Genome research proposes an East Asian origin for cannabis domestication

A worldwide genomic study published in July 2021 proposed that cannabis domestication began in East Asia. It connected the histories of fibre and drug crops through their ancestry, while offering a chronology that subsequent archaeological work treats as a hypothesis to test against physical remains.

Comparing present-day plants

Guangpeng Ren and colleagues assembled a panel of 110 accessions, combining newly sequenced material with existing genomes. After filtering, 104 accessions remained in the principal population analyses. The distinction matters when describing what was collected and what was ultimately compared.

The genetic groupings placed some Chinese landraces and feral plants closest to the ancestral population represented in the analysis. The researchers interpreted the overall pattern as supporting an East Asian domestication origin and later divergence between crops selected for different purposes.

A model of the past

The study estimated an early divergence around 12,000 years before present. Its reported 95 per cent confidence interval extended from about 6,458 to 15,728 years. That broad range is part of the result, rather than a minor qualification to an exact date.

The analysis also proposed later specialization into fibre and drug crops. This gives a way to investigate how selection for stems, branching and resin could shape populations over time. It does not establish that early cultivators divided the plant into the same legal or commercial categories used today.

Archaeology provides another test

Rita Dal Martello and colleagues’ later study of cannabis seed measurements emphasizes the need to compare genetic chronologies with archaeological evidence. They note the wide uncertainty and the absence of ancient genomic data to calibrate the proposed timescale.

Their Haimenkou research illustrates a complementary approach. Instead of inferring ancestry from modern genomes, it measures preserved material from an excavated settlement. Such evidence can locate plants in a particular archaeological context, while still leaving their precise use uncertain.

What the finding changes

The genomic study supplies evidence relevant to a long-running debate over where cultivation began. Its conclusions depend on the sampled populations, analytical model and interpretation of ancestry. A modelled divergence date is not equivalent to excavating a cultivated plant of that age.

The database therefore records the publication in 2021 as a research event associated with China. The ancient chronology remains inside the account, with its uncertainty intact. This adds cultivation and breeding history without presenting a disputed origin model as a settled first event.^[1][2]