Wednesday, February 15, 2012

Correspondence between ChromoPainter clusters and ADMIXTURE components in Balkans/West Asia

I took the 25 different inferred clusters from my recent ChromoPainter analysis, and calculated their normalized median components in terms of the K12b calculator. This is a quite useful exercise, since it can show in what sense clusters are different from each other.




Here are two ways in which you may use this correspondence.

1. Different clusters of a single population

For example, the Turks with partial Balkan ancestry tend to belong to pop10, whereas those of Anatolian ancestry to pop13, and those from northeastern Anatolia to pop22. If we compare the admixture proportions of these three groups, we notice e.g.,

  • An excess of Atlantic_Baltic and North_European in pop10
  • An excess of Caucasus in pop22
Or, there is a group of 5 Iranians that belong to pop12, whereas the overwhelming majority of Iranians and Kurds belong to pop21. Strikingly, pop12 differs from all other populations in having substantial levels of East_African and Sub_Saharan. So, it seems that fineSTRUCTURE was able to infer that some Iranian individuals had this feature in common. These individuals were already evident in the Iranian population portrait (right), but fineSTRUCTURE was able to group them even though there were no African populations in the ChromoPainter analysis; presumably, the software was able to detect that these individuals shared a set of chunks that were quite different than is the norm for the Balkan/West Asian area.

2. Related clusters


fineSTRUCTURE grouped the different populations in a tree structure. For example, it grouped pop18, the "North Balkan" cluster with pop23, the "Bulgarian-Romanian" one.

Looking at the admixture proportions, we can tell that the two clusters do indeed seem quite similar, but there are some differences, e.g., an excess of North_European in pop18, and an excess of Caucasus in pop23. This makes sense given the geographical origin of individuals belonging to the two clusters.

Tuesday, February 14, 2012

ChromoPainter/fineSTRUCTURE analysis of Balkans/West Asia

I have carried out a ChromoPainter/fineSTRUCTURE analysis of Balkans/West Asia. This is a slightly different dataset than the one used in the previous fastIBD analysis of the same region. It also took much longer (about a week, with two CPUs dedicated to the task) to complete, so it is not something that can be done routinely.

Technical details (skip if you want)


413 individuals from 33 populations were studied, on 258,100 SNPs, after --geno 0.03 --maf 0.01 filters were applied. Data were phased in Beagle with the default 10 iterations. Genetic maps from the HapMap were used. fineSTRUCTURE was used on ChromoPainter output, with 500,000 burnin/runtime iterations each.

25 Inferred Populations


fineSTRUCTURE imposes a tree structure on a number of inferred populations. The following heatmap shows this tree structure; columns represent donor populations, rows, recipient ones.


There was a total of 25 populations, labeled pop0, pop1, ..., pop24.

The following table summarizes how many individuals from each original population were assigned to each inferred population:


I will limit myself to populations which include Dodecad Project members:

  • pop6 includes a Project North Ossetian, as well as all Yunusbayev et al. North Ossetians
  • pop7 is mainly Armenian
  • pop16 is also mainly Armenian; it would be interesting to see whether this bipartite division of Armenians is in agreement with the one inferred in the previous fastIBD analysis
  • pop8 is mainly Greek, and appears to be "continental Greek"; it also includes some other Balkan individuals
  • pop14 is also Greek, and includes a variety of people with ancestry from Crete, the Aegean, Cyprus, Asia Minor, Cappadocia, and the Pontus as well as continental Greek. It could be labeled "eastern Greek"
  • pop11 is Cypriot, including the single 100% Greek Cypriot of the Project, all 3 100% Turkish Cypriots, as well as a Turkish individual of partial Turkish_Cypriot ancestry
  • pop10 is Turkish, and includes people with some ancestry from the Balkans, as well as Anatolia. It could be labelled "Balkan Turkish"
  • pop13 is also Turkish, and seems to include people with ancestry exclusively from Anatolia, including almost all the Behar et al. Turks
  • pop15 is Assyrian; some Assyrians also fall on the aforementioned pop16 which includes mainly Armenians
  • pop18 could be labelled "North Balkan"; there is probably structure to be uncovered within this cluster, once more participants from the Balkans join the Project
  • pop20 is "Georgian-Abkhazian"
  • pop21 is "Kurdish-Iranian"
  • pop22 could be labeled "Northeastern Anatolia" or (more classically) "Pontus-Colchis". It appears to unite various individuals from Northeastern Turkey and neighboring Georgia, having Karadeniz Turkish, Armenian, Pontic Greek, and Kartvelian ancestry. I strongly encourage participants from this region to join the Project, especially Pontic Greeks, as there are no 100% Pontic Greeks currently in the Project.
  • pop23 is "Bulgarian-Romanian" mainly, and also includes one Serb. Once again, I emphasize that the power of this approach using haplotypes depends on participation, so I encourage all people from the Balkans to consider joining the Project.
Principal Components Analysis


I have also used the PCA feature of fineSTRUCTURE to carry out principal components analysis. I am plotting the first two dimensions of this PCA, using my own visualization code that places labels in the average position on the plane:


Results


Results for Project participants are included in the spreadsheet.

