Updated: Jun 29
Albert Perry carried a secret in his DNA: a Y chromosome so distinctive that it reveals new information about the origin of our species. It shows that the last common male ancestor down the paternal line of our species is over twice as old as we thought.
One possible explanation is that hundreds of thousands of years ago, modern and archaic humans in central Africa interbred, adding to known examples of interbreeding – with Neanderthals in the Middle East, and with the enigmatic Denisovans somewhere in southeast Asia.
Perry, recently deceased, was an African-American who lived in South Carolina. A few years ago, one of his female relatives submitted a sample of his DNA to a company called Family Tree DNA for genealogical analysis.
Geneticists can use such samples to work out how we are related to one another. Hundreds of thousands of people have now had their DNA tested. The data from these tests had shown that all men gained their Y chromosome from a common male ancestor. This genetic “Adam” lived between 60,000 and 140,000 years ago.
DNA Report An African American Paternal Lineage Adds an Extremely Ancient Root to the Human Y Chromosome Phylogenetic Tree https://www.cell.com/ajhg/fulltext/S0002-9297(13)00073-6
Genealogy of A00, A0, and the Reference Sequence Lineages on which mutations were identified and lineages that were used for placing those mutations on the genealogy are indicated with thick and thin lines, respectively. The numbers of identified mutations on a branch are indicated in italics (four mutations in A00 were not genotyped but are indicated as shared by Mbo in this tree). The time estimates (and confidence intervals) are indicated kya for three nodes: the most recent common ancestor, the common ancestor between A0 and the reference (ref), and the common ancestor of A00 chromosomes from an African American individual and the Mbo. Two sets of ages are shown: on the left are estimates (numbers in black) obtained with the mutation rate based on recent whole-genome-sequencing results as described in the main text, and on the right are estimates (numbers in gray) based on the higher mutation rate used by Cruciani et al.6
"His Y chromosome was like no other so far analysed. Michael Hammer, a geneticist at the University of Arizona in Tucson, heard about Perry’s unusual Y chromosome and did some further testing and concluded:
Bonnie and her team’s research revealed something extraordinary: Perry did not descend from the genetic Adam. In fact, his Y chromosome was so distinct that his male lineage probably separated from all others about 338,000 years ago Jacqueline Johnson's unidentified male cousin's Y-DNA mutation seemed to be older than current estimates for the age of anatomically modern humans. For example Y-DNA Haplogroup A, also known as Y-chromosome Adam, is the father of all human males, and is estimated to be 254,000 ybp according toMendez et al 2013. However Y-chromosome Adam's descendant A00 seems much older than 254,000 ybp although there has been some healthy debate on it's age — Elhaik et al 2014 places the age of A00 at 208,300 ybp and Karmin et al. 2015 dated it to between 192,000 and 307,000 ybp (95% CI). This also means Y-chromosome Adam is even older than once thought. While A00's age may be subject to debate, it is clearly the most ancient divergent Y-DNA haplogroup yet discovered. And it was found in Jacqueline Johnson's male cousin from South Carolina.
Jacqueline Johnson traced this cousin’s paternal line back to a former slave named Albert Perry (born between 1819 and 1827) who lived in South Carolina and first appeared on the 1870 census five years after the civil war and the emancipation of slaves.
Age in 1870:43Birth Date:abt 1827
Dwelling Number:336Home in 1870:Landsford, Chester, South Carolina
Race:BlackGender: MalePost Office:Landsford
Read: YesCannot Write:YesMale Citizen
Inferred Spouse:Rosanna Perry