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Tajima's D

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population size and/or balancing selection. However, calculating a conventional "p-value" associated with any Tajima's D value that is obtained from a sample is impossible. Briefly, this is because there is no way to describe the distribution of the statistic that is independent of the true, and unknown, theta parameter (no pivot quantity exists). To circumvent this issue, several options have been proposed.
53:. A randomly evolving DNA sequence contains mutations with no effect on the fitness and survival of an organism. The randomly evolving mutations are called "neutral", while mutations under selection are "non-neutral". For example, a mutation that causes prenatal death or severe disease would be expected to be under selection. In the population as a whole, the 136:
estimates of the population genetic parameter theta, and so are expected to equal the same value. If these two numbers only differ by as much as one could reasonably expect by chance, then the null hypothesis of neutrality cannot be rejected. Otherwise, the null hypothesis of neutrality is rejected.
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Finally, genome wide scans of Tajima's D in sliding windows along a chromosomal segment are often performed. With this approach, those regions that have a value of D that greatly deviates from the bulk of the empirical distribution of all such windows are reported as significant. This method does
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A more nuanced approach was presented in a paper by Simonsen et al. These authors advocated constructing a confidence interval for the true theta value, and then performing a grid search over this interval to obtain the critical values at which the statistic is significant below a particular alpha
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Suppose you are a geneticist studying an unknown gene. As part of your research you get DNA samples from four random people (plus yourself). For simplicity, you label your sequence as a string of zeroes, and for the other four people you put a zero when their DNA is the same as yours and a one when
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A negative Tajima's D signifies an excess of low frequency polymorphisms relative to expectation, indicating population size expansion (e.g., after a bottleneck or a selective sweep). A positive Tajima's D signifies low levels of both low and high frequency polymorphisms, indicating a decrease in
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A very rough rule of thumb to significance is that values greater than +2 or less than -2 are likely to be significant. This rule is based on an appeal to asymptotic properties of some statistics, and thus +/- 2 does not actually represent a critical value for a significance test.
30:. Tajima's D is computed as the difference between two measures of genetic diversity: the mean number of pairwise differences and the number of segregating sites, each scaled so that they are expected to be the same in a neutrally evolving population of constant size. 2303:
value. An alternative approach is for the investigator to perform the grid search over the values of theta which they believe to be plausible based on their knowledge of the organism under study. Bayesian approaches are a natural extension of this method.
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The strength of genetic drift depends on population size. If a population is at a constant size with constant mutation rate, the population will reach an equilibrium of gene frequencies. This equilibrium has important properties, including the number of
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not assess significance in the traditional statistical sense, but is quite powerful given a large genomic region, and is unlikely to falsely identify interesting regions of a chromosome if only the greatest outliers are reported.
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of a neutral mutation fluctuates randomly (i.e. the percentage of individuals in the population with the mutation changes from one generation to the next, and this percentage is equally likely to go up or down) through
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1 2 Position 12345 67890 12345 67890 Person Y 00000 00000 00000 00000 Person A 00100 00000 00100 00010 Person B 00000 00000 00100 00010 Person C 00000 01000 00000 00010 Person D 00000 01000 00100 00010
93:). To standardize the pairwise differences, the mean or 'average' number of pairwise differences is used. This is simply the sum of the pairwise differences divided by the number of pairs, and is often symbolized by 2298:
and dividing it by the number of samples. Simulations have shown this distribution to be conservative, and now that the computing power is more readily available this approximation is not frequently used.
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Elgvin, Tore O.; Trier, Cassandra N.; Tørresen, Ole K.; Hagen, Ingerid J.; Lien, Sigbjørn; Nederbragt, Alexander J.; Ravinet, Mark; Jensen, Henrik; Sætre, Glenn-Peter (2 June 2017).
587: 366: 253: 2291:, the magnitude of the statistic is expected to increase the more the data deviates from a pattern expected under a population evolving according to the standard coalescent model. 2294:
Tajima (1989) found an empirical similarity between the distribution of the test statistic and a beta distribution with mean zero and variance one. He estimated theta by taking
1572: 1937: 749: 2194: 1870: 1538: 1664: 454:, so that they are no longer expected to be equal. The difference in the expectations for these two variables (which can be positive or negative) is the crux of Tajima's 500: 1905: 1696: 452: 404: 111: 2603: 1601: 736: 699: 674: 542: 521: 479: 1819: 1624: 432: 87: 2659: 128:
DNA for at least 3 individuals. Tajima's statistic computes a standardized measure of the total number of segregating sites (these are DNA sites that are
414:, demographic fluctuations and other violations of the neutral model (including rate heterogeneity and introgression) will change the expected values of 1958:
Notice the four polymorphic sites (positions where someone differs from you, at 3, 7, 13 and 19 above). Now compare each pair of sequences and get the
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Since this is a statistical test, you need to assess the significance of this value. A discussion of how to do this is provided below.
