African indigenous pigs (Sus scrofa domesticus) are a vital genetic and cultural resource. Historically distributed across the continent, these pigs are now primarily raised by smallholder farmers in remote Sub-Saharan Africa. According to the FAO, Africa is home to 49 indigenous pig breeds, yet over half have an uncertain conservation status, with 5% classified as endangered. These animals are prized for their remarkable resilience, able to thrive on poor-quality feed, withstand harsh climates, and exhibit resistance to local pathogens like the African swine fever virus. Their flavorful, marbled meat is also highly valued by consumers.

Despite their importance, the genetic origins of these pigs have long been a mystery. While wild boars are native to North Africa, no evidence links them directly to modern breeds. The vast geographic separation between pig populations in Western and Eastern Africa also suggested a complex history, making a single African origin unlikely.

To solve this puzzle, a collaborative research team from the Sino-Africa Joint Research Center (Kunming Institute of Zoology) and African institutions analyzed genetic data from pigs across six countries: Benin, Cameroon, The Gambia, Nigeria, Tanzania, and Uganda. The study utilized near-complete mitochondrial DNA (mtDNA) genomes and sequences from male-specific Y-chromosome genes.

The analysis reveals that African indigenous pigs belong to a mtDNA lineage (sub-haplogroup E2) that diverged from European/North African wild boars around 9.7–5.2 thousand years ago (kya). A more specific split between African pigs and those from the Iberian Peninsula occurred later, approximately 5.2–2.6 kya. The effective population size remained stable until about 500 years ago, after which it expanded rapidly. Statistical modeling (Approximate Bayesian Computation) strongly supports a scenario where a founder population from the Iberian Peninsula arrived in Western Africa around 5.25 kya. This research provides the first robust evidence identifying the Iberian Peninsula as the source for African indigenous pigs, shedding new light on ancient human migration and trade networks that shaped the continent's food systems. Subsequently, a subset of these pigs migrated eastward, diverging to form the Eastern African populations around 1.98 kya, likely via a terrestrial route (Fig. 1).

Fig. 1: A schematic map illustrates the probable dates of the earliest occurrences of African indigenous pigs from Europe and East Asia, as inferred from this study's mtDNA and Y–chromosome analysis.

The study situates this pig translocation within the broader context of other historic food system movements across Africa, offering a deeper understanding of its agricultural history. This study, "Integrated Mitogenome and Ychromosome Analysis Untangles the Complex Origin of African Pigs" was published in iScience. The project was led by Dr. Adeniyi C. Adeola, with Lameck Ajuma Odongo as the lead author. Funding was provided by grants from the Sino-Africa Joint Research Center, Chinese Academy of Sciences, the National Foreign Expert Project, and the Chinese Academy of Sciences President’s International Fellowship Initiative, ANSO scholarship for young talent, and the Yunnan Revitalization Talent Support Program.

Weblink: https://doi.org/10.1016/j.isci.2026.114643