In April 2015, a small biotech startup in San Francisco announced it was going to make rhino horn. Pembient's first profile in TechCrunch described a company founded by a software engineer and a genetic engineer, working out of IndieBio's shared lab space, with a single physical prototype sitting in a hand-carved wooden box on the founder's desk. The pitch was simple: rhino horn is keratin, keratin can be grown, and if biofabricated horn can be produced cheaply enough, it might undercut the wild market.
The conservation response was immediate and largely negative. What followed was not a short-lived controversy but a durable dispute that has now run for nearly a decade. It produced academic papers, NGO position statements, competing economic models and, eventually, a blockchain-backed product launch. It did not produce consensus.
What Pembient is arguing
Matthew Markus's case for substitution rests on a single economic claim. If buyers cannot reliably distinguish wild horn from biofabricated horn, and if the synthetic version is substantially cheaper, then sellers have an incentive to move toward the cheaper product. In that scenario, the wild market begins to resemble what George Akerlof called a “market for lemons,” where uncertainty about authenticity pushes prices toward the level of the lower-cost substitute.
The logic predates Pembient. It is the same broad mechanism often used to explain shifts from natural to synthetic goods in markets like indigo, vanilla or fur, with one important caveat: those markets do not all behave the same way. Pembient's bet was that rhino horn would behave like a commodity market, not like a prestige market in which authenticity commands a premium. If that bet is right, substitution could weaken poaching incentives. If it is wrong, synthetic horn could end up legitimizing consumption while leaving the premium wild market intact.
The 2015 Guardian profile is where Markus first names this approach “Conservation 2.0.” The contrast is explicit. Enforcement and demand reduction are treated as slow and structurally limited; technological substitution is presented as a faster market intervention. That framing helped define the terms of the debate that followed.
What the NGOs are arguing
The institutional opposition formed quickly. By February 2016, the Center for Biological Diversity had filed a formal petition asking USFWS to ban trade in synthetic rhino horn under the Endangered Species Act. WildAid and TRAFFIC were named as co-petitioners. Their concern was structural: if synthetic horn is biologically close enough to wild horn to satisfy buyers, it may also be close enough to make enforcement harder, provide cover for laundering and weaken demand-reduction messaging.
The same argument appears in more public-facing language in statements from Save the Rhino and TRAFFIC. Cathy Dean described “general horror at the idea,” while Crawford Allan, quoted in the New Scientist news item, called the substitution approach a risk too large to take with a population this small. The underlying point is consistent across the NGO response: even if substitution might work in theory, the downside risk of normalizing horn consumption or obscuring enforcement is too high.
The April 2016 TRAFFIC Bulletin feature by Steven Broad and Gayle Burgess remains the most careful version of that position. Their analysis compares cases where substitutes displaced wild products with cases where parallel premium markets persisted. Their conclusion is not blanket rejection so much as a warning that Pembient's case depends on untested assumptions about consumer preference, authentication and market structure. That is a more useful formulation, because it places the disagreement where it belongs: on uncertain empirical ground.
What the economists are arguing
The most useful contribution to the debate has come from the academic economists who looked at it formally. Frederick Chen's 2017 essay accepts Pembient's substitution mechanism in principle but argues that Pembient's preferred product is not necessarily the one most beneficial for conservation. In Chen's view, a conservation-optimal fake would be one that buyers cannot distinguish from real horn but do not especially value, thereby suppressing demand rather than satisfying it.
Chen and Michael 't Sas-Rolfes's 2021 paper extends the analysis through a formal permit-system model. Their framework identifies two competing effects: a price effect, which may reduce poaching by lowering the returns to wild horn, and a laundering effect, which may increase poaching by giving illegal sellers cover. Which effect dominates depends on market conditions, especially whether demand is price-sensitive. For rhino horn, drawing on the price-inelasticity literature, they conclude substitution is more likely to help than harm, though not without risk.
What matters here is that both papers narrow the dispute. The question is not whether substitution is morally elegant or intuitively alarming. The question is how a specific illicit market behaves under specific conditions, most of which remain only partially measured.
What Pembient did next
In August 2017, Pembient launched PembiCoin. The newsletter explicitly positioned the offering against John Hume's legal-trade auction in South Africa two days earlier. The argument was that farming rhinos for horn was a backward-looking solution, and that biofabricated horn offered a different path: synthetic supply without live animal management.
PembiCoin did not resolve the core technical question, because the product itself was still under development. But it did clarify the strategic landscape. By that point, Pembient was no longer arguing only against enforcement-first conservation. It was also differentiating itself from the pro-trade ranching model. The debate had become triangular: demand reduction, legal trade and substitution.
What remains unresolved
The substitution debate has not been settled because the key variables were never measured at the scale the argument required. Whether biofabricated horn would reduce poaching or intensify it depends on demand elasticity in Vietnam and China, on the size of any premium for authenticated wild horn, and on how much laundering capacity synthetic goods would create in practice. The literature remains far more theoretical than empirical.
Pembient's 2016 white paper for the IUCN African Rhino Specialist Group is still the clearest articulation of the substitution thesis. It addresses laundering, certification and market dynamics directly. What it did not receive was a comparably empirical rebuttal from the organizations trying to stop it. The NGO position may still prove correct, but much of the public dispute turned on precautionary reasoning rather than tested market evidence.
That gap is what makes the thread important. A technical proposal entered a conservation system that was structured to treat uncertainty as a reason to block experimentation, while its proponents treated the same uncertainty as a reason to test a new approach. The result was not resolution but institutional deadlock.