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Theta-Pi greater than Theta-k (Observed>Expected). More haplotypes (more average heterozygosity)than # of segregating sites.
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Theta-Pi less than Theta-k (Observed<Expected). Fewer haplotypes (lower average heterozygosity) than # of segregating sites.
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for the sequence in question. However, in real world uses, one must be careful as past population changes (for instance, a
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The purpose of Tajima's test is to identify sequences which do not fit the neutral theory model at equilibrium between
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such as Tajima's D, the critical question is whether the value calculated for the statistic is unexpected under a
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is calculated by taking the difference between the two estimates of the population genetics parameter
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However, this interpretation should be made only if the D-value is deemed statistically significant.
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Theta-Pi equivalent to Theta-k (Observed=Expected). Average Heterozygosity= # of Segregating sites.
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Recent selective sweep, population expansion after a recent bottleneck, linkage to a swept gene
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evolving randomly ("neutrally") and one evolving under a non-random process, including
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it is different. (For this example, the specific type of difference is not important.)
2801: 121: 59: 50: 2342:"Statistical method for testing the neutral mutation hypothesis by DNA polymorphism" 2807: 2618: 652: 89:, and the number of nucleotide differences between pairs sampled (these are called 34: 27: 145:
Under the neutral theory model, for a population at constant size at equilibrium:
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Population evolving as per mutation-drift equilibrium. No evidence of selection
1963: 1907:, whereas Hartl & Clark use a different symbol to define the same parameter 124:. In order to perform the test on a DNA sequence or gene, you need to sequence 2631: 1787:{\displaystyle {\hat {k}}={\frac {\sum \sum _{i<j}k_{ij}}{\binom {n}{2}}}.} 2422: 1193:{\displaystyle c_{2}=b_{2}-{\frac {n+2}{a_{1}n}}+{\frac {a_{2}}{a_{1}^{2}}}} 54: 23: 2597: 2440: 2414: 2538: 2489: 2375: 2505:"Properties of statistical tests of neutrality for DNA polymorphism data" 2031:
Person C 00000 01000 00000 00010 Person D 00000 01000 00100 00010
2025:
Person B 00000 00000 00100 00010 Person D 00000 01000 00100 00010
2019:
Person B 00000 00000 00100 00010 Person C 00000 01000 00000 00010
2013:
Person A 00100 00000 00100 00010 Person D 00000 01000 00100 00010
2007:
Person A 00100 00000 00100 00010 Person C 00000 01000 00000 00010
2001:
Person A 00100 00000 00100 00010 Person B 00000 00000 00100 00010
1995:
Person Y 00000 00000 00000 00000 Person D 00000 01000 00100 00010
1989:
Person Y 00000 00000 00000 00000 Person C 00000 01000 00000 00010
1982:
Person Y 00000 00000 00000 00000 Person B 00000 00000 00100 00010
1976:
Person Y 00000 00000 00000 00000 Person A 00100 00000 00100 00010
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described above is the difference between these two numbers—the
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number of polymorphisms between two sequences. There are "five
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number of polymorphisms found in pairwise comparison (2) and
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Since there were n=5 individuals and S=4 segregating sites
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The purpose of Tajima's D test is to distinguish between a
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The first estimate is the average number of SNPs found in
1497:{\displaystyle a_{2}=\sum _{i=1}^{n-1}{\frac {1}{i^{2}}}} 2503:
Simonsen, KL.; Churchill, GA.; Aquadro, CF. (Sep 1995).
