Table S1 The fifty most frequent surnames in Costa Rica. Electors in the 2012 Elections. RODRIGUEZ VARGAS JIMENEZ MORA ROJAS GONZALEZ SANCHEZ RAMIREZ HERNANDEZ CASTRO ARAYA LOPEZ SOLANO ALVARADO CHAVES QUESADA CAMPOS GOMEZ PEREZ MORALES ARIAS ZUÑIGA QUIROS FERNANDEZ SALAZAR BRENES VILLALOBOS GUTIERREZ GARCIA ALFARO CALDERON VALVERDE VEGA AGUILAR CHAVARRIA ALVAREZ CASTILLO SALAS MURILLO SOLIS CHACON SOTO ESPINOZA CORDERO MONGE MARTINEZ MENDEZ HERRERA MONTERO BARRANTES 65,508 56,567 55,654 54,127 48,964 45,858 40,729 40,470 40,160 31,360 30,194 29,850 29,477 28,127 27,822 27,392 27,277 26,900 26,856 26,663 26,502 25,586 25,530 25,322 22,830 22,701 22,560 21,769 21,200 21,082 20,659 20,555 20,537 20,381 19,934 19,005 18,898 18,466 18,105 18,037 17,995 17,936 17,886 17,688 17,603 17,465 17,256 17,229 16,823 16,348 Table S2 Distribution of isonymy parameters in 81 cantons of Costa Rica: ID, Identification; N, number of individuals; Na, number of paternal surnames; I, Random Isonymy; α, as effective surname number; Fst, coefficient of random consanguinity. Cantons San José (Central) Escazú Desamparados Puriscal Tarrazú Aserrí Mora Goicoechea Santa Ana Alajuelita Vásquez de Coronado Acosta Tibás Moravia Montes de Oca Turrubares Dota Curridabat Pérez Zeledón León Cortés Alajuela San Ramón Grecia San Mateo Atenas Naranjo Palmares Poás Orotina San Carlos Zarcero Valverde Vega Upala Los Chiles Guatuso Cartago Paraíso La Unión Provinces San José San José San José San José San José San José San José San José San José San José San José San José San José San José San José San José San José San José San José San José Alajuela Alajuela Alajuela Alajuela Alajuela Alajuela Alajuela Alajuela Alajuela Alajuela Alajuela Alajuela Alajuela Alajuela Alajuela Cartago Cartago Cartago ID SJ 1 SJ 2 SJ 3 SJ 4 SJ 5 SJ 6 SJ 7 SJ 8 SJ 9 SJ10 SJ11 SJ12 SJ13 SJ14 SJ15 SJ16 SJ17 SJ18 SJ19 SJ20 AL 1 AL 2 AL 3 AL 4 AL 5 AL 6 AL 7 AL 8 AL 9 AL10 AL11 AL12 AL13 AL14 AL15 CA 1 CA 2 CA 3 N 223,719 40,764 145,416 24,786 10,689 37,976 17,680 85,476 28,400 45,363 46,430 14,468 54,670 40,447 40,775 4,192 4,808 44,388 99,330 8,222 174,181 54,223 51,414 3,819 17,705 28,249 25,581 18,407 13,120 89,550 8,024 12,877 22,132 9,413 9,136 106,642 40,239 59,863 Na 5,964 2,566 2,681 506 321 930 770 2,686 1,629 1,283 1,617 299 2,298 2,126 2,639 272 248 2,388 1,017 240 2,679 910 883 315 559 588 590 553 552 1,215 298 414 789 565 494 1,594 703 1,801 I 0.0057 0.0072 0.0071 0.0154 0.0181 0.0115 0.0110 0.0068 0.0082 0.0074 0.0087 0.0237 0.0066 0.0071 0.0058 0.0165 0.0164 0.0059 0.0101 0.0205 0.0085 0.0116 0.0141 0.0144 0.0135 0.0110 0.0157 0.0136 0.0091 0.0103 0.0327 0.0153 0.0070 0.0075 0.0085 0.0095 0.0128 0.0072 α 175.7 137.9 140.8 64.2 54.6 86.0 90.5 147.2 122.0 135.4 114.1 41.3 