MBE Advance Access published online on December 20, 2006
Genetic Evidence for the Convergent Evolution of Light Skin in Europeans and East Asians
Heather L. Norton et al.
Human skin pigmentation shows a strong positive correlation with ultraviolet radiation (UVR) intensity, suggesting that variation in skin color is, at least partially, due to adaptation via natural selection. We investigated the evolution of pigmentation variation by testing for the presence of positive directional selection in six pigmentation genes using an empirical FST approach, through an examination of global diversity patterns of these genes in the CEPH-Diversity Panel, and by exploring signatures of selection in data from the International HapMap project. Additionally, we demonstrated a role for MATP in determining normal skin pigmentation variation using admixture mapping methods. Taken together (with the results of previous admixture mapping studies), these results point to the importance of several genes in shaping the pigmentation phenotype and a complex evolutionary history involving strong selection. Polymorphisms in two genes, ASIP and OCA2, may play a shared role in shaping light and dark pigmentation across the globe while SLC24A5, MATP, and TYR have a predominant role in the evolution of light skin in Europeans but not in East Asians. These findings support a case for the recent convergent evolution of a lighter pigmentation phenotype in Europeans and East Asians.
Link
December 31, 2006
Genetic components of Argentinean population
American Journal of Physical Anthropology (Early view)
Argentine population genetic structure: Large variance in Amerindian contribution
Michael F. Seldin et al.
Abstract
Argentine population genetic structure was examined using a set of 78 ancestry informative markers (AIMs) to assess the contributions of European, Amerindian, and African ancestry in 94 individuals members of this population. Using the Bayesian clustering algorithm STRUCTURE, the mean European contribution was 78%, the Amerindian contribution was 19.4%, and the African contribution was 2.5%. Similar results were found using weighted least mean square method: European, 80.2%; Amerindian, 18.1%; and African, 1.7%. Consistent with previous studies the current results showed very few individuals (four of 94) with greater than 10% African admixture. Notably, when individual admixture was examined, the Amerindian and European admixture showed a very large variance and individual Amerindian contribution ranged from 1.5 to 84.5% in the 94 individual Argentine subjects. These results indicate that admixture must be considered when clinical epidemiology or case control genetic analyses are studied in this population. Moreover, the current study provides a set of informative SNPs that can be used to ascertain or control for this potentially hidden stratification. In addition, the large variance in admixture proportions in individual Argentine subjects shown by this study suggests that this population is appropriate for future admixture mapping studies.
Link
Argentine population genetic structure: Large variance in Amerindian contribution
Michael F. Seldin et al.
Abstract
Argentine population genetic structure was examined using a set of 78 ancestry informative markers (AIMs) to assess the contributions of European, Amerindian, and African ancestry in 94 individuals members of this population. Using the Bayesian clustering algorithm STRUCTURE, the mean European contribution was 78%, the Amerindian contribution was 19.4%, and the African contribution was 2.5%. Similar results were found using weighted least mean square method: European, 80.2%; Amerindian, 18.1%; and African, 1.7%. Consistent with previous studies the current results showed very few individuals (four of 94) with greater than 10% African admixture. Notably, when individual admixture was examined, the Amerindian and European admixture showed a very large variance and individual Amerindian contribution ranged from 1.5 to 84.5% in the 94 individual Argentine subjects. These results indicate that admixture must be considered when clinical epidemiology or case control genetic analyses are studied in this population. Moreover, the current study provides a set of informative SNPs that can be used to ascertain or control for this potentially hidden stratification. In addition, the large variance in admixture proportions in individual Argentine subjects shown by this study suggests that this population is appropriate for future admixture mapping studies.
Link
December 30, 2006
New edition of YHRD database is online
From the curators of YHRD:
Hi Dienekes,
we have launched release 20 of the YHRD database, the largest update ever with 4,755 new haplotypes. See the news below and a geographical overview as an attachment.
