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Post by sundiata on Jun 22, 2010 11:47:50 GMT -5
From a mtDNA point of view, the most informative of these genetic markers is the North African clade U6. On the basis of complete mtDNA sequences, it has been proposed that U6 lineages, mainly found in North Africa, are the signatures of a return to Africa around *****39,000–52,000 ya....This stresses the importance of its detailed study in order to trace one of the earliest Caucasian arrivals to Africa. Hacks like these annoy me to no end. I seriously had no clue that "Caucasians" even existed 52,000 ybp (a mere 8,000 years after humans left Africa).
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Post by djoser-xyyman on Jun 25, 2010 9:55:40 GMT -5
OOA?? Attachments:
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Post by djoser-xyyman on Jul 1, 2010 7:40:46 GMT -5
@ Zarahan. There are many links from the site. Note some studies put humans leaving about 40kya ======== www.sciencedaily.com/releases/2007/01/070112104129.htm'Out Of Africa' Theory Boost: Skull Dating Suggests Modern Humans Evolved In Africa Reliably dated fossils are critical to understanding the course of human evolution. A human skull discovered over fifty years ago near the town of Hofmeyr, in the Eastern Cape Province of South Africa, is one such fossil. A study by an international team of scientists led by Frederick Grine of the Departments of Anthropology and Anatomical Sciences at Stony Brook University in New York published in Science magazine has dated the skull to 36,000 years ago. This skull provides critical corroboration of genetic evidence indicating that modern humans originated in sub-Saharan Africa and migrated about this time to colonize the Old World. (Science January 12, 2007) The Hofmeyr Skull. Scientists have now dated the skull as being 36,000 years old. The great similarity of this skull to skulls of the same age from Eurasian finds confirms the "Out of Africa"-hypothesis. Modern humans broke out of their place of origin around 40,000 years ago - from Africa south of the Sahara - and populated the world. "The Hofmeyr skull gives us the first insights into the morphology of such a sub-Saharan African population, which means the most recent common ancestor of all of us - wherever we come from," said Grine. Although the skull was found over half a century ago, its significance became apparent only recently. A new approach to dating developed by Grine team member Richard Bailey and his colleagues at Oxford University allowed them to determined its age at just over 36,000 years ago by measuring the amount of radiation that had been absorbed by sand grains that filled the inside of the skull’s braincase. At this age, the skull fills a significant void in the human fossil record of sub-Saharan Africa from the period between about 70,000 and 15,000 years ago. During this critical period, the archaeological tradition known as the Later Stone Age, with its sophisticated stone and bone tools and artwork appears in sub-Saharan Africa, and anatomically modern people appear for the first time in Europe and western Asia with the equally complex Upper Paleolithic archeological tradition. In order to establish the affinities of the Hofmeyr fossil, team member Katerina Harvati of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, used 3-dimensional measurements of the skull known to differentiate recent human populations according to their geographic distributions and genetic relationships. She compared the Hofmeyr skull with contemporaneous Upper Paleolithic skulls from Europe and with the skulls of living humans from Eurasia and sub-Saharan Africa, including the Khoe-San (Bushmen). Because the Khoe-San are represented in the recent archeological record of South Africa, they were expected to have close resemblances to the South African fossil. Instead, the Hofmeyr skull is quite distinct from recent sub-Saharan Africans, including the Khoe-San, and has a very close affinity with the European Upper Paleolithic specimens.The field of paleoanthropology is known for its hotly contested debates, and one that has raged for years concerns the evolutionary origin of modern people. A number of genetic studies (especially those on the mitochondrial DNA) of living people indicate that modern humans evolved in sub-Saharan Africa and then left between 65,000 and 25,000 years ago to colonize the Old World. However, other genetic studies (generally on nuclear DNA) argue against this African origin and exodus model. Instead, they suggest that archaic non-African groups, such as the Neandertals, made significant contributions to the genomes of modern humans in Eurasia. Until now, the lack of human fossils of appropriate antiquity from sub-Saharan Africa has meant that these competing genetic models of human evolution could not be tested by paleontological evidence. The skull from Hofmeyr has changed that. The surprising similarity between a fossil skull from the southernmost tip of Africa and similarly ancient skulls from Europe is in agreement with the genetics-based "Out of Africa" theory, which predicts that humans like those that inhabited Eurasia in the Upper Paleolithic should be found in sub-Saharan Africa around 36,000 years ago. The skull from South Africa provides the first fossil evidence in support of this prediction. Reference: F.E. Grine, R.M. Bailey, K. Harvati, R.P. Nathan, A.G. Morris, G.M. Henderson, I. Ribot, A.W.G. Pike. Late Pleistocene Human Skull from Hofmeyr, South Africa and Modern Human Origins. Science, 12. January 2007
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Post by djoser-xyyman on Jul 1, 2010 8:11:03 GMT -5
www.research-horizons.rsd.cam.ac.uk/researchnews/new-evidence-for-the-origin-of-modern-man.aspxNew evidence for the origin of modern man An exhaustive study of over 60,000 skulls has provided compelling evidence that modern humans originated from a single point of origin. The origin of modern humans has always been a hotly debated issue: did Homo sapiens arise in Africa and migrate to other parts of the world to replace other hominid species, or did earlier hominids such as Homo erectus leave Africa at an earlier time, later evolving into Homo sapiens in their new locations? The first theory, for a single point of origin, has been called the ‘Out of Africa’ model and it is this argument that is supported by new evidence recently published in Nature magazine. Dr Andrea Manica from the University’s Department of Zoology and lead researcher on the project explains how the team studied diversity in populations both from a genetic perspective and by taking measurements of skulls kept in academic collections: ‘We have combined our genetic data with new measurements of a large sample of skulls to show definitively that modern humans originated from a single area in sub-Saharan Africa.’ Their findings showed that the further away populations are from Africa, the more the diversity has been depleted by ‘bottlenecks’ – whereby only a few individuals leave an existing population to start a new population – phenomena that characterised the rapid migration out of the African cradle. As Dr Manica says: ‘The major strength of our data is that it uses two independent datasets and yet both yield virtually identical results: that anatomically modern humans came out of Africa relatively recently, around 55,000 years ago, and eventually replaced older hominid species across the world.’ For more information, please contact Dr Andrea Manica (am315@cam.ac.uk). This research was published in Nature (2007) 448, 346–348.
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Post by zarahan on Jul 2, 2010 1:03:45 GMT -5
@ Zarahan. There are many links from the site. Note some studies put humans leaving about 40kya ======== www.sciencedaily.com/releases/2007/01/070112104129.htm'Out Of Africa' Theory Boost: Skull Dating Suggests Modern Humans Evolved In Africa Reliably dated fossils are critical to understanding the course of human evolution. A human skull discovered over fifty years ago near the town of Hofmeyr, in the Eastern Cape Province of South Africa, is one such fossil. A study by an international team of scientists led by Frederick Grine of the Departments of Anthropology and Anatomical Sciences at Stony Brook University in New York published in Science magazine has dated the skull to 36,000 years ago. This skull provides critical corroboration of genetic evidence indicating that modern humans originated in sub-Saharan Africa and migrated about this time to colonize the Old World. (Science January 12, 2007) The Hofmeyr Skull. Scientists have now dated the skull as being 36,000 years old. The great similarity of this skull to skulls of the same age from Eurasian finds confirms the "Out of Africa"-hypothesis. Modern humans broke out of their place of origin around 40,000 years ago - from Africa south of the Sahara - and populated