State programmes behind the curtain
Agent: Biopreparat (USSR); the United States biological warfare programme
Source / date: 1943–1969 (US); 1970s–1992 (USSR, after signing the treaty banning it)
Reference: Biopreparat
Large-scale biological work genuinely concealed from the public, confirmed afterwards from the inside. This is the honest evidence base for “it happens where people cannot see” — and it is also a record of how such things end up known.
Class: Directed modification actually performed by people, on the record, with names and dates.
What was actually concealed
The Soviet Union signed the Biological Weapons Convention in 1972 and then ran Biopreparat, a civilian-fronted network employing tens of thousands of people across dozens of facilities, in violation of it. The United States ran its own offensive programme at Fort Detrick until President Nixon ended it in 1969.
In 1979 an accidental release of anthrax spores at Sverdlovsk killed dozens of people downwind. The official explanation was contaminated meat, and it held until 1992, when Boris Yeltsin acknowledged the military source. The programme itself was exposed by the defections of Vladimir Pasechnik in 1989 and Ken Alibek in 1992.
What it does and does not license
Does: the claim that governments have conducted concealed biological programmes at scale, lied about them for over a decade, and been believed, is simply true. Anyone who assumed otherwise was wrong, and the record proves it.
Does not: none of it involved designing species, and all of it eventually came out — through defectors, leaks, epidemiology and satellite imagery. Every confirmed case of hidden biological work is confirmed because it did not stay hidden. A programme spanning all plants and animals over geological time would need a level of secrecy that no documented programme has achieved over decades.
That is not a refutation of the larger idea. It is the correct weight to give this evidence: it establishes capability and willingness, not permanence of concealment.