December 28 YHRD update (Lutz Roewer, Sascha Willuweit)
The largest update since the database was started in 2000! Release 20 is out with 46,720 haplotypes in 386 populations. 44,863 haplotypes of these are completely typed for 9 and 17,824 for 11 loci. Twenty-nine populations were added today: from Ningxia in China (Han), from Qinghai in China (Salar), from Hungary including Romani speakers, from Germany (Bonn), from Sweden (Saami from Jokkmokk), from Norway (Bergen), from Libya (Tripolis), from Yemen (Sanaa), from Mexico (Chihuahua and Mexico City), from Serbia (Novi Sad), from Siberia (Stony Tunguska Evenks, Yakut speaking Evenks, Yakuts, Yukaghir, Tuva), from Western Russia (Belgorod, Kaluga, Mineralnye Vody, Nizhnii Novgorod, Orel, Pskov, Saratov, Tula, Vladimir, Volot, Yaroslavl) and from Southeastern Poland. Ten populations were updated: from Colombia (province Antioquia), from Ningxia in China (Hui), from Taiwan (Han), from Norway (Eastern, Central, Northern, Southern, Western parts and from Oslo) as well as from Russia (Novgorod). In two populations erroneous allele calls were corrected: Taraz (Kazakhstan) and Andalucia/Extremadura (Spain). We would like to thank the following colleagues for submissions, updates and corrections: Bofeng Zhu and his group (Shaanxi, P.R.China), Pamszav Horolma and her group (Budapest, Hungary), Anke Junge and her group (Bonn, Germany), Cheng-Hwai Tzeng and his group (Taipei, Taiwan), Andreas Karlsson and his group (Linkoeping, Sweden), Anibal Gaviria and his group (Medellin, Colombia), Thomas Rothaemel and his group (Hannover, Germany), Berit Myhre Dupuy and her group (Oslo, Norway), Uta Immel and her group (Halle, Germany), Hector Rangel-Villalobos and his group (Ocotlan, Mexico), Miljen Maletin and his group (Novi Sad, Serbia), Brigitte Pakendorf and her group (Leipzig, Germany), Marcin Wozniak and his group (Bydgoszcz, Poland), Grzegorz Kaczmarczyk and his group (Krakow, Poland) and Maria Jose Farfan and her group (Sevilla, Spain).
We wish you a happy new year !
Lutz Roewer, Sascha Willuweit
YHRD curators
December 29, 2006
Long Life and Good Mental Function Gene Identified
Single Gene Could Lead to Long Life, Better Mental Function
Barzilai and his colleagues examined 158 people of Ashkenazi, or Eastern European Jewish, descent who were 95 years of age or older. They chose Ashkenazi Jews since current generations stem from a relatively limited number of ancestors. This means they have a comparatively uniform genetic makeup, making it easier to identify important genetic differences.
The scientists gave these volunteers a common test of mental function, consisting of 30 questions. Correctly answering 25 of the questions meant a subject passed the test. Those centenarians who passed were two to three times more likely to have a common variant of a particular gene, called the CETP gene, than those who did not. When the researchers studied another 124 Ashkenazi Jews between 75 and 85 years of age, those subjects who passed the test of mental function were five times more likely to have this gene variant than their counterparts.
December 28, 2006
Kicking is more dangerous than fists or weapons
Feet, Not Fists, Cause More Severe Injuries, Report Says
Researchers at Cardiff University in Wales examined the medical records of nearly 25,000 people treated in a local hospital between 1999 and 2005 (related photos: the new Wales).
The researchers tallied the victims' injuries according to a five-point triage scale based on the urgency of treatment needed.
Reporting in a recent issue of the journal Injury Prevention, lead study author Jonathan Shepherd and colleagues found that while kicks were less common, such assaults caused greater damage than either punches or attacks with weapons.
Sexual practices and preferences in China
Arch Sex Behav. 2006 Dec 23; [Epub ahead of print]
Sexual Practices and Sexual Satisfaction: A Population Based Study of Chinese Urban Adults.
Parish WL, Luo Y, Stolzenberg R, Laumann EO, Farrer G, Pan S.
This study examined sexual satisfaction and its social and behavioral correlates among urbanites aged 20-64 in China, using data from a nationally representative sample of 1,194 women and 1,217 men with a spouse or other long-term sexual partner with whom they had sex during the last year. The results from structural equation models suggest a multiplex set of determinants of sexual satisfaction, including relationship characteristics, sexual knowledge and personal values, physical vitality, and environmental impediments. A large proportion of the effect of these background characteristics was mediated by frequent orgasms, varied sexual practices, and perceived partner affection. In particular, much of the effect of knowledge and beliefs was mediated through variety in sexual practices. While many of the observed patterns were shared among women and men, much of the effect of relationship characteristics was mediated through perceived partner affection for women. Men, in contrast, paid greater attention to his partner's physical attractiveness and to her extramarital sex. A sexual transition is well underway in urban China, even if more rapidly for men than for women. While knowledge and values are arguably more important in this transitional period, many antecedents of sexual well-being drawn from the literature on sexual behavior in developed Western countries are also applicable to urban China.
