Although fruits such as wild bananas have seeds that can be grown to make new fruits, cultivated bananas lack them. Photo / iStock
These days, we take the way our fruits and vegetables look for granted. When we're kids, we learn that carrots are orange, bananas are yellow, and eggplants are big and purple. And that's how we always think about them. But look back into history - not even that far back - and you'll find that the fruits and vegetables we eat today were, well, they were pretty different.
Humans have been genetically manipulating fruits and vegetables for thousands of years through selective cultivation, always in search of a better taste, a more pleasing texture and a higher yield. In doing so, fruits and vegetables became a lot more colourful - and tasty.
As anyone who has tried a wild plum can tell you, wild fruits are often more tart with thick, bitter skins. The fruit and vegetable varieties we see in our grocery stores have been selectively bred over generations into nature's lollies: huge compared with their wild ancestors, sweet and easy to eat.
The eggplant, for example, was named because of its original resemblance to a small, white egg when it was first encountered by English speakers. Since then, it has grown through selective breeding into a large, fleshy, purple mass. The shape and colour changed as people bred eggplant into varieties with less bitter flesh and a larger nutritional yield packed into a single fruit.
It's not just our tastes influencing how we've cultivated fruit, however. Although wild carrots grow in a variety of colours from yellow to purple to stark white, Dutch folklore tells us that the orange carrot we know today was selectively bred in the Netherlands during the 17th century to honour William of Orange, who led the cause for Dutch independence. Historian Simon Schama writes in his book Patriots and Liberators that as time went on, patriotic moods shifted, and by the late 18th century, the Dutch patriot movement against the House of Orange saw the color orange as "the colour of sedition ... carrots sold with their roots too conspicuously showing were deemed provocative."
Politics continues to influence the choices that we make about what produce is acceptable or unacceptable, particularly as we take cultivation out of the field and into the lab.
SELECTIVE PLANTING
Genetically engineered crops have been under suspicion since the first genetically modified tomato, the "Flavr savr", hit grocery stores in 1994. But humans have been genetically modifying foods for about 12,000 years, since farming began, by selectively planting crops that were more desirable or resilient. Gregor Mendel's experiments with breeding pea plants in the mid-1860s showed how dominant and recessive traits in plants influence selective breeding, and paved the way for our modern understanding of genetics.
Today, corn is the most widely grown crop in the United States, and about 90 per cent of corn acres grown are genetically modified. The majority of US corn yield goes to livestock feed while the rest makes its way to Americans plates on the cob or in even more subtle ways such as corn syrup and cornstarch.
Genetically modified foods have been grown and eaten in larger and larger quantities since the first genetically modified foods were introduced to consumers in the 1990s, and respected scientific bodies such as the American Medical Association and the National Academies of Science have found no scientific reason to not eat them.
Still, a 2015 Pew Research Center poll found that more than half of consumers (57 per cent) consider GMOs potentially dangerous. This is in part because genetically engineered crops often rely on "monoculture" - or the growing of one specific variety of crop at once. That raises fears because monoculture's reliance on a single crop can increase the likelihood of disease.
GOING BANANAS
As it turns out, the banana is perhaps the best example of a fruit grown through monoculture. The cheery yellow Cavendish banana we see in our grocery stores was named after William Cavendish, devoted horticulturalist and sixth duke of Devonshire. The duke's gardeners were the first to grow the fruit in the extraordinary greenhouses at Chatsworth House in Derbyshire, England, in the 1830s. The banana was shipped to Samoa and the Canary Islands and brought into large-scale cultivation soon after.
Although fruits - including wild bananas - have seeds that can be grown to make new fruits, these cultivated bananas lack them. Cavendish bananas are cultivated from clones, or genetically identical plants grown asexually on the roots of a mother plant. This process results in the same predictably delicious fruit produced generation after generation.
Unfortunately, though, this also means that each successive generation is unable to keep up in the evolutionary arms race against diseases and pests.
The Cavendish banana became popular worldwide in the 1950s because of its resistance to Panama Disease, a fungus that decimated the previous popular variety, the cheekily named Gros Michel (or "Big Mike"). It certainly didn't become the dominant banana variety because of its taste, which has been called relatively bland compared with the Gros Michel.
With its thicker skin, the Cavendish was easier for growers to ship with less bruising than other varieties. Today the Cavendish variety represents 99 per cent of commercially exported bananas but its reign as king banana may come to an end. Years of monoculture has made the Cavendish susceptible to a new strain of Panama Disease. Once the disease reaches crops in Latin America, the Cavendish could be extinct in a matter of decades.