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is the mutation rate at the examined genomic locus, and
1024:{\displaystyle e_{2}={\frac {c_{2}}{a_{1}^{2}+a_{2}}}} 2164: 2042: 1913: 1881: 1830: 1807: 1707: 1672: 1642: 1612: 1588: 1546: 1516: 1436: 1422:{\displaystyle a_{1}=\sum _{i=1}^{n-1}{\frac {1}{i}}} 1368: 1352:{\displaystyle b_{2}={\frac {2(n^{2}+n+3)}{9n(n-1)}}} 1275: 1209: 1101: 1040: 963: 908: 752: 723: 686: 661: 602: 553: 529: 508: 487: 466: 440: 420: 392: 267: 154: 99: 75: 642:{\displaystyle D={\frac {d}{\sqrt {{\hat {V}}(d)}}}} 2759: 2718: 2675: 2265:Balancing selection, sudden population contraction 899: 676:statistic described above could be modeled using a 26:created by and named after the Japanese researcher 2188: 2117: 1931: 1899: 1864: 1821:, the total number of polymorphisms in the sample 1813: 1786: 1690: 1658: 1618: 1595: 1566: 1532: 1496: 1421: 1351: 1260: 1192: 1086: 1023: 948: 884: 730: 693: 668: 641: 581: 536: 515: 494: 473: 446: 426: 398: 360: 247: 105: 81: 2234:Observed variation similar to expected variation 1652: 1637: 2604:Online view of Tajima's D values in human genome 2118:{\displaystyle {3+2+2+3+1+3+2+2+1+1 \over 10}=2} 2248:Rare alleles abundant (excess of rare alleles) 701:value for a sample of sequences is outside the 2456:"Statistical tests of neutrality of mutations" 1087:{\displaystyle c_{1}=b_{1}-{\frac {1}{a_{1}}}} 2653: 2609:Python3 package for computation of Tajima's D 1774: 1761: 655:demonstrated by computer simulation that the 8: 2391:"The genomic mosaicism of hybrid speciation" 1966:two" (ten) comparisons that need to be done. 1574:are two estimates of the expected number of 949:{\displaystyle e_{1}={\frac {c_{1}}{a_{1}}}} 2556:Hartl, Daniel L.; Clark, Andrew G. (2007). 2262:Rare alleles scarce (lack of rare alleles) 1578:(SNPs) between two DNA sequences under the 1261:{\displaystyle b_{1}={\frac {n+1}{3(n-1)}}} 2660: 2646: 2638: 2128:The second estimate of the equilibrium is 2528: 2479: 2430: 2365: 2163: 2043: 2041: 1912: 1880: 1850: 1829: 1806: 1773: 1760: 1749: 1733: 1723: 1709: 1708: 1706: 1671: 1651: 1636: 1634: 1611: 1592: 1587: 1556: 1547: 1545: 1529: 1518: 1517: 1515: 1486: 1477: 1465: 1454: 1441: 1435: 1409: 1397: 1386: 1373: 1367: 1302: 1289: 1280: 1274: 1223: 1214: 1208: 1182: 1177: 1167: 1161: 1146: 1128: 1119: 1106: 1100: 1076: 1067: 1058: 1045: 1039: 1012: 999: 994: 983: 977: 968: 962: 938: 928: 922: 913: 907: 852: 836: 819: 810: 796: 795: 792: 766: 765: 759: 751: 727: 722: 690: 685: 665: 660: 616: 615: 609: 601: 557: 556: 554: 552: 533: 528: 512: 507: 491: 486: 470: 465: 439: 419: 391: 329: 317: 306: 296: 266: 216: 204: 193: 183: 153: 98: 74: 2210: 1797:The second estimate is derived from the 45:, demographic expansion or contraction, 2332: 2036:The average number of polymorphisms is 582:{\displaystyle {\sqrt {{\hat {V}}(d)}}} 361:{\displaystyle E=\theta =E\left=2N\mu } 248:{\displaystyle E=\theta =E\left=4N\mu } 7: 2560:(4th ed.). Sinauer Associates. 378:is the number of segregating sites, 1765: 1666:pairwise comparisons of sequences 1641: 1567:{\displaystyle {\frac {S}{a_{1}}}} 523:, and D is calculated by dividing 386:is the effective population size, 14: 2731:Models of nucleotide substitution 2632:A video explanation of Tajima's D 2558:Principles of Population Genetics 16:Population genetic test statistic 1576:single nucleotide polymorphisms 410:is the index of summation. But 1932:{\displaystyle \theta =4N\mu } 1840: 1834: 1714: 1685: 1673: 1523: 1343: 1331: 1320: 1295: 1252: 1240: 876: 873: 861: 829: 801: 783: 777: 771: 633: 627: 621: 574: 568: 562: 277: 271: 164: 158: 1: 2454:Fu, YX.; Li, WH. (Mar 1993). 