Icelandic names and consanguinity

In the "searching the news for something not utterly horrible" category, there is this recent story on the Islendiga-App - the App for Icelanders.  Basically, this smartphone app allows any two individuals to "bump phones" and discover how closely related they are as a preventative measure against inbreeding.  Apparently, the app makes use of the Islendingabok, the online genealogical database for Icelanders which cross-references the extensive census records, church registries and personal genealogies with molecular DNA data.  I should note that, in reference to a major personal research interest, Iceland is probably the only western nation where traditional isonymy research is ineffective due to the use of patronymic (and occasionally matronymic) name systems.  In other words, Icelandic children derive their surname from the first name of their father (and occasionally mother).  For example, my surname would be "Thomasson", whereas my son would be "Kevinsson."  This pretty much invalidates the surname as a genetic proxy, although in the case of Iceland the extensive geneaological records provide an alternative for assessing consanguinity via archival methods.

The Demography of the Aleutian Islands

The Oct-Dec 2010 issue of Human Biology is dedicated to various biological, archaeological and biohistorical studies of the indigenous populations of the Aleutian Islands.  Of particular interest to this blog is the article by Katherine Reedy-Maschner regarding the demographic shifts that impacted the male Aleut population throughout the 19th and 20th centuries.  Using both historical data and ethnographic fieldwork, Reedy-Maschner recounts how various political and economic forces acted to effectively replace the male population via cultural assimilation and displacement.  Today, many Aleuts bear Russian, Scandinavian and other European ancestry within their lineages.  This article also contains a cautionary tale for demographers using surnames as genetic analogs.  Aleut men baptized into the Russian Orthodox Church often took the names of their Russian sponsors, which obviously complicates the direct analogy between surnames and Y-chromosome pattern. 

Reedy-Maschner, Katherine, 2010.  Where did all the Aleut men go? Aleut male attrition and related patterns in Aleutian historical demography and social organization.  Human Biology, 82(5-6): 583.

Isonymy in small populations

Just another follow up on the responses to my isonymy poster presentation:  one comment that came up a few times was from both students and professors was that they would love to use isonymy in their own work, but since they were working with a single population it was impractical.  In those cases, I recommend two articles by Lasker and Mascie-Taylor dealing that use isonymy at very small scales, including between and within households. 

Lasker, GW and Mascie-Taylor CGN,  2001, The genetic structure of English villages:  surname diversity changes between 1976 and 1997.  Annals of Human Biology, 28 (5): 546-553.

Lasker, GW, 1997, Census versus sample data in isonymy studies:  relationship at short distances.  Human Biology, 69 (5): 733-738.

The Irish Isonymy Project

For an example of how to conduct a multidimensional project in isonymy, have a look at the Irish Isonymy Project of Don MacRaild and Malcolm Smith.  The main focus of the project is the use of random isonymy to track 19th century Irish migration into Britain.  One particularly interesting sub project is their exploration of the use of first names as a research tool.  Naturally, first names don't track genetic trends, but they can be used to measure cultural trends (such as the spread of non-Irish first names among the population of Ireland).

It is this last aspect of the Irish Isonymy Project which leads into a particular line of questions I've had for isonymy research in general.  Ever since its inception, surnames have been vetted as a neutral marker for population studies.  But are there situations in which selective pressure should be taken into account?  I will be exploring this topic in posts to come.

A short introduction to Isonymy (surname genetics)

Think you need a lab to do population genetics research?  Chances are, you already have everything you need for basic population structure analysis right at home. All you really need is a phonebook, a set of equation and either a pencil, paper and a calculator or, preferably, a computer with a good spreadsheet program.  What follows here is a very short introduction to using surnames as genetic markers in population and kinship studies.

In our culture, along with other European derived societies, surnames are inherited from the father.  As such, they behave as a system analogous to Y-chromosome inheritance, which has been shown to reflect actual genetic within and between populations.  Surnames have been used for decades by biological anthropologists as measures of genetic relationships.  Medical geneticists have also used surnames to study genetic linkages with various diseases, such as certain cancers. 

