That's a random result of rolling the dice... or if you prefer, a random result of natural variations in weather. (planet3.org)
In other words, the meltdown could be explained by natural variations in the weather, not long - term climate trends. (newscientist.com)
These studies are hampered by large natural variation from person to person, which makes it hard to align brain scans to reveal key differences in specific structures. (newscientist.com)