Recently one of my friends was seen to praise a politician known to seriously employ the slogan "People before the planet!" Boggling somewhat, since my friend is an intelligent person, I mentioned the fundamental problem with this. His reply:
...this is a positive approach to counter the anti-evolutionary madness promoted by some Greens. Evolutionarily speaking, anything that impedes or does not actually advance the human race is a toxic dead-end. Humans are no longer bound inexricably to this planet (in fact the sooner we get a viable population off it the better). The comment makes imminent [sic] sense in that context.My friend is wrong, for illuminating reasons. More than a century and a half after Darwin's On the Origin of Species, it seems its message is still contaminated with one of the major cultural myths it was intended to replace: the notion of the "Great Chain of Being", whereby everything that exists is ranked on a linear, ascending scale of worth from inanimate objects through vegetables, invertebrates, fish, reptiles, mammals and primates to Man -- and further up through various ranks of angels, archangels and seraphs to God Himself.
While versions of this idea had been around since mediaeval times or earlier, Gottfried Leibniz (best known for discovering calculus around the same time Isaac Newton did) argued that it explained one of the world's great puzzles: the similarities between living things. Apes were like humans, Leibniz believed, because they were just below us on the Great Chain. Sponges were between animals and vegetables. Fossils were between living things and rocks. Darwin -- theoretically -- changed all that. His great insight rested on two common-sense observations: that living things inherit their distinctive features from their parents, and that if you have too many there won't be enough food to go around. From this it followed that, over generations, features that granted their bearers more than their share of the food (water, oxygen, distance from predators, etc.) would become the norm. Accumulating successive improvements, species would evolve.
Darwin's contemporaries grasped one major divergence from prior theories: life changes through time without boundaries or limits. Many resisted even this idea, but many others endorsed it. Two further consequences, however, were largely downplayed or forgotten, though not by Darwin himself.
First, evolution accumulates only inherited improvements; individual achievements die with their makers. And second, there is no scale of worth -- all living things come from equally successful ancestors, humans and beetles and jellyfish and mushrooms alike. Only by being successful did their ancestors get to be ancestors in the first place. Unfortunately, the Great Chain of Being was so ingrained in Western thought that Darwin could not follow his own advice: "Never use the terms higher and lower."
There was another old idea hanging around as well. Christians traditionally believe that Christ rendered the Jews obsolete, though today they politely say "the Old Law" rather than "the Jews". The concept of history as a succession of stages, leaving the "primitive" coughing in the dust of their "advanced" betters, took hold with the Age of Discovery and the Enlightenment, and was firmly established by Darwin's day.
So when people began to accept that living things indeed did change, they took evolution to mean that you could climb the Great Chain by superseding lesser beings. Nearly all popular discourse about evolution -- cartoons of apes marching into manhood; the word "dinosaur" for anything no longer useful; Nazi paranoia about race-pollution; the Agent's speech to Morpheus in The Matrix; and, yes, the idea that "evolution" obliges us to leave the planet -- is befuddled by this error.
We often hear one course of action recommended over another on the grounds that it's "the way of the future". I think C. S. Lewis best captured the fundamental silliness of this: we are all going to end up in the future, regardless of whether we march in step with Progress. "The future" will be what we make of it.
At this point, I imagine my friend will have a ready retort. Here I am typing this article on a computer and preparing to post it on the internet. Wouldn't I say that things have improved since the days when I would have had to write every individual copy myself with a goose-feather quill?
Well, yes. Many things accumulate over time, and some of these things are good. In biological evolution, natural selection tends to ratchet complexity upwards rather than downwards. In human society, useful knowledge tends to get passed on, while mistaken ideas are found out and discarded; in this way, overall knowledge and capability increases. However, biological and technological evolution also share features which undermine the concept of the March of Progress.
First of all, they're basically random. We're often fooled into thinking that technological evolution is aimed at a far-off horizon, but think what this implies -- that an inventor, foreseeing the final form of her invention, deliberately creates an inferior version so it can be improved on. No, she will make the product as good as she can right from the beginning. Improvements will wait on haphazard events such as increases in funding, or, mostly, new technologies coming from elsewhere.
Technology does not advance toward a goal any more than living things do. It switches direction and changes focus. Back in the 1950s, only the boldest futurists dared to predict Moon landings before the next decade was over. Those same futurists also predicted we'd be on Mars by now. A few had some inkling of cellphones; none ever dreamed of the internet.
Another similarity appears on a longer-term view. Here and there about the world, civilizations have appeared with the expertise and ambition to build tremendous monuments. I'm sure you can think of several off the top of your head: Stonehenge, the Pyramids, the moai of Easter Island. I hope you don't mind if I quote Shelley at you--
My name is Ozymandias, king of kings;Remember what had happened to Ozymandias and all his works, and the terrible irony of the word despair. Civilizations that put too much of their resources into monuments, and not enough into the soil, are doomed.
Look on my works, ye mighty, and despair!
It's the same with species that grow ever-more flamboyant ornaments, or that enter into "arms races" between predator and prey. As a good general rule, species that turn out to be the ancestors of great lineages millions of years later are mostly small and unassuming. Why this should be for species, I can't say with confidence, and any guess I might make would be far too long-winded for my purpose here.
