Monthly Archives: April 2008

The excellent preservation of ancient Egyptian hair.

Abstract: Developments in microfocus synchrotron techniques have led to new results regarding the long-term alteration of archaeological samples of biological origin. Here, ancient hair samples from two Egyptian mummies have been analyzed using a conjunction of structural and elemental synchrotron methods. In this favored context of conservation, structural analysis revealed a remarkable preservation of keratin supramolecular organization at any observed length scale. Bulk keratin structure has therefore not been modified significantly over 2000 years. However, infrared spectroscopy indicated a partial disorganization of keratins close to the hair surface through polypeptide bond breakage. Elemental mapping showed a strongly heterogeneous distribution which can be related to mummification and cosmetic treatments.

Essentially, other than the surface being a little disturbed by by the mummification chemicals and cosmetics, the hair is in remarkably good shape. I suppose that’s what comes of being in a pitch black environment with a stable temperature.

The pyramid builder’s DNA.

Who were the pyramid builders?
After comparing DNA samples taken from the workers’ bones with samples taken from modern Egyptians, Dr Moamina Kamal of Cairo University Medical School has suggested that Khufu’s pyramid was a truly nationwide project, with workers drawn to Giza from all over Egypt. She has discovered no trace of any alien race; human or intergalactic, as suggested in some of the more imaginative ‘pyramid theories’.

Effectively, it seems, the pyramid served both as a gigantic training project and – deliberately or not – as a source of ‘Egyptianisation’. The workers who left their communities of maybe 50 or 100 people, to live in a town of 15,000 or more strangers, returned to the provinces with new skills, a wider outlook and a renewed sense of national unity that balanced the loss of loyalty to local traditions. The use of shifts of workers spread the burden and brought about a thorough redistribution of pharaoh’s wealth in the form of rations.

Almost every family in Egypt was either directly or indirectly involved in pyramid building. The pyramid labourers were clearly not slaves. They may well have been the unwilling victims of the corvée or compulsory labour system, the system that allowed the pharaoh to compel his people to work for three or four month shifts on state projects. If this is the case, we may imagine that they were selected at random from local registers.

But, in a complete reversal of the story of oppression told by Herodotus, Lehner and Hawass have suggested that the labourers may have been volunteers. Zahi Hawass believes that the symbolism of the pyramid was already strong enough to encourage people to volunteer for the supreme national project. Mark Lehner has gone further, comparing pyramid building to American Amish barn raising, which is done on a volunteer basis. He might equally well have compared it to the staffing of archaeological digs, which tend to be manned by enthusiastic, unpaid volunteers supervised by a few paid professionals.

The Pyramid Builders of Ancient Egypt: A Modern Investigation of Pharaoh’s Workforce by AR David (Boston and Henley, London, 1986)

I’d be a lot happier if I could see the DNA results from the source.

Seventies Nubian mummy hair study.

KEY WORDS Hair analysis . Hair form Mummy hair .
Nubia – Meroitics
ABSTRACT

Hair samples from 76 burials at Semna South (Sudanese Nubia) were examined using a variety of techniques. Electrophoresis and fluorescence microscopy indicated some oxidation of the cuticule and keratin protein had taken place. However, the cuticular structure and the lack of fluorescence
of the cortex indicate that the low humidity and non-alkaline conditions preserved the physicaland chemical properties of the hair well. Pigmentation, even allowing for oxidation of melanin, showed a higher proportion of lighter samples than is currently associated with the Nubian area. Hair form analysis showed medium diameter and scale count; the curling variables were intermediate between European and African samples. There was a high ratio of maximum to minimum curvature (a measure of irregularity), approached only by Melanesian samples. Meroitic and X-group burial types were not statistically significantly different (largely due to sample sizes), but the X-group, especially males, showed more African elements than the Meroitic in the curling variables. Principal components analysis showed the Semna sample to be significantly different from seven populations examined earlier.

Though several studies have been conducted on ancient hair, because of small sample sizes, few have allowed adequate statistical quantification, and none has dealt with Nubian material. Egyptian mummy samples have been examined in the past for color and structure by Pruner-Bey (18771, Virchow (18981,
and reportedly by Minakow (18993. Woodbury and Woodbury(’32) and Trotter (‘431 have examined ancient Peruvian material using metric techniques; they found the ancient hairs to generally fall in the range of modern variation. Brothwell and Spearman(’63) studied North African and other material using a
variety of techniques, including microscopic examination, fluorescence microscopy, and reflectance spectrophotometry; they found the state of preservation of the samples closely related to environmental factors of the burial sites. More recently, Chiarelli et al. (’70/’71) studied ancient Egyptian samples with scanning electron microscopy, finding significant loss of cuticular scale edges. Using microscopic and macroscopic techniques, Titlbachova AM. J. PHYS. ANTHROP. (1978) 49: 277-262. and Titlbach (’77) studied Egyptian mummies in Czechoslovakian collections; they found generally good preservation, with the samples resembling modern European populations with significant African admixture.

