Time to most-recent common ancestor (TMRCA) estimates for targetted pairs When this is valid: - Comparing two BigY-700 tests (works tolerably well for YElite or WGS tests with coverage of ~14.5 Mbp) - Comparing two people where one or both have tested because they have a suspected relationship Caveats: - These ranges have been drawn from randomly generated pairs of tests (Monte-Carlo simulation). Given this and the caveats below, it is important to treat these ranges as guides only. This is the reason the ranges don't increase purely sequentially in either direction. - This is not valid for comparing generic matches in the database, because it doesn't account for the increase in the number of cousins testers have in successively more-distant generations. - The genetic distance for STRs is to be read as a step-wise distance, not the number of mismatching alleles. Family Tree DNA's matches are shown using this method: https://learn.familytreedna.com/y-dna-testing/ftdna-tip/report-page-sometimes-show-difference-genetic-distance-number-mismatches/ - This does not account for hidden changes in multi-copy markers due to swapping of marker orders. - This assumes a typical overlap between two tests of about 14.6 +/- 0.5 Mbp. Lower overlaps should scale approximately linearly with time. (E.g., for a BigY-700 versus BigY-500 test, multiply by about 1.5). - SNPs should be counted consistently with coverage of the test. There is no one-to-one correspondence possible here for any company without going heavily into the raw data. For Family Tree DNA customers, the number of SNPs that is appropriate will normally be somewhere between the number of non-matching variants and the sum of both sets of private variants. - No account has been made of the physicality of generation lengths. A rate of 35 years/generation has been used to convert the STR mutation rates to per-year mutation rates. - This calculation assumes a fixed mutation rate of 8.33x10^-10 SNPs/base pair/year across the whole Y chromosome. This is broadly true across the tested regions as a whole, but specific regions like the centromere, DYZ19 and Yq12 should technically be excluded from SNP counts and coverage. They are retained here for ease of comparison. - An overall, combined uncertainty of ~10% in the STR and SNP mutation rates, and generation length has been allowed for. - As with all TMRCA estimates, this calculation fundamentally assumes that mutations occur purely randomly. How to use this chart: - Look vertically for the number of SNPs the differ between two tests. - Look horizontally for the genetic distance between two tests at Y-111. - The corresponding cell contains two values. These represent the 95% confidence interval of the result. Given the validity and caveats above, 95% of relationships should have a common ancestor who lived between these two numbers of years before the present. - To convert these to date of your MRCA's birth, subtract these numbers from your averaged birth dates. If this is not known, a good approximation is 1956 AD/CE. Hence, a genetic distance of 2/111 with 3 mis-matching SNPS should be read as 48-313 years. This becomes 1643-1908 AD at 95% confidence. - If your numbers of SNPs and STRs fall within the regions marked --------- then you have an exceptionally rare combination. It is likely that one of the tests has complications that are not accounted for in this process, such as one or more null STRs, or a complex mutation or read error that is masquerading as multiple SNPs. Note that null STRs should not be counted in the genetic distance, and care should be taken interpreting genetic distance on multi-copy markers. MNPs (e.g. SNPs at sequential positions, or positions very close to each other) should be ignored. #SNP\#STR 0 1 2 3 4 5 6 7 8 9 10 11 0 0- 94 5- 141 13- 193 32- 238 43- 347 --------- --------- --------- --------- --------- --------- --------- 1 5- 148 14- 188 24- 247 34- 268 46- 276 49- 328 89- 316 --------- --------- --------- --------- --------- 2 13- 177 23- 231 35- 272 44- 305 64- 326 76- 372 93- 394 119- 450 --------- --------- --------- --------- 3 22- 223 42- 254 48- 313 69- 358 79- 372 86- 406 