22:is a population genetic test 2223:Biological interpretation 2 2189:{\displaystyle d=2-1.92=.08} 1865:{\displaystyle E(S)=a_{1}M.} 1533:{\displaystyle {\hat {k}}\,} 717:) can bias the value of the 502:. This difference is called 2220:Biological interpretation 1 1659:{\displaystyle n \choose 2} 2839: 2787:Nonsynonymous substitution 2594:(Mac OS X, Linux, Windows) 2521:10.1093/genetics/141.1.413 2472:10.1093/genetics/133.3.693 2358:10.1093/genetics/123.3.585 544:by the square root of its 382:is the number of samples, 1992:You vs D: 3 polymorphisms 1985:You vs C: 2 polymorphisms 1979:You vs B: 2 polymorphisms 1973:You vs A: 3 polymorphisms 1605:effective population size 495:{\displaystyle \theta \,} 2275:Determining significance 2137:a1=1/1+1/2+1/3+1/4=2.08 1900:{\displaystyle M=4N\mu } 705:then one can reject the 2782:Synonymous substitution 2726:Models of DNA evolution 2619:Bio::PopGen::Statistics 2340:Tajima, F. (Nov 1989). 2203:Interpreting Tajima's D 2016:B vs C: 2 polymorphisms 2010:A vs D: 2 polymorphisms 2004:A vs C: 3 polymorphisms 1582:model in a sample size 374:In the above formulas, 2415:10.1126/sciadv.1602996 2190: 2119: 2033: 2028:C vs D: 1 polymorphism 2022:B vs D: 1 polymorphism 1998:A vs B: 1 polymorphism 1956: 1933: 1901: 1866: 1815: 1788: 1692: 1660: 1620: 1597: 1568: 1534: 1498: 1476: 1423: 1408: 1353: 1262: 1194: 1088: 1025: 950: 886: 732: 695: 670: 643: 583: 538: 517: 496: 475: 448: 428: 400: 362: 328: 249: 215: 141:Scientific explanation 107: 83: 2705:Stabilizing selection 2690:Directional selection 2580:Computational tools: 2296:Watterson's estimator 2191: 2120: 1971: 1951: 1934: 1902: 1867: 1816: 1789: 1693: 1691:{\displaystyle (i,j)} 1661: 1621: 1598: 1569: 1535: 1499: 1450: 1424: 1382: 1354: 1263: 1195: 1089: 1026: 951: 887: 733: 715:population bottleneck 696: 671: 644: 584: 539: 518: 497: 476: 449: 429: 401: 363: 302: 258:for diploid DNA, and 250: 189: 108: 84: 39:directional selection 2818:Statistical genetics 2695:Disruptive selection 2162: 2040: 1911: 1879: 1828: 1805: 1705: 1670: 1633: 1610: 1586: 1544: 1514: 1434: 1366: 1273: 1207: 1099: 1038: 961: 906: 750: 742:Mathematical details 721: 684: 659: 600: 551: 527: 506: 485: 464: 447:{\displaystyle \pi } 438: 418: 399:{\displaystyle \mu } 390: 265: 152: 106:{\displaystyle \pi } 97: 91:pairwise differences 73: 2813:Molecular evolution 2760:Molecular processes 2685:Balancing selection 2669:Molecular evolution 2407:2017SciA....3E2996E 2217:Mathematical reason 2214:Value of Tajima's D 1596:{\displaystyle n\,} 1187: 1004: 731:{\displaystyle D\,} 703:confidence interval 694:{\displaystyle D\,} 669:{\displaystyle D\,} 537:{\displaystyle d\,} 516:{\displaystyle d\,} 474:{\displaystyle D\,} 47:genetic hitchhiking 43:balancing selection 2700:Negative selection 2279:When performing a 2186: 2115: 1929: 1897: 1862: 1811: 1784: 1744: 1688: 1646: 1616: 1593: 1564: 1530: 1494: 1419: 1349: 1258: 1190: 1173: 1084: 1021: 990: 946: 882: 728: 691: 666: 639: 593:, by definition). 