The absence of known life beyond Earth can’t be used as proof of a higher being. PHOTOGRAPH BY NASA/THE LIFE PICTURE COLLECTION/GETTY

Recently, the Wall Street Journal published a piece with the surprising title “Science Increasingly Makes the Case for God.” At least it was surprising to me, because I hadn’t heard the news. The piece argued that new scientific evidence bolsters the claim that the appearance of life in the universe requires a miracle, and it received almost four hundred thousand Facebook shares and likes.

The author of the piece, Eric Metaxas, is not himself a scientist. Rather, he’s a writer and a TV host, and the article was a not-so-thinly-veiled attempt to resurrect the notion of intelligent design, which gives religious arguments the veneer of science—this time in a cosmological context. Life exists only on Earth and has not been found elsewhere. Moreover, the conditions that caused life to appear here are miraculous. So doesn’t that mean we must have come from a miracle at the hand of God? “Doesn’t assuming that an intelligence created these perfect conditions require far less faith than believing that a life-sustaining Earth just happened to beat the inconceivable odds to come into being?” Metaxas writes.

In response, I should begin by noting that the science of “astrobiology”—which, loosely stated, searches for signs of life elsewhere and explores the astrophysical and cosmological conditions that might allow for life to exist in our universe—is still in its infancy. Consensus on many issues has not yet been achieved, and the quality of work in the field varies significantly.

Still, what we have unequivocally learned over the past decade or so is, to paraphrase Hamlet, that there are many more things in Heaven and Earth than were dreamt of in our imagination. The opportunities for the development of life in various systems, and the possible forms of life we know of, have exploded. Metaxas believes that our increased understanding of our evolutionary history implies that the origin of life on Earth is increasingly inexplicable. But the evidence seems to point in the opposite direction.

Let’s start with the first point raised in the _Journal _piece, which is that the more we have learned about our own evolutionary history on Earth, the more we appreciate the many different factors that may have been important in allowing that evolution. For example, we know that had Jupiter, with its massive gravity, not existed, asteroids and comets would have bombarded Earth throughout its history, disrupting the stable evolutionary development of multicellular organisms. Moreover, we know that if our sun were not in the outer part of our galaxy, life as it exists would have been impossible, both because of the impact of harmful cosmic radiation and because of gravitational perturbations that might easily have disrupted stable planetary orbits. The moon formed during a collision involving the nascent Earth, giving the planet the tilt that allows for seasonal variations and tides. Earth exists in the habitable zone where liquid water is possible. Liquid water was possible only on early Earth because of the high concentration of carbon dioxide in the atmosphere.

By considering each of these many factors and imagining the probability of each separately, one can imagine that the combination is statistically very unlikely, or impossible. “Today there are more than 200 known parameters necessary for a planet to support life—every single one of which must be perfectly met, or the whole thing falls apart,” Metaxas writes. “The odds against life in the universe are simply astonishing.”

Such a claim is fraught with statistical perils, however. The first is a familiar mistake of elaborating all the factors responsible for some specific event and calculating all the probabilities as if they were independent. In order for me to be writing this piece at this precise instant on this airplane, having done all the things I’ve done today, consider all the factors that had to be “just right”: I had to find myself in San Francisco, among all the cities in the world; the sequence of stoplights that my taxi had to traverse had to be just right, in order to get me to the airport when I did; the airport security screener had to experience a similar set of coincidences in order to be there when I needed her; same goes for the pilot. It would be easy for me to derive a set of probabilities that, when multiplied together, would produce a number so small that it would be statistically impossible for me to be here now writing.

This approach, of course, involves many fallacies. It is clear that many routes could have led to the same result. Similarly, when we consider the evolution of life on Earth, we have to ask what factors could have been different and still allowed for intelligent life. Consider a wild example, involving the asteroid that hit Earth sixty-five million years ago, wiping out the dinosaurs and a host of other species, and probably allowing an evolutionary niche for mammals to begin to flourish. This was a bad thing for life in general, but a good thing for us. Had that not happened, however, maybe giant intelligent reptiles would be arguing about the existence of God today.

An even more severe problem in Metaxas’s argument is the assumption of randomness, namely that physical processes do not naturally drive a system toward a certain state. This is the most common error among those who argue that, given the complexity of life on Earth, evolution is as implausible as a tornado ravaging a junkyard and producing a 747. The latter event is, indeed, essentially statistically impossible. However, we now understand that the process of natural selection implies that evolution is anything but random. Is it a miracle that the planet produced animals as complex as, and yet as different from, humans, dolphins, and cicadas, each so well “designed” for its own habitat? No. Natural selection drives systems in a specific direction, and the remarkable diversity of species on Earth today, each evolved for evolutionary success in a different environment, is one result.

Non-randomness is now understood to have a likely impact on the first appearance of life. For example, new insights into geophysical and chemical processes in extreme environments suggest that early Earth naturally favored the production of relatively large organic molecules. Moreover, we have continued to find in space the more sophisticated components associated with the evolution of life on Earth. The build-up of these complex precursors of life is, therefore, far from purely random. Furthermore, a recent interesting, if speculative, proposal suggests that, when driven by an external source of energy, matter will rearrange itself to dissipate this energy most efficiently. Living systems allow greater dissipation, which means that the laws of physics might suggest that life is, in some sense, inevitable.

Beyond this, two exciting scientific advances in recent decades have identified new ways in which life can evolve, and new locales where it can do so. First, we have discovered a surprisingly diverse group of new solar systems. And we now understand that, even in our solar system, there are a host of possible sites where life might have evolved that were long considered unlikely. Moons of Jupiter and Saturn may have vast oceans of liquid water, underneath ice covers, which are heated by gravitational tidal friction associated with their giant hosts. On Earth, scientists have had to revise old rules about where and how life can survive. The discovery of so-called extremophiles—life forms that can live in extreme acids, or under extreme heat or pressure—has vastly increased the set of conditions under which we can imagine life existing on this planet.