People who follow SETI, the Search for Extra-Terrestrial Intelligence, likely know about the Drake equation. It was the brainchild of one of the founding fathers of SETI, Frank Drake. In order to estimate the probable number of other intelligent civilizations in the galaxy, he wrote his famous equation as the product of a series of factors, such as the number of stars, those with planets in the habitable zone, those on which life emerges, the fraction of those who evolve intelligent life, and the lifetime of a communicating civilization.
An equation is only as useful as its inputs. Almost every variable in the Drake equation is pure guesswork. Consequently, you get optimistic or pessimistic answers depending on your assumptions. This led origin-of-life champion Stanley Miller to quip in his book The Origins of Life on the Earth, after showing a table with conservative estimates from Harlow Shapley and optimistic estimates by Drake and Sagan, “Also included in the table is space for the reader to put in his own numbers. These can be considered as reliable as the other two estimates” (p. 214).
Is there any value in such an exercise, when the answers can vary over many orders of magnitude? Perhaps. At least the equation drew attention to minimum requirements for intelligent life. It could be argued that Drake did not take into account all the requirements, but the eight factors he did include allowed other SETI researchers to go to work constraining this or that variable. The bottom line is still ignorance, but a more sophisticated ignorance.
The OoL Frequency Equation
In the tradition of Drake, Caleb Scharf from the Columbia Astrobiology Center and Leroy Cronin of Glasgow University decided to hone in on the “entry point” for speculations about SETI, the origin of life (OoL). They explain their purpose in their paper in the Proceedings of the National Academy of Sciences:
In 1961, Frank Drake introduced an equation to illustrate the factors involved in estimating the potential number of communicative civilizations in the Milky Way galaxy. This formula, now generally known as the Drake Equation, has served as a useful tool for focusing discussion on the extent to which we do, or do not, have constraints on its various factors and for stimulating ideas about how to make scientific progress on the problem of finding life in the universe over a given period. There are however serious limitations to actually using the Drake formula to produce meaningful estimates of life’s frequency in the universe. A particular issue is that although the formula seeks to describe the entire galaxy’s living population, it does not explicitly allow for the possibility of life spreading and expanding between planets. Thus, the factors in the equation may not be independent at all.
Here, we propose that a focus on the detailed parameters involved in planetary OoL offers a better-constrained entry point to this type of estimation and could produce practical results, especially when combined with the search for potentially “habitable” exoplanetary systems. Assuming that life on Earth did originate in situ — in other words, that the transition, or the key transitions, between a nonliving state and a living state occurred within the planetary environment and not from far off-world (e.g., panspermia beyond the planetary system) — it should be possible to construct a high-level quantitative description of the basic features of an OoL, irrespective of the details. [Emphasis added.]
Their resulting “OoL Frequency Equation” considers the following factors, which can be seen as expansions of Drake’s variable fl, the fraction of habitable planets on which life does arise. The mean number of OoL events, which they call Nabiogenesis, is a function of:
Nb = The number of potential building blocks. Presumably life is more probable if more ingredients are present.
no = The mean number of building blocks per “organism” or “biochemically significant system” capable of reproduction and evolution.
t = The time available on a planet for life to appear.
fc = The fractional availability of building blocks during time t.
Pa = The probability of assembly per unit time.
The structure of the equation need not concern us as much as the significance of each factor. The last factor Pa is clearly the most significant of all. It’s about probability. Scharf and Cronin recognize that the origin of life, in their own perspective, boils down to one thing: a lucky accident. Unless the probability is sufficiently high for a minimal cell to self-assemble, the other terms don’t matter. In his book Evolution from Space, Sir Fred Hoyle estimated it to be “an outrageously small probability that could not be faced even if the whole universe consisted of organic soup” (p. 24).
Others have calculated similar outrageously small probabilities, including Walter Bradley and Charles Thaxton (The Creation Hypothesis) and Biologic Institute director Doug Axe (cited by Stephen Meyer in Signature in the Cell). Using Axe’s estimate of functional sequences in sequence space, Meyer calculates a 1 in 10164 chance of getting a single moderately small protein 150 amino acids long. This extreme improbability, 14 orders of magnitude smaller than Dembski’s universal probability bound of 1 in 10150, obliterates the equation’s usefulness. It would be like finding you have to pay a 10164 % tax on a one-dollar purchase. No amount of tweaking the other factors would make a difference; nobody would buy it.