591:standard deviation 579: 534: 513: 492: 471: 444: 424: 396: 358: 245: 103: 79: 2823:Statistical tests 2795: 2794: 2677:Natural selection 2269: 2268: 2202: 2107: 1969:Person Y is you! 1814:{\displaystyle S} 1779: 1772: 1729: 1717: 1650: 1619:{\displaystyle N} 1562: 1526: 1507: 1506: 1492: 1417: 1347: 1256: 1188: 1156: 1082: 1019: 944: 880: 879: 825: 804: 787: 786: 774: 678:beta distribution 637: 636: 624: 577: 565: 427:{\displaystyle S} 340: 337: 227: 224: 134:method of moments 82:{\displaystyle S} 68:segregating sites 2830: 2772:Gene duplication 2736:Allele frequency 2662: 2655: 2648: 2639: 2571: 2543: 2542: 2532: 2500: 2494: 2493: 2483: 2451: 2445: 2444: 2434: 2395:Science Advances 2386: 2380: 2379: 2369: 2337: 2287:. For Tajima's 2281:statistical test 2256:Tajima's D>0 2242:Tajima's D<0 2211: 2195: 2193: 2192: 2187: 2124: 2122: 2121: 2116: 2108: 2103: 2044: 1938: 1936: 1935: 1930: 1906: 1904: 1903: 1898: 1871: 1869: 1868: 1863: 1855: 1854: 1820: 1818: 1817: 1812: 1793: 1791: 1790: 1785: 1780: 1778: 1777: 1764: 1758: 1757: 1756: 1743: 1724: 1719: 1718: 1710: 1697: 1695: 1694: 1689: 1665: 1663: 1662: 1657: 1656: 1655: 1640: 1625: 1623: 1622: 1617: 1602: 1600: 1599: 1594: 1580:neutral mutation 1573: 1571: 1570: 1565: 1563: 1561: 1560: 1548: 1539: 1537: 1536: 1531: 1528: 1527: 1519: 1503: 1501: 1500: 1495: 1493: 1491: 1490: 1478: 1475: 1464: 1446: 1445: 1428: 1426: 1425: 1420: 1418: 1410: 1407: 1396: 1378: 1377: 1358: 1356: 1355: 1350: 1348: 1346: 1323: 1307: 1306: 1290: 1285: 1284: 1267: 1265: 1264: 1259: 1257: 1255: 1235: 1224: 1219: 1218: 1199: 1197: 1196: 1191: 1189: 1186: 1181: 1172: 1171: 1162: 1157: 1155: 1151: 1150: 1140: 1129: 1124: 1123: 1111: 1110: 1093: 1091: 1090: 1085: 1083: 1081: 1080: 1068: 1063: 1062: 1050: 1049: 1030: 1028: 1027: 1022: 1020: 1018: 1017: 1016: 1003: 998: 988: 987: 978: 973: 972: 955: 953: 952: 947: 945: 943: 942: 933: 932: 923: 918: 917: 900: 891: 889: 888: 883: 881: 857: 856: 841: 840: 828: 827: 826: 824: 823: 811: 806: 805: 797: 793: 788: 776: 775: 767: 764: 760: 737: 735: 734: 729: 711:neutral mutation 700: 698: 697: 692: 675: 673: 672: 667: 648: 646: 645: 640: 638: 626: 625: 617: 614: 610: 588: 586: 585: 580: 578: 567: 566: 558: 555: 543: 541: 540: 535: 522: 520: 519: 514: 501: 499: 498: 493: 480: 478: 477: 472: 458:test statistic. 453: 451: 450: 445: 433: 431: 430: 425: 405: 403: 402: 397: 367: 365: 364: 359: 345: 341: 339: 338: 330: 327: 316: 297: 254: 252: 251: 246: 232: 228: 226: 225: 217: 214: 203: 184: 112: 110: 109: 104: 88: 86: 85: 80: 2838: 2837: 2833: 2832: 2831: 2829: 2828: 2827: 2798: 2797: 2796: 2791: 2777:Silent mutation 2767:Gene conversion 2755: 2714: 2710:Selective sweep 2671: 2666: 2587:DNAsp (Windows) 2578: 2568: 2555: 2552: 2547: 2546: 2502: 2501: 2497: 2453: 2452: 2448: 2401:(6): e1602996. 2388: 2387: 2383: 2339: 2338: 2334: 2329: 2317: 2277: 2205: 2160: 2159: 2146:The lower-case 2045: 2038: 2037: 2035: 2032: 2026: 2020: 2014: 2008: 2002: 1996: 1990: 1986: 1983: 1977: 1968: 1967: 1955: 1949: 1945: 1909: 1908: 1877: 1876: 1875:Tajima defines 1846: 1826: 1825: 1803: 1802: 1759: 1745: 1725: 1703: 1702: 1698:in the sample, 1668: 1667: 1635: 1631: 1630: 1608: 1607: 1584: 1583: 1552: 1542: 1541: 1512: 1511: 1482: 1437: 1432: 1431: 1369: 1364: 1363: 1324: 1298: 1291: 1276: 1271: 1270: 1236: 1225: 1210: 1205: 1204: 1163: 1142: 1141: 1130: 1115: 1102: 1097: 1096: 1072: 1054: 1041: 1036: 1035: 1008: 989: 979: 964: 959: 958: 934: 924: 909: 904: 903: 848: 832: 815: 