Link
Sexual Practices and Sexual Satisfaction: A Population Based Study of Chinese Urban Adults.
Parish WL, Luo Y, Stolzenberg R, Laumann EO, Farrer G, Pan S.
This study examined sexual satisfaction and its social and behavioral correlates among urbanites aged 20-64 in China, using data from a nationally representative sample of 1,194 women and 1,217 men with a spouse or other long-term sexual partner with whom they had sex during the last year. The results from structural equation models suggest a multiplex set of determinants of sexual satisfaction, including relationship characteristics, sexual knowledge and personal values, physical vitality, and environmental impediments. A large proportion of the effect of these background characteristics was mediated by frequent orgasms, varied sexual practices, and perceived partner affection. In particular, much of the effect of knowledge and beliefs was mediated through variety in sexual practices. While many of the observed patterns were shared among women and men, much of the effect of relationship characteristics was mediated through perceived partner affection for women. Men, in contrast, paid greater attention to his partner's physical attractiveness and to her extramarital sex. A sexual transition is well underway in urban China, even if more rapidly for men than for women. While knowledge and values are arguably more important in this transitional period, many antecedents of sexual well-being drawn from the literature on sexual behavior in developed Western countries are also applicable to urban China.
Link
December 25, 2006
Handsome surgeons
According to this study, movie-surgeons are handsomer than real surgeons, who are handsomer than physicians. Famous surgeons in movies that come to mind are the Jack character in Lost and the Harrison Ford character in The Fugitive, plus many people in shows like Grey's Anatomy and ER which I haven't really watched. Any other famous surgeons in movies or TV, handsome or otherwise?
Surgeons are taller and better looking than other doctors
Surgeons are taller and better looking than other doctors
Phenotypic differences between male physicians, surgeons and film stars
Surgeons are taller and more handsome than physicians, finds a study in this week's Christmas issue of the BMJ.
Doctors at the University of Barcelona Hospital noticed that the tallest and most handsome male students were more likely to go for surgery, and the shortest (and perhaps not so good looking) ones were more likely to become physicians.
So they decided to test the theory that, on average, surgeons are taller and better looking than physicians.
They selected a random sample of 12 surgeons and 12 physicians from the hospital plus four external controls (well known film stars who played surgeons or physicians). All subjects were matched by age (52 +/- 7 years) and sex (all men), their height was recorded and they were asked to submit a digital picture.
Pictures of all subjects were then randomly organised and shown to an independent group of eight female observers (all in the same age group as the study subjects). Observers used the "good looking score" to classify each participant (ranging from 1, ugly to 7, very good looking).
The results show that, on average, senior male surgeons are significantly taller and better looking than senior male physicians. They also show that film stars who play doctors are significantly better looking than real surgeons and physicians.
There are several potential explanations for these findings, say the authors. For example, surgeons spend a lot of time in operating rooms, which are cleaner, cooler, and have a higher oxygen content than the average medical ward, where physicians spend most of their time. They also often wear clog-type shoes that adds 2-3 cm to their perceived height.
In contrast, physicians have a tendency to hang heavy stethoscopes around their necks, which bows their heads forward and reduces their perceived height.
Further studies are needed to assess if these findings also apply to junior male surgeons and physicians, as well as to senior and junior female staff, they add.
Happy Danes
Why are Danes the world's happiest nation?
Earlier this year, Denmark came top in a world map of happiness (the UK ranked 41st out of 178 nations). And for more than 30 years it has ranked first in European satisfaction surveys. So what makes Danes so content?
Researchers in this week's Christmas issue of the BMJ decided to find out why life satisfaction in Denmark substantially exceeds that in Sweden and Finland, the two countries most similar to Denmark.
Their hypotheses range from the unlikely (hair colour, genes, food and language) to the more plausible, such as family life, health and a prosperous economy.
However, their analysis points to two explanatory factors. Firstly, winning the 1992 European Football Championship put Danes in such a state of euphoria that the country has not been the same since. This may explain the high level of life satisfaction in Denmark after 1992, they write.
