Self-Replicating Chemicals Evolve Into Lifelike Ecosystem
May 6, 2010
I have already written several blogs about Life… You know, the scientific aspects of Life… Trying to understand it all a bit better… Asking really ‘silly’ questions about things like “When Does Life Really Become Life?” Or “What Is Life?” All the way through to “Just How Did Life Seed Here On Earth?” Thrown in with clangers like “Might We Be Able To Create Life In The Laboratory To Recreate Those Initial Conditions That Gave Rise To Life As We Know It Here On Earth?” And, would you believe, I even thought I could attempt to discuss “What This Experience Of Being Alive Really Is And How It Came About!” Wow… What delusions of grandure, eh? Lock me up and throw away the key…
Anyway… Would you believe, after all that, I’m back at this door again??? Trying to understand whether it’s as obvious as it seems… As obvious as it feels, even… That Life naturally happens, whether you want to believe it or not, independently and regardless of any divine creator or omnipotent god that we care to imagine. This time someone else has opened the doorway to another side – and another aspect – of this reality that we think we understand so well… They’ve prised it open just that little bit further than before… Just ever-so-slightly more… And with that, what we can now see shinning back through that widening crack, would you believe… Is that it seems self-replicating chemicals can evolve into lifelike ecosystems!?!? Similar to those found here on Earth!?!?
So… Along with the fractal geometry that lies hidden within the heart of our cellular make up… And what with all the other properties of the universal star stuff of atoms… Which are like Lego building blocks… Isn’t that almost enough to allow us to begin to see past the delusions of the yester-year? Can’t we just accept that life is a natural aspect of universal unfolding? That we all come from natural cosmic phenomena? And one day we will all go back there…
Well… I certainly can’t tell you what to think. So I’ll just have to let you decide for yourselves on that one…
But first, before you make up your mind, just have a “butchers-hook” at this…
Self-Replicating Chemicals Evolve Into Lifelike Ecosystem
Life makes more of itself.
And now so can a set of custom-designed chemicals. Chemists have shown that a group of synthetic enzymes replicated, competed and evolved much like a natural ecosystem, but without life or cells.
“So long as you provide the building blocks and the starter seed, it goes forever,” said Gerald Joyce, a chemist at the Scripps Research Institute and co-author of the paper published Thursday in Science. “It is immortalized molecular information.”
Joyce’s chemicals are technically hacked RNA enzymes, much like the ones we have in our bodies, but they don’t behave anything like those in living creatures. But, these synthetic RNA replicators do provide a model for evolution — and shed light on one step in the development of early living systems from on a lifeless globe.
Scientists believe that early life on Earth was much more primitive than what we see around us today. It probably didn’t use DNA like our cells do. This theory of the origin of life is called the RNA World hypothesis, and it posits that life began using RNA both to store information, like DNA does now, and as a catalyst allowing the molecules to reproduce. To try to understand what this life might have looked like, researchers are trying to build models for early life forms and in the process, they are discovering entirely new lifelike behavior that nonetheless isn’t life, at least as we know it.
As Joyce put it, “This is more of a Life 2.0 thing.”
The researchers began with pairs of enzymes they’ve been tweaking and designing for the past eight years. Each member of the pairs can only reproduce with the help of the other member.
“We have two enzymes, a plus and a minus,” Joyce explains. “The plus assembles the pieces to make the minus enzyme, and the minus enzyme assembles the pieces to draw the plus. It’s kind of like biology, where there is a DNA strand with plus and minus strands.”
From there, Joyce and his graduate student Tracey Lincoln, added the enzymes into a soup of building blocks, strings of nucleic bases that can be assembled into RNA, DNA or larger strings, and tweaked them to find pairs of enzymes that would reproduce. One day, some of the enzymes “went critical” and produced more RNA enzymes than the researchers had put in.
It was an important day, but Joyce and Lincoln wanted more. They wanted to create an entire population of enzymes that could replicate, compete and evolve, which is exactly what they did.
“To put it in info speak, we have a channel of 30 bit capacity for transferring information,” Joyce said. “We can configure those bits in different ways and make a variety of different replicators. And then have them compete with each other.”
But it wasn’t just a bunch of scientist-designed enzymes competing, like a miniature molecular BattleBots sequence. As soon as the replicators got into the broth, they began to change.
“Most of the time they breed true, but sometimes there is a bit flip — a mutation — and it’s a different replicator,” explained Joyce.
Most of these mutations went away quickly, but — sound familiar? — some of the changes ended up being advantageous to the chemicals in replicating better. After 77 doublings of the chemicals, astounding changes had occurred in the molecular broth.
“All the original replicators went extinct and it was the new recombinants that took over,” said Joyce. “There wasn’t one winner. There was a whole cloud of winners, but there were three mutants that arose that pretty much dominated the population.”
It turned out that while the scientist-designed enzymes were great at reproducing without competition, when you put them in the big soup mix, a new set of mutants emerged that were better at replicating within the system. It almost worked like an ecosystem, but with just straight chemistry.
“This is indeed interesting work,” said Jeffrey Bada, a chemist at the Scripps Institution of Oceanography, who was not involved with the work. It shows that RNA molecules “could have carried out their replication in the total absence” of the more sophisticated biological machinery that life now possesses.
“This is a nice example of the robustness of the RNA world hypothesis,” he said. However, “it still leaves the problem of how RNA first came about. Some type of self-replicating molecule likely proceeded RNA and what this was is the big unknown at this point.”
I mean… Seriously… Throw in a bit of self-similarity, along with many, many, many lashings – so many that it might well ‘seem’ to boarder with infinity – of complexity, and can we surely not begin to see obvious parallels between how human life arose on Earth from the “primordial soup” and those three “clouds of winners” that arose from the broth of enzymes? Aren’t these really just similar phenomena unfolding across vastly different scales of both size and time? A vast ocean of atomic interactions that occur upon the closed ecosystem that we call Earth vs. another closed ecosystem of much smaller proportions i.e. the very humble sterile laboratory flask? Are these not self-similar patterns… Patterns that elude toward a subtle and intrinsic ideal of temporal universal unfolding?
Dare I say it… Could we even begin to call this phenomenon “GOD“!? Well… If you want to equate the Mandelbrot set, via modes of analogy, to the thumb print of God, primarily because we observe these fractal like patterns almost everywhere within nature… And, thus, we begin to use them to describe God as Spinoza did i.e. “God, or Nature” as an ‘unknowable’ and ‘unfathomable’ reality of the whole of existence/creation, then I just might possibly begin to agree with you.
To find out where I sourced this article from, please click here.
And to read more about Professor Gerald Joyce, please click here.
OR to read more about the amazing research being done at the Scripps Research Institute, please click here.