Secrets in Aisle 3: See how our fruits and vegetables once looked
Peaches were once green; carrots, slender and yellow. Where are we headed next? Well, bananas with a vaccine punch, and cabbages with a sting, are on the cards.
The ghosts of who our fruits and vegetables once were still hover in our midst… in the carvings on Egyptian tombs, in Ancient Roman frescoes, and in art works dating to centuries ago.
Here, peaches are green; carrots are small, slim and yellow; and the watermelon has white flesh.
Over thousands of years, humans have hybridised plants to make them easier to digest, more nutritious, higher in sugars and carbs, or simply better-tasting.
Some would become so integral, they would travel the world. Key among these was the apple. It was eaten so widely, on trade routes criss-crossing Central Asia (where it has its roots), its core then tossed to the side to take root where it could, that the genetic material of the average apple today is an undecipherable mishmash, says Robert Spengler, director of paleoethnobotany at the Max Planck Institute for the Science of Human History, and author of Fruit from the Sands: The Silk Road Origins of the Foods We Eat (2019).
The result: One may plant an apple core and never know what variety the resultant tree will yield. The fruit itself, meanwhile, started out so small that as many as five might have fit in one hand.
Today, it is far easier to bioengineer food. We don’t have to wait as long or be as uncertain of the result. But this too has a flip side: the loss of genetic diversity.
“Putting all our eggs, peaches or rice in one basket is not a risk we should be taking,” says Gary Crawford, a retired professor of anthropology at the University of Toronto, Mississauga who has been studying the origins of agricultural plants for over 25 years.
As the global economy focuses on financially profitable crops at the expense of resilience and, often, nutrition, it is crucial to appreciate the thousands of years of careful cultivation that went into developing the produce we have today. These are achievements that cannot be replicated overnight, as Crawford puts it.
Meanwhile, the changes we make today will continue to unfold for millennia, and could affect how vegetables and fruit look in the future, adds Spengler.
Click here for more on our most dramatic efforts in that direction. But first, here’s a look at how our most common fruits and vegetables got to where they are today.
.
Core value, trade roots: The apple
In myth, of course, the apple goes all the way back to the start.
In reality, it’s hard to tell when it first evolved, because the last Ice Age, which ended about 11,700 years ago, more or less wiped it out across much of the planet (along with a lot of flora and most megafauna).
Among the species that remained was a small wild apple called the Malus sieversii, which grew in Central Asia (and still grows in the cool mountains of Kazakhstan). These fruits the size of chicken eggs had red-and-yellow cheeks, and a flavour that was a mix of sweet and tart.
They were designed to entice large herbivores and omnivores to swallow them and spread the seeds.
Among the omnivores that took to the juicy, nutritious fruit were humans. There is evidence of apple orchards being tended as far back as 3,000 BCE.
By about the 2nd century BCE, the apple got an unexpected boost from an unlikely source. As the Silk Route took shape, this fruit became a quick and convenient source of nutrition. Humans ate it; horses ate it. More importantly, they travelled with it.
As they tossed the cores onto the plains along their route, and as their horses ate some of those cores and excreted the seeds, the apple began to crop up in new territories.
Even today, the largest, sweetest and reddest apples in Europe share genetic material with parent species from Central Asia, says Robert Spengler, director of paleoethnobotany at the Max Planck Institute for the Science of Human History and author of Fruit from the Sands: The Silk Road Origins of the Foods We Eat (2019).
In a strange twist, the original Malus sieversii in Kazakhstan is now on the International Union for Conservation of Nature’s (IUCN’s) Red List of Threatened Species. Orchards growing its domesticated descendant, Malus domestica, are invading what is left of its territory. Isn’t that an odd case of an apple falling far from the tree.
.
Hue’s hue?: The carrot
Genetic research has traced the carrot’s lineage as far back as the Cretaceous-Paleogene boundary, about 66 million years ago. Its long history has made it a hardy plant that thrives in a range of soil types and climates.