Let’s see if Scharf and Cronin recognize the problem. They fudge Pa a bit by allowing for some “cosmic exchange” of building blocks (a form of accidental panspermia), hoping to expand the playing field for chance.
Eq. 1 makes no assumptions about Pa; the equation is simply the probability of assembly per unit time per set of building blocks when all other necessary conditions are met, but a further exploration of the potential influence of mutually exclusive building blocks could prove instructive.
Live Science says it’s like having “a trillion test tubes” working the problem. But as we just said, if the sequencing probability is already beyond the universal probability bound, it wouldn’t matter if the whole universe were stuffed with building blocks. It isn’t going to happen.
When life originates on a planet, whether Earth or a distant world, the newborn life-forms may have to overcome incredible odds to come into existence — and a new equation lays out exactly how overwhelming those odds may be.
Against these “incredible odds,” astrobiologists believe it did happen, at least on earth. But you can’t make a case with a sample size of one. Nor can a materialist beg the question by saying that life on earth arose by naturalistic processes.
In short, the equation reduces to the probability question. Paul Davies told Live Science:
“We don’t know the mechanism whereby nonlife turns into life, so we have no way of estimating the odds … It may be one in a trillion trillion (it’s easy to imagine that), in which case, Earth life may be unique in the observable universe,” Davies told Space.com in an email. “But Pa may be quite large. We simply can’t say.”
How useful is the OoL Frequency Equation, then? Like the Drake equation, it puts a veneer of sophistication on ignorance. It clouds the probability issue with other less relevant factors.
“We’re being kind of sneaky,” Scharf said. “I think it’s one of the beautiful things about it: If you write the equation this way, you don’t necessarily have to worry about all the fine, fine details, but what you do do is, you start to break open the factors that you might be able to put some numbers to.”
This is a distraction. The “probability of assembly” must be faced. A minimal cell has to emerge in one place in the amount of time available, such as on the surface of the earth after it has cooled and before it burns up by an aging sun. The building blocks must assemble into functional forms; it’s a sequencing problem, comparable to the origin of meaningful text. Furthermore, as Meyer explains, the building blocks must join up in a one-handed form and avoid damaging cross reactions (for proteins, this means left-handed amino acids only forming peptide bonds). If getting one small protein to spontaneously form is already beyond the universal probability bound, how much more a whole suite of proteins and enzymes (about three hundred according to some estimates), a genetic code, and a membrane to hold it all together?
Evolutionists are eager to leap over the OoL hurdle so that they get where they feel more comfortable, with Darwinian evolution. Once life exists, natural selection becomes their magic wand, able to turn protocells into philosophers’ brains. Thus, Washington State University announces, “If life can make it here, it can make it anywhere” — meaning, “If the origin of life is common on other worlds, the universe should be a cosmic zoo full of complex multicellular organisms.”
That’s a big if. WSU astrobiologist Douglas Schulz-Makuch says that “once life originates, the evolution of organisms functionally similar to plants or animals on Earth will naturally follow given enough time and a suitable environment.” This is the potential of natural selection to evolutionists — an interesting question for another time. But prior to it, there’s that origin-of-life probability question:
The one caveat is that the research doesn’t address the likelihood of the origin of life occurring elsewhere or of there being aliens with human like intelligence. Earth is the only planet where life is known to exist, and humans are the only known species to have developed technology. So it is impossible to say whether this should be a common occurrence on other worlds, a very rare event or something in between.
Actually, it is possible to say. If nothing but chance is available to sequence the ingredients needed for a minimal cell, the probability is so tremendously beyond the universal probability bound as to rule it out of court. By contrast, we know of a cause that can organize building blocks into functional complex structures. That cause, of course, is intelligence.
Image credit: Spiral galaxy NGC 6814, by ESA/Hubble & NASA.