Then God said, “Let the land produce vegetation: seed-bearing plants and trees on the land that bear fruit with seed in it, according to their various kinds.” And it was so. (Gen 1:11)
And God said, “Let the water teem with living creatures, and let birds fly above the earth across the vault of the sky.” (Gen 1:20)
And God said, “Let the land produce living creatures according to their kinds:the livestock, the creatures that move along the ground, and the wild animals, each according to its kind.” And it was so. (Gen 1:24)
The views of theism versus naturalism with regards to the origin of life couldn’t be more diametrically opposed. On one hand, you have creation of life by a divine intelligence. On the other hand you have a random combination of inanimate materials, in an unguided process, evolving into complex animate organisms also know as “dumb luck.”
For the moment, no one knows precisely how short strands of polynucleotides—the stuff that makes up our DNA and RNA molecules—would stick together to form longer chains eventually allowing an RNA molecule to form that could self-replicate so life would begin. No one has conducted an experiment leading to a self-replicating ribozyme. But the minimum length or “sequence” that is needed for a contemporary ribozyme to undertake what the distinguished geochemist Gustaf Arrhenius calls “demonstrated ligase activity” is known. It is roughly 100 nucleotides.
Whereupon, just as one might expect, things blow up very quickly. As Arrhenius notes, there are 4100, or roughly 1060 nucleotide sequences that are 100 nucleotides in length. This is an unfathomably large number. It exceeds the number of atoms in the universe, as well as the age of the universe in seconds. If the odds in favor of self-replication are 1 in 1060, no betting man would take them, no matter how attractive the payoff, and neither presumably would nature.1
Following that description, American philosopher and author David Berlinski notes that Arrhenius seeks to escape his own dilemma by proposing that such long self-replicating sequences may not have been as rare in the primeval earth as they are today. He then answers:
Why should self-replicating RNA molecules have been common 3.6 billion years ago when they are impossible to discern under laboratory conditions today? No one, for that matter, has ever seen a ribozyme capable of any form of catalytic action that is not very specific in its sequence and thus unlike even closely related sequences. No one has ever seen a ribozyme able to undertake chemical action without a suite of enzymes in attendance. No one has ever seen anything like it.
The odds, then, are daunting; and when considered realistically, they are even worse than this already alarming account might suggest. The discovery of a single molecule with the power to initiate replication would hardly be sufficient to establish replication. What template would it replicate against? We need, in other words, at least two, causing the odds of their joint discovery to increase from 1 in 1060 to 1 in 10120. Those two sequences would have been needed in roughly the same place. And at the same time. And organized in such a way as to favor base pairing. And somehow held in place. And buffered against competing reactions. And productive enough so that their duplicates would not at once vanish in the soundless sea.
In contemplating the discovery by chance of two RNA sequences a mere forty nucleotides in length, Joyce and Orgel concluded that the requisite “library” would require 1048 possible sequences. Given the weight of RNA, they observed gloomily, the relevant sample space would exceed the mass of the Earth. And this is the same Leslie Orgel, it will be remembered, who observed that “it was almost certain that there once was an RNA world.” 2
This section of Berlinski’s article deals with just one step of a multi-step process that would fashion the first life. Other pieces include the advancement from self-replicating RNA to a fully working cell producing the appropriate amino acids and nucleic acids to function as well as assembling the right nucleic acids to construct the polynucleotides to begin with. And we haven’t even factored in the problem of chirality. However, looking at Berlinski’s numbers alone, it seems clear that a reasonable person would not assume life came about by dumb luck.