Secondly, while Danes are very satisfied, their expectations for the coming year are rather low. In contrast, Italy and Greece, which rank low on life satisfaction, rank high on expectations for the year to come, together with Swedes and Finns.
The causes of the stolid depth of Danish wellbeing are undoubtedly multifactorial, they say. The Danish football triumph of 1992 has had a lasting impact, but the satisfaction of the Danes began well before 1992, albeit at a more moderate level. The key factor that explains this, and that differentiates Danes from Swedes and Finns, seems to be that Danes have consistently low (and realistic) expectations for the year to come.
So the key to happiness may lie in the fact that if you lower your expectations enough you might feel a bit better next Christmas, they conclude.
Earlier this year, Denmark came top in a world map of happiness (the UK ranked 41st out of 178 nations). And for more than 30 years it has ranked first in European satisfaction surveys. So what makes Danes so content?
Researchers in this week's Christmas issue of the BMJ decided to find out why life satisfaction in Denmark substantially exceeds that in Sweden and Finland, the two countries most similar to Denmark.
Their hypotheses range from the unlikely (hair colour, genes, food and language) to the more plausible, such as family life, health and a prosperous economy.
However, their analysis points to two explanatory factors. Firstly, winning the 1992 European Football Championship put Danes in such a state of euphoria that the country has not been the same since. This may explain the high level of life satisfaction in Denmark after 1992, they write.
Secondly, while Danes are very satisfied, their expectations for the coming year are rather low. In contrast, Italy and Greece, which rank low on life satisfaction, rank high on expectations for the year to come, together with Swedes and Finns.
The causes of the stolid depth of Danish wellbeing are undoubtedly multifactorial, they say. The Danish football triumph of 1992 has had a lasting impact, but the satisfaction of the Danes began well before 1992, albeit at a more moderate level. The key factor that explains this, and that differentiates Danes from Swedes and Finns, seems to be that Danes have consistently low (and realistic) expectations for the year to come.
So the key to happiness may lie in the fact that if you lower your expectations enough you might feel a bit better next Christmas, they conclude.
Increase of weight in Greek schoolchildren in 20th century
Med Sci Monit. 2006 Dec 18;13(1):RA8-11 [Epub ahead of print]
The secular trend of body weight of Greek schoolchildren in the 20(th) century.
Papadimitriou A, Douros K, Fretzayas A, Nicolaidou P.
Background: Improvements in socioeconomic conditions in the 20(th) century had a dramatic impact on the growth and development of children, resulting in greater somatic growth and earlier pubertal maturation. Furthermore, in the last part of that century childhood obesity took on epidemic proportions in many countries The aim of the study was to present the secular trend of body weight of Greek schoolchildren in the 20(th) century. Material/Methods: The data were taken from growth studies the authors conducted themselves or were able to find in the Greek literature. All studies were cross-sectional and spanned the years from 1920 to 1995. The studies referred mainly to children living in Athens or other major cities of the country. Results: The data were taken from growth studies the authors conducted themselves or were able to find in the Greek literature. All studies were cross-sectional and spanned the years from 1920 to 1995. The studies referred mainly to children living in Athens or other major cities of the country. Conclusions: Improvement in the socioeconomic conditions in Greece resulted in an increase in body weight in Greek schoolchildren in the 20(th) century. However, this increase tended to stop in adolescent girls.
Link
The secular trend of body weight of Greek schoolchildren in the 20(th) century.
Papadimitriou A, Douros K, Fretzayas A, Nicolaidou P.
Background: Improvements in socioeconomic conditions in the 20(th) century had a dramatic impact on the growth and development of children, resulting in greater somatic growth and earlier pubertal maturation. Furthermore, in the last part of that century childhood obesity took on epidemic proportions in many countries The aim of the study was to present the secular trend of body weight of Greek schoolchildren in the 20(th) century. Material/Methods: The data were taken from growth studies the authors conducted themselves or were able to find in the Greek literature. All studies were cross-sectional and spanned the years from 1920 to 1995. The studies referred mainly to children living in Athens or other major cities of the country. Results: The data were taken from growth studies the authors conducted themselves or were able to find in the Greek literature. All studies were cross-sectional and spanned the years from 1920 to 1995. The studies referred mainly to children living in Athens or other major cities of the country. Conclusions: Improvement in the socioeconomic conditions in Greece resulted in an increase in body weight in Greek schoolchildren in the 20(th) century. However, this increase tended to stop in adolescent girls.
