A Western Brown snake, Pseudonaja nuchalis
Intrigued by the information I unearthed while researching for my recent blog post about Australia's elapsid snakes and how skinks have evolved resistance to their venom, I discovered that these snakes have evolved from a common ancestor that once lived in the sea, and, while there, picked up a number of 'jumping genes' that are only found in marine animals as diverse as fish, sea squirts, sea urchins, bivalve molluscs and turtles.
The more we learn about genomes, the clearer it becomes that evolution is not a neat or predictable process—it is messy, opportunistic, and deeply influenced by historical contingency. A striking example of this comes from a recent genomic study that traced the origins of Australia’s iconic elapid snakes—not just through their DNA, but through the foreign DNA embedded within it. Researchers have identified at least 14 distinct horizontal gene transfer (HGT) events in these snakes, in which transposable elements—“jumping genes” — from unrelated marine organisms such as fish, tunicates, molluscs, and turtles have been incorporated into the snake genome.
This is compelling evidence that the ancestors of modern Australian elapids passed through a marine environment, acquiring genetic material from the organisms they encountered there. The transfers are not random. They show ecological specificity, temporally sequenced occurrence, and a nested pattern of inheritance — hallmarks of an evolutionary process rather than the actions of an intelligent designer.
For proponents of Intelligent Design creationism, this presents a serious interpretive problem. The idea that different species share features because of a “common designer” does not explain why Australian elapids should contain such a unique suite of genes from marine animals—genes absent in closely related snakes that remained on land. Nor does it account for the fact that many of these sequences serve no obvious function, are neutral or even mildly deleterious, and resemble the genetic detritus typical of unguided evolution.
ID advocates will likely claim this is just more evidence of “design reuse” or “genetic toolkits.” But such claims are not only ad hoc; they fail to explain the clear environmental and phylogenetic patterns observed in the data. The evolutionary explanation, by contrast, is both predictive and parsimonious: snakes dispersed through a marine environment, interacted with marine organisms, and as a result, their genomes bear the signature of that history.
In what follows, we will explore how this discovery not only sheds light on the evolutionary past of Australian elapids, but also exposes the weaknesses in ID’s core explanatory framework. The genome of a snake tells a story—and it's not the story of design.
