The Goldilocks principle in biology-fine-tuning the `just right` signal load
(PHYSorg.com Biology)

In the fairy tale `Goldilocks and the Three Bears,` Goldilocks invades the bears` house, where she finds three bowls of porridge, but only one has just the right temperature. Similarly, in biological processes, there often exist `just right` conditions-this is called the Goldilocks principle. This is what an international research team has done by demonstrating that in order to get the right amount of signaling for symbiosis in the roots of legumes, a specific enzyme called chitinase (CHIT5) must be present.