Link
Haplogroups H and U and Alzheimer's
Cell Mol Neurobiol. 2006 Dec 21; [Epub ahead of print]
Do Haplogroups H and U Act to Increase the Penetrance of Alzheimer's Disease?
Fesahat F, Houshmand M, Panahi MS, Gharagozli K, Mirzajani F.
1. Alzheimer's disease (AD) is the most common form of dementia in the elderly in which interplay between genes and the environment is supposed to be involved. Mitochondrial DNA (mtDNA) has the only noncoding regions at the displacement loop (D-loop) region that contains two hypervariable segments (HVS-I and HVS-II) with high polymorphism. mtDNA has already been fully sequenced and many subsequent publications have shown polymorphic sites, haplogroups, and haplotypes. Haplogroups could have important implications to understand the association between mutability of the mitochondrial genome and the disease.2. To assess the relationship between mtDNA haplogroup and AD, we sequenced the mtDNA HVS-I in 30 AD patients and 100 control subjects. We could find that haplogroups H and U are significantly more abundant in AD patients (P = 0.016 for haplogroup H and P = 0.0003 for haplogroup U), Thus, these two haplogroups might act synergistically to increase the penetrance of AD disease.
Link
Do Haplogroups H and U Act to Increase the Penetrance of Alzheimer's Disease?
Fesahat F, Houshmand M, Panahi MS, Gharagozli K, Mirzajani F.
1. Alzheimer's disease (AD) is the most common form of dementia in the elderly in which interplay between genes and the environment is supposed to be involved. Mitochondrial DNA (mtDNA) has the only noncoding regions at the displacement loop (D-loop) region that contains two hypervariable segments (HVS-I and HVS-II) with high polymorphism. mtDNA has already been fully sequenced and many subsequent publications have shown polymorphic sites, haplogroups, and haplotypes. Haplogroups could have important implications to understand the association between mutability of the mitochondrial genome and the disease.2. To assess the relationship between mtDNA haplogroup and AD, we sequenced the mtDNA HVS-I in 30 AD patients and 100 control subjects. We could find that haplogroups H and U are significantly more abundant in AD patients (P = 0.016 for haplogroup H and P = 0.0003 for haplogroup U), Thus, these two haplogroups might act synergistically to increase the penetrance of AD disease.
Link
Y chromosomes of Huichol tribe of Mexico
Leg Med (Tokyo). 2006 Jul;8(4):220-5. Epub 2006 Jun 21.
Y-linked haplotypes in Amerindian chromosomes from Mexican populations: genetic evidence to the dual origin of the Huichol tribe.
Paez-Riberos LA, Munoz-Valle JF, Figuera LE, Nuno-Arana I, Sandoval-Ramirez L, Gonzalez-Martin A, Ibarra B, Rangel-Villalobos H.
We studied six Y-linked short tandem repeats (Y-STRs) to describe the internal diversity of the Amerindian haplogroup Q-M3 in 129 males from eight Mexican populations. The low gene diversity in the Huichol tribe demonstrated the effects of genetic drift, attributable to geographic isolation and founder effect. The presence of two principal paternal lineages supported the historical and anthropometric records, which indicate that Huichols were formed by the fusion of two ancestral Mexican tribes. Moreover, genetic distances and close relationships of haplotypes between Huichols and Tarahumaras were in agreement with their linguistic affiliation. The high genetic diversity of the Purepechas and wide distribution of haplotypes along the constructed network-joining tree suggest that the present genetic composition was influenced by Purepecha dominance in western Mesoamerica. The Y-haplotypes shared between populations suggest that, among the Amerindian tribes studied herein, the paternal genetic pool of Nahuas could have contributed more importantly to the European-admixed population, the Mexican-Mestizos.
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Y-linked haplotypes in Amerindian chromosomes from Mexican populations: genetic evidence to the dual origin of the Huichol tribe.
Paez-Riberos LA, Munoz-Valle JF, Figuera LE, Nuno-Arana I, Sandoval-Ramirez L, Gonzalez-Martin A, Ibarra B, Rangel-Villalobos H.