There have been many, many kinds of carrots over the millennia. The most common wild carrot in Europe was white. The earliest cultivated versions in Central Asia were purple or yellow. Records show that the latter two varieties were being traded in Europe by the 12th century.
“Of the two, the yellow carrots were more popular, likely due to their taste,” Massimo Iorizzo, associate director of North Carolina State University’s Plants for Human Health Institute, said in a statement in 2023, following the publication of a study on why carrots are orange.
The orange, it turns out, is a result of the cross-breeding of the yellow and white varieties, which created a supremely healthy snack. At some point, the genetic variations caused carotenoids to accumulate in such high concentrations that they turned the whole root a vivid orange.
The orange carrot appeared in Europe in the 15th century and was instantly popular because of its bright hue, large size and sweeter flavour profile. It was soon being packed and hauled onto ships headed for the remotest shores, as a durable source of vital nutrition.
Not long after Christopher Columbus’s crossings of the Atlantic in the late-1400s, orange carrots began to be planted around the world.
.
Time for a pit stop: Peaches
Peaches are an auspicious gift in China, symbolising prosperity, in what could very well be an ancient tradition. There is evidence of peach orchards here as far back as 7,500 years ago.
The fruit from these orchards would have been smaller, more acidic, less fleshy and a greenish colour. “Nevertheless, I suspect the peaches were tasty, which encouraged people to work with them to increase their production and predictable fruiting,” says Gary Crawford, an anthropological archaeologist and retired professor of anthropology at the University of Toronto, Mississauga, who has been studying the origins of agricultural plants for over 25 years.
Over the millennia, the fruit spread to Japan, India and the Roman Empire. It pops up in 2,000-year-old Roman frescoes, recognisable by its distinct shape, but still green.
As farmers began cross-breeding peaches, they became fleshier and sweeter, and acquired their distinct shade of orangey pink. “Strains have also been selected for their diverse ripening periods, making peaches available through more months in the year,” Crawford says. “As they were bred for these various desirable traits, the fruit’s diversification proved beneficial for its survival too, allowing peach populations to expand while remaining genetically diverse.”
.
Back to the rind: Watermelon
When Mark Twain described the watermelon as “chief of the world’s luxuries” in his 1894 novel Pudd’nhead Wilson, he was only exaggerating slightly.
This fruit needs so much water and sunlight to grow that, even in Ancient Egypt, it was a prized commodity. We know this because watermelons were carved into depictions of feasts on temple and tomb walls dating as far back as 4,300 years ago.
This wasn’t, however, the watermelon we know now. It was an oblong fruit that had already been somewhat domesticated. But from what parent species? Until recently, this remained unclear.
Scientists had traced the fruit to a group of possible wild ancestors in Africa, but there had been errors in classification before. So who was its closest relative?
Then, finally, they got a break. “The oldest known watermelon seeds, dating to 6,000 years ago, were found in Libya in the 1990s,” says Guillaume Chomicki, a professor in evolutionary biology at Durham University, England.
By 2021, using that genetic material, Chomicki had finally traced today’s fruit to the mildly flavoured, white-fleshed Kordofan melon (his findings were published in Proceedings of the National Academies of Sciences that year).
Incidentally, most members of the watermelon genus are bitter. The bitterness was tempered in the Kordofan melon by a genetic mutation. The mutated variants were the ones likely picked for selective breeding early on to make the flesh sweeter and red.
As a result of all that selective breeding, however, this fruit has lost much of its genetic diversity, and is therefore less climate-resilient and less resistant to disease. Researchers have lately been identifying ways to address this, using genetic material from strains that still grow in the wild. “Reintroducing these genes could reintroduce much-needed traits such as drought tolerance that were once present in the Kordofan melon,” Chomicki says.
.
A leaf history of time: Cabbages
Everyone knows how greatly the different kinds of cabbage differ in appearance…” Charles Darwin wrote in his 1868 book, The Variation of Animals and Plants Under Domestication.