  • Population matrix, shows how many individuals from each population were assigned to each cluster
  • Z score population matrix, shows the normalized number of "chunks" from each donor population (columns) to each recipient (row). Do not compare across rows! The way to read this table is the following: for each row, higher values indicate more sharing. For example, the "Cypriots" population has pop11 as its main donor.
  • Individual assignments: the pop number that all Project and reference IDs were assigned to
  • Individual Chunkcounts: the number of chunks copied from its donor population (column) to each individual
  • Individual PCA: your PCA co-ordinates that can help you find your dot on the Principal Components Analysis graphic (see above)
Averaged results were included only for populations with >=5 members.
The raw chunkcounts for all 413x413 individuals can be found here.

Monday, February 6, 2012

Other testing companies

The Dodecad Project is not affiliated with any genetic testing companies. Until now, I have included Project participants from 23andMe and FamilyTreeDNA "Family Finder" tests, but it has come to my attention that there are new players in the field, such as Ancestry.com (see post on Your Genetic Genealogist) and Lumigenix (see post on GenomesUnzipped).

If you have data from any company entering this field, please contact me at dodecad@gmail.com (do not send data right away!). That way, I can find out how many markers are in common between the new tests and my existing datasets, and figure out how easy it will be to convert them for use in the Project and in DIYDodecad.

Tuesday, January 31, 2012

'K12b' and 'K7b' calculators

I am releasing two new calculators with K=12 and K=7 components, named 'K12b' and 'K7b'. You can scroll down to the bottom if you are just interested in the downloads, or read on.


New Features

The new 'K12b' calculator is an update of the previous K12a one, that was inferred using all the new samples submitted during the last submission opportunity. The 12 components are still roughly the same, although their allele frequencies may have changed by a bit, so existing participants can expect to have slightly altered results, and new participants in the Project more so, since their data are now contributing to the creation of the new tool. Non-participants can, of course, use the new calculator with DIYDodecad.

I have also taken the opportunity to do some minor tweaks. I am releasing population portraits for K12b (which were lacking in K12a); I've changed my visualization code so that the sample IDs of non-Dodecad populations can now be seen in the barplots. This may be useful for anyone else using these reference populations, by quickly identifying potential outliers in them.

I have also decided to use normalized median admixture proportions for the populations. For example, if 5 individuals in a population have 0, 0, 0.2, 0.5, 10.0% of a particular component, then the average is 2.14%, but the median is 0.2%. By using the median, the proportions become less susceptible to the presence of outliers (such as the 10%). However, if the median is calculated over every component separately, it is no longer guaranteed that the components will add up to 100%; this can be addressed by re-normalizing them (scaling them by a constant factor) so that they do. I believe that use of the normalized median will not only give better proportions that are less susceptible to outliers, but will also improve results of the new Dodecad Oracle for K12b.

At the same time I am also releasing 'K7b' which is an update of the existing 'eurasia7' calculator and which has been built on exactly the same dataset as 'K12b' but at a lower (K=7) level of detail.

Information on K7b


Information spreadsheet.

Normalized median admixture proportions barplot for all included populations (a high resolution version of this is included in the download bundle):


Table of Fst divergences:

Neighbor-joining tree (based on above):

Information on K12b


Information spreadsheet.


Normalized median admixture proportions barplot for all included populations (a high resolution version of this is included in the download bundle):

Table of Fst divergences:

Neighbor-joining tree (based on above):
Multidimensional Scaling Plots of K12b and K7b


I have created MDS plots using synthetic individuals representing the 12 ancestral components of K12b and the 7 ancestral components of K7b. By including both in the same plot, one gets an idea of the relationship of the components at different resolution. The first 10 dimensions can be seen below:

Here is a blowup of the main West Eurasian groups from the plot of the first two dimensions:

Some observations:

  • The Atlantic_Med component which is bi-modal in Basques and Sardinians occupies the apex of the figure; this makes sense, since Southwest Europe is quite distant (along land routes) to both Asia and Africa.
  • The Caucasus component is surrounded by most of the others; this is consistent with my theory elaborated in The womb of nations: how West Eurasians came to be.
  • The Atlantic_Baltic component (from K=7) is intermediate between the Atlantic_Med and North_European components.
  • Similarly, the West_Asian component (from K=7) is intermediate between the Caucasus and Gedrosia components; the Gedrosia component diverges in the direction of the Asian groups (not shown in this figure), and in particular of South Asians. This divergence can also be seen in the plot of dimension #3.
  • The Northwest_African component diverges in the direction of Sub-Saharan Africans.

