What the elders kept
Long before there were laboratories, the interior of Santiago kept its own record. An elder could name a man's fathers back five and six generations, village by village, and could tell you which people, across the water, a family came from. Genetic findings add another line of evidence to that history. They do not replace it, and they answer different questions.
What the paternal line shows
The Y chromosome passes from father to son almost unchanged, so a man's Y-DNA follows a single line of descent: his father, his father's father, and on back. Testing it places that line on a branch of the human paternal tree, called a haplogroup.
Among the 417 men in the project's study whose paternal grandfathers were born on Santiago, 369 belong to four branches that the study groups together, all widespread in sub-Saharan Africa:
- E1b1a, the branch that includes E-M2 and is common across West Africa: 265 men.
- E1a: 72 men.
- A1a, part of haplogroup A, whose lineages are among the deepest-rooting branches of the human paternal tree: 26 men.
- E2b: 6 men.
The other 48 belong to E1b1b, a branch found in North and East Africa, the Mediterranean, and the Middle East, which the study reports separately. The full analysis sets out the methods, the comparison between islands, and the limits of the data.
What a branch can and cannot tell you
A haplogroup shows shared ancestry across a wide region and a long span of time. It cannot by itself name the people, kingdom, or village a forefather came from. The same broad branches are carried by many neighbouring peoples, and they were spread across West Africa long before the Atlantic trade.
Finer branches, called subclades, can narrow the picture, but only where published studies have sampled the relevant peoples well enough to show where a subclade is common. Until such an association is documented, a match to a particular branch is a research lead, not an identified ancestral route. Family memory, parish records, and place-names are what turn a lead into a history.
The maternal thread
Mitochondrial DNA passes from a mother to all her children and follows the maternal line. Published studies of Cabo Verdean mitochondrial DNA report that most maternal lineages on the islands are of sub-Saharan African origin, in the L haplogroups. They are the lines of the African women who founded these communities and held them together through hunger, exile, and centuries of pressure.
DNA as reconnection
For a people whose written record was deliberately kept thin, whose parish books recorded the enslaver's name and not the father's, and whose homelands were an ocean away, genetic lineage is one more way back. It does not tell us who we are; we already know that, in the language we speak and the drum we keep. It can help show where a line ran, and point toward the regions and peoples worth searching further.
Our task is to read it carefully, and to name our fathers and mothers aloud.
Lineage data is summarised on the Genetics page, led by Badiu Nation’s own Y-chromosome analysis. Related studies, including Brehm and others on Cabo Verdean mitochondrial DNA, are kept in the notes and further reading.