This study analyzes hair samples from Semna South in Sudanese Nubia using several biochemical and metric techniques. The samples contain Meroitic( First Century A.D. to Fourth Century A.D.), X-group (Fourth Century to Sixth Century A.D.), and Christian period (Seventh Century to Tenth Century A.D.) material. Strouhal has pointed out (’77) that the physical relationship of Meroitic and Postmeroitic
populations is not clear. It is still not known whether X-group burials represent a migration of an ethnically distinct people or change in situ of the Meroitics. It is more generally accepted that Christian period inhabitants were the descendants of the X-group.

Hence this study adds perspective to the physical anthropology of the area. ‘ Current address: Department of Microbiology and Molecular Genetics, Harvard Medical SchwI, Boston, Massachusetts 021 15.
277 The hair samples were analyzed by quantitative hair form analysis (Hrdy, ’73), electrophoresis of hair keratins (Hrdy and Baden, ‘731, qualitative hair pigmentation analysis (Martin and Saller, ’62), and  fluorescence microscopy (Brothwell and Spearman. ’63). The findings of the quantitative hair form analysis were compared to four populations examined by Hrdy (’73).

MATERIALS AND METHODS
The sample consisted of 56 Meroitic, 15 X group, and 5 Christian individuals from Semna South collected between 1966 and 1968 in the course of the excavations of the Oriental Institute of the University of Chicago directed by L. V. Zabkar (Zabkar, ’73/’74, “78). Specific information on individual burials is located in Zabkar(’78). There was no embalming; mummification resulted from burial conditions alone. Burials  were either of a simple pit grave type, or of more complex types, including separate burialchambers, ramps, and vaults. The hair was either attached to the skull or associated with the remains in the fill. Hair from infants under six months, and samples of insufficient size for measurement were excluded from the analysis. Age and sex determinations and burial type were according to the criteria of Zabkar (’78).
Electrophoretic studies were carried out as outlined in Hrdy and Baden (‘731, with the addition of soaking the samples overnight in 0.05 M EDTA and 0.05 M Tris buffer at pH 9.6 to chelateheavy metals that interfere with chemical extraction of keratin. Fluorescence microscopy was done using the method of
Brothwell and Spearman (‘631, using 0.1% Acridine Orange dye at pH 4.9. Qualitative hair color analysis was performed with a Fischer-Saller hair color standard (Peabody Museum, Cambridge, Massachusetts) (Martin and Saller, ’62).

Quantitative hair form analysis was carried out by the method of Hrdy(‘731, using the principal components analysis variables: diameter (in microns, an average of several determinations); scale count (the number of curicularscale ridges per 0.52 mm); average curvature (the inverse of the radius of curvature); ratio of maximum to minimum curvature (a measure of regularity of hair curling); crimp (number of reverse twists along the hair shaft per unit distance); and ratio of natural to straight length (a measure of functionalhair shortening due to curling). Principal components analysis was performed using scores standardized on the seven population sample (Hrdy, ’73) and the Semna sample.

RESULTS
Electrophoresis of alpha SCM-keratin protein from three samples (identification numbers: Meroitic N224-B, N455; X-group M107) showed similar patterns for all samples. There was a large band at the origin and a large band at the buffer from which represented SCMKB. This aberrant pattern indicates that the fibrous protein had aggregated at the origin, probably from cross linking of the protein chains.

Fluorescence microscopy on modern controls showed a greenish fluorescence throughout the cortex and cuticle, with areas of bright orange associated with fractures in the shaft, as reported by Brothwell and Spearman (’63). These fractures and areas of orange were more pronounced on hairs that had been bleached. Of nine Semna samples, all had a completely orange cuticle, with brighter orange highlighting
the cuticular structure, which was intact on all samples. Debris clinging to the shaft was also bright orange. The cortex on all samples was greenish, except where the shaft was broken, which was orange. Hair which was blond or “bleached” appearing (M048, M061, M205, M228) fluoresced identically to the brown samples (M069, M098, M107, M188, M246). Macroscopically the hair was in generally good condition, with approximately one percent of the shafts damaged. Eight of the 76 samples had debris clinging to the shafts; the remainder were relatively clean. Two of the samples were braided.

