WonderQuest with April Holladay, Article printer-friendly version

HMS Bounty's cargo before the mutiny; Human bloodhounds

Q: What was the Bounty (Lieutenant Bligh's and Fletcher Christian's doomed ship) carrying and to where? Goop, Pleasanton, New York, USA

The mutineers setting Lt. Bligh (in white) and his men adrift. Drawing courtesy of artist & engraver Robert Dodd (1790) and Wikipedia.

A: The ill-fated ship carried breadfruit trees, gathered in Tahiti, bound for the West Indies. However, the 1,015 plants, stored in the captain's great cabin, never made it. When the crew mutinied, they took the ship eventually to the Pitcairn Islands, where they burned her.

But all was not lost. Captain Bligh (promoted in the intervening years) captained yet another ship to get breadfruit trees. The new crew collected 2,126 Tahitian trees, and delivered them to the West Indies, where they flourished. The idea was to establish this most bountiful tree (up to 200 fruits yearly from a tree) where its fruit would feed West Indian slaves nutritiously and cheaply.

Breadfruit tree and fruit. The grapefruit-sized cooked fruit tastes somewhat like potatoes or freshly baked bread. Top image courtesy of Kowloonese and Wikipedia; the drawing is from Bligh's 1792 account, A Voyage to the South Sea.

The plant itself is a "puzzle," writes Nyree J.C. Zerega in Natural History. Many plants are sterile, seedless and only reproduce by the method Bligh used — taking cuttings and transporting them to a new location. In fact, that's exactly how Polynesian sailors spread the productive plant throughout myriad Pacific islands. But, where did the ancestral, fertile plant grow originally? Tracking the domestication and spread of the breadfruit would help determine Pacific peoples' origin and migratory routes. We have a couple of theories but, as yet, don't know.

Q: Compared with animals, how good a sense of smell do people have? Is there any difference between men and women? George, Sarnia, Ontario, Canada

A crawling person (left) following a chocolate scent, and zigzagging in a manner similar to a dog (right) tracking a pheasant at night. Photos courtesy of Jessica Porter and the University of California at Berkeley.

A: We have a better sense of smell than we might think, but not as good as, say, a dog or a rodent. Many of us can follow a trail of chocolate oil.

A group of 32 men and women got down on their hands and knees, sniffed the chocolate odor like a bloodhound and tracked it over a ten-meter (30 ft.) course that took a 45-degree bend. See figure. Given three chances, twenty one (66 %) managed to stay on the trail to the end in a recent study headed by biophysicist Jessica Porter and neuroscientist Noam Sobel at the University of California at Berkeley. Blindfolded, ear-plugged and wearing heavy gloves, the human hounds relied on their sense of smell alone.

"Some got it [followed the trail to the end] the first time, some the second, some the third. If they didn't get it by the third, we counted them in the 'couldn't do it' category," says Porter.

Moreover, they used both nostrils to tell which way the scent was stronger, somewhat as we use both ears to determine which ear hears the sound first, and therefore, the direction it comes from.

Women seem to have a better sense of smell than men, but "women are not necessarily born with a better olfactory sense; it's that they pay more attention to smells," says neurologist Jay Gottfried, professor at Northwestern University in Chicago. As Porter's group found out, humans can train themselves to improve their sense of smell.

Smell trivia:

People can detect a single drop of a chemical (androstenedione, found in human sweat) in an Olympic-sized swimming pool filled with water. [Noam Sobel]
Children can identify their siblings from other kids the same age, by smell alone. [Tim Jacob]
Babies can recognize their mother's scent, and mothers can distinguish their babies' scent. [Jacob]
A panel of women sniffed underarm swabs, and could tell the difference between smells of people who had watched 'sad' or 'happy' movies. Men could not distinguish between the two types of smells so well. [Jacob]

The Question of the Month (published on the first Tuesday of the month), readers contribute answers:

Most definitely women! We smell smoke and flowers quicker than men do.

Ruth, Orlando, Florida, USA
I think men and women both have the same sense of smell.

Hanna, Palatine, Illinois, USA
Why would men and women have a different sense of smell? We have a nose simply to smell. There's no difference.

Sheila Damogo, Manila, Philippines