Nature’s own gene splicing
Agent: No agent. Endosymbiosis argued by Lynn Margulis, 1967; transfer confirmed by genome sequencing from the 1990s
Source / date: Roughly two billion years, and continuing now
Reference: Horizontal gene transfer
The premise that species were assembled by moving genes between unrelated organisms is correct. It happened, it is still happening, and what it did not require is a technician.
Class: An undirected process confirmed by evidence. No designer required, and none found.
Three cases that settle it
- Your cells run on a captured bacterium. Lynn Margulis argued in 1967 that mitochondria and chloroplasts are engulfed free-living bacteria that were never digested. The paper was turned down by around fifteen journals before it appeared. It is now textbook, and it means the boundary between two domains of life was crossed once and permanently.
- Mammal pregnancy runs on a virus. Syncytin, the protein that fuses cells to form the placental barrier, is the envelope gene of an ancient retrovirus that inserted itself into an ancestral genome and was repurposed. Around 8% of the human genome is retroviral in origin. A virus wrote the gene that makes live birth work.
- A staple crop is naturally transgenic. Agrobacterium transfers its own DNA into plant cells as its ordinary way of life — the exact trick the GM industry later borrowed. In 2015, sequencing found Agrobacterium T-DNA in the genome of cultivated sweet potato, in all 291 varieties tested. It has been in the crop since before agriculture, put there by a bacterium.
What this does to the question
It does not answer it, but it moves it. “Genes from unrelated kinds were combined to produce the species we see” stops being an extraordinary claim, because that is demonstrably part of how genomes are built. The extraordinary part is only ever intent.
So the honest form of the question in this section is not could life be spliced? — it plainly can be and was — but is there evidence of aim? Nature performs the operation constantly and blindly, which is why the blind version has to be excluded before a deliberate one is needed.