Evolution in Four Dimensions
Source: https://mitpress.mit.edu/9780262525848/evolution-in-four-dimensions/ ↗
Jablonka and Lamb argue that inheritance operates through four channels, not one: genetic, epigenetic, behavioural, and symbolic.
Each system has its own rules of variation and transmission, and they interact in ways that the gene-centred Modern Synthesis never accounted for.
Epigenetic inheritance -- heritable changes in gene expression without changes to DNA sequence -- is now an established field, vindicating much of what the authors proposed.
The symbolic dimension, unique to humans, is where cultural evolution theory meets biology most directly.
This is the updated biology that almost nobody outside specialist circles cites yet, but which reshapes how we should think about what gets inherited and how change propagates through populations.
Central argument
Jablonka and Lamb argue that biological inheritance operates through four distinct systems — genetic, epigenetic, behavioural, and symbolic — each with its own mechanisms for generating variation and transmitting it across generations. The central thesis is that the gene-centred Modern Synthesis is incomplete: heritable change can occur through epigenetic modifications (alterations in gene expression without DNA sequence changes), learned behaviours passed between individuals, and symbolic systems unique to humans. Evolution, on this account, is a multi-channel process where these systems interact and constrain each other, producing outcomes no single-inheritance model can explain.
Critique
The four-dimensional framework is intellectually compelling but risks becoming unfalsifiable in practice: when any of four interacting inheritance systems can be invoked to explain a given outcome, the model gains explanatory breadth at the cost of predictive precision. The symbolic dimension in particular — the most relevant to human cultural change — receives the least mechanistic grounding of the four, which leaves the theory's most ambitious reach resting on its weakest empirical footing. A rigorous critic would ask what observations would count as evidence against the framework, not merely evidence for one channel over another.
Why it matters for product
Product organisations inherit constraints through multiple channels simultaneously — codified processes (genetic analogue), informal norms that persist without being written down (epigenetic), demonstrated behaviours from senior practitioners (behavioural), and the conceptual vocabulary teams use to frame problems (symbolic). Jablonka and Lamb's model suggests that attempts to change product culture by rewriting documentation or restructuring teams will fail if the epigenetic and behavioural channels transmit the old pattern unchanged — a direct challenge to any CPO relying on org redesign or OKR rollouts as the primary lever for strategic change. The symbolic dimension is especially actionable: the definitions a product organisation uses for 'done', 'customer value', or 'success' are heritable units that shape what gets built long after the people who coined them have left.