The Origins of Life

In “What’s Next” I promised a dedicated post on the beginnings of life. Well, here it is, and it’s gonna be a long one so buckle up and grab an adult beverage to sustain you.

The origins of life have been hotly debated for a very long time. The early favorite — long before science intruded with its profane heresies — was that some sort of divine intervention put us here. Those with a Judeo-Christian heritage like to credit a supreme entity they call “God”, but nearly every culture that has ever existed (and left a verbal or written record) also puts the onus on some level of intelligent design. While the names and timing may have changed to adjust to the needs of the specific culture, the end result was always the same: the earth is here and so are we. Even J.R.R. Tolkien, in The Silmarillion, crafted a creation myth to explain how Middle Earth got to wherever it was.

It’s tempting to accept Intelligent Design and Divine Creation and move on — this is surely an easier (and ultimately safer) approach — but the scientist in me (and after too many years eavesdropping through the heater vent while the adults in my life tried to juggle the Bible vs. reality), I feel duty-bound to at least brush upon some of the scientific possibilities.

Marker Bed, my novel and geology primer is now available on Amazon. With heroes and a villain — and Xoix of course — the story takes place 300,000,000 years from now and documents the recognition of humanity in the fossil record. It is a must read for anyone who loves the earth and hopes that it will survive our tender mercies. If you haven’t already obtained your copy, I encourage you to do so now. Click here to go to the Amazon website and lock in your copy.

So, I’d like to use this post to take what will be an obviously imperfect look at the evolution of the scientific versions for the origins of life. I’ll leave the much more complex look at the origins of universal reality for a later post (and will surely write it long after 5:00 has come to lubricate my synapses).

One caveat before we jump in: Nothing below is offered as the final word on creation. Spoiler Alert: I wasn’t there! Whether I personally choose to believe in divine creation or science, my viewpoint is entirely based upon faith. That’s an easy and acceptable statement when it comes to having faith in God, but many science-minded dudes (and dudettes) like to think their version is best because it puts faith where it belongs and relies on cold, hard facts. But, since few if any of them actually did the experiments and collected the data they rely upon, their worldview is also faith-dependent. In the end, it all boils down to what we choose to put our faith in: the Bible or Bill Nye.

So, with my derrière (hopefully) covered, let’s dive into the deep end.

The traditional approach to the origin of life pretty much boils down to finding some way to create living and self-replicating packets of energy out of inorganic materials, through some magical process that has yet to be fully defined in unambiguous and acceptable terms.

These early efforts to explain the miracle usually included warm and shallow tropical seas, followed by some sort of external force to shock the system into action. This spark was often provided by some type of electrical discharge — typically lightning — that set the process in motion. This made abundant sense for a very long time, and spontaneous creation may still be the answer for how life got started on this planet.

But I have a few problems with this. Drawing on my admittedly imperfect understanding, the big one is as follows: all cellular life — as we know it — is based upon an organic molecule called DNA.

I was fortunate to do my half-day student teaching for my secondary credential in a high school biology class. I was also fortunate that DNA was on the menu while I was there. As I’ve said before: all the way through my version of high school I tried to keep as far from science as possible. So when I got to Mr. Boyea’s biology class, I pretty much had no idea what was going on, and was forced to learn along with the students. I’d like to think it was a win-win for all of us.

I was hopelessly captivated by DNA. One of the factoids I learned is that the DNA molecule is very complex — although absurdly simple — and yes again, it forms the basis of life on this planet: from me and you to redwood trees and banana slugs, panda bears and radioactive acid slime, even the primitive bacteria that keep everything clicking along smoothly — they all have DNA. Versatile stuff to be sure.

The DNA molecule is an intricate double-helix with over three billion base pairs. There are approximately six feet of DNA in each and every cell in your body! This two meter strand fits inside a cell nucleus measuring only six micrometers across by tightly winding around proteins called histones. If you stretched out the DNA from every cell in your body and laid the strands end-to-end, the chain would stretch roughly thirty-seven billion kilometers — reaching from the earth to the sun and back a hundred and twenty-five times!

So, here’s my question: How did an inorganic earth spontaneously craft the admittedly complex organic DNA compound, with its billions of base pairs, using just a little bit of warm water and a flash of lightning? Even single-celled bacteria — arguably the original life forms, no matter how they got here — had over ten million base pairs!

So… inorganic water and goo, to ten million base pairs in literally a flash of lightning? That’s the one step in the traditional process that always forces me to look for other alternatives. I just cannot seem to get my feeble brain to make the leap of faith…

So let’s move on, shall we?

Another process that has been bandied about for the beginnings of life doesn’t involve warm lagoons and lightning, but vents of hydrothermal fluids (hydro + thermal = water + hot) that discharge boiling-hot water into the deep, cold abyss of the planet’s oceans. These 350°C hydrothermal vents — also called “black smokers” because of the dissolved sulfur and metals they contain — have been recognized along every spreading axis on earth, and are locations for the formation of massive sulfide mineral deposits (hence my initial rabid interest).

