Michelangelo
Michelangelo returned to Florence in 1499. The republic was changing after the fall of its leader, anti-Renaissance priest Girolamo Savonarola, who was executed in 1498, and the rise of the "gonfaloniere" Piero Soderini. Michelangelo was asked by the consuls of the Guild of Wool to complete an unfinished project begun 40 years earlier by Agostino di Duccio: a colossal statue of Carrara marble portraying David as a symbol of Florentine freedom to be placed on the gable of Florence Cathedral. Michelangelo responded by completing his most famous work, the statue of David, in 1504. The masterwork definitively established his prominence as a sculptor of extraordinary technical skill and strength of symbolic imagination. A team of consultants, including Botticelli and Leonardo da Vinci, was called together to decide upon its placement, ultimately the Piazza della Signoria, in front of the Palazzo Vecchio. It now stands in the Academia while a replica occupies its place in the square.
Separation of Light from Darkness
Several authors have proposed that Michelangelo concealed anatomical images in this fresco and that these anatomical images account for its unusual features. In an article published in the journal "Neurosurgery" in May 2010, Ian Suk, a medical illustrator, and Rafael Tamargo, a neurosurgeon, both from the Johns Hopkins University School of Medicine, suggested that Michelangelo concealed three neuroanatomical images in the "Separation of Light from Darkness." Suk and Tamargo explained that Michelangelo started to dissect cadavers at the age of 17–19 years and continued his anatomical studies throughout his life. As a result of his dissections, Michelangelo probably developed a detailed understanding of gross anatomy of the brain and spinal cord. They showed that the anatomical details in God's neck are unlike those of either other necks painted by Michelangelo in the Sistine Chapel or of other necks painted by Michelangelo's contemporaries, such as Leonardo da Vinci and Raffaello Sanzio (Raphael). The unusual anatomy of God's neck is particularly evident when it is contrasted with the anatomy of the neck of the ignudo facing God in the upper left corner of the panel. The position of the neck of this ignudo is almost identical to that of God's neck, yet the ignudo's neck does not have any of the unusual lines found in God's neck. It is possible that Michelangelo placed these two analogous neck perspectives side by side to emphasize and contrast the hidden image in God's neck.