Qualitative grading of the samples on the Fischer-Saller scale is shown in table 1. Samples that were graded on the red scale (I-VI) for degree of red pigmentation were also graded on the blond-brown-black scale (A-Y) for degree of black pigmentation. Twenty-six percent (29% of the Meroitic, 13% of the Xgroup) of the total sample had some red pigmentation, and 10.5% (8.9 Meroitic, 13% Xgroup) had “blond” pigmentation (Fischer- Saller category G or less). The crude variables of the quantitative hair form analysis are presented in table 2. The results are also broken down for subpopulations of Meroitic,  X-group, and Christian; male and female; and simple burial type and more complex. Results from Hrdy (’73) for Northwest European, East African, Bougainville (Melanesian), and Japanese populations are presented for comparison. In no variable was the Meroitic significantly different from the X-group, male from female or simple burial type from non-simple. However, the X-group sample showed higher curling variables than the Meroitic, especially in males (the Christian group is too small to make valid comparisons).

The sample as a whole was significantly different from the other populations in average curvature, ratio of maximum to minimum curvature, crimp, and ratio of natural to straight length. Diameter was significantly different from Japanese and Bougainville, and scale count significantly different from the European,
Bougainville, and African populations.

Principal components analysis (Hrdy, ’73) results on the first three components (accounting for 80% of the variance) are shown in table 3 for the total population, with comparative populations from Hrdy (’73). In
component I, which is heavily loaded on general curling variables and scale count, the total sample centroid was significantly different from European and African samples, though it was definitely more European than African.Component 11, loaded on diameter, was not significantly different from the comparison populations. Due to the large amount of irregularity (high ratio of maximum to minimum curvature values), the Semna sample had a higher score on component 111, which was heavily loaded on that variable, than the African and European samples. Only Melanesian samples had a higher score on this
component.

DISCUSSION
 Hair keratin is remarkably stable due to cross-chain disulfide linkages. However, prolonged exposure to harsh conditions will alter the keratin. The Semna samples were in contact with sand for over a thousand years, and hence were at risk for oxidation of the protein molecules. There undoubtedly was some oxidation, as shown by the aggregation of the protein on electrophoresis and the orange fluorescence
of the cuticle by fluorescence microscopy.

However, the cortex did not have this oxidized pattern, unlike samples from Egypt examined by Brothwell and Spearman (‘531, which fluoresced orange throughout. Since hair form is probably determined by physical arrangements of the alpha helical proteins within the cortex (Hrdy and Baden, ’731, the
apparent limitation of oxidation to the cuticle in the Semna sample argues for the maintenance
of hair form in the samples in spite of their age. In line with this is the large variability in hair form (rather than the uniformity that one would expect if a uniform environmental force was acting on the sample),
and the lack of macroscopic cuticular and shaft damage. Also arguing for intact keratin is the large number of samples with intact cuticle, as opposed to the ancient Egyptian sample analyzed using scanning electron microscopy by Chiarelli et al. (’70/’71). In general, low humidity and non-alkaline conditions
are optimal for preservation of keratin; both conditions were met in the Semna samples.

As Brothwell and Spearman(‘63) point out, reddish-brown ancient hair is usually the result of partial oxidation of the melanin pigment. This color was seen in a large proportion of the Semna sample, and also noted by Titlbachova and Titlbach(‘77) on Egyptian material, where it also may have resulted from the mummification process. However, the large number of blond hairs that are not associated with the cuticular damage that bleaching produces, probably points to a significantly lighter-haired population than is now present in the Nubian region. Brothwell and Spearman (’63) noted genuinely blond ancient Egyptian samples using reflectance spectrophotometry. Blondism, especially in young children, is common in many dark haired populations (e.g., Australian, Melanesian), and is still found in some Nubian villages(J. Zabkar, personal communication).Only one sample (M197) showed cuticular damage and irregularities definitely consistent with bleaching, although bleaching could not be ruled out in some of the blond samples.

The average diameter of the Semna sample was close to both the N.W. European and East African samples, which are of medium thickness. Of the variables that best distinguish European and African samples, the total Semna sample was closer to the European on average curvature, crimp, and ratio of length. The ratio of curvature, however, was higher than either, indicating a degree of irregularity approached only by Melanesian samples. Obviously the sample has a greater degree of African admixture than the Egyptian hair sample described by Titlbachova and Tiltbach (‘771, which had three of 14 samples showing “Negroid elements.” Although there is not a consistent statistically significant difference between the X-group and Meroitic samples, it is interesting that the X-group sample, especially the males, had higher curling variables, indicating more of an African element. Although larger sample sizes are needed for statistically significant results, the results here are consistent with the evidence summarized by Strouhal (‘77) for skeletal material, which shows X-group very similar to Meroitic, but having increased negroid elements.

