James was born out of wedlock to Thomas Fairbairn and Elizabeth Simpson, but the parents were later married in 1856 before emigrating to New Zealand with their growing family. They settled on the Otago peninsula just outside of the city of Dunedin, in the province of Otago.
It may be possible to confirm family relationships with James by comparing test results with other carriers of his Y-chromosome or his mother's mitochondrial DNA.
However, there are no known yDNA or mtDNA test-takers in his direct paternal or maternal line.
It is likely that these autosomal DNA test-takers will share DNA with James: