Darwinism finally got its laboratory test. Here is the result sheet.
The usual complaint against Darwinism is that nobody can watch it happen. Evolution needs geological time, the argument goes, and we only have lifetimes, so the whole theory has to be inferred from bones and comparisons and never actually observed doing the thing it claims to do.
That complaint is now out of date, and Christians who keep making it are arguing against a position the other side abandoned decades ago.
Since February of 1988, twelve populations of E. coli have been growing in flasks in a laboratory, transferred into fresh medium every single day. Each transfer gives the bacteria roughly six and a half generations. Multiply that out across more than thirty-five years of unbroken daily work and you arrive at a number that genuinely deserves respect: over seventy-five thousand generations, from twelve independent starting lines, under continuous observation, with frozen samples at every milestone so that any generation can be thawed and competed directly against its own ancestors.
Nothing in the history of biology comes close to it as a test. If you want to know what mutation and natural selection actually produce when you give them enormous numbers and let them run, this is the experiment to look at. So let us look at it honestly — which means first giving it full credit, and then reading the result sheet without flinching.
Give It Full Credit First
Here is what the experiment unambiguously demonstrates, and any believer who denies it is not defending Scripture, he is defending a talking point:
- Mutation happens, continuously and spontaneously. No designer intervention required for new genetic variation to appear.
- Natural selection is real and powerful. Beneficial variants sweep through the populations and displace their competitors, repeatedly and predictably.
- The populations got measurably better at living in that flask. Fitness, measured by direct competition against the frozen ancestor, climbed steeply at first and has kept creeping upward for decades without flattening out entirely.
- Cell size, growth rate, and metabolism all changed. The descendants are visibly and biochemically different organisms from the strain that went into the first flask in 1988.
That is evolution, observed, measured, and replicated. And here is the part that surprises people on both sides of this argument: no serious creationist — young-earth or old-earth — disputes a word of it. Change within a population by mutation and selection has never been the point of contention. Breeders knew about it before Darwin wrote about it.
The disagreement has always been about a single question: does this mechanism scale? Run it long enough and does it compose new organs, new molecular machinery, new body plans — or does it do something more limited, no matter how long you run it?
Seventy-five thousand generations is the best data we will ever have on that question. So what did the mechanism build?
Reading the Result Sheet
Look at what actually drove the fitness gains, and a consistent pattern appears. Over and over, the winning mutations are changes that break, delete, or down-regulate something the bacterium already had.
The clearest example came early. All twelve populations independently lost the ability to metabolize ribose, through deletion of the relevant operon, within the first couple of thousand generations — and that loss was beneficial. In a flask where glucose is the only food on the menu, the machinery for processing a sugar that is not there is pure overhead. Throw it overboard and you grow faster. Selection rewarded the jettison, twelve times out of twelve.
That is the shape of most of the early adaptive story: mutations knocking out or dialing down regulatory genes, global controls, and unused capacity. Later, roughly half the populations suffered defects in their DNA repair machinery and became what are called mutators — cranking the mutation rate up by orders of magnitude. Also a broken system. Also, in that environment, advantageous.
A bacterium streamlining itself for a flask of sugar water is doing something real. It is not, however, doing the thing the grand claim requires. You cannot get from a single cell to a trilobite by a long enough series of well-chosen deletions. Subtraction is a genuine evolutionary force, and it is the wrong direction.
The One Real Innovation — and What It Was Made Of
Now the famous result, and the honest apologist deals with it head-on rather than pretending it did not happen.
Somewhere past generation thirty-one thousand, one of the twelve populations acquired the ability to feed on citrate in the presence of oxygen. This matters because the inability to do that is practically a textbook identifying trait of E. coli — it is one of the properties used to tell the species apart from its relatives. The medium had always contained citrate, sitting there unused for decades. One line learned to eat it, and that population promptly exploded in density.
That is a brand new capability, arising in real time, by mutation and selection. Full stop. It is a legitimate and impressive finding.
But then ask the question that actually settles the extrapolation argument: what was the innovation made out of?
The researchers traced it. E. coli already possessed a citrate transporter — a working protein for pulling citrate into the cell, used under oxygen-free conditions and switched off when oxygen is present. The innovation was a tandem duplication that placed a copy of that existing transporter gene behind a different, oxygen-active promoter. In other words: an existing part was copied, and the copy was plugged into a switch that was already in the genome.
