Coordinated Defense

Abstract

A body at rest never really is. If we could envision the activity within our cells, we might liken it to a beehive or ant colony. Chemicals come in, chemicals go out. They are transported and transformed by dozens, perhaps hundreds, of proteins. Some of these proteins act as enzymes, some as chemical transporters, while others turn genes on and off as they respond to chemical signals. Some of the oxygen permeating my cells will become highly reactive, touching off a cascade of defensive proteins, produced by a genetic blueprint that first came into being billions of years ago. The lunch I ate at noon will break down into its molecular components—fats, sugars, and proteins, in addition to various elements and minerals. Some will pass through while others will be absorbed by specialized gut cells and distributed throughout my body, and still others, perhaps plant toxins, will be transformed by a series of enzymes. Oxygen will no doubt interact with some of those nutrients, and with other molecules and metabolites. The iron from last night’s kale will be extracted, and perhaps bound within a heme group, which will use the oxygen to metabolize those molecules presenting a threat to my body. All these chemicals travel highly evolved pathways.

An important question in biology is how cells and organisms maintain homeostasis in a variable environment. The need to deal with physical, chemical, and biological stressors has driven the evolution of an array of gene families and pathways … that afford protection from challenges.

Jared Goldstone

The most adaptable and successful organisms, though wildly diverse in appearance and behavior, are all organized in a similar manner. Universally, they avoid the trap of centralized, top-down control by giving wide ranging power to multiple independent sensors to observe and respond to environmental change and threats.

Raphael Sagarin

The extent and content of metazoan gene repertoires are governed principally by the evolutionary turmoil of environmental genes.

Chris Ponting