Lemons Are ‘Manmade’ Hybrid Fruits That ‘Don’t Occur Naturally’?

Claim:

Lemons are not a “naturally occurring” fruit as they are a manmade hybrid of a sour orange and a citron.

Rating:

False

Context

Thousands of years ago, bees likely facilitated the transfer of pollen between the sour orange and the citron, which resulted in the creation of lemons – a natural hybrid of the two species. Humans later cultivated the fruit through grafting and cuttings to preserve its desirable traits, but humanity did not invent the lemon.

For years, a rumor has circulated online that the lemon is a manmade fruit that does not occur, or did not come to be, naturally.

One X user, whose post had garnered more than 10 million views as of this writing, claimed in early September 2024 that lemons “are not naturally occurring.” They said the fruit is a “hybrid” created by humans “cross breeding” bitter oranges and citrons.

“So basically, life never gave us lemons, we created them ourselves,” the X user wrote.

Similarly, a 2019 Reddit post claimed: “Since there are only three naturally occurring citrus fruits in the world (of which lemons and limes are not a part of), and all others are just hybrids from them. Life did not give us lemons. We made lemons out of life.” A 2016 post echoed this by stating: “TIL lemons are a manmade hybrid of an orange and a citron.”

This claim spread across various platforms, including Instagram, Facebook, Threads, TikTok, and YouTube.

In short, the claim that lemons are not “naturally occurring” because they are a manmade hybrid of two different fruits is false. While it’s true lemons are a hybrid of sour oranges and citrons, the hybridization process occurred naturally thousands of years ago, with bees transferring pollen between species of citron and sour orange. Humans then propagated (in other words, bred or cultivated) lemons through horticultural methods like grafting and cuttings to maintain their desirable traits.

A History of Lemons

As explained in a 2017 National Geographic article (archived), lemons exist because of genetic mutations across the citrus genus:

Almost all citrus has the rare genetic combination of being sexually compatible and highly prone to mutation. Such traits allow their genes to mix, for thousands of years on their own, and eventually, at the hands of humans. The product of so much natural crossing in the wild and selective breeding at research farms and in fields is every orange, lemon, lime, and grapefruit you’ve ever eaten.

A 2016 study titled “Phylogenetic origin of limes and lemons revealed by cytoplasmic and nuclear markers” highlighted the complexity of citrus taxonomy, noting that “the origin of most lemons and limes remains controversial or unknown.” However, a 2018 study published in scienfici journal Nature confirmed lemons are a hybrid of sour orange and citron, and further clarified that sour orange itself is a hybrid of pummelos and pure mandarins (see image below).

(www.nature.com)

Patrick Ollitrault, a citrus genetics researcher from the French Agricultural Research Centre for International Development (CIRAD), confirmed via email the hybridization of sour orange and citron occurred naturally. He also explained how bees facilitated the process (emphasis ours):

Phylogenomic studies clearly demonstrate that lemon result from sexual hybridization beetween sour orange and citron, that sour orange is an hybrid beetween pummelo and mandarin, that clementine is an hybrid beetween Mediterranean mandarin and sweet orange etc… All these hybridization occured NATURALLY (for lemon, a bee take pollen on a citron flower and then go on a flower of sour-orange; then man selected lemon because of its interesting characteristics and propagated vegetatively -grafting, cuttings, layering … ). 

Ollitrault further emphasized how natural hybridization has been a major driver of citrus evolution and domestication, adding that most modern citrus fruits are the result of hybridization between four ancestral species: citron (Citrus medica), mandarin (C. reticulata), pummelo (C. maxima), and a wild Philippine species (C. micrantha).

In a follow-up email, he also said social media posts claiming lemons do not occur naturally are false.

Professor Emeritus Mikeal L. Roose, a specialist in citrus genetics, genomics, and breeding at the University of California, Riverside, said via email that early humans may have consumed and transported lemon’s parental varieties during migrations, breaking their geographic isolation and enabling natural hybridization, likely facilitated by bees:

Lemons could certainly be a natural hybrid. We know what the parents are as stated, but whether this occurred naturally is not known because they are too old (probably at least 2000 years). There may be a human role in that the parental varieties may have originally been geographically isolated, but early humans ate the fruit and carried it on migrations which ended the geographic isolation and allowed natural hybridization to occur, likely via bees. 

Professor of Horticultural Sciences Fred Gmitter, from the Citrus Research and Education Center at the University of Florida, who specializes in citrus breeding, genetics, and genomics, said via email there is no evidence to suggest lemon hybridization was a human-driven event:

There is no evidence to support a human-driven hybridization event (breeding, if you wish to call it that) which gave rise to lemon. It was most likely a natural hybridization event that took place several thousand years ago, giving rise to the first lemon tree. All true lemons we know today (Eureka, Lisbon, Femminello, etc., etc.) arose as chance mutations over time from the ancestral first lemon. This same story is true for the sweet oranges (Valencia, Navel, blood oranges, etc.), though the parents were different from those contributing to lemon’s origin. 

