You
are receiving this because your address is subscribed at: www.jaunay.com/newsletter.html |
|
 |
| No: 119 |
January 2016
|
|
News January Seminars No seminars in January February Seminars 3 Feb: How to be a successful family historian (1st of 7 weekly sessions) WEA Centre Adelaide 8:00 to 9:30pm All bookings must be made with the hosting organisation. See the seminar program for more details and bookings. State Records relocation State Records' Research Centre is relocating from the State Library on North Terrace to the main repository at Gepps Cross. The move will take place during an extended end of year closure from 25 Dec 2015. State Records’ Research Centre will reopen at 115 Cavan Road on Tuesday 19 Jan 2016. Opening hours are yet to be advised. Are DNA tests worth it? People attending my seminars and regular readers of this newsletter may have picked up the fact that I am a sceptic when it comes to using DNA profiles as a tool in family history research! See Newsletter 107 for a background to the testing regime. See also Newsletters 29 and 76. You may have heard of someone claiming descent from the Mongolian warlord, Genghis Khan—more than 14M people have been told by DNA testing companies that they do. How is this possible? Genghis Khan's remains have never been located and hence no DNA has been tested! While the convergence of genetics and genealogy into a new science called genetic genealogy is some way off, deoxyribonucleic (DNA) tests by one-name groups are already claiming valuable and challenging results. I suspect that one day DNA studies could become the third strand of family history research… but not just yet! By the way the other two tried and tested strands are locating distant living relatives and undertaking the pursuit of a paper trail. The former of these two traditional strands has some links with DNA testing. In many cases, these tests cannot tell you what you do not already know. |
In
this issue: |
Graham Jaunay Services |
| Surveys suggest the main reasons for testing are: • verifying an existing family tree. • seeking new relatives. • verifying family stories/rumours. • adoptees or descendants of adoptees seeking parents or ancestors. • overcoming a dead-end in research. • determining where a family originated. The most popular ancestry tests are Y chromosome testing (yDNA) and mitochondrial DNA testing (mtDNA) which test direct-line paternal and maternal ancestry, respectively. New developments in accessing the Autosomal DNA (atDNA) are allowing people to locate closer relatives. DNA tests are primarily used to determine a person’s comprehensive genetic make-up in an effort to determine relationships with other living persons and/or ethnic origins. A man’s patrilineal ancestry or male-line ancestry can be traced using the DNA on his Y chromosome because the Y chromosome passes down almost unchanged from father to son. A man’s test results when compared to another man’s results can determine the time frame in which the two individuals shared a most recent common ancestor. The closer the test results match, the more recent was their common ancestor. Women who wish to determine their direct paternal DNA ancestry need to ask a person who shares a common patrilineal ancestry to take the test. A person’s matrilineal ancestry can be traced using the DNA in his or her mitochondrial DNA as this is passed down by the mother unchanged, to all her children. To determine a relationship in this case the match must be perfect. Relationships between people can be revealed via their Autosomal DNA that compares blocks of DNA across the twenty-two autosomal chromosomes revealing that the closer the relationship the greater the match. If you send the testing company some DNA from a simple swab of your cheek and a good-sized chunk of money (although costs are falling rapidly) they will test your DNA and tell you some basic information. DNA testers list amongst their claims that they can: • Determine if two people are related. • Determine if two people descend from the same ancestor. • Find out if you are related to others with the same surname. • Prove or disprove your family tree research. • Provide clues about your ethnic origin. The 5 major companies of the top 24 are:
*Note: A single nucleotide polymorphism often abbreviated to just SNP is a variation in a single nucleotide which may occur at some specific position in the genome, where each variation is present to some appreciable degree within a population. The human genome has approximately ten million SNPs. Most genetic ancestry tests involve the analysis of small snippets of the total DNA package of a person, known as a genome. This small sample means that most relatives are likely to be missed! The reports you receive will rarely be specific. The tests cannot tell you who your distant relatives are unless they too have had the test with the same company. Some companies allow you to share your results around. Secondly the test can only be guaranteed if you share the same surnames or have hard evidence that your direct male ancestry shared the same name. Such tests only work with males and only provide information about a single ancestral line—your surname line. It also assumes that your surname has been passed down consistently and that means none of the following has happened in the past to your surname line: • an illegitimate male child taking any surname but that of his biological father. • an illegitimate male child within a marriage. • a husband adopting his wife’s surname. • stepchildren adopting their stepfather’s surname. • an adopted male child taking the surname. • a foreign name altered to resemble an existing local surname. • a male purchaser of property adopting the seller’s surname. • a mis-spelling at some point that switches to a new surname entirely. • a condition for an inheritance. • an admirer or lackey taking on a superior’s name. • a male hiding his identity for any number of reasons. • a male rejecting his name for personal or societal reasons. In spite of what you may be told, the yDNA test is incapable of giving reliable results if surnames are not the same. More importantly they leave out the vast majority of your ancestors—everyone on every female line! In ten generations that means one of your 1022 ancestors! Biogeographical ancestry can be revealed by checking for markers that indicate a very broad geographical heritage—European, Asian, African, Indian and so on. Various ethnic groups have particular markers but due to world migration in the past and the mixing of the races the chance of error increases, thus an Autosomal test may help you find out where your great-grandfather came from. But his distant ancestors could ultimately come from other places. So, most of your genetic ancestry will still be a question mark, no matter how many tests you purchase. It has been widely reported that a major company's (name withheld) mtDNA test is unreliable—Google the key words in the sentence to find out the Company name and why. Yet another company indicates matches to new clients that are anonymous and require them to make a request to share—subscribers indicate that this permission is often not forthcoming leaving them knowing a match exists but not being able to access it—how frustrating must that be, not to mention you wasted your money on the test! It is surprising to me at how many people take a DNA test and keep it locked up so others cannot see it. I can understand the need keep the living people anonymous, but to keep a family tree back several generations under wraps just does not make sense and certainly lacks the spirit of genealogy which is a sharing hobby and experience. One genealogy junkie had her tests done by the four major providers and all differed:
What does this mean? Which company is more correct? Perhaps the better question to ask is—will these genetic percentages have an impact on your research? While the results may or may not surprise, in fact what are you supposed to do with this information? Take on board as an interesting fact. How are you supposed to use the information to find relatives? It is of no use as a finding relatives aid. How is this of any genealogical benefit? It has no benefit in progressing research whatsoever! Another person approached the task a little more scientifically by determining their ethnicity from what they knew and then approached several companies:
Genetic genealogy is not an exact science because it involves interpretation to calculate probability. Although your DNA does not lie, genetic genealogy can suggest, but not prove, a relationship. Are DNA tests worth it? Well that rather depends on what you expect to find out! Still want to take a DNA test? Then: 1. make yourself aware of genetic genealogy. 2. clarify what you hope to learn from a DNA test. 3. expect very generalised answers. 4. shop round to get the company that provides the service you seek. |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| To
unsubscribe send a blank email via the following link using the same
address you subscribed to: newsletter-leave@jaunay.com |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||