Apologetics · Creation — natural selection can only reward what works in the generation it appears, which is exactly the trouble when nothing works until both halves exist
There is a plant in the American Southwest that cannot reproduce without a particular moth, and a moth that cannot feed its young without that particular plant. Neither is a curiosity on the edge of biology. Together they are one of the clearest tests you can put to the claim that undirected variation and selection built the living world.
Let me describe it carefully, because the details are the argument.
What the Yucca Moth Does
A female yucca moth enters a yucca blossom at night. She does not drink nectar; the adults of several species in this group barely feed at all. She goes to the anthers and gathers pollen using a pair of long, curling mouthparts found in no other moths on earth — appendages whose only known use is handling yucca pollen. She packs it into a ball, sometimes larger than her own head, and tucks it under her chin.
Then she flies to a different yucca flower. She climbs the pistil, inspects it, and in many species she will reject a flower another moth has already used. She drills her ovipositor into the flower’s ovary and lays eggs directly among the developing seeds. And then she does the thing no other insect in the world does: she climbs back to the top of the stigma and deliberately stuffs her pollen ball into it.
She is not pollinating by accident, the way a bee dusted with pollen pollinates. She is actively, purposefully fertilizing the flower she has just laid her eggs in — because unless that flower is fertilized, it will drop, and her larvae will die with it. Her larvae eat yucca seeds and nothing else. The yucca, for its part, is pollinated by these moths and almost nothing else.
The fig runs a version of the same arrangement, and more severely. A female fig wasp crawls through a passage so narrow that she typically tears off her wings and antennae getting in, pollinates the enclosed flowers, lays her eggs, and dies inside the fig. Her sons hatch wingless, mate, and chew a tunnel so their sisters can get out carrying pollen. Each of hundreds of fig species has historically relied on its own wasp.
The Problem Stated Precisely
Darwinism is not a theory of outcomes. It is a theory of paths. Natural selection has no foresight and no memory. It cannot preserve a half-built structure because of what that structure will be good for later. Every single step has to pay its own way in its own generation or it is discarded.
So count what has to be in place at once for the yucca arrangement to function.
- Anatomy that exists nowhere else, dedicated to collecting and carrying one plant’s pollen.
- A behavioral sequence of at least five ordered steps — gather, pack, carry, oviposit, then deliberately deposit — in which the payoff arrives only after the final step.
- A plant whose reproduction has become dependent on that one insect rather than on wind or generalist pollinators.
- A larval diet restricted to that plant’s seeds, which the plant must produce in surplus so that enough survive to propagate.
- Restraint on both sides: a moth that lays few enough eggs to leave the plant viable, and a plant that aborts flowers which were overloaded.
A moth with the mouthparts and no program is carrying a useless tool. A moth with the program and no plant that needs it is wasting the one night of its life. A plant that has surrendered generalist pollination before the moth is reliable is a plant with no next generation.
Now the Honest Part
I am not going to pretend no one has worked on this. That would be dishonest, and the Christian who argues dishonestly deserves to lose.
There is a real research program here. The standard account is coevolution from a generalist start: moths that were originally seed parasites laying eggs in yucca ovaries, with incidental pollen transfer on the body, which selection then refined into deliberate pollination as the plants came to favor the visitors that fertilized them. Phylogenetic work on these moths supports a sequence in which seed parasitism came first and active pollination came later. Researchers also point to so-called cheater species — moths in the same group that lay eggs without pollinating — as evidence that these behaviors can be gained and lost rather than being all-or-nothing.
That is a serious proposal from serious people, and it should be stated at its strongest before anyone answers it. I cannot imagine how that happened is not an argument. It is an autobiography.
Where the Account Still Comes Up Short
But notice what that proposal actually supplies, and what it quietly assumes.
It supplies an order — parasite first, pollinator second. It does not supply a mechanism for the hardest item on the list. Mouthparts can be imagined as modifications of existing structures. The behavior cannot be imagined that way, because behavior is not a shape. A moth that climbs to the stigma and packs pollen into it is running a sequence of instructions, and the reward for that sequence arrives after the last instruction executes. Selection cannot reward step two for the sake of step five.
Cheater species cut the other way as well. A cheater demonstrates that the pollinating behavior can be lost, which nobody disputes; degradation is easy and well documented. Losing a program is not evidence for how the program was written, any more than a car with its engine removed explains the invention of the internal combustion engine.
And the appeal to deep time does not rescue it, because time is not a mechanism. Time only multiplies the number of trials. The question is whether the trials available can produce coordinated, information-rich instructions in two separate lineages such that each partial state is survivable in both at once. That has never been demonstrated. It has been narrated.
Darwin himself set the standard, and it is worth holding him to it. In the Origin he wrote that if it could be shown that any complex organ existed which could not possibly have been formed by numerous successive slight modifications, his theory would absolutely break down. He asked for a path. A plausible story about which partner came first is not a path. It is a sketch of one, with the load-bearing section left blank.
What the Book Says About Small Things
Scripture is not embarrassed by instinct. It treats the engineered behavior of small creatures as evidence of a mind, and it says so in a passage most readers walk past.
There be four things which are little upon the earth, but they are exceeding wise: The ants are a people not strong, yet they prepare their meat in the summer. (Proverbs 30:24-25, KJV)
Exceeding wise. Not clever — wise, and the wisdom is not theirs. An ant has no concept of winter. The instruction to prepare for one was written into it. Solomon’s point is that a creature with no capacity for reasoning can still execute a plan, which tells you a planner was involved.
O LORD, how manifold are thy works! in wisdom hast thou made them all: the earth is full of thy riches. (Psalm 104:24, KJV)
In wisdom. That is the claim the yucca and the fig press on you. Not merely power — wisdom, the fitting of one thing to another thing so that both live.
The Real Disagreement
Let me name the actual dividing line, because it is not the moth.
If you have decided in advance that only undirected material causes may be considered, then every system in biology will be explained by undirected material causes — not because the evidence compelled it, but because nothing else was permitted in the room. The conclusion was installed before the data arrived.
Paul says exactly that happens, and he says it is not primarily an intellectual failure:
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)
Clearly seen. The problem was never a shortage of evidence.
Where This Lands
So do not argue this badly. Do not say scientists are fools; many of them are doing careful work. Do not say the moth proves God; an argument from one organism will not bear that weight, and overclaiming is how Christians lose the room.
Say the narrower thing, which is harder to answer. A theory of paths owes us a path. Where the function arrives only at the end of a coordinated sequence running in two separate creatures, no path has been shown — and the one everyone keeps repeating is told with the hardest step left out.
And then go further than the argument goes, because an argument has never saved anyone.
The same God who wrote a moth’s instructions so that one creature carries the cost of another’s life did not leave that pattern in the desert. He entered the world he had made, bore a cost that was not his to bear, and died so that people who could not reproduce a single righteous act could live. All things were made by him; and without him was not any thing made (John 1:3, KJV) — and a few verses later, that same Word was made flesh.
The fig and the moth are a signature. The cross is the message.
Teaching the Word. Watching the Times.
— SmithForChrist