794: 748: 747: 744: 719: 718: 707:null hypothesis 682: 681: 657: 656: 598: 597: 549: 548: 525: 524: 504: 503: 483: 482: 462: 461: 436: 435: 416: 415: 388: 387: 301: 292: 263: 262: 188: 179: 150: 149: 143: 95: 94: 71: 70: 17: 12: 11: 5: 2836: 2834: 2826: 2825: 2820: 2815: 2810: 2800: 2799: 2793: 2792: 2790: 2789: 2784: 2779: 2774: 2769: 2763: 2761: 2757: 2756: 2754: 2753: 2751:Fay and Wu's H 2748: 2743: 2738: 2733: 2728: 2722: 2720: 2716: 2715: 2713: 2712: 2707: 2702: 2697: 2692: 2687: 2681: 2679: 2673: 2672: 2667: 2665: 2664: 2657: 2650: 2642: 2636: 2635: 2628: 2627: 2626: 2625: 2616: 2614:MEGA4 or MEGA5 2611: 2606: 2601: 2595: 2589: 2577: 2576:External links 2574: 2573: 2572: 2567:978-0878933082 2566: 2551: 2548: 2545: 2544: 2495: 2466:(3): 693–709. 2446: 2381: 2331: 2330: 2328: 2325: 2324: 2323: 2321:Fay and Wu's H 2316: 2313: 2276: 2273: 2267: 2266: 2263: 2260: 2257: 2253: 2252: 2249: 2246: 2243: 2239: 2238: 2235: 2232: 2229: 2225: 2224: 2221: 2218: 2215: 2204: 2201: 2185: 2182: 2179: 2176: 2173: 2170: 2167: 2114: 2111: 2106: 2102: 2099: 2096: 2093: 2090: 2087: 2084: 2081: 2078: 2075: 2072: 2069: 2066: 2063: 2060: 2057: 2054: 2051: 2048: 2030: 2024: 2018: 2012: 2006: 2000: 1994: 1988: 1981: 1975: 1952: 1944: 1941: 1928: 1925: 1922: 1919: 1916: 1896: 1893: 1890: 1887: 1884: 1873: 1872: 1861: 1858: 1853: 1849: 1845: 1842: 1839: 1836: 1833: 1810: 1799:expected value 1795: 1794: 1783: 1776: 1771: 1768: 1763: 1755: 1752: 1748: 1742: 1739: 1736: 1732: 1728: 1722: 1716: 1713: 1687: 1684: 1681: 1678: 1675: 1654: 1649: 1645: 1639: 1615: 1591: 1559: 1555: 1551: 1525: 1522: 1509: 1508: 1505: 1504: 1489: 1485: 1481: 1474: 1471: 1468: 1463: 1460: 1457: 1453: 1449: 1444: 1440: 1429: 1416: 1413: 1406: 1403: 1400: 1395: 1392: 1389: 1385: 1381: 1376: 1372: 1360: 1359: 1345: 1342: 1339: 1336: 1333: 1330: 1327: 1322: 1319: 1316: 1313: 1310: 1305: 1301: 1297: 1294: 1288: 1283: 1279: 1268: 1254: 1251: 1248: 1245: 1242: 1239: 1234: 1231: 1228: 1222: 1217: 1213: 1201: 1200: 1185: 1180: 1176: 1170: 1166: 1160: 1154: 1149: 1145: 1139: 1136: 1133: 1127: 1122: 1118: 1114: 1109: 1105: 1094: 1079: 1075: 1071: 1066: 1061: 1057: 1053: 1048: 1044: 1032: 1031: 1015: 1011: 1007: 1002: 997: 993: 986: 982: 976: 971: 967: 956: 941: 937: 931: 927: 921: 916: 912: 893: 892: 878: 875: 872: 869: 866: 863: 860: 855: 851: 847: 844: 839: 835: 831: 822: 818: 814: 809: 803: 800: 791: 785: 782: 779: 773: 770: 763: 758: 755: 743: 740: 726: 689: 664: 650: 649: 635: 632: 629: 623: 620: 613: 608: 605: 576: 573: 570: 564: 561: 532: 511: 490: 469: 443: 423: 395: 369: 368: 357: 354: 351: 348: 344: 336: 333: 326: 323: 320: 315: 312: 309: 305: 300: 295: 291: 288: 285: 282: 279: 276: 273: 270: 256: 255: 244: 241: 238: 235: 231: 223: 220: 213: 210: 207: 202: 199: 196: 192: 187: 182: 178: 175: 172: 169: 166: 163: 160: 157: 142: 139: 102: 78: 15: 13: 10: 9: 6: 4: 3: 2: 2835: 2824: 2821: 2819: 2816: 2814: 2811: 2809: 2806: 2805: 2803: 2788: 2785: 2783: 2780: 2778: 2775: 2773: 2770: 2768: 2765: 2764: 2762: 2758: 2752: 2749: 2747: 2744: 2742: 2739: 2737: 2734: 2732: 2729: 2727: 2724: 2723: 2721: 2717: 2711: 2708: 2706: 2703: 2701: 2698: 2696: 2693: 2691: 2688: 2686: 2683: 2682: 2680: 2678: 2674: 2670: 2663: 2658: 2656: 2651: 2649: 2644: 2643: 2640: 2633: 2630: 2629: 2624: 2620: 2617: 2615: 2612: 2610: 2607: 2605: 2602: 2599: 2596: 2593: 2590: 2588: 2585: 2584: 2583: 2582: 2581: 2575: 2569: 2563: 2559: 2554: 2553: 2549: 2540: 2536: 2531: 2526: 2522: 2518: 2515:(1): 413–29. 