Right-click on the animation and open to see it at full size! To see the images of the Mayfair Witches used, see this Parlor gallery (three of them are different):

The Mayfair Witches Vintage Gallery

From Anne Rice's Mayfair Witches on AMC

Generation	Percentage on Average of DNA Inherited From Each Generation
Parents	50%
Grandparents	25%
Great Grandparents	12.5%
2nd Great Grandparents	6.25%
3rd Great Grandparents	3.13%
4th Great Grandparents	1.56%
5th Great Grandparents	0.78%

Relationship	23andMe	AncestryDNA	Family Tree DNA
2nd Cousin or Closer	>99%	100%	>99%
3rd Cousin	~90%	98%	>90%
4th Cousin	~45%	71%	>50%
5th Cousin	~15%	32%	>10%
6th Cousin or Further	<5%	<11%	<2%

The averages in the charts are averages only. They are estimates based upon only one line of descent/one common ancestor. Obviously, family trees like that of the Mayfairs are going to have vastly different averages of shared DNA because of how many lines of descent any given Mayfair will have.

Mona Mayfair is described (by herself and others) as a "twentyfold Mayfair", meaning twenty different lines of descent. But what does that mean, exactly?

In recent years, there has been a huge uptick in the amount of interest in our family trees, our genetics, and what they tell us about genealogy. We have learned a lot of surprising things. We've learned these things through what is usually referred to as "genetic genealogy".

The second chart above gives averages from three different DNA testing products. They each have their own testing thresholds. Each of them can provide valuable information about our DNA.

While this site is not about true crime, I will say this: genetic genealogy has had an incredible impact on cold cases. Crimes committed decades ago have been solved and unidentified persons have finally been identified, many times after decades of being known as Jane or John Does with unique additional names to distinguish one Doe from another. One example: Jane "Arroyo Grande" Doe, whose name, Tammy Corrine Terrell, was finally returned to her after 41 years.

So, how can we apply what we know now to the study of the Mayfair family tree?

DNA Q&A: Genealogical vs. Genetic Family Trees

DNA Sequencing

Something I think is important to have a basic knowledge of when studying family trees like this one is a couple of terms.

This is the part where I have to advise caution. Family trees that show considerable pedigree collapse due to either or both of the terms I will provide definitions for can be an extremely sensitive subject in a lot of ways.

So I want to make it clear that this study of the Mayfair family tree is one that describes characters in fiction. It is here to help further examine the genealogy of the Mayfair Witches as part of the plot in the novels based on what is known about genealogy and genetics. It is for this and no other reason that this is discussed on Come Into My Parlor.

Pedigree Collapse: In genealogy, pedigree collapse describes how reproduction between two individuals who share an ancestor causes the number of distinct ancestors in the family tree of their offspring to be smaller than it could otherwise be. (Wikipedia)

Endogamy: The cultural practice of mating - usually in the form of marriage - within a specific social group, religious denomination, caste, or ethnic group, rejecting those from others as unsuitable for marriage or other close interpersonal relationships.

A long term pattern of endogamy in a region may increase the risk of repeated cousin marriage during a long period of time, referred to as inbreeding. It may cause additional noise in the DNA autosomal data, giving the impressions that DNA matches with roots in that region are more closely related than they are. (Wikipedia)

Incest: in·cest
noun
noun: incest

sexual relations between people classed as being too closely related to marry each other.
the crime of having sexual intercourse with a parent, child, sibling, or grandchild. -From Oxford Languages

Pedigree Collapse on Wikipedia

Endogamy on Wikipedia

DNA RNA Replication

Mayfair Family Tree

Come Together - The Mayfair Witches

The Taltos and the Theory of Evolution