the world. "The Hofmeyr skull gives us the first insights into the morphology of such a sub-Saharan African population, which means the most recent common ancestor of all of us - wherever we come from," said Grine. Although the skull was found over half a century ago, its significance became apparent only recently. A new approach to dating developed by Grine team member Richard Bailey and his colleagues at Oxford University allowed them to determined its age at just over 36,000 years ago by measuring the amount of radiation that had been absorbed by sand grains that filled the inside of the skull’s braincase. At this age, the skull fills a significant void in the human fossil record of sub-Saharan Africa from the period between about 70,000 and 15,000 years ago. During this critical period, the archaeological tradition known as the Later Stone Age, with its sophisticated stone and bone tools and artwork appears in sub-Saharan Africa, and anatomically modern people appear for the first time in Europe and western Asia with the equally complex Upper Paleolithic archeological tradition. In order to establish the affinities of the Hofmeyr fossil, team member Katerina Harvati of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, used 3-dimensional measurements of the skull known to differentiate recent human populations according to their geographic distributions and genetic relationships. She compared the Hofmeyr skull with contemporaneous Upper Paleolithic skulls from Europe and with the skulls of living humans from Eurasia and sub-Saharan Africa, including the Khoe-San (Bushmen). Because the Khoe-San are represented in the recent archeological record of South Africa, they were expected to have close resemblances to the South African fossil. Instead, the Hofmeyr skull is quite distinct from recent sub-Saharan Africans, including the Khoe-San, and has a very close affinity with the European Upper Paleolithic specimens.The field of paleoanthropology is known for its hotly contested debates, and one that has raged for years concerns the evolutionary origin of modern people. A number of genetic studies (especially those on the mitochondrial DNA) of living people indicate that modern humans evolved in sub-Saharan Africa and then left between 65,000 and 25,000 years ago to colonize the Old World. However, other genetic studies (generally on nuclear DNA) argue against this African origin and exodus model. Instead, they suggest that archaic non-African groups, such as the Neandertals, made significant contributions to the genomes of modern humans in Eurasia. Until now, the lack of human fossils of appropriate antiquity from sub-Saharan Africa has meant that these competing genetic models of human evolution could not be tested by paleontological evidence. The skull from Hofmeyr has changed that. The surprising similarity between a fossil skull from the southernmost tip of Africa and similarly ancient skulls from Europe is in agreement with the genetics-based "Out of Africa" theory, which predicts that humans like those that inhabited Eurasia in the Upper Paleolithic should be found in sub-Saharan Africa around 36,000 years ago. The skull from South Africa provides the first fossil evidence in support of this prediction. Reference: F.E. Grine, R.M. Bailey, K. Harvati, R.P. Nathan, A.G. Morris, G.M. Henderson, I. Ribot, A.W.G. Pike. Late Pleistocene Human Skull from Hofmeyr, South Africa and Modern Human Origins. Science, 12. January 2007 Thanks for the info. Good links. I wonder then about the so called appearance of "Eurasian" U6 some 52,000 years ago. Gonzalez puts the range at 66kya. But other studies show humans did not leave Africa until about 50kya, or the article gives a huge range -65,000 and 25,000 years ago. But whatever estimate is used, how could the 'Caucasoid' mutants "return" or "backflow" to Africa when modern humans had not even left yet? So we have that huge date discrepancy. I see various scholars are trying to cover by using massive time ranges, but it still won't work. In any event, it seems that all these attempts are stymied by the fact that any returnees or "backflowees" would be people ALREADY looking like black Africans, not Europeans or Middle Easterners. So hopes of very ancient "incoming Caucasoids" via backflow still won;t work either. The "incoming" would look like tropical Africans. The "outgoing" into Europe during the Neolithic would ALSO look like tropical Africans according to Brace 2005.
