RootsChat.Com

You are confusing two different DNA scenarios. Matching with descendants of common ancestors is accurate and indisputable above match lengths of about 16-20 cM. With match lengths less than that, the chances that the purported match is false increase significantly the lower the match length, so that at 6 cM (which is the lowest match length that most DNA testing companies will report) there may be around a 50% likelihood that the proposed match isn't a genuine match at all.

The reasons for that are complex and varied, but because match lengths to ancestors decrease with successive generations, and therefore the generational distance between current relatives, it is generally accepted that a genuine match can only be determined over 5 to 8 generations at an absolute maximum.

But ethnicity estimates are a different (pseudo) science. They do not attempt to match you with relatives who have descended from a common ancestor within the last 5 - 8 generations. Instead, the theory is that segments of your DNA are compared to segments which the testing companies believe may be commonly found in groups of people (whether more recently related or not) who originated from particular regions within the last several hundred to a few thousand years ago.

As previous replies have said, the definitions of particular regions differ between different testing companies. The reference populations that are used to determine those regions are incredibly small in comparison to the actual populations of those regions - often only a few hundred people and in some cases fewer than ten. Ethnicity estimations to continental level are considered to be more reliable than those to individual country level or even regions within countries, and again, lower percentages allocated to particular regions are likely to be more suspect, so a supposition that you have 45% English ethnicity is quite likely to have some bearing of truth, whereas an indication that you inherited 2% Swedish ethnicity may well be totally incorrect.

So the assertion by one testing company that my ethnicity (as determined from my transferred to them Ancestry DNA test) is 98% European is, I think, quite likely to be reasonably accurate, but is it at all useful? Most people could probably give me an estimate with a similar degree of accuracy just by looking at me

Whether you choose to believe and place any reliance on your ethnicity estimates is your choice. There may be a degree of expectation bias involved in people who claim that they are accurate. Personally, as already said, I choose to treat them as an informative but not necessarily accurate ploy to sell DNA tests to people who would otherwise have no interest in testing and the hard work involved in researching and identifying relatives descended from common ancestors.

I prefer to concentrate on using DNA matches with other people to further (and confirm or disprove) my research into my own ancestral lineage.

I have recently been researching a similar situation re one of my ancestors, also a mariner, but in Kent. This text, from a document published by the Kent Archaeological Field School, helps explain the number of mariners in 18th century England. Although the document itself is primarily about the development of Faversham, this paragraph refers to the use of waterways and coastal traffic around England due to the general lack of passable roads for freight traffic. I assume that, besides the fishing trade, many mariners would have been engaged in general goods transport akin to the jobs of train and lorry drivers today. So it was likely to have been a fairly common job amongst people living near the coast and waterway networks.

“Throughout the 18th century the principle highway of England was the sea. Before canals or railways, and while roads remained impassable, coastal shipping remained the cheapest, safest and speediest means of conveying freight. Hence ports were vital, not just for trade, but also as nurseries of the Royal Navy, the fisheries, and the whaling fleets. All of the front-rank towns of the kingdom were either ports or had easy river access to the sea (Selley 1962: 199). Besides the ships of the Royal Navy and merchantmen trading overseas, there were large numbers of small craft trafficking in the waters about Britain. “There are supposed to be about eighteen hundred ships and vessels in the coal trade and about nine hundred more in what they call the Northern trade”, wrote a naval officer in 1774 (Ashton, 1924: 200). North Kent was endowed with one passable road (Watling Street) and numerous waterways. It possessed an extensive coastline along the Thames south shore and to the east, a navigable river from Sandwich to Fordwich (and thence to Canterbury), and to the west the Medway River from Rochester to Maidstone. Fortuitously “the water transport was available where it was most needed” (Thirsk 1967: 199). Contemporaries were aware of this favourable circumstance, and noted particularly “the benefits of water carriage (from Kent) to and from the Metropolitical City, or Chief Mart” (Harris, 1719: 357). Throughout the year coastal hoys operated a weekly schedule from these North Kent ports.”

I quote the catalogue reference for the collection (and document if known) as shown in the Discovery catalogue, plus the short title and description, followed by a short summary of exactly what I am looking for and who/what it relates to. I've always tried to keep it as short as possible, as I can't see the staff wanting to made through paragraphs of text, but at the same time you need to ensure that all the information you think they will need to find and confirm the item you are interested in has been explained to them.

The attached image shows the description I gave for one of my more recent orders, with the TNA response above.

I'm not aware that you can order low resolution copies. The fees document showing copying costs refers in every instance to research quality copies. All my orders have been digital images of documents, not paper copies, but the quality of reproduction has been excellent, even for large documents.

Any indications of a specific relationship are just suggestions based on the most probable estimate of a relationship between two individuals at the given length of their DNA match. You need to investigate the match through your own ancestors and those of the match to establish where the common link between you occurs.

If you enter the match length in cM into the DNA painter tool at

https://dnapainter.com/tools/sharedcmv4

it will give a list of possible relationships based on probabilities. The relationship with the highest probability is the most likely, but that doesn't mean it is necessarily the actual relationship between you and your match. Any of the other probabilities are possible, and someone has to fit them, or they wouldn't be included.

Same for us. Our first labrador was the daughter of a field training champion. Fifteen years later, we got another puppy from a different breeder. Our first lab's father was also in the pedigree of the second dog as great however many times grandfather (I can't remember exactly how many generations now).

Quite a few cousins in my tree that I'm related to in 2 or 3 different ways. It can be a pain when you're hoping to evidence a connection to a specific ancestor, but you can't show with certainty whether your match is related through that person/family or not, because of the other connections.

My uncle told me many years ago that he and my father were related in one way or another to just about every other child in the village where they grew up. It turns out that he wasn't far wrong, and that it's not at all uncommon in rural populations.