A young planet sits in wobbly orbit, still a bit amorphous and unsure of its final shape. A gurgling, bubbling primordial soup simmers on the surface, stewing and brewing for millions upon millions of years as massive temperature fluctuations, atmospheric pressure shifts, and extended bouts of thunderous lightning mar the landscape. Radiation is a constant, steady force. Deep within the soup, a spark! The beginnings of life, the organic, single-celled compounds that will grow and reproduce and mutate into a hundred million fantastical forms, emerge. All the while, similar ? yet totally different ? conditions are occurring on other planets concurrently, but no spark is seemingly produced. Why is that?
Consider, for a moment, the plight of the modern feedlot cow, a species that evolution has ?constructed? to subsist most effectively on open grassland with plenty of access to sun and the freedom to roam. Instead, we stuff it full of corn, jam it into a filthy muddy pen, and pump it full of medication. Is it any wonder corn-fed cows sicken and produce substandard meat as a rule?
Sometimes called the Hawaiian squirrel, the mongoose has overrun most of Hawaii?s islands and disrupted the wildlife. Originally a transplant meant to combat the hordes of rats decimating the cane fields in the 1880s, the Hawaiian mongoose has decimated the wild bird population by targeting its eggs and nests. A seemingly innocuous, rather small species of mammal was essentially enough to damage an entire ecological niche beyond repair. It being island-based made things even worse, because the native inhabitants lived in a totally insular world. The longer you go without outside influence, the bigger an impact any outside influence will have.
Or what of the young boy who captures a handful of fiddler crabs at the beach and decided he?ll keep them as pets? Is table salt added to sand and water a suitable environment? Or is every single mineral present in seawater also crucial for the fiddler crab?s survival? Calcium, magnesium, potassium, chlorine, and sulfate are all present in seawater, along with sodium, to form the crab?s natural habitat. Tap water with salt added doesn?t work; I know because I was once that young boy.
The sad, slow decline of the giant panda can also be attributed to a series of unfortunate environmental shifts. The first shift was whatever made pandas switch from an omnivorous, diverse diet to a bamboo-based one, with the most plausible theory being that they did it to avoid competition with other, more capable omnivores. Rather than die out (like many species might have), they simply moved onto the low hanging fruit ? the endless, untouched forests of bamboo. Of course, this move set a course toward an evolutionary dead end, but that happens from time to time. They came to rely on a totally unnatural food source: bamboo. These are animals with the digestive system of a carnivore attempting to thrive on a diet of low-nutritive, starchy cellulose and plant matter. To get sufficient nutrients, pandas had to consume over fifty pounds of bamboo each day. They survived, but only barely. Females were fertile for a few days a year at the most, male sex organs were sometimes too small to get the job done, and the infants they sometimes produced were completely helpless for too long. And when man began leveling bamboo forests to make way for development, the panda?s already tenuous dominion over its ecological niche was shattered. Conservation efforts haven?t helped much, either. Even with all the bamboo they can eat made available, male pandas in captivity often have no idea how to mate with a female, and panda numbers only manage to stay consistent (or rise somewhat). They?re still in cages, or behind bars betting gawked at by zoo goers. All in all, the panda made a tragic turn somewhere along the road. What began as a momentary adaptation to a change in environment (the introduction of a rival, perhaps) has ultimately forced the panda into an unsustainable, unnatural lifestyle punctuated by even more damaging, man-made environmental pressures.
Both individual species and life itself requires a specific set of environmental parameters to be satisfied.
Life, scientists conclusively agree and these examples show, is exceedingly rare and fragile in all its forms. An impossibly complex sequence of specific, precise machinations and circumstances were necessary for life as we know it to come into existence ? so complex, in fact, that we?re still figuring out exactly how it all went down. We do know that life (on Earth) is a system of proteins and nucleic acids forming structures that reproduce and evince genetic variability with each successive generation (evolution). We suspect that before life, there were pre-biotic chemicals intermingling in what Darwin called a ?warm little pond? of primordial ooze, and that these chemicals reacted with each other and certain environmental pressures (radiation, heat, moisture) to produce something approximating a living organism. In 1953, Stanley Miller and Harold Urey sought to reproduce primeval conditions by subjecting water, ammonia, methane, and hydrogen (atmosphere) to electric currents (lightning); amino acids, the building blocks of proteins, were formed. And just recently, researchers created RNA, which counts as its descendant DNA, by mixing an assortment of phosphates, sugar, and nucleotides in water and heating, evaporating, and irradiating it. But researchers had been trying for decades to create RNA, and it?s only recently that they actually succeeded.