2514: 2510: 2506: 2499: 2496: 2491: 2487: 2482: 2477: 2473: 2469: 2465: 2461: 2457: 2450: 2447: 2442: 2438: 2433: 2428: 2424: 2420: 2416: 2412: 2408: 2404: 2400: 2396: 2392: 2385: 2382: 2377: 2373: 2368: 2363: 2359: 2355: 2352:(3): 585–95. 2351: 2347: 2343: 2336: 2333: 2326: 2322: 2319: 2318: 2314: 2312: 2308: 2304: 2300: 2297: 2292: 2290: 2286: 2282: 2274: 2272: 2264: 2261: 2258: 2255: 2254: 2250: 2247: 2244: 2241: 2240: 2236: 2233: 2230: 2228:Tajima's D=0 2227: 2226: 2222: 2219: 2216: 2213: 2212: 2209: 2200: 2197: 2183: 2180: 2177: 2174: 2171: 2168: 2165: 2157: 2153: 2149: 2144: 2143:=4/2.08=1.92 2142: 2138: 2135: 2132: 2131: 2126: 2112: 2109: 2104: 2100: 2097: 2094: 2091: 2088: 2085: 2082: 2079: 2076: 2073: 2070: 2067: 2064: 2061: 2058: 2055: 2052: 2049: 2046: 2029: 2023: 2017: 2011: 2005: 1999: 1993: 1987: 1980: 1974: 1970: 1965: 1961: 1950: 1942: 1940: 1926: 1923: 1920: 1917: 1914: 1894: 1891: 1888: 1885: 1882: 1859: 1856: 1851: 1847: 1843: 1837: 1831: 1824: 1823: 1822: 1808: 1800: 1781: 1769: 1766: 1753: 1750: 1746: 1740: 1737: 1734: 1730: 1726: 1720: 1711: 1701: 1700: 1699: 1682: 1679: 1676: 1647: 1643: 1627: 1613: 1606: 1589: 1581: 1577: 1557: 1553: 1549: 1520: 1487: 1483: 1479: 1472: 1469: 1466: 1461: 1458: 1455: 1451: 1447: 1442: 1438: 1430: 1414: 1411: 1404: 1401: 1398: 1393: 1390: 1387: 1383: 1379: 1374: 1370: 1362: 1361: 1340: 1337: 1334: 1328: 1325: 1317: 1314: 1311: 1308: 1303: 1299: 1292: 1286: 1281: 1277: 1269: 1249: 1246: 1243: 1237: 1232: 1229: 1226: 1220: 1215: 1211: 1203: 1202: 1183: 1178: 1174: 1168: 1164: 1158: 1152: 1147: 1143: 1137: 1134: 1131: 1125: 1120: 1116: 1112: 1107: 1103: 1095: 1077: 1073: 1069: 1064: 1059: 1055: 1051: 1046: 1042: 1034: 1033: 1013: 1009: 1005: 1000: 995: 991: 984: 980: 974: 969: 965: 957: 939: 935: 929: 925: 919: 914: 910: 902: 901: 898: 897: 896: 870: 867: 864: 858: 853: 849: 845: 842: 837: 833: 820: 816: 812: 807: 798: 789: 780: 768: 761: 756: 753: 746: 745: 741: 739: 724: 716: 712: 708: 704: 687: 679: 662: 654: 630: 618: 611: 606: 603: 596: 595: 594: 592: 571: 559: 547: 530: 509: 488: 467: 459: 457: 441: 421: 413: 409: 393: 385: 381: 377: 372: 371:for haploid. 355: 352: 349: 346: 342: 334: 331: 324: 321: 318: 313: 310: 307: 303: 298: 293: 289: 286: 283: 280: 274: 268: 261: 260: 259: 242: 239: 236: 233: 229: 221: 218: 211: 208: 205: 200: 197: 194: 190: 185: 180: 176: 173: 170: 167: 161: 155: 148: 147: 146: 140: 138: 135: 131: 127: 123: 122:genetic drift 119: 114: 100: 92: 76: 69: 63: 61: 60:genetic drift 56: 52: 51:introgression 48: 44: 40: 36: 31: 29: 25: 21: 2745: 2579: 2557: 2512: 2508: 2498: 2463: 2459: 2449: 2398: 2394: 2384: 2349: 2345: 2335: 2309: 2305: 2301: 2293: 2288: 2285:null process 2278: 2270: 2206: 2198: 2155: 2151: 2147: 2145: 2140: 2139: 2136: 2133: 2129: 2127: 2034: 2027: 2021: 2015: 2009: 2003: 1997: 1991: 1984: 1978: 1972: 1957: 1946: 1874: 1796: 1628: 1510: 894: 653:Fumio Tajima 651: 460: 455: 407: 383: 379: 375: 373: 370: 257: 144: 115: 64: 35:DNA sequence 32: 28:Fumio Tajima 19: 18: 2741:Ka/Ks ratio 738:statistic. 