We studied six Y-linked short tandem repeats (Y-STRs) to describe the internal diversity of the Amerindian haplogroup Q-M3 in 129 males from eight Mexican populations. The low gene diversity in the Huichol tribe demonstrated the effects of genetic drift, attributable to geographic isolation and founder effect. The presence of two principal paternal lineages supported the historical and anthropometric records, which indicate that Huichols were formed by the fusion of two ancestral Mexican tribes. Moreover, genetic distances and close relationships of haplotypes between Huichols and Tarahumaras were in agreement with their linguistic affiliation. The high genetic diversity of the Purepechas and wide distribution of haplotypes along the constructed network-joining tree suggest that the present genetic composition was influenced by Purepecha dominance in western Mesoamerica. The Y-haplotypes shared between populations suggest that, among the Amerindian tribes studied herein, the paternal genetic pool of Nahuas could have contributed more importantly to the European-admixed population, the Mexican-Mestizos.
Link
Y chromosomes of Zhuang Populations
Yi Chuan Xue Bao. 2006 Dec;33(12):1060-72.
Y-chromosome Genotyping and Genetic Structure of Zhuang Populations.
Jing C, Hui L, Zhen-Dong Q, Wen-Hong L, Wei-Xiong L, Rui-Xing Y, Li J, Shang-Ling P.
Zhuang, the largest ethnic minority population in China, is one of the descendant groups of the ancient Bai-Yue. Linguistically, Zhuang languages are grouped into northern and southern dialects. To characterize its genetic structure, 13 East Asian-specific Y-chromosome biallelic markers and 7 Y-chromosome short tandem repeat (STR) markers were used to infer the haplogroups of Zhuang populations. Our results showed that O*, O2a, and O1 are the predominant haplogroups in Zhuang. Frequency distribution and principal component analysis showed that Zhuang was closely related to groups of Bai-Yue origin and therefore was likely to be the descendant of Bai-Yue. The results of principal component analysis and hierarchical clustering analysis contradicted the linguistically derived north-south division. Interestingly, a west-east clinal trend of haplotype frequency changes was observed, which was supported by AMOVA analysis that showed that between-population variance of east-west division was larger than that of north-south division. O* network suggested that the Hongshuihe branch was the center of Zhuang. Our study suggests that there are three major components in Zhuang. The O* and O2a constituted the original component; later, O1 was brought into Zhuang, especially eastern Zhuang; and finally, northern Han population brought O3 into the Zhuang populations.
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Y-chromosome Genotyping and Genetic Structure of Zhuang Populations.
Jing C, Hui L, Zhen-Dong Q, Wen-Hong L, Wei-Xiong L, Rui-Xing Y, Li J, Shang-Ling P.
Zhuang, the largest ethnic minority population in China, is one of the descendant groups of the ancient Bai-Yue. Linguistically, Zhuang languages are grouped into northern and southern dialects. To characterize its genetic structure, 13 East Asian-specific Y-chromosome biallelic markers and 7 Y-chromosome short tandem repeat (STR) markers were used to infer the haplogroups of Zhuang populations. Our results showed that O*, O2a, and O1 are the predominant haplogroups in Zhuang. Frequency distribution and principal component analysis showed that Zhuang was closely related to groups of Bai-Yue origin and therefore was likely to be the descendant of Bai-Yue. The results of principal component analysis and hierarchical clustering analysis contradicted the linguistically derived north-south division. Interestingly, a west-east clinal trend of haplotype frequency changes was observed, which was supported by AMOVA analysis that showed that between-population variance of east-west division was larger than that of north-south division. O* network suggested that the Hongshuihe branch was the center of Zhuang. Our study suggests that there are three major components in Zhuang. The O* and O2a constituted the original component; later, O1 was brought into Zhuang, especially eastern Zhuang; and finally, northern Han population brought O3 into the Zhuang populations.
Link
December 20, 2006
High IQ and vegetarianism
See also Meat eating men's armpits smell bad to women
BMJ. 2006 Dec 15; [Epub ahead of print]
IQ in childhood and vegetarianism in adulthood: 1970 British cohort study.
Gale CR, Deary IJ, Schoon I, Batty GD, Batty GD.
