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View Full Version : Ancestry's 'ranges'



firemonkey
07-23-2016, 05:53 AM
Specifically for 0% regions that don't have a 0-0% range. Does this mean there may be some ancestry but if so it's small enough to register as zero?

Senegal 0-<1
Africa north 0-1
Native American 0-<1
Asia South 0-1
Finland/NorthWest Russia 0-1
Iberian Peninsula 0-2
European Jewish 0-2
Polynesia 0-<1
Middle East 0-2

loisrp
07-23-2016, 07:13 AM
Ancestry gives the explanation that their test does 40 scans of your genome, and then they come up with an average. So on an unknown number of those 40 scans, Ancestry came up with those highest values.

I know people have reported they got 0%, plus an actual range, on Ancestry, and then found the actual ancestry at 23AndMe.

Personally I'd see those as all possible if confirmed by matches.

Also, it might be that the percentage refers to a region that might be one or the other, but not both, or perhaps a mixture of both. Maybe the 2% or less could be either Middle East or Jewish (by Ancestry definitions), for example, but you probably don't have 4% combined. Just a guess.

My favorite range on my Ancestry report: 8-51% Scandinavian

loisrp
07-23-2016, 07:39 AM
I don't know the nature of how this "average" is calculated. I would hope something more sophisticated than a straightforward mean or median.

firemonkey
07-23-2016, 08:08 AM
There are certainly some wide ranges. For me : 3-44% Scandinavian ,0-48% Europe West and 0-33% Great Britain.

Stephen1986
07-23-2016, 11:02 AM
Most of mine seem to have fairly wide ranges - 38% Europe West with a range of 11-64%, 27% Ireland with a range of 10-45%, 26% Great Britain with a range of 0-57%.

LauraHolland
07-25-2016, 02:08 AM
Oh that's interesting I just took a look and I have 0-1% on Africa North, Iberian Peninsula, European Jewish, Middle East and Caucasus.

jpb
07-25-2016, 05:00 PM
I have 0-1 on Finland Northwest Russia, too. I am wondering if this is real or not. Some of my ranges are: 0-23 Scandinavian, 0-20 Great Britain 22-80 Europe West. So wide!

AJL
07-25-2016, 05:10 PM
I don't know the nature of how this "average" is calculated. I would hope something more sophisticated than a straightforward mean or median.

If it's a range its probably a confidence interval.

loisrp
07-26-2016, 09:34 AM
If it's a range its probably a confidence interval.

I agree it's likely a confidence interval, but I'm not sure how the "final answer", the single number that people notice (as most people never look at their ranges) is calculated. It's often half-way in the middle, but not always.

geebee
07-26-2016, 04:16 PM
Here's what Ancestry says about how the range is calculated:


When we calculate your estimate for each ethnicity region, we run forty separate analyses. Each of the forty analyses gives another estimate of your ethnicity, and each one is done with randomly selected portions of your DNA. Why forty? Ethnicity estimation can be variable from comparison to comparison different combinations of DNA can give us different information, so doing multiple analyses can give us a more accurate estimate, as well as the likely range.

Also


We look at each of the 40 estimates and find the average amount predicted for each region. This average becomes the percent that is displayed in the estimates. Our confidence that your actual genetic ethnicity is EXACTLY the average is not high.


There is often a wide range among these 40 estimates. The range shown in the product experience encompasses most of the variability found in the estimates. Our confidence that your actual genetic ethnicity falls within this range is relatively high.


The product shows the average estimate as the given percent for each region. The general spread of the 40 estimates is shown as the probable range. Our analysis suggests that your actual ethnicity for this region lies somewhere in this range.

The average estimate is typically very close to the middle of the range, expressed as an integer (presumably the nearest, but it could just be truncated). But it isn't the midpoint, but the mean, so it may be skewed slightly toward either the high or low.

geebee
08-06-2016, 08:00 PM
I've said it before, but I really have to say it again: Ancestry needs to provide some sort of chromosome browser. Or failing that, they ought to at least tell us a bit more than just "so many centimorgens shared across so many segments."

I was going through some of my DNA matches that have "hints", comparing the amount of DNA that would be average for the stated genealogical relationship to the amount of shared DNA actually reported. When the reported amount was less than the average, it was usually at least in the same ballpark.

But in a number of cases, there was quite a bit more actual DNA than expected DNA. For example, in one case the "Hint" showed us to be 6th cousins. The reported average sharing for this relationship is 0.83 cM, while Ancestry says we share "23.6 centimorgans ... across 2 DNA segments". It's of course possible that even a large segment may be passed on intact over multiple generations, but it's also possible there is an additional, closer relationship.

Knowing the length of each segment would be helpful here, and whether they are on the same chromosome or not. Segments which are relatively close together on the same chromosome might have been part of a single segment just one generation previous; but segments located on different chromosomes can never have been part of a single segment.

At 23andMe or at FTDNA, it's easy for me to tell very quickly whether a segment is paternal or maternal, because my father has also been tested. But I can also often tell which of my grandparents it's from, just by looking at where the segment is located; and sometimes even which great grandparent.

