Round single cells may have been the first creatures to see Earth
N. Schuergers et al/eLife 2016
After all those years of people looking into microscopes at bacteria, it turns out that some of the bacteria are (sort of) looking back.
Synechocystis bacteria focus light in a roughly eyeball-like process, says Conrad Mullineaux of Queen Mary University of London. Light shining through their spherical cells focuses on the opposite side, where light-sensitive substances react, he and colleagues report February 9 in eLife.
Biologists knew cyanobacteria move toward light, but this method of detecting it was a surprise. Human vision differentiates between two points about 1,000 times better than do the cyanobacteria, but Mullineaux calculates that the bacterial resolution should be enough for Synechocystis to pick out the outline of his head and shoulders bending over them.