How many times has nature ?tried? to do the same thing and failed miserably? Among all the billions upon billions of planets in the universe, how often have the perfect conditions arisen to allow the creation of life ? let alone its affluence? There?s no way to know (yet), of course, but I?d imagine that since the sky isn?t lit up with a steady stream of interstellar traffic, intelligent life on the level and complexity of Earth?s isn?t very common. We had committed, brilliant minds whose sole fixation was to produce a key precursor to organic life working around the clock, and they still barely managed to do it.
The basic building blocks of life aren?t unique to Earth, either, so other planets have had their chance. Meteorites and comets are known to house amino acids, nucleotides, and other prebiotic materials and many scientists posit a hail of prebiotic-bearing meteorites actually sparked life on Earth. Those same prebiotics undoubtedly slammed into every other planet, too, but whether any were able to make use of them remains to be seen. As far as we can tell from observing those planetary bodies within range of our instruments and assuming similar contact with prebiotic-bearing interstellar bodies, life had its chance to arise but did not (or if it did, it was brief and generally unsuccessful).
So, why us? Are we special?
We?re not exactly special; we aren?t anointed, chosen beings. We?re just lucky. And that?s even more beautiful, in my opinion. Just think. Life almost didn?t make it! If one little variable?s off ? maybe, I dunno, the seas were twice as salty ? life doesn?t form. How crazy is that?
On the global scale, life on Earth could not, and would not, survive, prosper, or even have come into existence without things the way they were and are. All those chemicals, elements, swirling gases, molten lava, boiling seas, lightning strikes, and shifting tectonic plates made life possible. Without each and every environmental variable in place, those phosphates and nucleotides might never have produced anything but inert brown goo. And without water, and an oxygen-rich atmosphere, life wouldn?t have flourished. Life, then, is completely reliant on a very specific environment.
The same holds true for individual species, which arise because of extremely specific environmental pressures and often come to thrive only when continually subjected to those same pressures. If the environment in which a species evolved changes or is eradicated, the species? fitness suffers. Sometimes that species adapts successfully, while others like the panda attempt to adapt but may ultimately fail. Either way, it changes the species forever. Individual species, then, thrive in the environment in which they were conceived and to which they are adapted.
For some reason, people forget that humans are beholden to the very same rules as every other life form. We forget that we remain animals, that we are the only remaining hominids heading a long line of bipedal, big-brained, meat-eating tool users. As such, we are even more susceptible to environmental pressures that conflict with our natural tendencies because we largely discredit evolution and ignore its implications for our lives.
Ignore evolution at your peril. Ignore the undeniable fact that the human animal (like any other) arose under certain environmental pressures, pressures that persisted for most of our formative years. Even more important than what our ancestral environments looked like is what they did not look like. They were not grocery stores with tons of refined carbohydrates and cereal grains lining the aisles. They were not sitting in traffic for an hour each way. They were not gallons of vegetable oils. They were not legions of obese diabetics.
And I?ll be the first to admit that we?re highly adaptable. We are, thanks to our massive meat-fueled brains. But though we can adapt to an alien lifestyle and survive, bear children, and lead seemingly normal lives, it isn?t ideal. It?s like the cow chowing down on soy and corn; he?s just eating what he’s given. It seems sufficiently food-like for his purposes, just as a breakfast of white toast, margarine, and jam seems like food to most people. That?s just skating by, though. That?s just surviving. Do we really want to be like the panda and subsist on nutritionally-bereft food just cause it?s there?
We are animals, and we are subject to evolutionary pressures. We came of age in a time without processed foods, sedentarism, and chronic stress. That is the environment for which we are adapted, and it is the environment towards which we should strive ? if we?re interested in optimum health, happiness, and longevity, that is.
Let me know your thoughts in the comment board. Thanks for reading!