Antonio García-Bellido, discoverer of the invisible boundaries within living beings, dies

One of the world's most celebrated scientists, the British Francis Crick, co-discoverer of the structure of DNA, alerted the world in the summer of 1975 to the revolutionary ideas emerging from a Madrid laboratory that were going largely unnoticed. A person is a being of 30 trillion cells arranged, through an inconceivable choreography, from a single fertilized egg. Those Spaniards, working with fruit flies, had discovered that living organisms, after the multiplication of the first solitary cell, develop in modules, in watertight compartments regulated by a handful of genes: wings here, legs there, eyes over there. No cell crosses these invisible boundaries, like the one that marks the limit between the back of an arm and its front. The leader of that laboratory, the Madrid-born biologist Antonio García-Bellido , one of the greatest scientists in Spanish history, died this Monday at the age of 89.

The researcher recounted how he was one of those children determined to “take apart the toy and see how it worked.” After training from 1959 in the United Kingdom, Switzerland, and the United States, García-Bellido set up his own laboratory in 1968 at the Center for Biological Research of the Spanish National Research Council (CSIC) in Madrid. He wanted to find out how, starting from a single cell, a hand, a wing, an antenna could appear. “The problem is how form is created, why organs have shape. It’s a problem of cell populations, of what they tell each other to have more or fewer cells in a given dimension; and of size, which is specific to the species. It’s still a great challenge to understand how the genes in cells cause cell populations to have dimensions prescribed by the genes, and how that information is transformed into size and shape,” the biologist reflected in an interview with EL PAÍS in 2006, on the occasion of his retirement.

The findings in flies astonished scientists. García-Bellido developed the concept of "selector genes," a kind of conductor in the DNA that is activated in each area of ​​the body, defining the identity of the cells in each compartment. If something goes wrong, a fly can have four wings instead of two. And the most amazing thing is that these master genes are interchangeable between completely different species. If the appropriate human gene is introduced into a wingless mutant fly, it will grow wings.

The discoveries from García-Bellido's laboratory, made public by Francis Crick and his colleague Peter Lawrence , had momentous implications. Around 540 million years ago, during the so-called Cambrian explosion , the impressive diversity of animal types that now populate the Earth emerged in a brief period. The common ancestor must have already possessed that handful of selective genes, capable of organizing any body type, whether it had wings or tentacles. For Javier Sampedro , biologist and journalist for EL PAÍS, and grandson of García-Bellido, the Madrid laboratory ended up illuminating “the most surprising and enigmatic set of facts that genetics has discovered in its entire history, because it reveals that all the dazzling animal diversity of this planet, from carpet mites to Ministers of Culture, passing through cockles and the worms that parasitize them, are nothing more than minor adjustments of a meticulous design plan that evolution invented only once, some 600 million years ago,” as he summarized in his book Deconstructing Darwin (Crítica publishing house).

The 19th-century British naturalist Charles Darwin proposed that all living things had evolved from a single common ancestor through natural selection: among individuals of the same generation with slight differences in their inherited characteristics, those best adapted to the environment survived. The discoveries of García-Bellido and his colleagues pointed to the possibility of modular evolution, with abrupt changes based on the emergence of new compartments regulated by the same ancestral selector genes. “Evolution is very conservative,” the biologist explained to this newspaper . “I jokingly say that evolution has had very little imagination; it hasn't created new things, what it has done is combine existing traits with immediate results. [...] The biggest change in evolution is in which organisms genes are expressed and when,” he reflected.

García-Bellido was one of only two Spaniards invited to be members of both the Royal Society of the United Kingdom and the National Academy of Sciences of the United States. The other was his student Ginés Morata, with whom he began collaborating more than half a century ago . “Antonio García-Bellido was one of the very few scientific pioneers that Spain has produced,” says Morata. “He was able to integrate classical concepts of developmental biology with genetic analysis, and by doing so, he created a Spanish school of developmental biology that has had a great international impact and continues to do so. It is truly a great loss for Spanish science,” laments his student.

Fifteen years ago, biologist Alfonso Martínez Arias published a brief history of Spanish genetics, with illustrative headings: the pioneers, the Civil War, Antonio García-Bellido. “Antonio has probably been the most important Spanish biologist after Santiago Ramón y Cajal and Severo Ochoa. I would even venture to say that, intellectually, he was far more significant than Ochoa,” states Martínez Arias, from Pompeu Fabra University in Barcelona.

García-Bellido was “the most decorated living Spanish scientist,” according to the University of Málaga, to which he donated 75 boxes of his documents. The Madrid-born biologist had been a member of the Royal Academy of Sciences since 1984 , won the Prince of Asturias Award that same year, and the National Research Prize in 1995. His “terrible temper, a character of the so-called impossible kind,” was also well-known, as journalist Malén Aznárez remarked to him in that 2006 interview. “Some say that this temperament is to blame for him not receiving the Nobel Prize, since he couldn't maintain a team around him to develop his ideas,” the reporter suggested. “If I haven't received the Nobel Prize, it's obviously because I didn't deserve it, it's that simple, or because others deserved it more,” García-Bellido concluded.