The principal components analysis showed the Semna population in a unique position on the three component space when compared to seven other populations (Hrdy, ’73). The combination of high ratio of curvature with moderate diameter and curling differentiates the sample from the Melanesian, European, African, and Mongoloid groups.

The Semna sample had high coefficients of variation compared to four other populations, especially in scale count, average curvature, and ratio of curvature. This high intra-population variability undoubtedly reflects the heterogeneous nature of the Nubian population during the Meroitic and Post-meroitic periods.

If I read this correctly, the conclusion is that the Nubian samples are showing a mix of European and African hair, with a few natural blondes in their number. This study doesn’t seem to be recent, but as I understand there hasn’t been any real change in the study of hair over the last few decades. This tallies with the Mt DNA study of Nubian mummies that shows them to be about 60% non Sub Saharan African.

I would just like to add that the blond Melanesian gene isn’t found in Africa anywhere, it’s an in situ mutation in the Australoids. The only known blond gene known in Africa and Europe is traceable to Northern Europe, and is only about 10,000 years on, which makes it pretty specific to European ancestry.

There’s a tendency for Afrocentrists to include Melanesians into their calculations. They shouldn’t, Melanesians and Australoids aren’t even closely related to Africans, and are the people on the planet least related to them. Also, no Australoids were ever in Nubia or Egypt.

Percentage genetic distances among major continents based on 120 classical polymorphisms
  Africa Oceania East Asia Europe
Oceania 24.7      
East Asia 20.6 10    
Europe 16.6 13.5 9.7  
America 22.6 14.6 8.9 9.5

As you can see from this Africa shows the most genetic distance from Australoids (Oceania). Chart from a study by Cavalli-Sforza using 120 blood polymorphisms provides information on genetic distances of the various continents. This chart also matches the work of geneticist Niell Risch, who has shown that the people most closely related to the Aborigines are Asians. You’ll note, Europeans are significantly more closely related to Aborigines than Africans. The people most closely related to Africans are… Europeans.

The Minoans, DNA and all.

Starting with the breaking DNA news, and this rather sinks the ‘Black Athena’ theory from Bernal…

DNA sheds light on Minoans

Crete’s fabled Minoan civilization was built by people from Anatolia, according to a new study by Greek and foreign scientists that disputes an earlier theory that said the Minoans’ forefathers had come from Africa.

The new study – a collaboration by experts in Greece, the USA, Canada, Russia and Turkey – drew its conclusions from the DNA analysis of 193 men from Crete and another 171 from former neolithic colonies in central and northern Greece.

The results show that the country’s neolithic population came to Greece by sea from Anatolia – modern-day Iran, Iraq and Syria – and not from Africa as maintained by US scholar Martin Bernal.

The DNA analysis indicates that the arrival of neolithic man in Greece from Anatolia coincided with the social and cultural upsurge that led to the birth of the Minoan civilization, Constantinos Triantafyllidis of Thessaloniki’s Aristotle University told Kathimerini.

“Until now we only had the archaeological evidence – now we have genetic data too and we can date the DNA,” he said.

Archeological dates for the colonisation of Crete are about 7,000 BC.

In more detail

The most frequent haplogroups among the current population on Crete were: R1b3-M269 (17%), G2-P15 (11%), J2a1-DYS413 (9.0%), and J2a1h-M319 (9.0%). They identified J2a parent haplogroup J2a-M410 (Crete: 25.9%) with the first ancient residents of Crete during the Neolithic (8500 BCE – 4300 BCE) suggesting Crete was founded by a Neolithic population expansion from ancient Turkey/Anatolia. Specifically, the researchers connected the source population of ancient Crete to well known Neolithic sites of ancient Anatolia: Asıklı Höyük, Çatalhöyük, Hacılar, Mersin/Yumuktepe, and Tarsus. Haplogroup J2b-M12 (Crete: 3.1%; Greece: 5.9%) was associated with Neolithic Greece. Haplogroups J2a1h-M319 (8.8%) and J2a1b1-M92 (2.6%) were associated with the Minoan culture linked to a late Neolithic/ Early Bronze Age migration to Crete ca. 3100 BCE from North-Western/Western Anatolia and Syro-Palestine (ancient Canaan, Levant, and pre-Akkadian Anatolia); Aegean prehistorians link the date 3100 BCE to the origins of the Minoan culture on Crete. Haplogroup E3b1a2-V13 (Crete: 6.7%; Greece: 28%) was suggested to reflect a migration to Crete from the mainland Greece Mycenaean population during the late Bronze Age (1600 BCE – 1100 BCE). Haplogroup J1 was also reported to be found in both Crete and Greece (Crete: 8.3%; Greece: 5.2%), as well as haplogroups E3b3, I1, I2, I2a, I21b, K2, L, and R1a1. No ancient DNA was included in this study of YDNA from the Mediterranean region.