No new protein was invented. No novel molecular machine was assembled. A functioning component was duplicated and re-wired to run at a time it had not previously run.
And there is a second detail that cuts even deeper. The same mutation would not work in the other eleven populations. That line had accumulated earlier changes that made it receptive — the researchers call it potentiation. The innovation was contingent on a specific prior history. Which means that even a modest rewiring of existing parts required thirty-one thousand generations of setup in a population of billions, and eleven parallel lines of equal size never got there at all.
The Honest Rejoinder
Here is where a lot of Christian apologetics goes wrong, so let me state the other side as strongly as I can, because a case that only survives by misrepresenting the opposition is not a case.
Defenders of the theory will say, fairly, that this is a single-celled asexual organism in a deliberately constant, simple, impoverished environment. There are no predators, no seasons, no migration, no sexual recombination shuffling variation between lineages, and no ecological complexity to reward anatomical novelty. A flask of glucose does not ask for an eye. They will add that seventy-five thousand generations of bacteria, however impressive in the lab, is a blink against the hundreds of millions of years and planet-wide ecological theater they claim built the biosphere. And they will point out that the fitness curve has not actually leveled off, which suggests the supply of improvements is not exhausted.
Every one of those points has force. The experiment does not disprove universal common descent, and no one should claim it does. We should also admit what the critics on our own side sometimes slide past: the broad claim that adaptive mutations are essentially always losses of function is contested by working biologists, and the citrate result is exactly the sort of case they raise against it.
So state the conclusion with the precision the evidence supports, and not an inch further.
What the Evidence Actually Licenses
The strongest fair statement is this. In the most favorable, most thoroughly monitored, longest-running test ever conducted — astronomical population sizes, every mutation that occurred available for selection, seventy-five thousand generations — mutation and natural selection demonstrated impressive power to optimize, tune, streamline, and re-deploy what was already present. They demonstrated no observed power to originate new functional machinery from scratch.
That is not a disproof of Darwinism. It is something more useful: it converts the central claim from an observation into an extrapolation. The grand narrative does not rest on watched events. It rests on the confidence that a process observed to fine-tune and rewire existing systems will, given vastly more time, compose systems that never existed. That may be true. But it is an inference, not a measurement, and it should be argued as one.
And this is where the apologetic posture matters. Our job is not to win by overstatement.
Prove all things; hold fast that which is good. (1 Thessalonians 5:21, KJV)
Where the Argument Points
Notice something about the whole exercise. Every one of those seventy-five thousand generations began with a cell that already had a genetic code, a translation apparatus, a membrane, a metabolism, repair enzymes, and the capacity to copy itself with high fidelity. The experiment can only modify what it was handed. Natural selection has to be given something that reproduces before it can do a single thing, which is why the origin of the first self-replicating cell is not a footnote to this debate. It is the question underneath it.
Scripture speaks to origins with a confidence that has nothing to defend:
And God created great whales, and every living creature that moveth, which the waters brought forth abundantly, after their kind, and every winged fowl after his kind: and God saw that it was good. (Genesis 1:21, KJV)
“After their kind” is not a claim that nothing changes — the flasks in that lab are full of change, and so is every field and forest. It is a claim that there is an architecture to life, that living things come in genuine categories with real boundaries, and that the categories were established rather than accumulated.
For the invisible things of him from the creation of the world are clearly seen, being understood by the things that are made, even his eternal power and Godhead; so that they are without excuse. (Romans 1:20, KJV)
The Decision Point
If you are a believer who has been quietly uneasy — suspecting that the evidence is stacked against you and you had better not look too closely — go look. The actual data in the actual experiments is far less threatening than the summary you were handed in school, and infinitely less threatening than the version you have been imagining.
And if you are a skeptic who has been told that creationists simply deny observed evolution, you have now read one who does not. The bacteria adapted. The ribose operon went overboard. The citrate switch got rewired. All of it happened, and it is fascinating work.
The question we actually differ on is whether that process, extended, explains the whole of life — and on that question the laboratory has been running for thirty-five years and has not yet shown us the mechanism doing it.
Seventy-five thousand generations later, the cell in the flask is still a cell in a flask: leaner, faster, cleverer about its lunch, and recognizably the same creature that went in. That is the result sheet. Read it for yourself, and let the weight of the evidence fall wherever it honestly falls.
Teaching the Word. Watching the Times.
— SmithForChrist