David Attenborough, 87, noted naturalist, BBC executive, and filmmaker, knighted by the Queen in his native Britain, was recently quoted by the Times of London as calling humanity “a plague on the Earth.” Mixing his metaphors, he continued, “It’s coming home to roost over the next 50 years or so. It’s not just climate change; it’s sheer space, places to grow food for this enormous horde. Either we limit our population growth or the natural world will do it for us, and the natural world is doing it for us right now.”
In a few short sentences Sir David likens the human race to a virulent disease spreading death across the planet, a vast flock of birds befouling its earthly nesting place, and a teeming throng of ravenous humans overconsuming their way to a massive die off. I don’t dispute his metaphors. I just don’t agree with his premise — that there’s a conflict between humanity and Nature.
Attenborough sees us humans as the greediest of all species, taking more than our fair share of the Earth’s resources, crowding out other life forms to occupy the best living space, overworking and paving over fertile soil, depleting and poisoning fresh water sources, overharvesting plants and animals we like to eat and killing off others we consider weeds and pests, and polluting the very air we breathe and overheating it to the point where the planet’s climate cycles are being disrupted and the threat of runaway global warming is upon us. Again, all true, all obvious to anyone who’s been paying attention. But he seems to be critical of his fellow man, like we’re doing something wrong. I just don’t get it.
Let’s step back and look at things more objectively than Attenborough does, not as a human who feels guilty about trashing his planet’s ecosystem, but as a detached, dispassionate observer of life on the third planet from the Sun. From that perspective, one cannot possibly be concerned about what Homo sapiens has been up during its brief appearance on Earth. Why, they’ve only just arrived, in terms of geologic time, much less cosmic. The planet was formed about 4.5 billion years ago, but humans have only been around for about 200,000 years, a veritable blink of the eye. They haven’t even had time to become the dominant life form on the planet. That would be bacteria. They’re everywhere. They vastly outnumber humans. In fact, there are more bacterial cells in every human, ten times more, than there are human cells. They’ve been around a lot longer than humans, billions of years longer. They’ve seen many other species come and go during that time, and they will no doubt outlast Homo sapiens, as well. Indeed, 98 percent of all the species that have lived on Earth are already extinct, and thousands of species are dying out every year in this, the sixth mass extinction event in Earth’s history. Yeah, all right, humans may be the cause of this particular extinction, for all the reasons mentioned above, and more, but what other choice did they have? They’re not Leporidae (bunny rabbits), they’re Homo sapiens (human beings). Man’s gotta do what man’s gotta do.
And anyway, stuff happens, with or without humans. The previous five mass extinctions were caused by combinations of such factors as impacts of large objects, volcanic activity, toxic gasses, climate extremes, plate tectonics, gamma rays, and other disturbances to the fragile habitable zone in which life on Earth can exist. There’s only a very thin layer of land, water, and air, just a few miles from the highest to the lowest point, that is livable. If Earth were a big onion, life would be possible only on the outermost layer of skin. You know, that layer you don’t even have to peel away, that literally breaks apart and falls off at the least disturbance? Five mass extinctions. Do you detect a trend here? Is a large comet already heading our way? Is a supervolcano about to erupt? Perhaps, but life on Earth is no longer dependent on such natural disasters for periodic reboots now that Homo sapiens is on the scene. And if they can pull it off, it’ll still be a “natural” disaster, for as much as they set themselves apart (even Attenborough distinguishes humans from “the natural world”), they are nevertheless just another of nature’s life forms, a branch of the Hominid evolutionary tree, a nearly hairless ape, chock full of bacteria, with a knack for making tools.
Nature programs all its life forms with genetic capabilities and tendencies. Fish gotta swim. Birds gotta fly. Bunnies gotta reproduce. Bacteria occasionally gotta go berserk and embark on mass killing sprees (like Yersinia Pestis, bubonic plague, pictured above and more popularly known as the Black Death). Clever humans have figured out how to do all those things, and whatever they figure out how to do, they gotta do. It’s not right or wrong. It’s just the way things are. So, relax, Sir David. You can’t fight human nature. Just enjoy the time you have left with friends and family, and don’t worry about a future you cannot control.
Now, I don’t want to end on a sour note, so let me remind you that somehow life always finds a way. Every time it’s almost been snuffed out on Earth, it has come back. That’s how humans got their chance, after dinosaurs were swept away in the fifth mass extinction. Who knows what sentient life forms will follow us, after the sixth? And who knows what wondrous beings inhabit other planets among the 150 billion in just our own Milky Way galaxy, not to mention the innumerable galaxies and planets in the infinite universe beyond? Of course, even if advanced extraterrestrial life forms are plentiful, their existence may be as relatively brief as ours, since they would be subject to the same sorts of periodic planetary mass extinctions, self-inflicted or otherwise, that we are. Ironically, it may be that the more “advanced” a creature is, the less likely are its prospects for long term survival. This could explain why intelligent life forms cannot communicate with each other across vast cosmic distances. By the time a message reaches its destination, there’s nothing but bacteria left alive on either end of the line.
[Correction: Bacteria are not the most abundant life form on Earth. Viruses that infect them, bacteriophages, have earned that honor, "their numbers far exceeding that of stars in the universe," according to the National Geographic ("The Secret World of Microbes"). So, it's the trillions of viral killers within each of us that constitute the real "plague on Earth," Sir David. Bacteria and humans can just get in line.]