So far the only information I can find on Cretan mitochondrial DNA places them overwhelmingly with the European and Near Eastern populations.

History

The first settlers introduced cattle, sheep, goats, pigs, and dogs, as well as domesticated cereals (wheat and barley) and legumes. The first settlers seem to be aceramic, the first ceramics appeared about a thousand years later. Quite possibly the technology was imported, as it appears in a fairly sophisticated form.

The plain chalice is an example of Pyrgos ware, one of the earliest forms of Cretan pottery. Minoan sites are commonly dated by the style of their pottery.

Minoan ceramics became increasingly ornate. After the Thera explosion and tsunami, marine creatures were frequently used to decorate the pottery.

 

 

The Minoans traded extensively with just about everyone in the Mediterranean, and Minoan pottery is often found in Egypt, Cyprus, the Cylades, and Mycenae. 

The Minoan palaces

The palace of Knossos, exterior.

And interior, other images here.

The inside of the palaces also had a flushing toilet and a primitive sort of shower. They were very advanced for the time. The same kind of indoor plumbing was found in Santorini, a Minoan colony

The first Palace was built around 2000 BC and destroyed 300 years later.

On the same site a new Palace was built, more elaborate than the previous, only to be severely damaged from an earthquake one hundred years latter.

During this period we see the development of a series of satellite buildings like the “Little Palace”, the “Royal Villa” and the “South House”. Knossos has now developed into a large city whose population – judged by the adjacent cemeteries – must have not been less than 100 000 inhabitants.

The Minoan civilisation was dealt a serious blow by the explosion of Santorini in 1645 BC. A major Tsunami about 15m high destroyed their fleet and coastal towns, and left them starving and vulnerable to invasion.

The Minoan society itself seemed to matriarchal and not particularly interested in warfare, although they did possess swords and other weapons. Mostly, the worship was of goddesses, carried out by priestesses. There was also the famous bull leaping ritual, depicted in it’s art repeatedly.

The Minoans developed their own writing system, known as linear A (as yet only partially deciphered) and Linear B. The Phaistos disc below is of an unknown script similar to Anatolian Heiroglyphs and Linear A, as yet undeciphered.

 

Red hair, skin pigmentation and the MC1R variants.

Just a collection of ginger-related articles .

Melanocortin 1 Receptor Variants in an Irish Population

Received 11 November 1997; Revised 25 February 1998; Accepted 13 March 1998.

The identification of an association between variants in the human melanocortin 1 receptor (MC1R) gene and red hair and fair skin, as well as the relation between variants of this gene and coat color in animals, suggests that the MC1R is an integral control point in the normal pigmentation phenotype. In order to further define the contribution of MC1R variants to pigmentation in a normal population, we have looked for alterations in this gene in series of individuals from a general Irish population, in whom there is a preponderance of individuals with fair skin type. Seventy-five per cent contained a variant in the MC1R gene, with 30% containing two variants. The Arg151Cys, Arg160Trp, and Asp294His variants were significantly associated with red hair (p = 0.0015, p < 0.001, and p < 0.005, respectively). Importantly, no individuals harboring two of these three variants did not have red hair, although some red-haired individuals only showed one alteration. The same three variants were also over-represented in individuals with light skin type as assessed using a modified Fitzpatrick scale. Despite these associations many subjects with dark hair/darker skin type harbored MC1R variants, but there was no evidence of any particular association of variants with the darker phenotype. The Asp294His variant was similarly associated with red hair in a Dutch population, but was infrequent in red-headed subjects from Sweden. The Asp294His variant was also significantly associated with nonmelanoma skin cancer in a U.K. population. The results show that the Arg151Cys, Arg160Trp, and Asp294His variants are of key significance in determining the pigmentary phenotype and response to ultraviolet radiation, and suggest that in many cases the red-haired component and in some cases fair skin type are inherited as a Mendelian recessive.

 

Effect of Val92Met and Arg163Gln variants of the MC1R gene on freckles and solar lentigines in Japanese.

