Here, There and Everywhere: What We Really Know About the Origin of Life
Starting the week by looking at how science speculates on how it all started.
A while back I saw part of a National Geographic show about astrobiology (or exobiology) — the science of looking for life outside of the Earth. I didn’t get to see the whole program, but what I did see featured some amazing facts about where life can find a niche on earth — and maybe elsewhere?
The operative word there, of course, is maybe. It’s a word that applies to life on other worlds, and also to theories of how life got its start on earth, if you take the position that God didn’t create it.
As it turns out, for those who don’t believe God wasn’t responsible for the origin of life, we know just as much about how it might have gotten started on its own here as we know about life on outside of Earth: pretty much nothing.
But let’s start with some things we do know:
Amazing Life on Earth
There are microorganisms in boiling pools at Yellowstone, where the pH is 1 (about the same as battery acid), and you or I would quickly dissolve if we fell in.
There are tall tube worms at the dark bottom of the ocean, living without access to the solar energy the rest of earth’s life depends on. They get their energy and nutrients from searingly hot (600° — they didn’t say whether Fahrenheit or Celsius) mineral plumes issuing from deeper in earth’s crust.
If life could thrive there, who knows where else it might exist? There are ice crystals just inches below the surface of Martian soil. Maybe deeper down, there’s enough pressure to liquefy that ice into water. There could be life there.
Europa, one of Jupiter’s moons, is covered with water ice. It, too, might have enough internal heat for liquid water to exist below the surface. Maybe there’s enough tectonic activity to produce usable energy down there. Maybe life has developed there, too.
Titan, Saturn’s largest moon, has a methane atmosphere. It’s so cold there — hundreds of degrees below zero — that methane falls like rain and flows across the surface like water. Sure, it isn’t really water, but as one scientist on the show said, it’s at least fluid: it’s a medium where things can move around and interact. And who can say? Maybe life could develop in other chemistries besides water.
The (cough) “Known Universe” of Maybes
Maybe. Might have. Maybe. Maybe. Who knows? Lots and lots of questions.
Here’s the kicker, though: the title of that show was The Known Universe.
What do we really know, then, about life elsewhere? Lots of maybes.
Some of those maybes are worse than unlikely. Pardon me for not being a chemist or anything, but one thing I’m pretty sure we know is that evolution requires time, lots and lots of it. It also requires chemical reactions. Lots of them; astronomical numbers of them. But chemistry happens a lot slower in extreme cold. If Titan is home to life it would take a truly titanic set of fortuitous coincidences. More likely it’s the speculation involved there that’s titanic.
Speaking of coincidences, though, right now I’m listening to an online jazz program. Currently playing, and I’m not making this up: Tom Tallitsch’s cover of “Life on Mars.” It’s better than David Bowie’s version. It’s also better than any life on Mars so far discovered.
Maybe, Maybe, Maybe: The Origin of Life on Earth
But forget what we know about life elsewhere; what do we know about how the first life evolved on earth? From LiveScience.com, here are some possibilities:
- “Lightning may have provided the spark needed for life to begin.”
- “The first molecules of life might have met on clay, according to an idea elaborated by organic chemist Alexander Graham Cairns-Smith at the University of Glasgow in Scotland.”
- “The deep-sea vent theory suggests that life may have begun at submarine hydrothermal vents spewing key hydrogen-rich molecules.”
- “Ice might have covered the oceans 3 billion years ago, as the sun was about a third less luminous than it is now, scientists say. This layer of ice, possibly hundreds of feet thick, might have protected fragile organic compounds in the water below from ultraviolet light and destruction from cosmic impacts. The cold might have also helped these molecules to survive longer, allowing key reactions to happen.”
- “Nowadays DNA needs proteins in order to form, and proteins require DNA to form, so how could these have formed without each other? The answer may be RNA, which can store information like DNA, serve as an enzyme like proteins, and help create both DNA and proteins.”
- “Instead of developing from complex molecules such as RNA, life might have begun with smaller molecules interacting with each other in cycles of reactions. These might have been contained in simple capsules akin to cell membranes, and over time more complex molecules that performed these reactions better than the smaller ones could have evolved.”
We Know About Life’s Origin Here About as Well as on Europa
What do we really know about the origin of life on earth? From those first six theories: “May have.” “Might have.” “may have.” “Might have/might have.” “May be.” “Might have.” “Perhaps.” The language suggests our knowledge of life’s origin here is no better than its possibility on Mars or Europa. And if that language doesn’t convince you, number 7 should:
7. “Perhaps life did not begin on Earth at all, but was brought here from elsewhere in space, a notion known as panspermia.”
Here’s what that tells us about learning how life first evolved on earth. It tells us we might have to answer the problem of life’s origin somewhere very far away, before we can solve the problem here.
So next time someone tells you we know life came about by evolution, tell them he’s got a titanic problem to solve before he can make that claim. None of theories are worth hanging your hat on. None of them explains the origin of life.
But an Intelligent Designer certainly could.
Originally appeared at ThinkingChristian.net. Republished with permission.