I've posted a link to this article on a Facebook Basenji site. Reposting here with addition info in case you haven't seen it.

The link to the interactive article is at bottom. One can select Basenji and see that only two other breeds have some Basenji dna, the Rat Terrier and the Azawakh. But not much. Out of a 100, the RT is 4.7 and the Azawakh at 1.7.

The data shows that Basenji's are not only the oldest breed, but were relatively isolated for a long time after being bred into existence. They appear to be the only dog in their own "clad" or grouping based on genetic similarity.

Heidi Parker, an author of the article replied to a reader's question in the comment section, "What does it mean if there is only 1 dog in a section [clad], such as the Basenji?" that, "It means that those breeds don't share significant ancestry with any one group on the tree. Sometimes they share with multiple groups and sometimes it may be that we haven't identified their closest relatives, yet. In the case of the Basenji it may be a little of both since they are unique. We can see haplotype sharing (supplemental DF1) with the Azawakh (another African breed) and the rat terrier, probably a recent event." In other words, those latter breeds were bred later and have some Basenji DNA as noted.

I wrote to one of the authors, Elaine Ostrander, to confirm the above and inquire if she knows of scientific research on the Basenji rut. I'm guessing there isn't any.

https://www.cell.com/cell-reports/fulltext/S2211-1247(17)30456-4?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS2211124717304564%3Fshowall%3Dtrue&fbclid=IwAR2paobuwCsL0E2CvYrL_pgYlQmvss-EIhzmOMecg9X1dp2OmTeUVezV9us#

Based on that landmark genomic study, the Guardian created an interesting interactive.

"Interactive: see how your favourite dog breeds are related to each other"

You can select Basenji and it shows the connection to the Rat Terrier and the Azawakah noted above.

Not sure if I posted this one. Chromosome-length genome assembly and structural variations of the primal Basenji dog (Canis lupus familiaris) genome

Here's the key takeaway in my view for the breed's history.

"Basenjis are an ancient breed that sits at the base of the currently accepted dog phylogeny [10 {above article}]. Basenji-like dogs are depicted in drawings and models dating back to the Twelfth Dynasty of Egypt [11] and they share many unique traits with pariah dog types. Like dingoes and New Guinea Singing dogs (NGSD), Basenjis come into oestrus annually—as compared to most other dog breeds, which have two or more breeding seasons every year. Basenjis, dingoes and NGSDs are prone to howls, yodels, and other vocalizations over the characteristic bark of modern dog breeds. One explanation for the unusual vocalisation of the Basenji is that the larynx is flattened [12]. The shape of the dingo and NGSD larynx is not reported.

Basenjis were originally indigenous to central Africa, wherever there was tropical forest. Primarily, what is now the DRC Congo, Southern Sudan, Central African Republic and the small countries on the central Atlantic coast. Today their territory has shrunk to the more remote parts of central Africa. The Basenji probably made its debut in the western world in around 1843. In a painting of three dogs belonging to Queen Victoria and Prince Albert entitled “Esquimaux, Niger and Neptune”, Niger is clearly a Basenji. In total, 71 Basenjis have been exported from Africa and, to date, ~ 56 have been incorporated into the registered Basenji breeding population."

Here's a link to that painting, unfortunately, a monochrome reproduction.

sanjibasenji