DNA






  


DNA


DNA and the Family Historian

 

DNA testing and the convergence of genetics and genealogy are being touted as the "next big thing" to revolutionize family history. While a "genetic genealogy" future is still some way off, current tests by one-name groups in the U.K. and the U.S. are already revealing valuable and challenging results.

There are two basic DNA tests of interest to family historians: the Y-chromosome test and the mitochondrial test. The Y-chromosome in the nuclear DNA of every living man resembles that of his father and his paternal grandfather. It is carried by male cousins of any degree that share the same male ancestor. It creates a clear marker, known as a haplotype, that distinguishes one male-to-male lineage from another. The mitochondrial test looks at the DNA signature of mitochondria, a special part of nearly all human cells, which is passed on female-to-child and inherited down the female line. It is generally used to study long-term population developments such as migrations.


 

  DNA Testing for Genealogical Purposes: A Basic Introduction


DNA Testing for Genealogical Purposes: A Basic Introduction

The science of DNA analysis is an amazing tool that many genealogists can benefit from in their efforts to link families together. However, like any tool, it is important to understand what a DNA analysis can and cannot reveal. Once you learn when to use DNA testing, you'll be able to solve genealogy problems that otherwise might be unsolvable.

The most important aspect of DNA testing, or any research project for that matter, is having an idea of what you want to determine, and defining the evidence that will prove or disprove a conclusion. With DNA testing this means selecting the right person (or people) to be tested. In some cases, testing the DNA of more than one person is the only way to solve genealogy roadblocks. In order to know whom to test, you must understand who has inherited the DNA in question.

Why Use Genetic Genealogy?
Ask yourself the following:

  • Are you looking to validate or invalidate genealogical records?
  • Do you think you may have a surname spelling change or adoption in your line?
  • Are you looking to verify relationships with a family from a region where you believe your line may have lived?
  • Do you believe, for any other reason, that you have a common ancestor with another individual or group?

    If you answered "yes" to any of these questions, then a Genetic Genealogy test may help you find answers. Ancestry.com is once again offering several DNA testing kits that are helpful in family history research. For more information, visit: www.ancestry.com/rd/prodredir.asp?sourceid=831&key=P1025994

  • DNA AND IRELAND


    More About Genes - The Irish Really are a race apart
    By Dr. Emmeline Hill

    Men with Gaelic surnames coming from the west of Ireland are descendants of the oldest inhabitants of Europe. In a recent study, scientists at Trinity College, Dublin, created a new genetic map of the people of Ireland. By comparing this map to European genetic maps they have shown that the Irish are one of the last remnants of the pre-Neolithic hunters and gatherers who were living throughout Europe over 10,000 years ago, before the invention of agriculture. The Irish really ARE different.

    What's in a name?

    Surnames in Ireland have been passed from father to son for almost 1,000 years. The surname system in Ireland is thought to exist as one of the oldest applications of the hereditary surname system in the world. In Ireland this system was not introduced but rather it is thought that toponymics (names derived from place names) and nicknames were adopted. For example, the name O'Callaghan comes from the Irish O'Ceallachain, a diminutive of ceallach, which was taken to mean 'frequenter of churches.'

    Traditionally, newly married women have taken up residence in the homeland of their husband, meaning that family names have remained in the area of the particular clans or septs for generations. Surnames, except in the infrequent case of non-paternity, are therefore an indication of family history, and on a larger scale, of population history.

    In developing the new genetic map, the scientists studied the DNA of 221 men from all over the country. The DNA was separated into groups of people with names coming from the same area. For example, names that originated in Ulster, such as Gallagher and O'Reilly, were grouped together. Names from Munster (e.g. Hogan, Meagher, Ryan); Leinster (e.g. Conlan, Phelan, Rafter); and Connaught (e.g. Conway, Flynn, McHugh, Ruane) were all grouped accordingly and were considered to be Gaelic Irish. Also names of English (e.g. Harrison, Hill, Jacob, Moore) Scottish (e.g. Hamilton, Johnston, Knox), Norman (e.g. Barry, Bryan, MacNicholas) and Norse (e.g. Doyle) descent were grouped separately. These were considered to be non-Gaelic Irish. By separating the DNA as such, they could study the genes that were present in a particular region of Ireland over 1,000 years ago, when the surname system was adopted.