Short Communication

Pigment Cell Research. 20(2):140-143, April 2007.
Motokawa, Tomonori 1,*; Kato, Tomomi 1; Hashimoto, Yuki 2; Katagiri, Takayuki 1

Abstract:
Summary: Melanocortin-1 receptor (MC1R) is a highly polymorphic gene. The variety of the variants is dependent on the ethnic background of the individual. In Caucasians, specific variants, such as Arg151Cys, Arg160Trp, and Asp294His, are strongly associated with red hair, skin cancer and pigmented lesions. In Asians, there is no report so far indicating an association such as that observed in Caucasians. Here, we performed an association study on melanogenic phenotypes in 245 Japanese individuals. We focused on freckles and solar lentigines as melanogenic phenotypes. The 92Met allele and the 163Arg allele were positively associated with freckles and severe solar lentigines; the 163Gln allele showed a negative association. Those subjects who were homozygous for both the 92Met and 163Arg alleles had a highly elevated risk of developing freckles (OR: 7.92; 95% CI: 1.52-39.6) and severe solar lentigines (OR: 4.08; 95% CI: 1.34-13.1). Our study is the first report to show a clear association of MC1R variants on melanogenic phenotypes in Asians and also indicates the importance of Arg163Gln. In vitro studies by other groups demonstrated that Val92Met impaired MC1R function but Arg163Gln did not. Based on these in vitro studies, we believe that the result we observed for Val92Met could be attributed to impaired MC1R function, while, for Arg163Gln, other factors, e.g. effect of other loci, need to be considered.

Copyright (C) 2007 Blackwell Publishing Ltd.

 

The melanocortin-1-receptor gene is the major freckle gene

Maarten Bastiaens, Jeanette ter Huurne, Nelleke Gruis, Wilma Bergman, Rudi Westendorp1, Bert-Jan Vermeer and Jan-Nico Bouwes Bavinck+

Department of Dermatology and 1Department of Clinical Epidemiology, Leiden University Medical Centre, PO Box 9600, 2300 RC Leiden, The Netherlands

Received April 17, 2001; Revised and Accepted June 12, 2001.

Ephelides and solar lentigines are different types of pigmented skin lesions. Ephelides appear early in childhood and are associated with fair skin type and red hair. Solar lentigines appear with increasing age and are a sign of photodamage. Both lesions are strong risk indicators for melanoma and non-melanoma skin cancer. Melanocortin-1-receptor (MC1R) gene variants are also associated with fair skin, red hair and melanoma and non-melanoma skin cancer. The purpose of this study was to investigate the relationship between MC1R gene variants, ephelides and solar lentigines. In a large case-control study, patients with melanoma and non-melanoma skin cancer and subjects without a history of skin cancer were studied. In all participants, the presence of ephelides in childhood and solar lentigines by physical examination was assessed according to strict definitions. The entire coding sequence of the MC1R gene was analyzed by single-strand conformation polymorphism analysis followed by sequence analyses. Carriers of one or two MC1R gene variants had a 3- and 11-fold increased risk of developing ephelides, respectively (both P < 0.0001), whereas the risk of developing severe solar lentigines was increased 1.5- and 2-fold (P = 0.035 and P < 0.0001), respectively. These associations were independent of skin type and hair color, and were comparable in patients with and without a history of skin cancer. The population attributable risk for ephelides to MC1R gene variants was 60%, i.e. 60% of the ephelides in the population was caused by MC1R gene variants. A dosage effect was found between the degree of ephelides and the number of MC1R gene variants. As nearly all individuals with ephelides were carriers of at least one MC1R gene variant, our data suggest that MC1R gene variants are necessary to develop ephelides. The results of the study also suggest that MC1R gene variants play a role, although less important, in the development of solar lentigines.

 

Human melanocortin 1 receptor variants, receptor function and melanocyte response to UV radiation

M. Cathy Scott1, Kazumasa Wakamatsu2, Shosuke Ito2, Ana Luisa Kadekaro1, Nobuhiko Kobayashi3, Joanna Groden4, Renny Kavanagh1, Takako Takakuwa5, Victoria Virador6, Vincent J. Hearing6 and Zalfa A. Abdel-Malek1,*

Accepted 6 March 2002

 
Cutaneous pigmentation is determined by the amounts of eumelanin and pheomelanin synthesized by epidermal melanocytes and is known to protect against sun-induced DNA damage. The synthesis of eumelanin is stimulated by the binding of -melanotropin (-melanocyte-stimulating hormone) to the functional melanocortin 1 receptor (MC1R) expressed on melanocytes. The human MC1R gene is highly polymorphic and certain allelic variants of the gene are associated with red hair phenotype, melanoma and non-melanoma skin cancer. The importance of the MC1R gene in determining skin cancer risk led us to examine the impact of specific polymorphisms in this gene on the responses of human melanocytes to -melanotropin and UV radiation. We compared the ability of human melanocyte cultures, each derived from a single donor, to respond to -melanotropin with dose-dependent stimulation of cAMP formation, tyrosinase activity and proliferation. In each of those cultures the MC1R gene was sequenced, and the eumelanin and pheomelanin contents were determined. Human melanocytes homozygous for Arg160Trp, heterozygous for Arg160Trp and Asp294His, or for Arg151Cys and Asp294His substitutions, but not melanocytes homozygous for Val92Met substitution, in the MC1R demonstrated a significantly reduced response to -melanotropin. Additionally, melanocytes with a non-functional MC1R demonstrated a pronounced increase in their sensitivity to the cytotoxic effect of UV radiation compared with melanocytes expressing functional MC1R. We conclude that loss-of-function mutations in the MC1R gene sensitize human melanocytes to the DNA damaging effects of UV radiation, which may increase skin cancer risk.

