To those interested in variegation,
There is no scientific basis to this, but I once heard a theory that
variegation may be a natural adaptation to predatory insects.
Although not always, many variegated plants occur on the forest floor. The
theory was that insects crawling along the floor, would see light coming
through the leaf, and the paler areas would give the appearance that the leaf
had already been eaten away in parts, and was not fresh material. Who knows ?