For decades, the eye has been one of evolution's great enigmas. Charles Darwin said that thinking about the origin of such a sophisticated organ made him shudder. How could a structure capable of detecting light have been built in such a way that the brain could form three-dimensional images with which to interpret the world, from the accumulation of small and gradual changes? A new scientific hypothesis published in the journal Current Biologyproposes a surprising answer. Our eyes could come from a single ancestral eye located in the center of the head in very simple marine animals. Perhaps it is no coincidence that so many ancient mythologies imagined cyclops, beings with a single eye in the center of the forehead. Long before vertebrates with two lateral eyes existed, our ancestors might have actually had a single primitive central eye.The research, led by neurobiologists Dan-Eric Nilsson (Lund University, Sweden) and Tom Baden (University of Sussex, England), suggests that about 560 million years ago, the ancestors of vertebrates had a single central photosensitive system, similar to a “third eye”. Over time, this organ split into two, which gradually specialized to give rise to modern retinas.

In the historic Down House, the house where Charles Darwin lived for 40 years in Kent, England, there was a space that was key to developing the theory of evolution that would bring the English naturalist worldwide fame. And it's not the table where he wrote The Origin of Speciesbut rather his garden. There, Darwin spent hours conducting small experiments with plants, such as the so-called Darwin's orchid or Christmas orchid, from Madagascar. It is a very particular species, with an extraordinarily long nectary, over 20 centimeters. The scientist predicted the existence of an insect capable of reaching the hidden nectar. The butterfly would be discovered decades later, confirming an intuition based solely on botanical observation.

When Charles Darwin was to embark on the Beagle To travel around the world, one of her sisters told her to take a copy of PersuasionBut he hesitated because, he said, he knew the novel by heart. Darwin was passionate about Jane Austen's works and was fortunate enough to share that enthusiasm with Robert FitzRoy, the ship's captain. Perhaps that's why the naturalist wasn't so pleased to see the writer's image replace his own on the ten-pound note in 2017. In fact, it gave way to one of his favorite authors.