I’ve always been intrigued by how Nature communicates with itself. The Earth is constantly, billions of times a second, making minute alterations to the billions of little programs (aka life-forms) that are all running simultaneously across the globe. These new programming instructions are often part of feedback loops operating in sizes ranging from the interior of a single cell to an immense ecosystem.
I was just trying to think if there are any feedback loops that operate on a planet-wide basis, but I think if there are any worldwide feedback loops, they must be weak and tenuous and slow acting. For instance, as far as I know, the oceans do not have a great way of regulating their acidity—which is one of the big problems when it comes to global climate change. My guess is that since Ice Ages are recurrent, then Ice Ages could very well be part of some sort of mega-regulatory system that we do not yet understand. I was one of the first liberal minded people I knew who suggested that maybe this stretch of global warming could be largely bound up with the fact that Earth is still coming out of its last Ice Age.
In Superorganism by E.O. Wilson and Bert Holldobler, the authors explain how an ant colony has its own feedback loops and ways of communicating, largely centered on pheromones— chemical compounds interchanged between the ants. Often, when an ant receives a pheromone message from another ant, the molecules of information exchange are airborne. Thus, ants can be said to “smell” them with their antennae.
Many, many other animals also exchange information via pheromones. In fact, it is a striking characteristic of humans that we appear NOT to exchange much information this way. It seems that our pheromone system has grown dormant through the millennia. Of course, we’re still looking to be proven wrong on this—especially when it comes to sex-related pheromones– the holy grail of the human pheromone quest.
For ants, the use of pheromones is so persuasive and has such powerful effect on their behavior, that I like to think of pheromones as adjusting computer instructions that are uploaded into the giant super-program called an ant nest.
One important use of pheromones for ants is the marking of trails leading to food sources. An ant who has found some food will lay down a pheromone trail saying basically, “this way, girls” (Worker Ants all being female). Other ants out foraging take one whiff of this pheromone and know immediately which way to start marching for the picnic or other food source.
Besides ants, their cousins, the bees and the wasps, use pheromone communications in quite similar ways. Although, of the three groups, the ants rely the most on chemical communications– with ninety percent of their information exchange occurring by this route.
A Queen Bee can reprogram her entire hive by distributing what is known as the “Queen Substance.” This is a primer pheromone released from the Queen’s mandibular gland. As the Worker Bees to whom she releases it interact with the other bees, this pheromone gets passed around. Its job is to regulate the expression of several hundred genes in the bees which would normally cause the Queen’s Workers, at a certain point in their life-spans, to switch from inside chores (like nursing the Queen’s brood) to outside chores (like foraging). Thus, when the Queen senses that more nurses are needed, she can “upload” this reprogramming code to the network.
It is the contention of Wilson and Holldobler that ant colonies, wasp nests, and bee hives can, in many ways, be thought of as single large organisms. In this comparison, an ant acts much like a cell in an organism, and the colony is akin to the organism, itself. Whereas cells communicate with each other via hormones and other chemical signals, the ants and their cousins would largely use pheromones.
One thing that disappointed me about Superorganism was that most of this thick book did not deal directly with the authors’ superorganism contention. Sure, they explain the idea early in the book, but then spend the next several hundred pages describing the lives of the ants and bees in great detail (wasps get short shrift in this account). There was a fair amount of interesting information in these chapters– info that sometimes, indirectly, supported the superorganism claim– but not enough to justify the book’s misleading title. Basically, this was a book about the lives of ants and bees, with the idea of superorganism tossed in at the front.