Post-gastrulation amnioids - models with mimic the development of the amniotic sac forming as expected (top panel). Amnioids without a key calcium-buffering gene and its accompanying switch don't form as expected (bottom two panels).
Credit: Borzo Gharibi, Science Advances (2026).
Some 13 million years before anyone could have written a creation myth, a retrovirus inserted its genetic material into the genome of an ancestral ape. Today, part of that viral legacy helps regulate early human development. This presents creationists with several difficulties at once: a history vastly older than their biblical chronology permits, genetic material acquired from a virus, and an evolutionary innovation produced by putting an existing sequence to a new use. There is also an uncomfortable sting in the tail for advocates of a benevolent intelligent designer: cancer cells can exploit the same biological machinery.
The research, reported in Science Advances, concerns a remnant of an ancient retrovirus known as HERVH. This sequence acts as a switch controlling a form of calbindin, a protein involved in buffering calcium inside cells. Removing the switch or calbindin disrupted the growth and developmental behaviour of human embryonic stem cells and the organisation of models of early embryonic structures.
The evolutionary distinction matters. The original acquisition of viral DNA represents horizontal genetic transfer: genetic material crossed from a virus into its host, rather than arriving through ordinary inheritance from a parent. Once incorporated into the germ line, however, that material could pass vertically through successive generations. Its recruitment to regulate a host gene is an example of exaptation — the co-option of an existing feature for a different function. The virus did not need to invent calbindin, nor did evolution need to create an entirely new protein from scratch. A new regulatory relationship could arise by combining material with different evolutionary histories.
This is precisely the sort of process obscured by the creationist slogan that new genetic “information” requires an intelligent author. Biologically useful novelty can involve changes in when, where and how an existing gene is expressed. Imported DNA can supply a regulatory element; subsequent evolution can preserve and modify its contribution. Calling the result “information” does not erase the natural processes that produced it, still less establish that someone intended the outcome.
The chronology is equally inconvenient. Comparative primate evidence places this insertion roughly 13 million years ago, after the lineage leading to humans and the African great apes had separated from the orangutan lineage. Orangutans are themselves great apes; the relevant event occurred within the broader great-ape family tree. Either way, this is inherited molecular history extending far beyond the few thousand years allowed by a literal young-Earth reading of Genesis.
Yet a mechanism useful during development need not remain beneficial in every context. Earlier research showed that lung squamous cell carcinoma can activate this viral switch, helping cancer cells avoid senescence — a state in which cells stop dividing. The cancer biology is complex, but the central evolutionary point is clear: machinery that supports normal development can also become available for malignant cells to exploit.
That is consistent with an evolutionary cost-benefit trade-off. Natural selection can preserve a developmental advantage despite a vulnerability elsewhere in life; it has no foresight with which to guarantee lifelong protection from every possible consequence. But if intelligent-design advocates insist that useful genetic arrangements demonstrate deliberate engineering, they must apply that reasoning consistently. A designer credited with the developmental benefit cannot simply be excused responsibility for the exploitable weakness. On their own premises, the result raises questions about competence, benevolence, or even malevolent design. Evolution requires no such theological contortions: an ancient infection, inherited variation and the opportunistic reuse of existing material are sufficient ingredients for the story.




































