In almost every human cell, 2 meters of DNA has to fit within a nucleus that is just 8 millionths of a meter wide. Like wool around a spool, the extreme space challenge requires DNA to wrap around structural proteins called histones. This coiled genetic architecture, known as chromatin, protects DNA from damage and has a key role in gene regulation.
Click here for original story, Chromatin found to have originated in ancient microbes one to two billion years ago
Source: Phys.org