 

Evidence for Variable Selective Pressures at MC1R
References AbstractIt is widely assumed that genes that influence variation in skin and hair pigmentation are under selection. To date, the melanocortin 1 receptor (MC1R) is the only gene identified that explains substantial phenotypic variance in human pigmentation. Here we investigate MC1R polymorphism in several populations, for evidence of selection. We conclude that MC1R is under strong functional constraint in Africa, where any diversion from eumelanin production (black pigmentation) appears to be evolutionarily deleterious. Although many of the MC1R amino acid variants observed in non-African populations do affect MC1R function and contribute to high levels of MC1R diversity in Europeans, we found no evidence, in either the magnitude or the patterns of diversity, for its enhancement by selection; rather, our analyses show that levels of MC1R polymorphism simply reflect neutral expectations under relaxation of strong functional constraint outside Africa.

High polymorphism at the MC1R gene makes a major contribution to phenotypic diversity in Eurasian populations

Melanocortin-1 receptor (MC1R), the receptor for alpha-melanocyte stimulating hormone, is polymorphic and plays an important role in producing two types of melanin, pheomelanin (red) and eumelanin (black), which are present in human skin and hair. In this study we examined the distribution of MC1R gene polymorphisms in several Eurasian populations. A total of 2591 subjects from 49 populations were included in the present investigation. The subjects were not selected for skin and hair colour and were collected randomly. 5 variants of the MC1R gene (Val60Leu, Val92Met, Arg151Cys, Arg160Trp and Arg163Gln) were tested using ARMS-PCR. Arg151Cys and Arg160Trp alleles, which are common in individuals with red hair and fair skin, were found at highest frequencies in British (AF=0.128 and 0.069, respectively) and Orkadian populations (AF=0.106 and 0.099, respectively), with a decreasing gradient in the populations of European Russia to Central Asia. Previously reported to be common in European populations with light fair skin and light brown hair, allele Val60Leu was identified with high frequency in some populations of the Middle East, Europe and Caucasus. Central Asian populations showed middle range frequencies. The Val92Met variant was found to have an allele frequency from 0.194 to 0.01 in the middle meridian of Eurasia, with a maximum in Central and South East Asian populations. Our data suggest an increasing gradient of Arg163Gln frequency from Europe (0.039) to South East Asia (0.66). As anticipated, our data showed low frequencies of all investigated variants in the populations of South India with dark skin and dark hair. These results indicate that polymorphisms of the MC1R contribute to determining skin and hair colour is one of the significant factor in the phenotypic diversity found in different Eurasian populations and are consistent with the widely held assumption that genes influencing phenotypic variation in human skin and hair pigmentation are probably subject to selection associated with latitude and sunlight.

Are personality traits inherited?

Heritability of cooperative behavior in the trust game

David Cesarini*, Christopher T. Dawes, James H. Fowler,, Magnus Johannesson, Paul Lichtenstein, and Björn Wallace

*Department of Economics, Massachusetts Institute of Technology, 50 Memorial Drive, Cambridge, MA 02142; Political Science Department, University of California at San Diego, 9500 Gilman Drive 0521, La Jolla, CA 92093-0521; Department of Economics, Stockholm School of Economics, Box 6501, SE-113 83 Stockholm, Sweden; and Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Box 281, SE-171 77 Stockholm, Sweden

Edited by Elinor Ostrom, Indiana University, Bloomington, IN, and approved January 15, 2008 (received for review October 23, 2007)

Abstract

Although laboratory experiments document cooperative behavior in humans, little is known about the extent to which individual differences in cooperativeness result from genetic and environmental variation. In this article, we report the results of two independently conceived and executed studies of monozygotic and dizygotic twins, one in Sweden and one in the United States. The results from these studies suggest that humans are endowed with genetic variation that influences the decision to invest, and to reciprocate investment, in the classic trust game. Based on these findings, we urge social scientists to take seriously the idea that differences in peer and parental socialization are not the only forces that influence variation in cooperative behavior.

