Biologists recently analyzed special proteins in fish eyes that capture light photons, making vision possible. By comparing the sequences of a critical protein from different fish, they identified a particular alteration that likely occurred somewhere along the line of this fish’s ancestry. The altered protein resulted in the fish seeing visible light instead of ultraviolet rays, or UV.

For decades, researchers have noticed that tiny chemicals called “methyl groups” piggyback on DNA molecules, and that they occur in certain patterns. Intrigued by the meaning and function of methylation patterns, especially as they relate to medicine, a five-year, $ 190-million-dollar research effort funded by the National Institutes of Health began in 2008.

Charles Darwin admitted that the sudden appearance of fully formed creatures in fossil deposits was one of the biggest problems with his hypothesis that nature generated living creatures through natural selection.