A view of the Milky Way toward the constellation Sagittarius (photo by Steve Jurvetson)
With spring now performing its magic all around us, the origin of life often comes to mind. Was it a random, dumb, haphazard process, or is there a deep-seated intelligence to Nature?
Evolution is a fact, not a theory. But just as factual is that science doesn’t really know how life began, and what consciousness really is, and how it can arise in the first place – not a clue. A plethora of books “about consciousness” share in common a breathtaking employment of doubletalk and gibberish: no help there at all. And because scientists are rarely humble or candid enough to say they haven’t a clue, maybe they oughtn’t get too bent out of shape by others filling in the blanks with “intelligent design,” since that doesn’t explain anything either. These things might well remain mysteries forever, and perhaps it’s best to leave insuperable mysteries alone until you can actually come up with something smart to say.
We’re not even sure about the place where life originated. Until recently, most scientists dismissed the idea that earthly life came from deep space. After all, the fossil record shows that simple life began as soon as our planet became a hospitable abode, 3.9 billion years ago. Earth had carbon, water, lightning: everything you’d want in a primordial chemistry set.
Somehow very complex molecules sprang up, including the amino acids that are the building blocks of living matter. The question is: Did these originate on Earth, or were we “seeded” from space?
The issue has enormous implications. If Earth was the source, then it’s very unlikely that we’ll ever encounter lifeforms remotely similar to what we see around us. If, on the other hand, amino acids are strewn throughout the galaxy, then not only might life be exceedingly common, but it may even bear a superficial resemblance to Ricardo Montalban (“Khan”) – or at least Worf.
During the last few decades, spectrographs detected ever-more-complex molecules among the dark, dusty gas clouds of the Milky Way. Ethyl alcohol was first discovered celestially in the ’60s, opening the possibility of future wild parties in Sagittarius. Things like cyano-acetylene – precursors to the amino acids so basic to life – were found a decade later. Then the ’90s brought us a real eye-opener: glycine, the first bona fide amino acid, found in distant star-clouds.
At the same time, the signature of water was seen in faraway galaxies. But astronomers always assumed that the universe contains copious water, since it’s the most common compound in existence. Now that we’ve found an ocean under the ice of at least one moon of Jupiter, it’s obviously abundant. Finding water out there is no more surprising than finding socks under your bed. But finding glycine among the raven clouds of night, amidst the Milky Way that spreads across the heavens these very nights, is stunning.
There’s still plenty of room for caution. Even if amino acids managed to hitch rides out of their protective nebulae in meteors, ultraviolet radiation would quickly break such complex molecules into simpler ones. A romantic rain of meteors delivering the seeds of future life to a primordial Earth requires the implausible persistence of fragile compounds for millions of years. And yet, with a streptococcus managing to survive on our own sterilizing, airless Moon for nearly three years aboard the Surveyor spacecraft, who can say that some protective encasement – like inside deep cracks aboard meteors – mightn’t shield complex molecules during their ages-long journey?
Of course, this in no way explains the awesome, mysterious transformation of complex molecules into the magic of life itself. But we can all probably agree that the place where the first seeds of life originated is now very much an open question.