Technical Details


A dataset of 268 populations/3,115 individuals was assembled. A total of 265,519 SNPs are in common in the various source datasets as well as the 23andMe v2/v3 and Family Finder platforms. Iterative removal of distant relatives was performed by removing one individual from each pair within a population if that pair had a RATIO of 2.5 or greater or more than the mean and two standard deviations in IBD analysis performed in PLINK 1.07. A total of 2,675 individuals remained. 4 individuals were removed for low genotyping rate (less than 97%). 264,328 SNPs remained after removal of SNPs with less than 97% genotyping rate or 1% minor allele frequency. 166,770 SNPs remained after linkage-based disequilibrium pruning (--indep-pairwise 200 25 0.4). The final set thus consisted of 2,671 individuals/268 populations/166,770 SNPs. Ancestral populations (components) were inferred using ADMIXTURE 1.21, with K=7 and K=12 and default parameters.

No individuals were removed from the source datasets, except in the case of the Armenians_Y sample, where one individual (ID: armenia3) was dropped because he/she was the same as a Dodecad Project participant.

Downloads


K7b population portraits, spreadsheet, and DIYDodecad files.
K12b population portraits, spreadsheet, and DIYDodecad files.

Dodecad Oracle (K12b edition) can be downloaded from here. Please read the instructions of the previous Oracle on how to use this tool. Note that the number of populations is now 223.

To use either calculator with DIYDodecad, with your 23andMe or Family Finder data, follow the instructions in the README file, but substitute 'K12b' or 'K7b' for 'dv3'.

Project participant results for both K7b and K12b are found in the spreadsheets in the Individual Results tab.

Terms of Use


You are free to use K12b and K7b, including all downloaded files for any non-commercial purpose, as long as you attribute them to the Dodecad Project and to Dienekes Pontikos as follows:

The [K7b/K12b] admixture calculator is courtesy of Dienekes Pontikos and was developed as part of the Dodecad Ancestry Project; more information here.

Tuesday, January 24, 2012

Submission Opportunity is OVER

Thank you everyone for submitting their data. I will not accept any more data at this time. A couple of submissions came in at the last second, so I accepted one more than I promised, who got the brand new DPD001 ID.

Those who submitted in time will get their IDs and their results will be posted in the K12a spreadsheet.
Additionally, I will run all participants over world9, so that spreadsheet will also include everybody.

From now on, I will be reworking some of the Project tools to make use of newer samples submitted during this submission opportunity.

If you wish to submit your data during this off period, note that you must contact me at dodecad@gmail.com. Do not send data at this time, unless I indicate that I can accept it! I will let you know if I can process it, and note that I will normally only consider those who matched the eligibility criteria of the most recent submission period.

Monday, January 23, 2012

Open submission for everybody until DOD999

SUBMISSION OPPORTUNITY IS NOW OVER

Everyone on the planet is invited to submit their data, regardless of their ancestry.

All other rules apply, especially the no relatives clause. Additionally, I will accept a single submission from each submitter, so don't submit all your friends. Moreover, regardless of your ancestry, you should let me know the origin of your four grandparents.

There are 35 spots open, so hurry, since last time I had a free-for-all I had to close it down after about 12 hours due to overwhelming demand. I will close project submission after I assign DOD999.

All submissions after I post the end-of-submission announcement on the blog will be ignored. If you post this in any forums or mailing lists, include this post link so that people will know whether the opportunity is over.

Saturday, January 21, 2012

fastIBD analysis of Afroasiatic groups (Jews, Arabs, Assyrians, Berbers, Somalis, Amharas, etc.)

Please refer to the previous analysis on the Balkans/West Asia for more information about the interpretation of this type of analysis.

I am very pleased with the way this analysis of Afroasiatic groups has turned out, revealing an exceptional degree of resolution. I invite individuals from the Near East and Africa who are eligible, to submit their data, so that they can be included in future runs of this kind.

