell research, with even a possibility of being transformed into corneal cells. You never know when they could be viewed in a different light in the future."

Just as it was with the appendix.