“Naturally occurring hybridization, not involving deliberate human activity, is how these forms originated. Where human activity came into play was in finding those early lemons and sweet oranges in the wild,” Gmitter concluded, adding that it is “most unlikely” a human found the very first lemon:

How could we have been so lucky to find that original single lemon or orange tree? In reality, it is most unlikely that a human found the very first one of either. Rather, both of these citrus types (and many others, too) have a mutation that allows them to clone themselves, basically genetically identical trees, through seeds. That means that the original seedling trees of lemon or orange clonally reproduced themselves multiple times, as their seeds were spread naturally. So, undoubtedly one or more of our lucky human ancestors one day likely came upon stands of identical oranges or lemons; it would have been much easier and more likely to find 50-100 orange trees together in the forest than just a single one!

Gmitter summarized that “life really did give us lemons (and oranges), through lucky naturally occurring interspecific hybridizations (not human breeders), through the lucky mutation that allowed these trees to multiply themselves as genetically identical copies, and because of the lucky human ancestors who found the naturally occurring orange and lemon groves far back in time, long before we knew anything about breeding.” 

For further reading, in April 2011 Snopes investigated whether lemons “kill cancer cells” and are “10,000 times stronger than chemotherapy.” Moreover, in March 2020, we debunked a false rumor that hot water with lemons would cure or prevent COVID-19. 

Sources

Center, UF/IFAS Citrus Research and Education. Fred Gmitter – Citrus Research and Education Center (CREC) – University of Florida, Institute of Food and Agricultural Sciences – UF/IFAS. https://crec.ifas.ufl.edu/people/faculty/fred-gmitter/. Accessed 19 Sept. 2024.

CIRAD. “A New Look at the Evolution of Citrus.” CIRAD, 19 Oct. 2021, https://www.cirad.fr/en/press-area/press-releases/2018/a-new-look-at-the-evolution-of-citrus.

Grafting Ornamental Plants and Fruit Trees / RHS. https://www.rhs.org.uk/fruit/fruit-trees/grafting-ornamental. Accessed 19 Sept. 2024.

Gulsen, O., and M. L. Roose. “Lemons: Diversity and Relationships with Selected Citrus Genotypes as Measured with Nuclear Genome Markers.” Journal of the American Society for Horticultural Science, vol. 126, no. 3, May 2001, pp. 309–17. journals.ashs.org, https://doi.org/10.21273/JASHS.126.3.309.

Kasprak, Alex. “Will Lemons and Hot Water Cure or Prevent COVID-19?” Snopes, 26 Mar. 2020, https://www.snopes.com//fact-check/lemons-coronavirus/.

Mikkelson, David. “Do Lemons Cure Cancer?” Snopes, 18 Apr. 2011, https://www.snopes.com//fact-check/lemon-cancer-cure/.

Moore, Gloria A. “Oranges and Lemons: Clues to the Taxonomy of Citrus from Molecular Markers.” Trends in Genetics, vol. 17, no. 9, Sept. 2001, pp. 536–40. ScienceDirect, https://doi.org/10.1016/S0168-9525(01)02442-8.

‘New Plants From Cuttings’. Indiana Yard and Garden – Purdue Consumer Horticulture, https://www.purdue.edu/hla/sites/yardandgarden/extpub/new-plants-from-cuttings-text-only/. Accessed 19 Sept. 2024.

Ollitrault, Patrick, et al. “Citrus Taxonomy.” The Genus Citrus, edited by Manuel Talon et al., Woodhead Publishing, 2020, pp. 57–81. ScienceDirect, https://doi.org/10.1016/B978-0-12-812163-4.00004-8.

“The Citrus Family Tree.” Magazine, 11 Jan. 2017, https://www.nationalgeographic.com/magazine/article/explore-food-citrus-genetics.

UCR Profiles – Search & Browse. https://profiles.ucr.edu/app/home/profile/roose. Accessed 19 Sept. 2024.

Wu, Guohong Albert, et al. “Genomics of the Origin and Evolution of Citrus.” Nature, vol. 554, no. 7692, Feb. 2018, pp. 311–16. www.nature.com, https://doi.org/10.1038/nature25447.

—. “Genomics of the Origin and Evolution of Citrus.” Nature, vol. 554, no. 7692, Feb. 2018, pp. 311–16. www.nature.com, https://doi.org/10.1038/nature25447.

https://academic.oup.com/aob/article/117/4/565/2195970? Accessed 18 Sept. 2024.

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