Clusters Galore


45 clusters were inferred with 29 dimensions.


I can't comment on all 45 clusters, so I'll just limit myself to the ones that are significantly represented among Project participants: 1. Ashkenazi, 4. Assyrian/Mandaean, 6. Somali, 7. Moroccan, 8. Algerian/Tunisian, 9. Sephardic, 10. Morocco Jews, 11. Iran/Iraq Jews, 12. Non-Jewish Ethiopians, 13. Saudi, 14. Arab #1, 15. Arab #2, 16. Egyptian

Inter-Population IBD


Results for Project Participants


The results can be found in the spreadsheet.

I have also added the full IBD sharing matrix which lists how many Morgans of sequence are estimated to be IBD with probability greater than 10^-6 between all pairs of individuals.

You can google any non-Project sample IDs to get some more information about their origin. For example, GSM536710 is an Iraqi Jew who shares about half his genome with GSM536714, also an Iraqi Jew. These two samples are almost certainly first-degree relatives. Or, GSM537032, a Samaritan shares 740-1,480cM with the other 2 Samaritans, an exceptional amount in this small and probably highly inbred population.

You can manipulate this matrix in R. After you download it and unzip it, you can load it into R as follows:

X<-read.table('afroasiatic_ibd_sharing.txt',row.names=1,header=T)

Then, you can, for example, sort the IBD sharing for a particular individual, as follows:

sort(X['DOD026',])

fastIBD analysis of Central/Eastern Europe

Please refer to the previous analysis on the Balkans/West Asia for more information about the interpretation of this type of analysis.

Clusters Galore


The Clusters Galore can be found in the spreadsheet. After inspection of the 23 clusters inferred with 21 dimensions, they could be described as:

  1. Mordvin
  2. East Slavic
  3. Polish-Ukrainian
  4. East Balkan
  5. Vologda Russians
  6. Lithuanian
  7. Central European (combining many groups with small sample sizes)
  8. A couple of related (?) individuals
  9. Anatolian
  10. Greek
  11. Chuvash
  12. Ossetian
  13. A couple of related individuals
  14. A couple of related individuals
  15. Balkar
  16. A couple of related individuals
  17. Chechen
  18. Kumyk
  19. A couple of related individuals
  20. Adygei
  21. Lezgin #1 (main)
  22. Lezgin #2
  23. Lezgin #3
If you belong to a population with few other participants, you might end up latching onto a cluster dominated by a bigger group. This does not mean that your population is not distinctive, only that there are not enough samples to reveal its distinctiveness if it exists.

Inter-Population IBD


Results for Dodecad Participants

Results can be found in the spreadsheet.

If you have joined the Project, please consider leaving a comment in the Information about Project samples thread. That will help others make better sense of their results, e.g., if you find that you belong in the same cluster with some other individual, you might want to know something about their origins.

UPDATE: I have added the IBD sharing matrix.See here on how to use it.

Thursday, January 19, 2012

fastIBD analysis of South Asia

Please refer to the previous analysis on the Balkans/West Asia for more information about the interpretation of this type of analysis.

Clusters Galore


The Clusters Galore analysis can be found in the spreadsheet. 59 clusters were inferred with 47 MDS dimensions. The very fine-scale structure (I only considered the first 50 dimensions, but many more seemed significant than in any previous experiment) is probably the result of the size of the South Asian population, as well as the practice of endogamy associated with the caste system. High intra-population IBD sharing is also evident in the following (notice how well-defined the diagonal is):

Inter-Population IBD




Results for Dodecad participants

They can be found in the spreadsheet. Many Project participants belong to a population with 1 or 2 individuals, so cluster #1 seems to be a generalized catch-all for many such individuals. Individuals from he two sub-populations that I've identified recently Iyer_D, and Jatt_D all belong to the same cluster. The Iyer_D cluster (#4) also seems to include the Iyengar project participants as might be expected.

It is also interesting how all Dodecad participants fall in just 7 of the 59 clusters. This goes to show how truly diverse people from the Indian subcontinent are. I fully expect that with more participation further structure will be revealed, since it seems that due to endogamy it only takes a few participants from each ethnic group for a specific cluster pertaining to that group to be identified. So, I invite people from South Asia to join the Project during this submission opportunity.

Tuesday, January 17, 2012

fastIBD analysis of Iberia, France, Italy, Balkans, Anatolia and European Jews

On the heels of the previous analysis of Balkans/West Asia, a new experiment on a different set of populations. Please refer to the earlier post for some thoughts/explanations about this type of analysis, I'll stick to "just the data" for this post.