151.2 140.4 172.4 60.5 60.6 169.0 98.2 48.0 117.2 85.4 69.9 69.6 73.5 90.0 62.8 72.8 109.7 96.2 29.7 64.7 143.1 134.9 118.6 104.0 77.0 138.7 Fst 0.00144 0.00184 0.00177 0.00373 0.00448 0.00284 0.00273 0.00170 0.00207 0.00182 0.00220 0.00570 0.00166 0.00177 0.00145 0.00392 0.00406 0.00148 0.00253 0.00487 0.00212 0.00286 0.00346 0.00329 0.00326 0.00273 0.00396 0.00334 0.00225 0.00256 0.00761 0.00365 0.00175 0.00178 0.00207 0.00234 0.00321 0.00178 Jiménez Turrialba Alvarado Oreamuno El Guarco Heredia Barva Santo Domingo Santa Bárbara San Rafael San Isidro Belén Flores San Pablo Sarapiquí Liberia Nicoya Santa Cruz Bagaces Carrillo Cañas Abangares Tilarán Nandayure La Cruz Hojancha Puntarenas Esparza Buenos Aires Montes de Oro Osa Aguirre Golfito Coto Brus Parrita Corredores Garabito Limón (Central) Pococí Siquirres Talamanca Matina Guácimo Cartago Cartago Cartago Cartago Cartago Heredia Heredia Heredia Heredia Heredia Heredia Heredia Heredia Heredia Heredia Guanacaste Guanacaste Guanacaste Guanacaste Guanacaste Guanacaste Guanacaste Guanacaste Guanacaste Guanacaste Guanacaste Puntarenas Puntarenas Puntarenas Puntarenas Puntarenas Puntarenas Puntarenas Puntarenas Puntarenas Puntarenas Puntarenas Limón Limón Limón Limón Limón Limón CA 4 CA 5 CA 6 CA 7 CA 8 HE 1 HE 2 HE 3 HE 4 HE 5 HE 6 HE 7 HE 8 HE 9 HE10 GU 1 GU 2 GU 3 GU 4 GU 5 GU 6 GU 7 GU 8 GU 9 GU10 GU11 PA 1 PA 2 PA 3 PA 4 PA 5 PA 6 PA 7 PA 8 PA 9 PA10 PA11 LI 1 LI 2 LI 3 LI 4 LI 5 LI 6 10,692 52,139 8,764 31,077 27,945 85,753 27,845 30,931 23,079 29,797 13,342 16,106 13,945 18,578 27,069 38,308 35,999 35,076 11,373 20,376 17,494 11,805 13,248 7,526 9,404 5,173 77,385 19,134 27,656 8,771 18,840 16,815 25,047 26,192 9,993 28,460 8,872 61,603 76,365 34,968 15,697 18,360 23,972 354 917 276 640 699 2,550 989 1,266 728 1,086 746 985 717 1,043 846 1,152 749 910 549 766 705 463 467 365 541 268 1,541 742 561 455 711 690 902 610 492 984 660 2,832 1,506 1,351 1,192 1,013 946 0.0127 0.0092 0.0190 0.0157 0.0126 0.0071 0.0104 0.0101 0.0124 0.0131 0.0123 0.0133 0.0123 0.0093 0.0069 0.0069 0.0125 0.0128 0.0099 0.0112 0.0076 0.0077 0.0122 0.0108 0.0010 0.0146 0.0064 0.0084 0.0101 0.0104 0.0070 0.0078 0.0066 0.0086 0.0094 0.0065 0.0083 0.0042 0.0069 0.0058 0.0094 0.0058 0.0070 78.5 108.3 52.1 62.9 78.5 139.8 95.4 98.6 80.0 75.8 80.7 74.6 80.5 107.4 144.3 145.3 79.5 77.3 101.3 88.7 131.0 129.6 81.3 92.9 100.1 68.5 156.6 119.2 98.8 96.5 143.8 128.8 150.9 116.4 107.0 153.0 120.6 236.2 143.6 173.0 106.7 172.6 143.8 0.00305 0.0023 0.00455 0.00380 0.00319 0.00178 0.00255 0.00253 0.00300 0.00320 0.00320 0.00318 0.00301 0.00231 0.00176 0.00171 0.00316 0.00331 0.00237 0.00284 0.00191 0.00193 0.00289 0.00259 0.00250 0.00354 0.00159 0.00208 0.00258 0.00267 0.00171 0.00197 0.00161 0.00211 0.00248 0.00160 