But it is not a mystery for civilizations. Unless extremely scientifically conducted, farms do not leave the soil the way they find it; they leach out nutrients, leave salts behind, and expose ground surface to erosion. Farmland needs adjoining forest to remain fertile, and that forest is the first thing to go when ambitious civilizations expand their production. When food runs short, people fight over what's left, until the society as such ceases to exist.
Such a fate is in our near future if we do not, very quickly, find renewable alternatives to fossil fuels; but that's such a major issue that it'll take over the article if I pursue it any further. While highly pertinent to the lunatic slogan under discussion, I wanted to explore a different ramification of my friend's argument. I live in a land settled after heroic voyages by the Earth's two greatest ocean-going civilizations, and I have no wish to disparage the achievements of either. But I must point out that neither would have been possible if the settlers had had to import the entire ecosystem, atmosphere and all. And make no mistake, nothing less is required for the conquest of space. Most science fiction is a bit lacking in this regard -- to say the least. What do they eat on the Millennium Falcon, or the TARDIS, and where does it come from? It's passed over; it's irrelevant to the story. On the NCC-1701 Enterprise, it's created by magic. I know my friend to be a Robert Heinlein fan, but I shall be surprised if there are many written science fiction works that do any better.
Here are some figures: the Milky Way Galaxy is 100,000 light-years (9 with 17 zeroes kilometres) across, and is estimated to contain 500 million planets within the habitable zone of their star -- the region in which liquid water can exist. It is about nine billion years old, parts of it older. Humans are known to have evolved from a creature with a chimpanzee-like brain to one capable of flying to the Moon within a two-thousandth of that time.
You see what this implies; especially when I add that stars within the Galaxy typically move, relative to one another, at around 210--240 km per second. Even at such a low speed (cosmically speaking), it would take less than one-seventieth of the Galaxy's age to cross it from edge to edge. There has been ample time for alien civilizations to evolve and get here. Where are they? It's technically possible, I guess, that Earth is in some kind of interstellar national park. It's also possible that it's so terribly difficult for life to arise from non-living chemistry that it happens only once per galaxy per ten billion years; but various promising lab results (Google "Q-beta replicase" for just one) tell against that hypothesis. Or maybe only Earth life has managed to become multicellular, or turn its own waste product -- oxygen -- into an energy source, or cross some other threshold on our long journey.
In short, I wouldn't put money either way on whether there are civilized beings elsewhere in the Galaxy. But if there are, then something is stopping them from getting here. And if they can't get here, then we can't get there.
What might the barrier be? Well, you'll have figured out my guess by now. Exploring space is one thing, and we've already started. Exploiting space -- mining our own solar system for minerals -- I wouldn't rule out, though you'd have to convince me. But to colonize space, we would effectively have to dig up a country-sized chunk of ecosystem and throw it away. Forever.
That would take a much more urgent economic impetus than "Hurry up and make life look like Starship Troopers already. Spaceships are Kewl." And here's the kicker; in just about any sufficiently serious crisis, such as overpopulation, that chunk of ecosystem would be more use on Earth than in space.
There may have been civilizations out there that failed to stem population growth and collapsed. There may still be many civilizations out there that succeeded in stemming population growth, survived, and live sustainably within their own solar system. There are certainly no civilizations that have expanded indefinitely into the Galaxy without collapsing. It is sheer fantasy to think that ours is destined to be the first.
Yet, for the sake of argument, let's indulge that fantasy. Suppose we did have both the means and the motive to get offworld. Let's say there's a Doomsday asteroid headed our way. Unlike overpopulation, this won't sap our economic ability to undertake major projects before it arrives. Also unlike overpopulation, moving a large packet of ecosystem off the Earth is a genuinely useful response. (It would still make more sense to bring it back when the dust has settled, but we'll pass over that.)
What's our plan of action? This, to give you a hint, is not it: "Find a planet with air we can breathe, water we can drink, amenable soil and weather, a day/night cycle and seasonal variation that our crops can thrive in. Hop over there and exploit any indigenous life forms until our domesticates replace them, all while continuing to grow our own population and economy at their accustomed rate." Foreign continents on Earth during the Age of Discovery had those things. Other planets will not.
No, our agenda would look more like this: "Build a contained ecosystem. Account for absolutely everything -- water, oxygen, carbon dioxide, nutrients, wastes, energy. Slow population growth within the container to zero. Slow net economic exploitation of resources within the container to zero. Slow net waste production to zero. Maintain for hundreds of thousands of years while crossing the Galaxy. Maintain for thousands more while slowly transforming the chosen planet to something survivable."
We don't yet know how to do all of that. Right now, we don't need to know how to build an eco-container, cross the Galaxy, or terraform hostile planets; and if we don't develop our ecological balancing skills pretty quickly, we will never have the opportunity. Even were that not the case, we would still have to master that balancing act on Earth before we had a hope of surviving in space.
In short: clean contrary to my friend's argument, we must look after the planet, now and forever, if we ever want to get off it.