Evolution Icon Evolution
Intelligent Design Icon Intelligent Design
Physics, Earth & Space Icon Physics, Earth & Space

Gerald Joyce Defines Life as Darwinian Evolution


If life is synonymous with Darwinian evolution, then Darwinism must be true. Life exists, doesn’t it?

In an interview posted by NASA’s Astrobiology Magazine, Gerald Joyce of Scripps Research Institute discusses a definition for life that has become a sort of de facto standard at NASA:

If we ever hope to identify life elsewhere in the universe, we need to understand what separates living creatures from non-living matter. A working definition lately used by NASA is that “life is a self-sustaining system capable of Darwinian evolution.”

Joyce was quick to concede that this is his own concoction (it was the outcome of a discussion by a panel in 1992), not an official NASA definition (NASA does not endorse it or use it in projects). Still, he feels it makes a good “working definition,” even if life is a “popular term” not a scientific one, thus impossible to define rigorously.

Joyce seems enamored with the “Darwinian” aspect of the definition. He used the term “Darwinian evolution” 31 times in the short interview, 6 times in this paragraph alone:

The coolest thing in the discussion, which wasn’t in the plan document, was appreciating how Darwinian evolution achieves the key attribute of life, which is to allow complex systems to persist despite an often unpredictable and changing environment. And it does so through molecular memory in the form of genetic information that arises and is maintained by Darwinian evolution. Is there an entirely different way to do that? Not our life, not anything that we’ve ever seen, but perhaps there is another way to skin that cat? That would be a huge breakthrough, if there was some paradigm other than Darwinian evolution that gets you what Darwinian evolution gets you. That was a fun part of the discussion, but of course, no one had a specific alternative, and I’ve never heard anyone make a credible proposal of how to achieve all of that without Darwinian evolution. When we go in search of other forms of life, we need to be thinking about not just chemicals, but how they’re part of a system that has molecular memory and enables Darwinian evolution. (Emphasis added.)

By dismissing intelligent causes at the outset, Joyce and his peers were left with non-intelligent, natural causes. Thus, the only “credible” proposal that “gets you” life is Darwinian evolution. Simple!

No one doubts that variation is observable among populations of organisms. Not even the most ardent creationist would discount the built-in ability of organisms to adapt to changing environments. But the “Darwinian” aspect of Joyce’s definition entails much more: the common ancestry of all organisms, from chemicals to man, by means of unguided, impersonal, non-intelligent processes. Logically, everything in between, from flagellum to Flight to Flamenco guitar playing had to “arise” as “innovations” by unguided natural processes. Somehow that view is “credible.”

“Darwinian evolution” has an associated property list: you can’t have Darwinian evolution without self-replication or reproduction. You can’t have it without mutability, heritability, and variation of form and function. And metabolism is in there too. You can’t have Darwinian evolution without, at some level, a flux of higher-energy starting materials to lower-energy products that drive the processes of replication and whatever is necessary to support replication. And then there are the speciality [sic] properties like locomotion, irritability, ecological properties such as compartmentalization, and so on; those are all adaptations. And then things like photosynthesis, chemosynthesis, energy storage, and so on; those are just strategies of adaptation. All of that is subsumed by the “Darwinian evolution” part.

We know from uniform experience, however, that it is not credible to expect specified complexity (e.g., functional machines of multiple interacting parts, like those in locomotion and photosynthesis) to arise apart from intelligence.