There are two basic types of isonymy (literally "same name") studies; random and non-random.  Non-random studies are generally geared toward analyses of inbreeding levels in a population, and are usually centered on levels of surname repetition among married couples.  This was the technique employed by George Darwin (son of Charles Darwin) in his landmark study of inbreeding in first-cousin marriages in England.   

Random isonymy,  by contrast, involves calculating the kinship coefficient for a population based on the repetition of surnames throughout that population.  Calculating the random isonymy of either a single population or between two populations is the first step in any kinship study.  Unfortunately, there are many different methods of computing this figure, since many different researchers have worked out their own methods of calculating random isonymy.  One common method for calculating isonymy within a single population is:

Iii = ∑ n_ik (n_ik – 1)

Ni ( Ni-1)

            Iii equals random isonymy.  n_ik equals the number of occurrences of a particular surname within a population (say, for example, Anderson).  This is multiplied with the same number of the occurrences of Anderson minus 1.  So let’s say that Anderson occurs 6 times in a population.  You would multiply 6 * 5, getting 30.  The next step is to repeat this for every surname in the population.  Surnames that only occur once drop out of the equation (since 1 * 0 is always 0).  Then take the results of all these calculations and add them up, which is indicated by the sigma (∑) symbol.  Moving to the bottom of the equation, Ni equals the total number of surnames in the population.  This is multiplied by the total number of surnames minus 1.  Then divide the numerator by the denominator and you have the random isonymy for that population.

From the random isonymy score, you can calculate other metrics of kinship within a population.  The simplest of these are Laskers coefficient of relationship (which corresponds to Wrights coefficient of relationship) which is obtained by dividing random isonymy by 2 (Lasker, 1977).  Divide random isonymy by 4 and you have the coefficient of inbreeding.  These are the very basic elements of surname genetics, which I hope to explore in greater depth in the course of this blog.

References

Darwin, G.  1875.  Marriage between first cousins and their effects.  The Journal of the Statistical Society of London, 38: 153-184.

Lasker, GW. 1977.  A coefficient of relationship by isonymy: a method for estimating the genetic relationship between populations.  Human Biology, 49: 489-493.

Welcome to Southern Tier Biohistory

Welcome to the inaugural post for Southern Tier Biohistory.  My goal for this blog will be to create a nexus for information and research centering on an important subset of anthropological research, namely the use of archival and historical data sources.  My own background as a biological anthropologist will inevitably reflect the emphasis topics relevant to human biology.  However, as this weblog grows I hope to include posting relevant to all four subfields as they relate to the topic of archival data mining.

The genesis for this project lies within my circuitous route to my Ph.D in anthropology.  Prior to my graduate studies, I had been working as a field technician for contract archaeology firms in Upstate New York.  Initially starting graduate school as an archaeology student, I quickly became enamored of biological anthropology and evolutionary theory, which eventually saw me obtaining my Ph.D at Binghamton University with David Sloan Wilson.  However, throughout my graduate studies up to this very day, I continued working as a professional archaeologist, and am currently a project director for the Public Archaeology Facility of Binghamton University.  This then was my dilemma – I needed to unify the academic pursuit I had been engaged in for a significant part of my adult life with the occupation I had been engaged in for an even longer period of my life.  How would I do that?

The answer came in part when I got a hold of the edited volume Human Biologists in the Archives (edited by Ann Herring and Alan Swedlund).  This led to my interest in historical demography and the use of surnames as genetic markers (isonymy), which became a springboard for my current research focus.  Further book hoarding (a fairly common condition among both current and former graduate students, or so I am told) led me to Laskers Surnames and Genetic Structure.  The historical focus of these and other works in biological anthropology forms the nucleus of what I hope to cover in this weblog, and I am eager to hear from other anthropologists working the same vein (especially other bloggers).

Finally, a word about the blog title.  Southern Tier refers to the Southern Tier of New York State.  This is both my home and the focus of the lions share of my current research.  Thus I thought it appropriate to contextualize the work I am doing and create a more “localized” feel to the blog.  Context is essential in any historical (or biohistorical) work, and so the Southern Tier will occasionally figure prominently in the posts ahead.