I wouldn’t hold my breath waiting for social scientists to believe that. It always mystifies me that people seem perfectly happy to admit character traits are inherited in dogs, but not in humans.

I wonder if an increase in co-operative behaviour could be linked to lower criminality?

Cro Magnon clothing.


Woven cloth dates back 27,000 years

By BBC News Online science editor Dr David Whitehouse

Woven clothing was being produced on looms 27,000 years ago, far earlier than had been thought, scientists say.

It had been thought that the first farmers developed weaving 5,000 to 10,000 years ago.

But Professor Olga Soffer, of the University of Illinois, is about to publish details in the journal Current Anthropology of 90 fragments of clay that have impressions from woven fibres.

Professor Soffer revealed some her findings recently when she said that a 25,000-year-old figurine was wearing a woven hat.

If confirmed, her work could change our understanding of distant ancestors, the so-called Ice Age hunters of the Upper Palaeolithic Stone Age.

Accidental imprint

The evidence was obtained from a number of sites in the Czech Republic.

They were the sporadic homes of the Gravettian people who roamed between Southern Russia and Spain between 22,000 and 29,000 years ago scratching out a living on a semi-frozen landscape.
Close-up, the impression left by the fibres is clearly visible


 
Some of the fibre impressions may have been made accidentally, such as by sitting on a fresh clay floor or when wet clay was carried in woven bags.

“Other impressions may have been caused by deliberate action, such as lining a basket with clay to make it watertight,” said Professor Soffer.

A detailed examination of the impressions reveals a large variety of weaving techniques. There are open and closed twines, plain weave and nets. Professor Soffer told BBC News Online that twining can be done by hand but plain weave needed a loom.

It may be that many stone artifacts found in settlements may not be objects of art as had been supposed but parts of an ancient loom, which should now be considered as the first machine to be made after the wheel and aids such as the axe, club, and flint knife.

Women’s work

This research could force a re-evaluation of our view of ancient man, who lived tens of thousands of years ago, before the last Ice Age had ended and before the invention of agriculture.

The traditional view is of the male Ice Age hunters working in groups to kill large prey such as mammoths. But this may be a distorted and incomplete view of their lives.

This imprint in clay may have been left by a woven basket
 
All that scientists have from these ancient times are mostly solid remains such as stone, ivory and bone. Now they have evidence of textiles.

The discovery that they developed weaving as early as 27,000 years ago means that we must consider the role that women and children may have played more carefully.

The possibility that they made nets has fascinating implications according to Professor Soffer. It may be that nets were used by women and children to catch small prey such as hares and foxes.

By catching food this way, women and children could have made all the difference to their communities’ food budgets, allowing a surplus to be generated that permitted society to grow.

Further revelations are to be expected in this area of research. There are recent reports that fragments of burnt textiles have been found adhering to pieces of flint.

 

Bone needles such as these have been found dating back to over 25,000 years old. As one specialist in this field, Olga Soffer, pointed out, they are in no way strong enough to punch their way through hide or leather, but they will go through cloth. The standard explanation to this before was that the hole must have been made by a stone tool and the needle only used to guide the thread. However, the existence of loomed cloth would now make it more likely that they were used in the conventional way. At least one buried body was covered with tiny beads, suggesting they were sewn onto fabric that disintegrated, leaving only the beads, as beads were often found sewn onto hide clothing in graves, sometimes in their thousands. The most likely source for the plant fiber is nettle, that was use into the medieval times in Europe to make clothing.

As you can see from this collection of paleolithic Venus figurines from Kostenki in Russia, some form of woven band around the neck and waist seemed to be common. The rear view of the first lady clearly shows a hat with hair beneath.The partial figure in limestone at the end seems to be wearing a pair of woven handcuffs. These clothes wouldn’t have had any functional value, they were probably more social signals.

This is an illustration of how the the Venus of Willendorf’s hat might of looked. It’s a crop from this site . There’s a common misconception that these people were wandering around in crude furs using clubs, but the evidence shows they were more like they were like the plains Indians in America, but slightly more advanced in cloth technology.

 

For example, string skirts, as can be seen very clearly under the huge buttocks of this Venus (Lespugue), have been worn until relatively recently in Europe. This picture is a replica of one dated 6,000 BC. The woven top section could have been made on a simple tablet loom, like the one shown next to it. They were worn until the bronze age for ceremonial gymnastics in Denmark, as seen in the burial of Egtved girl.

 

Up until recently in a few places in Eastern Europe, girls were expected to start wearing string skirts at puberty, and they weren’t allowed to wear them before. So it’s probably more a social or ritual signal of sexual maturity and fertility in these stone age art pieces.