OBJECTIVE: To examine the relation between IQ in childhood and vegetarianism in adulthood. DESIGN: Prospective cohort study in which IQ was assessed by tests of mental ability at age 10 years and vegetarianism by self-report at age 30 years. SETTING: Great Britain. PARTICIPANTS: 8170 men and women aged 30 years participating in the 1970 British cohort study, a national birth cohort. MAIN OUTCOME MEASURES: Self-reported vegetarianism and type of diet followed. RESULTS: 366 (4.5%) participants said they were vegetarian, although 123 (33.6%) admitted eating fish or chicken. Vegetarians were more likely to be female, to be of higher social class (both in childhood and currently), and to have attained higher academic or vocational qualifications, although these socioeconomic advantages were not reflected in their income. Higher IQ at age 10 years was associated with an increased likelihood of being vegetarian at age 30 (odds ratio for one standard deviation increase in childhood IQ score 1.38, 95% confidence interval 1.24 to 1.53). IQ remained a statistically significant predictor of being vegetarian as an adult after adjustment for social class (both in childhood and currently), academic or vocational qualifications, and sex (1.20, 1.06 to 1.36). Exclusion of those who said they were vegetarian but ate fish or chicken had little effect on the strength of this association. CONCLUSION: Higher scores for IQ in childhood are associated with an increased likelihood of being a vegetarian as an adult.
Link
BMJ. 2006 Dec 15; [Epub ahead of print]
IQ in childhood and vegetarianism in adulthood: 1970 British cohort study.
Gale CR, Deary IJ, Schoon I, Batty GD, Batty GD.
OBJECTIVE: To examine the relation between IQ in childhood and vegetarianism in adulthood. DESIGN: Prospective cohort study in which IQ was assessed by tests of mental ability at age 10 years and vegetarianism by self-report at age 30 years. SETTING: Great Britain. PARTICIPANTS: 8170 men and women aged 30 years participating in the 1970 British cohort study, a national birth cohort. MAIN OUTCOME MEASURES: Self-reported vegetarianism and type of diet followed. RESULTS: 366 (4.5%) participants said they were vegetarian, although 123 (33.6%) admitted eating fish or chicken. Vegetarians were more likely to be female, to be of higher social class (both in childhood and currently), and to have attained higher academic or vocational qualifications, although these socioeconomic advantages were not reflected in their income. Higher IQ at age 10 years was associated with an increased likelihood of being vegetarian at age 30 (odds ratio for one standard deviation increase in childhood IQ score 1.38, 95% confidence interval 1.24 to 1.53). IQ remained a statistically significant predictor of being vegetarian as an adult after adjustment for social class (both in childhood and currently), academic or vocational qualifications, and sex (1.20, 1.06 to 1.36). Exclusion of those who said they were vegetarian but ate fish or chicken had little effect on the strength of this association. CONCLUSION: Higher scores for IQ in childhood are associated with an increased likelihood of being a vegetarian as an adult.
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The shape of beauty
J Cosmet Dermatol. 2006 Jun;5(2):190-4
The shape of beauty: determinants of female physical attractiveness.
Fisher ML, Voracek M.
Rarely has one research area gained as much attention as that which is observed for female physical attractiveness. The past decade has resulted in numerous, exciting developments, particularly with respect to three proposed determinants of beauty: waist to hip ratio (WHR), body mass index (BMI), and curvaceousness. The goal of our paper is to provide a highly necessary review of contemporary research on the female attractiveness, including an in-depth examination of these factors. In our review, we first discuss WHR, an index of fat deposition, which is calculated by measuring the circumference of the waist compared to the circumference of the hips. WHR is controlled by the sex hormones, and increases as women age, and hence, may influence perceptions of attractiveness. This factor has been hotly contested, as some researchers have claimed that a WHR of approximately 0.7 is universally most attractive, whereas others have found inconsistent findings, or suggest the importance of other factors, such as BMI. Body mass index (BMI), calculated by dividing the body weight (in kilograms) by height (in meters) squared, serves as a measure of body fat. Although WHR and BMI are correlated, they lead to different conclusions, and the importance of BMI as a measure of female attractiveness is debated in the literature. Similar to WHR research, BMI and its role in attractiveness is not cross-culturally consistent and is affected by the availability of resources within a given environment. It may be the case that both WHR and BMI influence female attractiveness. However, there has been little investigation of this possibility. We have explored this issue in our research, which revealed that both influence attractiveness, but in addition, we noticed that curvaceousness was also a factor. Curvaceousness is the degree of "hourglass" shape as determined, for example, by the size of the bust, relative to the circumference of the hips and waist, and the size of the buttocks. However, curvaceousness does not appear to be temporally stable as a marker of attractiveness, and it is not consistent across modes of presentation. For example, models in male-oriented magazines are more curvaceous than models in female-oriented magazines. In summary, faced with these recent findings, it is difficult to ascertain agreement among the various factors, especially when researchers investigate each determinant in isolation. We conclude that, although researchers have made many important initial steps in examining female attractiveness, there remains much to be discovered.