0.00205 0.00108 0.00175 0.00144 0.00239 0.00143 0.00169 12 Log (frequency of occurrences) 10 8 6 4 2 0 0 2 4 6 8 10 12 Log (occurrences) Fig. S1 - Variation of the number of occurrences in 2.9 million paternal surnames in Costa Rica. Electors of 2012 . Bilogarithmic scale, natural log. 5.8 5.6 5.4 Lasker's distance 5.2 5.0 4.8 4.6 4.4 4.2 4.0 -50 0 50 100 150 200 250 300 350 400 450 Geographic distance (kms) Fig. S2 - Variation of Lasker’s distance between cantons with geographic distance in Costa Rica. 0.8 0.7 Euclidean distance 0.6 0.5 0.4 0.3 0.2 0.1 0 50 100 150 200 250 300 350 400 450 Kilometers Fig. S3 - Variation of Euclidean distance between cantons with geographic distance in Costa Rica. 1.8 1.6 1.4 Nei's distance 1.2 1.0 0.8 0.6 0.4 0.2 0.0 0 50 100 150 200 250 300 350 400 450 Kilometers Fig. S4 - Variation of Nei’s distance between cantons with geographic distance in Costa Rica. Fig. S5A - Projection of the of the first two axes of PCA matrix of Lasker’s distances between the seven provinces of Costa Rica. (1° Fact: 66.7%; 2° Fact: 26.7%). Fig. S5B - Projection of the first two dimensions of MDS of Lasker’s distance between the seven provinces (stress= 1.23% %) 12S20 San José (S) S12 S17 S5 10 Alajuela (A) Cartago (C) Heredia (H) 8 S6 Guanacaste (G) S19 C8 Puntarenas (P) C 2 CC61 6 C7 S3 P3 S4 9 C3 S2 S18 -22 L3 -17 -12 L 5 -7 L4 -2 H10 G7 G5 G10 G1 A13 G 2G 6 C 5 S7 S16 S11 P8 P 5 S13L 2 P7 0 A9 -2 H 1 3 P10 P2 H 3 P1 A14 P 9C 4 S10 P6 2 S 8P11 L 6 S14 S15 S1 L1 Limón (L) S4 G9 A15 -4 G4 G11 8 A6 H 2 HH96 A 1 P 4H 5 A12A 2 A10 HA 88 H4 A4 H7 A3 A5 G8 13 18 A7 -6 G3 A11 -8 Fig. S6A - Projection on the first two factors of the PCA for the matrix of Lasker’s distances between the 81 cantons of Costa Rica. (1° Fact.: 59.15% ; 2° Fact.: 23.06% ; 3° Fact.: 6.36%). A14 1.3 C8 S15 C1 C2 C3 0.8 G6 C6 A15 G4 C7 A13 G7 G1 G11 -2.5 -2 G3 -1.5 -1 A11 A 2 H 5A 7 H10 P10 -0.5 0 -0.2 G5 S13 5 7 A 1H 2 CC4H AH81 H8 A12 H3 H4 A9 A3 A4 H 6 P11 G8 A0.3 5 PH4A10 9 A6 P7 P1 P2 S2 S14S 1 S18 S9 P8 S16 S 7 S19 S11 S 40.5 S12 S6 P5 L2 1.5 S17 P9 P3 S8 G9 G10 S1 5 P6 S20 S3 S10 L3 L6 -0.7 G2 L4 L5 San José (S) -1.2 Alajuela (A) Cartago (C) Heredia (H) -1.7 Guanacaste (G) Puntarenas (P) L1 Limón (L) -2.2 Fig. S6B - MDS projection of Lasker’s distance matrix between 81 cantons of Costa Rica (stress= 16.1%). Fig. S7 - Dendrogram of Costa Rica cantons. From Lasker’s distance matrix. PHYLIP package, Neighbor algorithm. A I II III B I II III Fig. S8 - Projection of Lasker’s matrix of surname distances on cantons in Costa Rica by mapping (A) the first three PCA’s factors (I: Factor 1= 44.36.5%; II: Factor 2 = 26.03%; III: Factor 3 = 13.86%); (B) the first three MDS’s dimensions (I: Dimension 1; II: Dimension 2; III: Dimension 3. Stress=16.1%).