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An autosomal DNA test (AKA universal lineage test) such as Family Finder is probably the most useful genetic test for finding relatively close kinship to people. It can certainly help adoptees find their genetic kin. However, this kind of test can require extensive analysis. Unlike the Y test, there is no surname correlation; many people confuse the two tests.

A-DNA tests your 22 autosomal (non-sex) chromosomes plus the X sex chromosome. The 22 autosomal chromosomes recombine with each successive generation, thus certain sequences get broken down. Females receive one X chromosome from their fathers, passed intact, and one X chromosome from their mothers, a product of the mother’s recombination. Men get one X chromosome from their mothers, which is a product of the mother’s recombination.

Recombined genes passed to the next generation are "diluted" so the "strength" of a DNA block deteriorates over time. gas up The optimal situation would be to test your parents or grandparents and their siblings, if at all possible. Choose a person in the oldest available generation for the line you are researching. electricity and magnetism study guide answers A practical limit in terms of how far the test can reach back is maybe 200 – 250 years – however some DNA blocks may survive considerably longer.

Two test takers who share a common set of parents or great-grandparents have a 99% or better chance of matching. If they share a set of great-great-grandparents (i.e., are third cousins), they stand a better than 90% chance of matching. If they share a set of 3g-grandparents, (i.e., are fourth cousins), they stand about a 50% chance of matching. The chances drop rapidly after that.

Y-DNA projects trace direct patrilineal lines. Usually they are surname studies, with each project tracing a particular surname and its variants. The impressive correlation between surname and Y data makes this test particularly powerful. Some Y-DNA projects look at geographic regions or several clans with documented histories, known to have inhabited certain territories. Y-DNA project goals often involve confirming or refuting what documented history tells us.

Most of the Y chromosome is non-combining so is considered very stable. p gasol Some of this stable DNA is used to identify the branches of the human family tree, going back many tens of thousands of years. In order to confirm your human family tree branch, you would have to get a special test. However, when you do a Y-DNA test, the testing laboratory (e.g. Family Tree DNA) will attempt to predict your family tree branch.

For genealogical purposes, some of the non-combining Y chromosome has up to 111 locations that are interesting to family historians. These locations (called markers) are what normally are tested when you order a Y-DNA test. Two testers who have identical or nearly identical matching DNA at these locations may share relatively recent common ancestry. These DNA locations are scientifically studied to determine how often they change (mutate). Some mutate very quickly (every few generations) and some mutate quite slowly (maybe once or twice in a thousand years). electricity kwh Taking into account different mutation rates at different addresses, the testing lab estimates how many generations back you and another tester shared a common ancestor. Average mutation rates are used in estimates, but a particular lineage might exhibit markers that are more stable than the averages, or more volatile than the averages.

A Y-DNA test taker who matches 10 out of 10 markers with another tester likely shares common ancestry within about 72 generations, which is not particularly practical for finding relatively recent cousins. (At three generations per century, the common ancestor would have lived about 24 centuries ago.) On the other hand, if the two testers match 111 out of 111 markers, they probably share a common male ancestor back within about six generations. Sometimes father and son can exhibit a few mutations between them and sometimes a second or third cousin might be a perfect 111 match. Results may definitely vary.

Unlike universal lineage testing, Y DNA testers don’t need to test a lot of close relatives and they don’t need to continually reanalyze their data. Rather, they can sit back and wait for genetic matches to show up if they want to take a more passive approach to research. Very active researchers who enjoy going outside their immediate family bounds and investigating others sharing their surname history and who like assisting others are good candidates for eventually becoming surname project administrators and co-administrators. If the interest extends further back, some testers take on regional and deeper ancestral (haplogroup) Y projects.

Because mtDNA changes so slowly over the course of thousands of years, and women usually moved to their husbands’ residences, trying to find very recent cousins can be difficult to do with the mtDNA test, which tests only one lineage. However, a match may turn up that could make sense to you – the direct maternal ancestor of your match lived about the same time and in close proximity to your maternal ancestor. In that case, you will have succeeded in learning a bit more about your maternal ancestor – that SHE in turn shared a direct maternal ancestor with that particular contemporary. c gastronomie plateaux repas Your test match might even know something about the common ancestor.

If two testers match identically through the mitochondrial Full Genomic Sequence (zero steps), there is a roughly 50% chance (i.e., probability to a 50% confidence level) that they share a common maternal ancestor within the past five generations (say, 125-150 years). It may not be possible to specify the exact nature of the relationship if there aren’t genealogical records available.

mtDNA testers don’t need to test lots of close relatives and continually reanalyze their data, if they want to take a more passive approach to research. It can be exceptionally difficult finding suitable candidates to test for particular female ancestors of interest. But there are regional and haplogroup projects mtDNA testers can join which may reveal more over time.