I've been getting queries about the ear wax paper...below the fold I've copied table 1, which shows the frequencies of the haplotypes in various populations.
First, note the sample sizes.
Keep these sample sizes in mind as you try to get an understanding of the clines the authors were talking about.
Greg Cochran points out that since dry ear wax is a recessive trait it seems plausible that the phenotype being selected is different. It might be dominant or additive so that a total approach toward fixation of the allele would not be necessary for the fitness to be maximized. Consider the earwax trait, if allele frequences are 0.5 for both A and G in a population, you have 0.25 = AA, 0.5 = AG and 0.25 = GG. So Only 1/4 benefit from the fitness increasing trait. If it is a dominant feature somewhere else, you flip it, and with a 0.5 A frequency 3/4 of the population would maximize their fitness.
On the bit about randon genetic drift vs. selection, look at the map, if this allele was approaching fixation via stochastic processes it seems peculiar that it would exhibit a continental cline. Fragmented populations can fix at alternative alleles, but the distribution would be patchy and intercalated, not suggestive of a broad trend around an East Asian mode.
Published online: 29 January 2006; | doi:10.1038/ng1733
A SNP in the ABCC11 gene is the determinant of human earwax type
Koh-ichiro Yoshiura, Akira Kinoshita, Takafumi Ishida, Aya Ninokata, Toshihisa Ishikawa, Tadashi Kaname, Makoto Bannai, Katsushi Tokunaga, Shunro Sonoda, Ryoichi Komaki, Makoto Ihara, Vladimir A Saenko, Gabit K Alipov, Ichiro Sekine, Kazuki Komatsu, Haruo Takahashi, Mitsuko Nakashima, Nadiya Sosonkina, Christophe K Mapendano, Mohsen Ghadami, Masayo Nomura, De-Sheng Liang, Nobutomo Miwa, Dae-Kwang Kim, Ariuntuul Garidkhuu, Nagato Natsume, Tohru Ohta, Hiroaki Tomita, Akira Kaneko, Mihoko Kikuchi, Graciela Russomando, Kenji Hirayama, Minaka Ishibashi, Aya Takahashi, Naruya Saitou, Jeffery C Murray, Susumu Saito, Yusuke Nakamura & Norio Niikawa
Table 1 Genotypes at the rs17822931 site and frequencies of alleles A and
27 of ABCC11 among different ethnic populations
No. of individuals with genotypes
Ethnic populationsTribes or inhabitants studiedAA(frequency)GAGGNo. of individuals genotypedFrequency of allele A
Frequency of allele
ChineseShanxi inhabitant (Northern Han Chinese)74(1.000)00741.000N.S.
Jingsu inhabitant (Northern Han Chinese)110(0.924)901190.962N.S.
Inhabitants of Fujian, Guanjgdong and Hunan Provinces (Southern Han Chinese)249(0.750)6383320.845N.S.
Han Chinese from multi-regions42(0.808)100520.9040/104D.S.L.
MongolianKhalkha tribe126(0.759)3641660.8670/252T.I., A.G.
JapaneseNagasaki inhabitant (western prefecture of Japan mainland)87(0.690)
Okinawa people (southwestern prefecture of Japan)30(0.517)253580.733T.K.
Yonakuni islander (western island of Japan)13(0.433)152300.6830/60S.S.
Ainu in Biratori-Nibutani village in Hokkaido32(0.552)242580.7590/116T.I., N.N.
VietnamesePeople from multi-regions82(0.536)60111530.732N.Na.
DravidianInhabitants of Tamil Nadu in India27(0.540)176500.7100/100T.I.
ThaiNorthern Thai (Lahu, Shan, Lisu, Hmong, Akha, Mlabri and Karen (Mae-sot Thai) tribes combined)215(0.505)163484260.6960/158 (Karen)T.I., K.H.
Central Thai in Bangkok31(0.633)108490.7351/100 (Bangkokian)T.I.
Southern Thai (Urak Lawoi and Sakai tribes combined)2(0.026)2352770.1750/52 (Sakai)T.I.
VeddaNative people in Sri Lanka7(0.350)121200.650T.I.
IndonesianDayak tribe in Kalimantan12(0.293)236410.573T.I.
Toraja and Bugis tribes in Sulawesi27(0. 270)49241000.515T.I.
Dani tribe in Irian Jaya0(0.000)231330.030T.I.
MalaysianSabah in North Borneo24(0.393)2710610.5660/132 (Sabah)K.H.
TaiwaneseTaiwan Aborigine (Yami and Ami combined)34(0.330)48211030.5630/100 (Ami)T.I.
FrenchFrom the CEPH families1(0.083)38120.2080/24CEPH
PapuanPapua, New Guinea1(0.026)1126380.1710/68T.I.
European AmericanFrom CEPH families without the French and Venezuelans1(0.012)1665820.1100/164CEPH
Vanuatu islanderAneityum and Santo islanders combined1(0.011)1774920.1030/266 (Any and Gau islanders)K.H.
VenezuelanInhabitants of Ye'Kuana and Sanuma villages0(0.000)329320.0470/64S.S.,CEPH
AfricanFrom various sub-Saharan nations0(0.000)110110.0450/22C.K.M.
D.-K.K., D.-K. Kim; N.S., N. Saitou; N.N., N. Niikawa; D.-S.L., D.-S. Liang; T.I., T. Ishida; A.G., A. Garidkhuu; T.K., T. Kaname; S.S., S. Sonoda; N.Na., N. Natsume; K.H., K. Hirayama; R.K., R. Komaki; G.K.A., G.K. Alipov; V.A.S., V.A. Saenko; C.K.M., C.K. Mapendanno; Coriell, from the Coriell Institute; CEPH, from the CEPH families.
^aOne exceptional case of dry cerumen who has
27 on the G allele is included.