Tag Archives: Biology


Recopilando el testimonio genético de los muertos de la Guerra Civil española

En una zanja profunda hasta la cintura junto con la Autovía 1 de España, una docena de voluntarios con guantes de goma cepillan arcilla oscura que cubre restos de huesos humanos. Sus rodillas se apoyan sobre cojines de espuma, y una carpa blanca los protege del sol del verano boreal. Es julio de 2011; 75 veranos después de que en España estallara una guerra civil que llevó a los huesos de 59 personas a ese suelo.

A pocos pasos de la zanja, los voluntarios sostienen micrófonos frente al murmullo de los ancianos de la localidad de Gumiel de Izán, en la región centro-norte de Castilla y León. Esos ancianos, que albergan recuerdos de ejecuciones sumarias en ese sitio, bien pueden ser los hermanos menores, los vecinos y los hijos de los que están en esa tumba. Pero al momento de la exhumación, nadie lo sabe a ciencia cierta. En lugar de ello, los voluntarios documentan y recogen los restos físicos, y consiguen y graban las memorias imperfectas que fueron suprimidas durante cuatro décadas de dictadura.

Tales sitios se encuentran esparcidos por toda España, desde las Islas Canarias hasta La Mancha y las Islas Baleares. Las estimaciones recientes sugieren que alrededor de 2.000 fosas comunes pueden guardar los restos de hasta 150.000 víctimas de apresuradas ejecuciones durante la guerra.

El resto del reportaje está disponible en Scientific American en Español: [html] [pdf].

Originalmente publicado por Sapiens en inglés: [html] [pdf] y republicado en Scientific American: [html] [pdf].


Unburying the Spanish Civil War

In a waist-high trench alongside Spain’s national Highway 1, a dozen volunteers wearing rubber gloves brush tan clay from crumbling human bones. Their knees rest on foam cushions, and a white tent shades them from the summer sun. It’s July 2011—a full 75 summers after Spain erupted in the Civil War that put the bones of 59 civilians in the ground here.

A few steps away from the trench, volunteers hold microphones up to the murmuring mouths of elders from the town of Gumiel de Izán, in the north-central region of Castilla y León. The elders, who harbor memories of summary executions at the site, may well be the younger siblings, neighbors, and children of those in the grave. But at the moment of exhumation, nobody knows for sure. Instead, the volunteers document and collect the physical remains, coaxing out and recording imperfect memories that were suppressed during four decades of dictatorship.

Such sites are scattered throughout Spain, from the Canary Islands to La Mancha to the Balearic Islands. Recent estimates suggest that some 2,000 mass graves may hold the remains of up to 150,000 victims of hasty wartime executions.

Read the full feature in Sapiens: [html]  [pdf].
It is also syndicated to Scientific American: [html] [pdfand Scientific American en Español: [html] [pdf].

A grow shop in Madrid sells cannabis seeds labeled as sativa and indica cross-breeds. Genetic research shows such labels rarely match reality. Photo: Lucas Laursen.

The cultivation of weed

Packets of cannabis seeds line the shelves of legal grow shops in Madrid. Many carry labels reporting the percentage of sativa and indica, two types of cannabis. Breeders often label plants that produce a more exciting high as sativa and plants that provide a more mellow feeling as indica, suggesting that cross-breeding tailors that buzz. The conceit is widespread. Botanist Jonathan Page at the University of British Columbia in Vancouver, Canada, says he sees the same at local grow shops.

For reasons that go beyond assessing the quality of the user experience, botanists such as Page are investigating the evolution and present-day diversity of cannabis. To do this, they must confront centuries-old taxonomic questions, including whether cannabis is one species, Cannabis sativa, with several subspecies or varieties, or if it is several distinct species, such as C. sativa, Cannabis indica and Cannabis ruderalis. “It’s complicated taxonomically because of its intimate relationship with humans for long periods of time,” Page says. People have long bred cannabis as a source of fibre, food and oil — as well as for its mind-altering effects (see page S10). As governments relax cannabis laws, commercial growers want more clarity about the chemical properties and capabilities of the herb’s many varieties. In parallel, regulatory bodies trying to establish a legal framework want to be able to classify whether a given type of plant is for fibre (hemp) or recreational or medical use (marijuana).

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Credit: Daniel Romero

Wild bees: Lone rangers

In a green field outside Madrid, at the foot of the snow-covered Guadarrama mountain range, lies a sun-faded snail shell. Its opening sealed with a cap of dried mud, the shell contains the larva of a wild, solitary bee, together with its first meal of bee bread — a mixture of pollen and nectar. Entomology graduate student Daniel Romero picks up the shell and, concluding that it contains the nest of a mason bee, stores it in a clear plastic tube, labels the red cap with a marker, and closes it.

Back at the Complutense University of Madrid, Romero sets ten tubes of the nesting bees he collected on his professor’s desk. They are just a fraction of the hundreds of samples that he and his colleagues will gather during a four-year Spanish government-funded study of how artificial chemicals are affecting the biodiversity of wild pollinators and their immune and reproductive systems. In the warmth of the office, some of the young adults twitch and scratch at their now-crumbly mud doors. Researchers watch the young adult bees slowly emerge into their new world. When the air cools and the humans leave the room, the bees return to their pollen pillows. Unlike honeybees, solitary bees buzz to their own drum.

See an album of photos I took while reporting this story.

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