Still Unexplained: The First Living Cell
Editor’s note: We are delighted to present a series by Walter Bradley and Casey Luskin on the question, “Did Life First Arise by Purely Natural Means?” This is the seventh entry in the series, a modified excerpt from the recent book The Comprehensive Guide to Science and Faith: Exploring the Ultimate Questions About Life and the Cosmos. Find the full series so far here.
In recent years, MIT physicist Jeremy England (pictured above) has gained media attention for proposing a thermodynamic energy-dissipation model of the origin of life. England’s view was summarized when he famously said that the origin and evolution of life “should be as unsurprising as rocks rolling downhill.” He continued, “You start with a random clump of atoms, and if you shine light on it for long enough, it should not be so surprising that you get a plant.”1Another physicist, ID theorist Brian Miller, has responded to England’s research.
Miller points out that the kind of energy that dissipates as a result of the sun shining on the Earth or other natural processes cannot explain how living systems have both low entropy (disorder) and high energy. As Miller puts it: “These are unnatural circumstances. Natural systems never both decrease in entropy and increase in energy — not at the same time.” Living cells do this “by employing complex molecular machinery and finely tuned chemical networks to convert one form of energy from the environment into high-energy molecules” — things that cannot be present prior to the origin of life because they must be explained by the origin of life. Without this cellular machinery to harness energy from the environment and drive down entropy, England’s energy-dissipation models cannot do the task they’ve been handed. As Miller said, England’s model cannot account for the origin of biological information, which “is essential for constructing and maintaining the cell’s structures and processes.”2
A Crucial Deficiency
Miller has highlighted a crucial deficiency in origin-of-life models: What is the origin of the cellular machinery, and the information that encodes the machinery that undergirds even the simplest cell? Forming a self-replicating RNA molecule, a seemingly impossible task under natural Earth conditions, is still a far cry from producing all the vast machinery required by cells to exist. A final obstacle for the RNA world — and any naturalistic account of the origin of life — is therefore its inability to explain the origin of the genetic code and the molecular machinery of life.
There is an important distinction between the genetic code and the information in DNA or RNA: The genetic code is essentially the language in which the genetic information in the DNA or RNA is written. In order to evolve into the DNA/protein-based life that exists today, the RNA world would need to evolve the ability to convert genetic information into proteins. However, this process of transcription and translation requires a large suite of proteins and molecular machines — which themselves are encoded by genetic information. This poses a chicken-and-egg problem, where essential enzymes and molecular machines are needed to perform the very task that constructs them.
To appreciate the obstacle this poses to materialistic accounts of the origin of life, consider the following analogy. If you have ever watched a DVD, you know that it is rich in information. However, without the machinery of a DVD player to read the disk, process its information, and convert it into a picture and sound, the disk would be useless. But what if the instructions for building the first DVD player were only found encoded on a DVD? You could never play the DVD to learn how to build a DVD player. So how did the first disk and DVD player system arise? The answer is obvious: Intelligent agents designed both the player and the disk at the same time, and purposefully arranged the information on the disk in a language that could be read by the player.
The Proper Machinery
In the same way, genetic information could never be converted into proteins without the proper machinery. Yet the machines required for processing the genetic information in RNA or DNA are encoded by those same genetic molecules — they perform and direct the very task that builds them. This system cannot exist unless both the genetic information and transcription/translation machinery are present at the same time, and unless both speak the same language. A functional living cell therefore can’t evolve in a piecemeal fashion, but the likelihood of it arising all at once by unguided natural processes is far too low to be considered a viable model.
Biologist Frank Salisbury explained this problem in American Biology Teacher in 1971, not long after the workings of the genetic code were first uncovered:
It’s nice to talk about replicating DNA molecules arising in a soupy sea, but in modern cells this replication requires the presence of suitable enzymes…[T]he link between DNA and the enzyme is a highly complex one, involving RNA and an enzyme for its synthesis on a DNA template; ribosomes; enzymes to activate the amino acids; and transfer-RNA molecules…How, in the absence of the final enzyme, could selection act upon DNA and all the mechanisms for replicating it? It’s as though everything must happen at once: the entire system must come into being as one unit, or it is worthless. There may well be ways out of this dilemma, but I don’t see them at the moment.3
An Unsolved Problem
The same problem confronts modern RNA world researchers, and it remains unsolved. As two theorists observed in a 2004 article in Cell Biology International:
The nucleotide sequence is also meaningless without a conceptual translative scheme and physical “hardware” capabilities. Ribosomes, tRNAs, aminoacyl tRNA synthetases, and amino acids are all hardware components of the Shannon message “receiver.” But the instructions for this machinery is itself coded in DNA and executed by protein “workers” produced by that machinery. Without the machinery and protein workers, the message cannot be received and understood. And without genetic instruction, the machinery cannot be assembled.4
Unless origin-of-life theorists can account for (1) the molecular machinery of the cell, (2) the information which encodes that machinery, and (3) the ability of cells to process that information to construct this machinery via a genetic code, the origin of even the simplest cell remains unexplained. Perhaps these seemingly intractable fundamental problems have an out: lots of time.
Next, “Origin of Life: Saved by Time?”
- Jeremy England quoted in Natalie Wolchover, “A New Physics Theory of Life,” Quanta Magazine (January 22, 2014), https://www.quantamagazine.org/a-new-thermodynamics-theory-of-the-origin-of-life-20140122/ (accessed November 18, 2020).
- Brian Miller, “Hot Wired,” Inference Review: International Review of Science 5 (May 2020), https://inference-review.com/article/hot-wired (accessed November 18, 2020).
- Frank B. Salisbury, “Doubts About the Modern Synthetic Theory of Evolution,” American Biology Teacher 33: 335-338 (September 1971).
- J.T. Trevors and D.L. Abel, “Chance and necessity do not explain the origin of life,” Cell Biology International, 28: 729-739 (2004).