He was referring not to cabbage as we define it but to a range of wild-mustard descendants that include cabbages, cauliflower, broccoli, kale, collard greens and kohlrabi. They look nothing like each other, yet they all trace their roots to a single species of wild mustard: Brassica oleracea.
“The diversity is fascinating. With tomatoes, there are big ones and small ones, but you always eat the fruit. With cabbages, you can eat the leaves (kale, head cabbage), the stalks (kohlrabi), the axillary buds (Brussels sprouts) or the flowers (cauliflower, broccoli),” Guusje Bonnema, a plant-breeding researcher at Wageningen University in the Netherlands, said in a statement following fresh research into its lineage, published in 2022.
Bonnema has been researching cabbages for over 20 years.
About 3,000 years ago, it is likely that none of these existed. There was just Brassica oleracea, growing along the rocky Mediterranean coast. It was humans that domesticated and selectively bred it, over and over, with each effort focused on a different part of the plant.
Early farmers focused on big, tender, less-bitter leaves. By the 1st century CE, cabbages had emerged, after farmers selectively bred Brassica oleracea for larger buds. Broccoli was selectively bred for its large florets, and kohlrabi for its enlarged stem.
“It was kind of a genetic bottleneck the species passed through,” as Bonnema put it. “All varieties of cauliflowers are very similar; there is very little genetic variation.”
.
Peeling back the layers: Bananas
Just 7,000 years ago, bananas were more or less inedible to humans. They were so fibrous that we couldn’t digest them, and were pitted with hundreds of large black seeds.
We know this because such bananas still grow in the wild, in regions such as the Pacific islands of Papua New Guinea; in Assam, Nagaland and Meghalaya in India; and in north-eastern Queensland in Australia.
Bananas were likely one of the earliest experiments in cross-breeding and selective breeding, researchers say, because this plant was already central to ancient cultures in the regions where it grew. “The fibres were used to make rope and cloth. The corm or underground stem and the male flowers could be eaten,” says Julie Sardos, a genetic resources scientist at Rome’s Alliance of Bioversity International and International Centre for Tropical Agriculture (CIAT).
Sardos has been studying the complicated history of the banana for almost a decade, leading scientific missions to the Pacific islands. “As humans homed in on seedless mutant varieties and bred them selectively, these first domesticates were hybridised further as they mixed with local wild bananas, making the cultivated bananas genetically more and more complex,” she says.
When Sardos used genetic markers to trace bananas to their wild ancestors, a new mystery emerged: that of a missing relative. “The DNA of today’s banana can be traced to ten wild species, of which one has still not been identified,” she says. It’s intriguing to think that this common fruit might still have a missing relative out there.
.
Ears and ears of evolution: Maize
Modern maize, a key player in global food security, has its roots in a bushy wild grass called Teosinte parviglumis. Native to Mexico, it started out being largely inedible to humans, with a hard outer case and tough seeds.
First domesticated 9,000 years ago, it was then crossbred with the species Teosinte Mexicana about 4,000 years ago, to yield the forerunner to modern maize. By this point, the hard outer case was gone, and each medium-sized cob held at least a few rows of starchy kernels.
Because of its vast influence on today’s corn, Teosinte Mexicana is often called the “Neanderthal of maize”. The cross-breeding made it a hardy plant, able to survive in cooler temperatures and at higher elevations.
Scientists are now trying to make it even hardier. At the Cold Spring Harbor Laboratory in New York, plant molecular geneticist Robert Martienssen and his team have created a genomic encyclopaedia called MaizeCODE that identifies sections in the corn genome responsible for adaptation. He hopes biologists and breeders will be able to use this open-access resource to create varieties that are more resistant to disease and more tolerant to drought, to prepare for conditions to come.
One Subscription.
Get 360° coverage—from daily headlines
to 100 year archives.
HT App & Website