114- 433 98- 510 116- 533 155- 534 --------- --------- 4 40- 280 51- 308 65- 343 73- 386 93- 395 102- 442 113- 510 151- 540 170- 529 167- 624 208- 628 --------- 5 57- 297 62- 354 79- 374 89- 405 111- 465 133- 475 148- 529 152- 531 168- 593 211- 679 220- 707 181- 638 6 68- 345 71- 377 99- 403 106- 446 116- 482 134- 549 165- 534 171- 608 176- 639 211- 661 239- 672 249- 840 7 59- 366 100- 436 98- 440 109- 486 128- 514 151- 560 166- 618 193- 603 194- 664 229- 668 229- 724 230- 786 8 --------- 110- 478 131- 508 157- 490 160- 549 176- 589 187- 593 209- 639 220- 678 254- 709 247- 777 312- 776 9 --------- 137- 500 143- 503 155- 554 161- 568 199- 612 205- 661 229- 679 247- 717 252- 712 250- 780 285- 847 10 --------- 123- 484 169- 598 161- 601 181- 611 199- 646 218- 674 249- 717 251- 762 259- 803 304- 778 314- 861 11 --------- --------- 170- 566 174- 669 201- 636 221- 697 238- 734 240- 744 275- 791 293- 835 324- 883 301- 894 12 --------- --------- 183- 576 226- 709 246- 671 242- 682 272- 741 265- 775 284- 816 313- 873 350- 944 372- 976 13 --------- --------- 240- 709 235- 655 245- 740 277- 739 263- 788 304- 820 293- 891 317- 892 351- 936 379- 941 14 --------- --------- --------- 252- 718 262- 770 279- 783 296- 835 311- 853 342- 902 372- 930 364- 961 399-1052 15 --------- --------- --------- 272- 699 297- 894 305- 822 347- 880 314- 874 315- 911 368- 972 389-1019 402-1005 16 --------- --------- --------- --------- 340- 782 304- 855 309- 893 343- 961 374- 946 391- 995 393-1018 441-1125 17 --------- --------- --------- --------- 341- 889 333- 913 365- 927 390- 938 392-1009 400-1010 448-1056 455-1083 18 --------- --------- --------- --------- 331- 751 374- 939 376- 880 394-1012 411-1005 426-1072 445-1091 459-1125 19 --------- --------- --------- --------- --------- 358-1029 402- 996 425-1039 427-1099 472-1089 450-1107 494-1159 20 --------- --------- --------- --------- --------- 371- 952 393-1057 461-1095 468-1080 470-1136 469-1186 497-1206 21 --------- --------- --------- --------- --------- --------- 415-1020 464-1136 472-1160 487-1233 505-1185 518-1253 22 --------- --------- --------- --------- --------- --------- 403-1019 459-1203 477-1157 505-1232 529-1196 553-1289 23 --------- --------- --------- --------- --------- --------- 504-1058 462-1209 531-1134 535-1208 577-1311 561-1310 24 --------- --------- --------- --------- --------- --------- --------- 550-1168 496-1255 549-1212 585-1386 599-1352 25 --------- --------- --------- --------- --------- --------- --------- 519-1122 545-1283 583-1312 597-1313 593-1405 26 --------- --------- --------- --------- --------- --------- --------- 527-1187 593-1282 573-1330 636-1423 618-1402 27 --------- --------- --------- --------- --------- --------- --------- --------- 596-1340 639-1255 596-1348 674-1425 28 --------- --------- --------- --------- --------- --------- --------- --------- 673-1334 658-1509 628-1336 699-1420 29 --------- --------- --------- --------- --------- --------- --------- --------- --------- 699-1674 702-1567 691-1395 30 --------- --------- --------- --------- --------- --------- --------- --------- --------- 674-1500 723-1471 667-1578 Y-111 only matches The following table gives the conversion from Y-111 genetic distance to TMRCA. It is appropriate for comparing between Y-STR markers on the standard (FTDNA) 111 set of markers, under the same caveats as listed above. It is not appropriate for comparisons other than Y-111, such as Y-67, Y-37, Y-25 or Y-12. GD 95%CI TMRCA range 0 1- 247 1 11- 380 2 31- 500 3 53- 613 4 81- 731 5 107- 837 6 144- 941 7 178-1081 8 218-1165 9 251-1313 10 285-1420 11 329-1530 BigY-700 matches that are not Y-111 matches The following table gives the conversion of number of mismatching SNPs to TMRCA when a person is not a Y-111 match, hence has a genetic distance of 12/111 or greater. The same caveats as listed above apply. SNP 95%CI TMRCA range 7 303- 836 8 313- 941 9 335- 929 10 345- 990 11 373-1019 12 376-1085 13 410-1093 14 429-1135 15 455-1180 16 491-1232 17 510-1286 18 520-1331 19 546-1353 20 575-1413 21 597-1484 22 625-1508 23 650-1563 24 669-1617 25 689-1670 26 724-1703 27 751-1752 28 787-1816 29 811-1867 30 832-1903