And so Gerald Joyce goes mystical, as the implications of his comments make clear. He personifies evolution as some kind of mysterious life force, like a puppeteer, that steers creatures upward and onward into increasing levels of complex information:

  • … there’s some Darwinian system that has brought about coded functional molecules that steer the chemistry into biochemistry.
  • What makes biochemistry different from chemistry is that it has history in it, and that history is written in the bits that were deposited through Darwinian evolution.
  • Self-sustained refers to the information necessary to undergo Darwinian evolution. Chemical information is the product of Darwinian evolution. So all of the information necessary for the system to undergo Darwinian evolution must be part of the system.
  • something within the system, within the collective system, must provide all of the information necessary to bring about Darwinian evolution.
  • So then you come back to: why is Darwinian evolution put front and center in thinking about life? Because it is a way for complex entities to maintain themselves, not as an individual but as a system, in the face of a changing environment that is subject to unanticipated change. A system evolves to adapt to environmental change. It has to be able to invent new functions because those environmental changes may be more than incremental.
  • Like a palimpsest, a document that’s written on again and again and again, biology is a record of what has proven adaptive at the time, time after time after time. It’s a really powerful way to organize matter.

Joyce denies, though, that Darwinian evolution has a puppeteer:

There’s not a puppeteer that handles all the information offstage, and then the molecules are just the puppet show. You could count the puppeteer as part of the system, but then the puppeteer also has to be evolving. So it’s pretty tricky. I find that a good way to avoid confusion is to ask yourself: where are the bits of information? If you’re talking Darwinian evolution, then you’re talking molecular information. Are the bits in the system or outside the system? If all the bits necessary for the system to evolve are in the system, then it can meet the working definition.

In actuality, Joyce has played puppeteer himself:

My own lab has developed a self-sustained chemical system capable of undergoing Darwinian evolution. All of the bits that are necessary for it to evolve are within the evolving system. So why isn’t that life? Well, there’s a little more to it, I think, which has to do with the “capable” part. We really need to expand that part of the working definition. Our laboratory system is capable of evolving, but thus far it has not evolved any new functions.

He seems to have missed the logic point that if he set up a system to undergo Darwinian evolution, he added bits to the system, employing intelligence to do it. But when he left it on its own, it “has not evolved any new functions” so far. He has not demonstrated his working definition of life; he has merely assumed it.

Let’s examine Joyce’s lab experiment more closely. In essence, he tried to set up a self-running puppet show, and then extricated himself from “the system” to watch what happens. It’s not running very well, yet (in terms of innovation), but it is “self-sustained” (as long as he keeps providing nutrients to the test tube).

To be consistent, Joyce has to believe that he himself evolved by Darwinian evolution. He is part of the system that emerged by Darwinian evolution. The bits in his brain, encoded in chemical information, are “inside the system.” He used his intelligence to set up an “artificial” system, but believes his own intelligence is the result of unguided chemical processes. On what basis, then, can he assert that his artificial system demonstrates Darwinian evolution? On what basis can he assert that Darwinian evolution is “front and center in thinking about life”? On what basis can be assert that Darwinian evolution is even true?

Some of his confusion might have been alleviated by reading the recent book edited by Discovery Institute’s John West, The Magician’s Twin: C. S. Lewis on Science, Scientism and Society, which cites this pertinent reflection by C.S. Lewis (p. 219):

Anything that professes to explain our reasoning fully without introducing an act of knowing thus solely determined by what it knows, is really a theory that there is no reasoning. But this, as it seems, is what Naturalism is bound to do. It offers what professes to be a full account of our mental behavior, but this account, on inspection, leaves no room for the acts of knowing or insight on which the whole value of our thinking, as a means to truth, depends.

Joyce is a deep thinker, but is not thinking deeply enough here. He has provided no example of Darwinian evolution coming up with innovation; he only assumes it did. He has spoken of information, but denied the only known cause of information, intelligence. He has ruled out intelligent causes in all of life, but employed them in his lab. He has denied a puppeteer, but played the part of one. He thought, but has undermined the validity of thinking.

Image: Earth as seen from Saturn, NASA/JPL-Caltech/Space Science Institute.

Evolution News

Evolution News & Science Today (EN) provides original reporting and analysis about evolution, neuroscience, bioethics, intelligent design and other science-related issues, including breaking news about scientific research. It also covers the impact of science on culture and conflicts over free speech and academic freedom in science. Finally, it fact-checks and critiques media coverage of scientific issues.