In terms of taste, broccoli is a divisive vegetable. But visually, it would be hard to find someone who does not find Romanesco broccoli aesthetically pleasing.
You’ve probably stopped by before to look at it: Romanesco broccoli – or “Romanesco” for short – is a breed of broccoli that looks like a giant green flower, with flowers in strange perfect geometric patterns that repeat themselves as you zoom in. This is the nautilus shell of vegetables: a perfect, ever-repeating spiral that pops up over and over again. As a late-fall and winter vegetable, it is found this time of year in most grocery stores across the United States, and it is enchanting to shoppers with its beautiful patterns.
These patterns are called fractals, and they are the key to understanding Roman broccoli.
“A fractal language is a shape or structure that is the same on different scales,” Edmund O. Harriss, a professor of mathematics at the University of Arkansas, wrote to Salon. “In other words, when you zoom in, you see the same (or sometimes related) structure.”
In the natural world, plants sometimes approach these self-repeating structures. Many ferns, for example, have leaves with fractal architecture. Pinecones, spiral nautilus shells and ice crystals also have self-repeating patterns.
But among recursive patterns found in living things, Romanesco broccoli is a fractal Excellence, it appears.
“Romanesco is considered the core model of fractal architecture in biology,” Zachary Stansell, a professor at Cornell University’s School of Integrative Plant Science, told Salon by email. “We know it shows a very unusual and recursive growth pattern compared to ‘normal’ (or Calabrese) broccoli. Almost paradoxically, it seems that some of the rules governing normal broccoli branching and development are ‘relaxed’ in Romanesco. “, which makes it possible to repeat the branching process … repeatedly. This iterative branching pattern corresponds to an interesting mathematics such as the Golden Ratio, a common theme in classical architecture.”
One of the oldest mathematical concepts, the Golden Ratio, whose value is about 1,618, is the ratio between two different sized objects in which the smaller one is to the larger one and the larger one to the sum of both. As John Edmark, a lecturer at Stanford University’s mechanical engineering and design program, told Salon, the Golden Ratio occurs “if you take a line and divide it into two segments, so that the ratio of the whole line to the longer segment is the same as the ratio of the longer segment to the shorter segment. “Edmark noted that” there is only one ratio that can meet the requirement – the Golden Ratio – and its value is about 1,618. “
The Golden Ratio has a history of history and traces back to the ancient Greek mathematician Euclid. It has been used by artists, architects, engineers and musicians, incorporated into their respective artworks. Some even believe that it can be used to explain beauty and understand how life in nature is designed.
This brings us back to the Roman broccoli. The spiral pattern on the broccoli displays the golden ratio, in that each small bud that grows outside the main growth has the same size ratio as its predecessor, specifically the Golden Ratio. In other words, the same formula that governs the appearance of Roman broccoli was exploited in their diapers by Leonardo Da Vinci and Piet Mondrian.
This is the math behind broccoli. But what about biology? What about Romanesco’s genetics makes it so … spiral?
Oddly enough, the reason Romanesco looks different from his almost genetically identical cousins - (normal) broccoli and cauliflower – still remains a genomic mystery.
“To my knowledge, no one has proven the genetic control of the patterns seen in Romanesco,” Stansell told Salon. “There are some known genes in the ‘laboratory rot’ of plants (Arabidopsis thaliana) which apparently causes a somewhat analogous behavior, but the genetic control remains a fixed question. ‘
Stansell’s Cornell colleague Thomas Björkman added these remarks by writing to Salon that “broccoli (like cauliflower) is built by the growth point that makes branches and flowers in a consistent repetition pattern. On the other hand, the more frequent appearance of Romanesco caused by the growth point that makes branches and flowers in an ever-changing pattern.In Romanesco the time and distance between new branches becomes longer.If you look at the point of a Romanesque head, you will see that the growth point is really large is easily visible to the naked eye. “
Stansell and Björkman know what they are talking about broccoli, as the two scientists published paper in October on the genetics behind broccoli. They studied broccoli genomes and learned that the iconic plant retained about half of the genetic diversity that existed in the original broccoli grown by Italians centuries and centuries ago – information that could be used to advance its taste. to change.
“Although modern broccoli is extremely uniform, it retains about half of the genetic diversity found in its Italian ancestors,” Björkman explained. “The diversity is valuable for resilience and continuous improvement.”
He added that he and his co-author, Stansell, “also found parts of the genome (the complete set of genetic instructions of the organism) where the genetic diversity is very low. The uniformity is a sign that a gene in that part of the genome is really important for making good broccoli and other versions have been eliminated. ‘It seems that people who grew broccoli consciously knew what traits they should encourage and which to diminish. It is interesting that this happened by farmers growing the vegetables long before people understood that there were genes.
The ‘characteristic flavor’ of brassica vegetables, the cabbage and mustard family in which broccoli is also found, is related to a group of compounds called ‘glucosinolates’, Stansell told Salon. “Certain glucosinolates contribute to the spicy or bitter flavors that people like (or detest) broccoli,” he noted.
Stansell also noted that human genetics may play a role in how we understand the relevance of broccoli genetics; some people have genes that make them more sensitive to glucosinolates.
“It is possible to grow brassica vegetables to have less of these bitter compounds, as the Dutch plant breeders Hans van Doorn did when he grew sprouts,” Stansell explained. “Greater knowledge of the genetic diversity in broccoli can allow plant breeders to select or cross-pollinate new broccoli varieties with different or even new flavor profiles.”
Perhaps breeders can eventually also enable such genetic knowledge to choose mathematically astonishing broccoli.