| | | We Live In Our Environment, But It Doesn't Contain Us |
We think of an organism as a thing of its own. A thing has boundaries to separate it from the rest of the world, and it has a beginning to its existence, and (generally) an end. We want a developing animal to start from a clean slate, read its own instructions and build itself, but that's just not the way it works. Eggs inherit information from their genes (from the nucleus and the mitochondria), but also directly from their mothers, in the egg's cytoplasm, and in guidance to the process of development.
The genes guide the embryo's development, and they also moderate the actions of the parents, so they do ultimately control most of the process, but they do it through this strange symbiosis between generations. Looking for a "beginning to life"--trying to pinpoint the moment when a developing organism becomes an independent thing--is an exercise in futility. The beginning of life was billions of years ago. For now, life just is. I am a continuous extension of my mother's life, as she was of her mother's and so on and on right back to the blue-green algae mats floating in shallow Pre-Cambrian seas.45
Spatial boundaries have a similar problem. We want a thing to exist, contained in its environment, as a brick might sit in an empty room. But the environment is not a simple container, and no living thing is as docile as a brick. Living organisms interact with their surroundings, often changing them in profound ways by the very act of living. A rabbit eats the grass in its fields; a beaver cuts down the trees in its woods. Some changes are minor, but some are dramatic: a virus might kill its host; Earth is habitable for us only because billions of years of plant photosynthesis have produced enough oxygen for us to breathe.
Life is not a Platonic Form, existing in some airy theoretical vacuum. Life is a process carried out in the constant dialogue between an organism and its habitat (which includes other organisms). Change one and you change the other.
A gene can't be read unless it's in the right sort of nucleus, in the right sort of cell, in the right sort of organism, which itself needs to be in the right sort of environment to thrive. Not only is there a continuity in time, as we trace our beginnings right back to the beginning of life, but there is a continuity in space, as we trace the chain of dependence out from the gene, like spreading ripples on a pond.
Genes did not evolve to satisfy the dictates of Platonic categories, so we shouldn't be surprised to find unexpected relationships between genes and their surroundings. Genes evolved by chance and natural selection. That is, they evolved to work, and nothing more. They work fabulously well, and have changed the planet by so doing, but the structure they have created is riddled with subtle and delicate interdependences, between different parts of the gene, between different cells, and between different organisms.
The nucleus incorporates the gene, and depends on it. Our environment incorporates us, and depends on us as well. Just as it makes little sense to attempt to search for the moment when life begins, it makes little sense to try to draw lines to separate ourselves from our environment; the threads of interdependence are far too tangled.
Unfortunately, the philosophical trend since Plato is to see ourselves apart from the rest of the world, as a separate (and exalted) thing. But the evidence for that view has always been thin, obtained largely by philosophical navel-gazing rather than accumulation of data. The past century's close scientific observation of how life works has shown this separation is nothing more than a vain illusion.
In a painting, one speaks of a relationship between the "figure" and the "ground," between the subject of the painting, and the space around it. The figure defines the ground, and the ground defines the figure. It makes no sense to talk of one without the context defined by the other, and a successful painting is one where the relationship between the two elements adds to the overall effect.
The study of genes has us on the beginning of an exciting road. But each new step in understanding how life carries on will reinforce this point: it is as impossible to separate any life from its context as it is to analyze a painting by only looking at the figure. It is pointless to analyze a developing embryo without considering the mother surrounding it, or to talk of that mother as separate from the water she drinks and the air she breathes.
We also need to take care. In a painting, it is impossible to make changes to the figure without also changing the ground. When we attempt to engineer life itself, we are tinkering with a system about which we know very little; we can do far more than we can understand. But we understand this: when you let a little piece of genetic material out into the world, you effect a permanent, possibly cascading, change in our world. For example, we know now that many of our genes were foisted upon us by bacterial invaders, through mechanisms as yet unknown.46 There is no empirical reason for confidence in bland assurances that the release of genetically engineered animals into the world are minor, or transient, changes. To be sure, reckless modification of our environment predates genetic engineering; ask anyone who's been attacked by the "killer bees" of South America. But the potential for mischief is now greater than ever. One hopes that the newfound humility of the geneticists will prove contagious. We could all benefit.
In the years to come, we will make some progress disentangling the threads of interdependence between organisms and their environment. We will understand much better how life works. But, possibly aside from screening and preventing simple genetic dysfunctions, it will be a long time--possibly forever--before we are able to engineer our children to have desirable behavioral traits, which are fantastically complicated results of the interplay of genes and environment. On the other hand, as we learn more about this interplay, we will come to understand, more deeply than ever before, how important the world around us is to our own lives, and how delicate the balance that maintains us. One hopes that the result of the advances of genetics will be an increasing awareness of the dimensions of our ignorance, and that the popular understanding of this fascinating science will shift from wonderment at its advances to a real appreciation of the the vastly greater complexity--and the precariously teetering structure--of the context in which those genes thrive: nucleus, cell, organism, and environment.
We Live In Our Environment, But It Doesn't Contain Us