Clusters Galore




24 clusters inferred with 17 MDS dimensions.

The Galore analysis provides increased resolution within Iberia (#6-9, 11), Italy, and the Ashkenazi Jewish group (#14-16).

The Iberian results are particularly interesting, showing the power of this approach compared to the one with unlinked data. There appear to be:

  • a Spanish Basque (#6), 
  • French Basque (#11) cluster, as well as 
  • a Portuguese/Galician/Castilla Y Leon (#9) cluster, and 
  • a complementary Castilla La Manch/Cantabria/Andalucia/Murcia (#7) cluster, and 
  • a smaller Aragon/Cataluna cluster (#8). 
There is overlap between these clusters, but the geographical contrasts are quite evident. I did not go through the results of Spanish Project participants (all the Portuguese fall in the Galician cluster, and our Basque member in the Basque cluster as expeccted), so it would be interesting to hear whether they fall in the cluster(s) which exist in their regions of origin.

Inter-Population IBD




Results for Project Participants


The results can be found in the spreadsheet.

Saturday, January 14, 2012

fastIBD analysis of Balkans/West Asia

Now that I've discovered a way to boost Clusters Galore analysis even further by using fastIBD, I will start experimenting with different regional populations. This analysis took about 5 hours to complete, so it appears to be quite practical.

For my first experiment, I carry out an analysis of various populations from the Balkans and West Asia.

Clusters Galore

27 different clusters were inferred with 17 MDS dimensions. Some interesting findings:
  • For the first time there emerge a couple of clusters that appear to be quite specific to Armenians (#2 and #3). 
  • Similarly, Assyrians are broken to a few clusters that appear fairly specific to them  (#9-11)
  • Georgians are split into three clusters, one of which (#14) is linked with the neighboring Abkhasians, who in turn have their own exclusive cluster (#25)
  • The cluster modal in Greeks (#6) includes 14 of 19 Greek participants, and a few Greeks are also in the Balkan cluster (#8) and an Iranian-Turkish cluster (#4)
  • The Behar Cypriot sample also splits into two, and the few Turkish Cypriot participants link to one of them (#13)
  • The Ossetian project participant links to one of the three North_Ossetian clusters
  • The major Balkan cluster (#8) still defies resolution. I am certain, however, that structure in this cluster will be uncovered with more participation. MCLUST adapts the cluster size and shape, and a "big", inclusive cluster spanning the Balkans appears more parsimonious than smaller clusters centered on the different groups. With larger participation, I anticipate that regional structure will be uncovered in the Balkans as well.
I cannot stress the importance of participation strongly enough. When groups have more participants, it is possible to both:

  1. Discover group-specific clusters, by identifying what is common between members of groups
  2. Discover within-group clusters, by identifying what is different between members of groups
For example, the great participation of Armenians in the Project has now allowed me to discover structure within the Armenian population. It appears, that cluster #2 corresponds to a more "western" Armenian group, and #3 to a more "eastern" one, with some overlap between the two.

Inter-population IBD


You can also see a visual representation of inter-population IBD:

I have only included populations with 5+ participants in this representation. Reddish shades express high IBD sharing; bluish ones low one. The heatmap has been scaled by row.

As you might expect, values across the diagonal are "reddish", since individuals within populations tend to have high IBD sharing with each other.

A few features "pop out" of the screen. Going from top to bottom:
  • Intra-Iranic sharing
  • Intra-Armenian sharing
  • Intra-Balkan sharing
  • Georgian-Abkhaz sharing
You can probably get more out of the figure, but these appear to be the most salient features.

Results for Project Participants


The results can be found in the spreadsheet, and include:
  • Probabilities of assignment in each of the 27 clusters of the Clusters Galore analysis
  • Z-scores of IBD between each individual and each of the 20 populations with 5+ participants. Higher values mean more IBD sharing. Note that Z-scores have been calculated for each row, hence each participant must scan his own row to find populations with an excess (+) or deficiency (-) of IBD sharing, and people should not compare across different rows.
Last but not least, I want to remind new project participants to leave a message in the Information about Project samples thread. Your comment will not appear immediately, since comment moderation is on, and also note that there are multiple pages of comments. 


If you haven't joined the Project yet, I encourage you to do so if you are eligible.

Wednesday, January 11, 2012

Clusters Galore (fastIBD edition) for some northern European participants

You can find some new Clusters Galore results here (scroll down for spreadsheet link). The new methodology described in that post has made it possible to infer even finer-level population structure than "classical" Clusters Galore.