(If interested, refer to earlier posts for a bit more on these types of base and precious metal deposits: “Minerals and Economic Warfare, Part 2”; and “The Phantom Tollbooth”. You can also review my report in the 1986 Oregon Geology magazine titled “Geologic Setting of the Turner-Albright Massive Sulfide Deposit” for the details of an Au, Cu, Zn, Ag, Co deposit built by black smokers 157 million years ago. For a wider view of hydrothermal systems and the rocks they are found in, check out my online Master’s Thesis “A Layperson’s Guide to the Josephine Ophiolite” which includes a detailed roadside tour.)

Anyway, back to the origins of life. Hydrothermal vents also host some of the most incredibly diverse chemosynthetic life forms you can imagine: giant tube worms; scaly-foot gastropods; yeti crabs; heat-resistant Pompeii worms; and fish with headlamps and really big teeth. According to the Natural History Museum, over three hundred animal species have been identified at hydrothermal vent sites, with roughly 95% of them found nowhere else on Earth.

Since these vents are generally below what’s called the “photic zone”, they cannot rely on photosynthesis to form the base of the food chain, but instead must call upon “chemosynthesis”: chemicals coming out of the hot water vents which sustain and support this deep-sea life.

There are a growing number of scientists who think that these undersea hydrothermal vents are the actual locations for the origin of life on this planet, making chemosynthesis the original creative spark behind the earth’s biosphere, and photosynthesis merely a convenient afterthought. (Question: Why can’t we have both — photosynthetic organisms derived from near-surface waters, and chemosynthetic lifeforms from deep-sea vents? It seems like each could have played its unique role in getting life going on this planet. But, again, I wasn’t there.)

Being who I am, however, I have to step back and take a broader perspective. What we’ve talked about so far is great for getting life on this planet, but what if there’s life elsewhere in the universe? How did it get there? Maybe they had warm shallow waters and cold deep waters as well, so we may not need another method to get life established on an exoplanet. But, it may not matter.

Let’s contemplate a third (or is it a fourth?) option…

But to set the stage we need to talk about snirtballs for a bit. We all know what happens when a snowstorm drifts into town: all the kids — and most of the adults — scamper outside, scoop up a double handful, and craft a snowball to throw at whoever happens to be nearby. But what if only half an inch of snow comes down? As Red will likely remind us in the comment section, “it just doesn’t snow like it used to!”

If less than an inch or so of the white stuff falls, we’re forced to scrape up snow from a much wider area, resulting in a handful of snow mixed with whatever might happen to be laying on the ground. Or, as is most likely, some of the ground itself. So, what we end up with is not a pristine white snowball, but a snirtball — part snow to be sure, but also in large measure dirt. The resulting ballistic sphere may be a couple flakes shy of kosher, but a snirtball throws just fine.

And then there are snockballs: innocent-looking snowballs with a dense rocky core. Snockballs are all too easy to make: simply pick up a rock — any rock will serve — and pack snow around it. It looks like any other snowball, and no one will have any idea about your evil intent… until it reaches its target. (Please note that while a snirtball is often the result of climate change and generally accidental, a snockball is always premeditated.)

Comets — often called “dirty snowballs” — are nothing more or less than giant snockballs in space. Essentially just frozen water and rock, they seem to be regular visitors to our solar system. Cometary impacts during the initial accumulation of our solar system are thought by many to be the source of much of the earth’s original hydrosphere.

But what if the water in a comet also contains the DNA molecule? Speaking only for myself, I really like this idea. It answers many of my most perplexing questions about the origins of reality.

(Lest you think I’ve flipped completely into the blue stuff, it should be noted that both NASA and the European Space Agency have launched cometary probes tasked, in part, with looking for “organic molecules and the chemical building blocks of life, such as amino acids, sugars, and nucleobases; the structural units that make up DNA”. They were apparently successful…)

Consider…

What if a comet is essentially a seed, bringing with it the organic compounds required to jump-start life, as well as the water needed to sustain that life and allow it to grow and flourish?

And, with time, evolve?

Think of any seed: drop it on the sidewalk and nothing happens. If it lands in a crack it may germinate, but will most likely wither and die all too soon. But drop it in the fertile soil of the tropics, and it will sprout and grow and lead to a forest of life.

Same with the myriad comets in orbit around our star. Slam one into Mercury, and nothing happens. Same with Jupiter or Pluto. But hit the earth — which is at the perfect distance from the sun to allow water to exist in all three phases at surface temperatures and pressures (called the “Goldilocks Zone” for reasons any preschool kid can understand) — and the seed will sprout and take root.

And, with time, evolve!

I envision a reality where all the stars (or at least many of them) also have accompanying planetary bodies… along with a passel of comets, each composed of water and the building blocks of DNA-based lifeforms. If even one of the planets orbiting all those pretty lights in the night sky is in that star’s Goldilocks Zone, it is possible, indeed likely, that life has had the opportunity to seed itself in every corner of the Universe.

A compelling image… at least to me.

This makes DNA a universal constant, and — again speaking only for myself — this is where God comes in.

Hey dude… nicely done!