    The science behind it

    In Issue 88 of INSIDE IRELAND, the article "Who are we? - It's in the Genes" outlined the basic science behind genetic studies of populations. Each cell in our body contains a signature of our past. Modern technology allows us to look directly at the amount of variation in the genes in these cells. Variation accumulates over time through a random process of mutation. Mutations occur at a constant rate. Therefore, the more different two people are genetically, the longer they have been separated.

    Using modern technologies to look at the differences between genes in the different peoples of Ireland, the scientists in Trinity College studied the genes on the Y chromosome. The Y chromosome is the male-specific sex chromosome that is passed from father to son in the same way that surnames are passed from father to son.

    A distinct genetic pattern

    By performing a number of genetic tests the scientists were able to identify a particular genetic pattern in the Y chromosome of the Irish. An ancient genetic marker, known as haplogroup 1, was found in most Irish men. Scientists think that most of the population of Western Europe carried this gene over 10,000 years ago. Over time however, through the movement and mixing of peoples, this gene was diluted. Now it is found in relatively fewer people throughout Europe.

    The greatest movement and migration of peoples in Europe has been the movement of farmers from the south-east of the continent after the invention of agriculture about 10,000 years ago. The farmers moved with their new technologies north-west into Europe, probably displacing the local hunter-gatherer populations that were living there at the time. In this way the haplogroup 1 genes in Europe were diluted, the farmers introducing new and different genes.

    Men with Gaelic names are more ancient

    This resulted in the formation of a gradient of haplogroup 1 genes throughout the continent, the lowest frequency of these ancient genes being found in Turkey, and the highest frequency in Ireland, with intermediate frequencies in continental populations. In Ireland 78.1% of all men have the haplogroup 1 gene.

    In Ireland men with Gaelic names have higher frequencies of this ancient marker than men with non-Gaelic names. For example, men in Ireland with surnames of English origin have 62% haplogroup 1 genes; men with Scottish names have 52.9% and men with Norman and Norse names have 83%. In Leinster, 73.3% of men with Gaelic surnames have this gene, in Munster, 94.6% and in Ulster 81.1%.

    Connaught men are the most Irish of the Irish

    The most striking finding was that in Connaught, the westernmost point of Europe, almost all men (98.3%) carry this particular gene. This means that the people of Connaught have been relatively isolated, genetically, from the movements of people that shaped the genetic makeup of the rest of the continent. By comparison, in the east of the country there has been a lot more mixing of genes coming from foreign sources.

    The prevalence of ancient genes in Ireland suggests that the Irish have largely maintained their pre-Neolithic genetic heritage. There has been little genetic influence from outside the country since the first people came to Ireland almost 9,000 years ago.

    The Early Bronze Age

    By looking at the amount of variation (the number of mutations that have accumulated over time) in the haplogroup 1 genes of these men it was possible for the scientists to estimate a date for the origin of the bulk of these genes in the country. They estimated that most of the genetic variation in Ireland has accumulated over the past 4,200 years following a rapid growth of the population at this time. This is the time of the Early Bronze Age in Ireland.

    The Early Bronze Age in Ireland, among other things, saw the appearance of megalithic tombs. Newgrange in Co. Meath is the best known example. The scale and magnanimity of these structures suggest that the creators belonged to a large, highly socially evolved society.

    The scientists have shown most of the genes present in Ireland today came from the people who were living at the time of Newgrange. These people were the descendants of the ancient hunter-gatherers of Europe.

     

    Any Nash/ Naish surname in the area of Kilcornan, Askeaton, Ballysteen, Newcastlewest, Rathkeale, Foynes or Shangolden that would like to participate in DNA testing can contact me at: Endos@aol.com


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