If Ancestry had a chromosome browser, I'd have a better chance of being able to at least determine a genealogical quadrant for unknown cousins, which is far more useful than just having a "predicted relationship" or even a relationship range.

JFWinstone
09-05-2016, 09:33 PM
Interesting. I went back and clicked on the regions that had come up as 0% and most of them do have ranges, most of them 0%-2% range.

crossover
09-05-2016, 11:31 PM
my grandpa's british rane is 0-25%

Area-1255
08-12-2017, 06:25 AM
It depends, the range is relevant to a degree, but it depends on other factors.
If you have a huge mix of different genetic contributions of which all give a fairly large - moderate percentage then the lower level "zero" percentages would appear as small consistencies in your DNA. They certainly aren't very large proportions and as one has said they are probably best assumed as median range being accurate. So if you see 0-3 assume 1.5 "percent". Though, because the number must add up to 100% and those outline your dominant DNA origins, then everything else are trace-trace percentages and likely close to meaningless. That doesn't mean they aren't a part of you - but in comparison to your other ethnic origins they are lesser and most likely the result of low percentage admixtures passed down and broken down repeatedly. So if you have 0-5% middle eastern then wherever the original middle eastern DNA comes from is an original trace percentage many many lines down on a grand parent somewhere.

The only way to figure it out would be to do DNA matching and test relatives to figure out where the consistency is and where it is not.

If they show up with a flat 0% (without a range) then consider it meaningless, but say if your Father or mother shows up with a slightly higher trace percentage (like 0-8% if you are 0-4% etc) then you will understand where its coming from. So essentially the answer here (and I know this is an old thread), is that the AncestryDNA "zero-range" percentages are meaningful to an extent, but they are trace amounts of the original trace amounts passed down and I would take 0-<1%'s as even less significant anything higher than that could possibly indicate trace heritage.

- If you have a flat zero (0%, no range) you confidently have none whatsoever.
- 0-<1% means practically or basically nil.
- 0-1% means some very tiny trace evidence of those DNA markers. (this is probably the result of trace percentages getting smaller per generation)
-0-2% - some small but significant evidence (moreso than 0-1%) that you have some trace origin of that country, probably something like a parent who's one side has had trace percentages etc
0-3% - even larger significance than above, you have some markers for sure.
0-4% - this percentage would likely to show up if your other mixtures were not present.
0-5% - basically assume you have a good degree of trace amount of this marker.

So anything from 0-1% and beyond means you can be hopeful that there is some of that in your DNA but as said above, if you really want to confirm use another test or DNA test your relatives with AncestryDNA to figure more about their DNA and give further insight into the percentages.

dp
08-12-2017, 05:05 PM
It depends, the range is relevant to a degree, but it depends on other factors.
If you have a huge mix of different genetic contributions of which all give a fairly large - moderate percentage then the lower level "zero" percentages would appear as small consistencies in your DNA. They certainly aren't very large proportions and as one has said they are probably best assumed as median range being accurate. So if you see 0-3 assume 1.5 "percent". Though, because the number must add up to 100% and those outline your dominant DNA origins, then everything else are trace-trace percentages and likely close to meaningless. That doesn't mean they aren't a part of you - but in comparison to your other ethnic origins they are lesser and most likely the result of low percentage admixtures passed down and broken down repeatedly. So if you have 0-5% middle eastern then wherever the original middle eastern DNA comes from is an original trace percentage many many lines down on a grand parent somewhere.

The only way to figure it out would be to do DNA matching and test relatives to figure out where the consistency is and where it is not.

If they show up with a flat 0% (without a range) then consider it meaningless, but say if your Father or mother shows up with a slightly higher trace percentage (like 0-8% if you are 0-4% etc) then you will understand where its coming from. So essentially the answer here (and I know this is an old thread), is that the AncestryDNA "zero-range" percentages are meaningful to an extent, but they are trace amounts of the original trace amounts passed down and I would take 0-<1%'s as even less significant anything higher than that could possibly indicate trace heritage.

- If you have a flat zero (0%, no range) you confidently have none whatsoever.
- 0-<1% means practically or basically nil.
- 0-1% means some very tiny trace evidence of those DNA markers. (this is probably the result of trace percentages getting smaller per generation)
-0-2% - some small but significant evidence (moreso than 0-1%) that you have some trace origin of that country, probably something like a parent who's one side has had trace percentages etc
0-3% - even larger significance than above, you have some markers for sure.
0-4% - this percentage would likely to show up if your other mixtures were not present.
0-5% - basically assume you have a good degree of trace amount of this marker.

So anything from 0-1% and beyond means you can be hopeful that there is some of that in your DNA but as said above, if you really want to confirm use another test or DNA test your relatives with AncestryDNA to figure more about their DNA and give further insight into the percentages.


Welcome to Anthrogenica.
-dp

mwauthy
08-12-2017, 07:14 PM
Europe West 19%-76%; 47%