130:polymorphic 2802:Categories 2746:Tajima's D 2327:References 126:homologous 20:Tajima's D 2600:(Windows) 2592:Variscan 2423:2375-2548 2175:− 1927:μ 1915:θ 1895:μ 1731:∑ 1727:∑ 1715:^ 1524:^ 1470:− 1452:∑ 1402:− 1384:∑ 1338:− 1247:− 1126:− 1065:− 868:− 808:− 802:^ 772:^ 680:. If the 622:^ 563:^ 489:θ 442:π 412:selection 394:μ 356:μ 322:− 304:∑ 284:θ 275:π 243:μ 209:− 191:∑ 171:θ 162:π 101:π 55:frequency 24:statistic 2598:Arlequin 2509:Genetics 2460:Genetics 2441:28630911 2346:Genetics 2315:See also 1603:from an 546:variance 118:mutation 2623:BioPerl 2539:8536987 2530:1206737 2490:8454210 2481:1205353 2432:5470830 2403:Bibcode 2376:2513255 2367:1203831 2158:. Thus 2152:average 1960:average 1943:Example 2719:Models 2564:  2537:  2527:  2488:  2478:  2439:  2429:  2421:  2374:  2364:  2130:M=S/a1 1964:choose 895:where 2550:Notes 2419:eISSN 589:(its 49:, or 2562:ISBN 2535:PMID 2486:PMID 2437:PMID 2372:PMID 2178:1.92 1738:< 1540:and 434:and 120:and 2808:DNA 2621:in 2525:PMC 2517:doi 2513:141 2476:PMC 2468:doi 2464:133 2427:PMC 2411:doi 2362:PMC 2354:doi 2350:123 2184:.08 1801:of 709:of 41:or 2804:: 2533:. 2523:. 2511:. 2507:. 2484:. 2474:. 2462:. 2458:. 2435:. 2425:. 2417:. 2409:. 2397:. 2393:. 2370:. 2360:. 2348:. 2344:. 2196:. 2125:. 2105:10 1939:. 1626:. 113:. 62:. 2661:e 2654:t 2647:v 2570:. 2541:. 2519:: 2492:. 2470:: 2443:. 2413:: 2405:: 2399:3 2378:. 2356:: 2289:D 2181:= 2172:2 2169:= 2166:d 2156:M 2148:d 2141:M 2113:2 2110:= 2101:1 2098:+ 2095:1 2092:+ 2089:2 2086:+ 2083:2 2080:+ 2077:3 2074:+ 2071:1 2068:+ 2065:3 2062:+ 2059:2 2056:+ 2053:2 2050:+ 2047:3 1924:N 1921:4 1918:= 1892:N 1889:4 1886:= 1883:M 1860:. 1857:M 1852:1 1848:a 1844:= 1841:) 1838:S 1835:( 1832:E 1809:S 1782:. 1775:) 1770:2 1767:n 1762:( 1754:j 1751:i 1747:k 1741:j 1735:i 1721:= 1712:k 1686:) 1683:j 1680:, 1677:i 1674:( 1653:) 1648:2 1644:n 1638:( 1614:N 1590:n 1558:1 1554:a 1550:S 1521:k 1488:2 1484:i 1480:1 1473:1 1467:n 1462:1 1459:= 1456:i 1448:= 1443:2 1439:a 1415:i 1412:1 1405:1 1399:n 1394:1 1391:= 1388:i 1380:= 1375:1 1371:a 1344:) 1341:1 1335:n 1332:( 1329:n 1326:9 1321:) 1318:3 1315:+ 1312:n 1309:+ 1304:2 1300:n 1296:( 1293:2 1287:= 1282:2 1278:b 1253:) 1250:1 1244:n 1241:( 1238:3 1233:1 1230:+ 1227:n 1221:= 1216:1 1212:b 1184:2 1179:1 1175:a 1169:2 1165:a 1159:+ 1153:n 1148:1 1144:a 1138:2 1135:+ 1132:n 1121:2 1117:b 1113:= 1108:2 1104:c 1078:1 1074:a 1070:1 1060:1 1056:b 1052:= 1047:1 1043:c 1014:2 1010:a 1006:+ 1001:2 996:1 992:a 985:2 981:c 975:= 970:2 966:e 940:1 936:a 930:1 926:c 920:= 915:1 911:e 877:] 874:) 871:1 865:S 862:( 859:S 854:2 850:e 846:+ 843:S 838:1 834:e 830:[ 821:1 817:a 813:S 799:k 790:= 784:) 781:d 778:( 769:V 762:d 757:= 754:D 725:D 688:D 663:D 634:) 631:d 628:( 619:V 612:d 607:= 604:D 575:) 572:d 569:( 560:V 531:d 510:d 468:D 456:D 422:S 408:i 384:N 380:n 376:S 353:N 350:2 347:= 343:] 335:i 332:1 325:1 319:n 314:1 311:= 308:i 299:S 294:[ 290:E 287:= 281:= 278:] 272:[ 269:E 240:N 237:4 234:= 230:] 222:i 219:1 212:1 206:n 201:1 198:= 195:i 186:S 181:[ 177:E 174:= 168:= 165:] 159:[ 156:E 77:S

Index

statistic
Fumio Tajima
DNA sequence
directional selection
balancing selection
genetic hitchhiking
introgression
frequency
genetic drift
segregating sites
pairwise differences
mutation
genetic drift
homologous
polymorphic
method of moments
selection
variance
standard deviation
Fumio Tajima
beta distribution
confidence interval
null hypothesis
neutral mutation
population bottleneck
single nucleotide polymorphisms
neutral mutation
effective population size
expected value
average

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