A new study unexpectedly reveals that cells thrive on chaos. Across the sciences, rules and laws help us make sense of the world around us, whether applied to cosmic scales or subatomic ones. However, in the biological world, things are a bit more complicated. That's because nature is often full of biological exceptions, and so “rules of biology” are also considered broad generalizations rather than absolute facts that explain and govern all known life. Some of these broad generalizations include things like Allen's Law, which dictates that body shapes in endotherms (warm-blooded animals) adapt to climatic conditions—short and stocky helps retain heat in cold climates, while tall and lanky helps dissipate heat in warmer ones. Another “law,” known as Bergmann's rule, states that species of a broadly distributed clade tend to be larger in colder climates and smaller in warmer ones (though of course, as with most biological rules, exceptions apply). At first glance, this new rule—called “selectively advantageous instability,” or SAI—seems to defy the underpinning assumptions of life in general, and pushes against the current assumption that life craves stability and a conservation of resources. While nature does tend toward stability (it's one reason why we see so many hexagonal shapes in the wild, including honeycombs and insect eyes), USC molecular biologist John Towers argues that instability in biological components like proteins and genes can actually be helpful to cells. These states allow for greater genetic diversity, which in turn can make organisms more adaptable. This indicates that SAI in these components is a necessary biological function. “Aging has proven to be difficult to define, but most definitions include an increased chance of death with age, and decreased reproductive fitness with age,” the paper reads. “SAI can create a cost for the replicator in terms of energy and/or materials, and this cost might be interpreted in terms of promoting aging.” Humans May Be Able to Grow New Teeth in 4 Years Scientists Made Glue So Strong, It Can Tow A Car