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The shape of beauty: determinants of female physical attractiveness.
Fisher ML, Voracek M.
Rarely has one research area gained as much attention as that which is observed for female physical attractiveness. The past decade has resulted in numerous, exciting developments, particularly with respect to three proposed determinants of beauty: waist to hip ratio (WHR), body mass index (BMI), and curvaceousness. The goal of our paper is to provide a highly necessary review of contemporary research on the female attractiveness, including an in-depth examination of these factors. In our review, we first discuss WHR, an index of fat deposition, which is calculated by measuring the circumference of the waist compared to the circumference of the hips. WHR is controlled by the sex hormones, and increases as women age, and hence, may influence perceptions of attractiveness. This factor has been hotly contested, as some researchers have claimed that a WHR of approximately 0.7 is universally most attractive, whereas others have found inconsistent findings, or suggest the importance of other factors, such as BMI. Body mass index (BMI), calculated by dividing the body weight (in kilograms) by height (in meters) squared, serves as a measure of body fat. Although WHR and BMI are correlated, they lead to different conclusions, and the importance of BMI as a measure of female attractiveness is debated in the literature. Similar to WHR research, BMI and its role in attractiveness is not cross-culturally consistent and is affected by the availability of resources within a given environment. It may be the case that both WHR and BMI influence female attractiveness. However, there has been little investigation of this possibility. We have explored this issue in our research, which revealed that both influence attractiveness, but in addition, we noticed that curvaceousness was also a factor. Curvaceousness is the degree of "hourglass" shape as determined, for example, by the size of the bust, relative to the circumference of the hips and waist, and the size of the buttocks. However, curvaceousness does not appear to be temporally stable as a marker of attractiveness, and it is not consistent across modes of presentation. For example, models in male-oriented magazines are more curvaceous than models in female-oriented magazines. In summary, faced with these recent findings, it is difficult to ascertain agreement among the various factors, especially when researchers investigate each determinant in isolation. We conclude that, although researchers have made many important initial steps in examining female attractiveness, there remains much to be discovered.
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December 17, 2006
Gene Wars
A reader posted this article in the comments section. It covers quite a lot of material regarding the use of population genetics for political reasons. See also Indigenous Populations don't trust Genographic Project, and Genetic vs. Mythical Origins.
December 16, 2006
mtDNA haplogroups M1 and U6 originated in Eurasia
See also a related National Geographic story regarding this article.
Science 15 December 2006:
Vol. 314. no. 5806, pp. 1767 - 1770
The mtDNA Legacy of the Levantine Early Upper Palaeolithic in Africa
Anna Olivieri et al.
Sequencing of 81 entire human mitochondrial DNAs (mtDNAs) belonging to haplogroups M1 and U6 reveals that these predominantly North African clades arose in southwestern Asia and moved together to Africa about 40,000 to 45,000 years ago. Their arrival temporally overlaps with the event(s) that led to the peopling of Europe by modern humans and was most likely the result of the same change in climate conditions that allowed humans to enter the Levant, opening the way to the colonization of both Europe and North Africa. Thus, the early Upper Palaeolithic population(s) carrying M1 and U6 did not return to Africa along the southern coastal route of the "out of Africa" exit, but from the Mediterranean area; and the North African Dabban and European Aurignacian industries derived from a common Levantine source.
Link
Science 15 December 2006:
Vol. 314. no. 5806, pp. 1767 - 1770
The mtDNA Legacy of the Levantine Early Upper Palaeolithic in Africa
Anna Olivieri et al.
Sequencing of 81 entire human mitochondrial DNAs (mtDNAs) belonging to haplogroups M1 and U6 reveals that these predominantly North African clades arose in southwestern Asia and moved together to Africa about 40,000 to 45,000 years ago. Their arrival temporally overlaps with the event(s) that led to the peopling of Europe by modern humans and was most likely the result of the same change in climate conditions that allowed humans to enter the Levant, opening the way to the colonization of both Europe and North Africa. Thus, the early Upper Palaeolithic population(s) carrying M1 and U6 did not return to Africa along the southern coastal route of the "out of Africa" exit, but from the Mediterranean area; and the North African Dabban and European Aurignacian industries derived from a common Levantine source.
Link
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