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Post by zarahan on Jul 2, 2010 1:42:10 GMT -5
This is one of the few studies that infer that MtDNA - N is African in Origin. Wasn't the neolithic farmers(female) N?? ===== Whole-mtDNA genome sequence analysis of ancient African lineages. Gonder MK, Mortensen HM, Reed FA, de Sousa A, Tishkoff SA. Department of Biology, University of Maryland, MD, USA. Abstract Studies of human mitochondrial (mt) DNA genomes demonstrate that the root of the human phylogenetic tree occurs in Africa. Although 2 mtDNA lineages with an African origin (haplogroups M and N) were the progenitors of all non-African haplogroups, macrohaplogroup L (including haplogroups L0-L6) is limited to sub-Saharan Africa. Several L haplogroup lineages occur most frequently in eastern Africa (e.g., L0a, L0f, L5, and L3g), but some are specific to certain ethnic groups, such as haplogroup lineages L0d and L0k that previously have been found nearly exclusively among southern African "click" speakers. Few studies have included multiple mtDNA genome samples belonging to haplogroups that occur in eastern and southern Africa but are rare or absent elsewhere. This lack of sampling in eastern Africa makes it difficult to infer relationships among mtDNA haplogroups or to examine events that occurred early in human history. We sequenced 62 complete mtDNA genomes of ethnically diverse Tanzanians, southern African Khoisan speakers, and Bakola Pygmies and compared them with a global pool of 226 mtDNA genomes. From these, we infer phylogenetic relationships amongst mtDNA haplogroups and estimate the time to most recent common ancestor (TMRCA) for haplogroup lineages. These data suggest that Tanzanians have high genetic diversity and possess ancient mtDNA haplogroups, some of which are either rare (L0d and L5) or absent (L0f) in other regions of Africa. We propose that a large and diverse human population has persisted in eastern Africa and that eastern Africa may have been an ancient source of dispersion of modern humans both within and outside of Africa. Nice find. What this does is establish M and N as having African origin. I think there may be additional support from Atkinson below who indicates a major expansion of L3 WITHIN Africa prior to any migrations out. Hence U6 may not at all be due to any "incoming Eurasians" but a mutation already part of an INTERNAL African expansion, that had already generated the necessary mutated strands or building blocks, before flowing out to other non-African populations. And the "incoming" would have looked like Africans anyway. "Past population size can be estimated from modern genetic diversity using coalescent theory. Estimates of ancestral human population dynamics in sub-Saharan Africa can tell us about the timing and nature of our first steps towards colonizing the globe. Here, we combine Bayesian coalescent inference with a dataset of 224 complete human mitochondrial DNA (mtDNA) sequences to estimate effective population size through time for each of the four major African mtDNA haplogroups (L0–L3). We find evidence of three distinct demographic histories underlying the four haplogroups. Haplogroups L0 and L1 both show slow, steady exponential growth from 156 to 213 kyr ago. By contrast, haplogroups L2 and L3 show evidence of substantial growth beginning 12–20 and 61–86 kyr ago, respectively. These later expansions may be associated with contemporaneous environmental and/or cultural changes. The timing of the L3 expansion—8–12 kyr prior to the emergence of the first non-African mtDNA lineages—together with high L3 diversity in eastern Africa, strongly supports the proposal that the human exodus from Africa and subsequent colonization of the globe was prefaced by a major expansion within Africa, perhaps driven by some form of cultural innovation."--Atkinson, et al (2010). Bayesian coalescent inference of major human mitochondrial DNA haplogroup expansions in Africa. Proc Biol Sci. 276(1655):367-73. Consolidating quotations here:africanamericanculturalcenterpalmcoast.org/historyafrican/quotes.htm
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Post by djoser-xyyman on Jul 2, 2010 7:11:33 GMT -5
That is why “Caucasoid” has no scientific base. Where does Negroid end and Caucasoid begin. After all, up to about 4kya Europeans were “Negroid”. The so called Caucasoid or modern European “features” did not appear until about Neolithic times. Cro-magnon and Grimaldi were termed Negroid. And these were the ancestors of modern European.
So I ask again – where does Negroid end and Caucasoid begin. In other words can a father be a Negroid and the son a Caucasoid. Totally irrational.
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Post by zarahan on Jul 2, 2010 10:39:17 GMT -5
That is why “Caucasoid” has no scientific base. Where does Negroid end and Caucasoid begin. After all, up to about 4kya Europeans were “Negroid”. The so called Caucasoid or modern European “features” did not appear until about Neolithic times. Cro-magnon and Grimaldi were termed Negroid. And these were the ancestors of modern European. So I ask again – where does Negroid end and Caucasoid begin. In other words can a father be a Negroid and the son a Caucasoid. Totally irrational. Indeed. And they know it, but prefer to keep up the line of deception. Its like those who espouse the vague 'Egyptianism" theory- who keep denying any link to "Africa" at all, as if Egypt was never even in Africa, as if the ancient Egyptians suddenly appeared out of nowhere, like space aliens. Heaven forbid that they came from the surrounding African environment.
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Post by egyptianplanet on Jul 2, 2010 11:21:18 GMT -5
Now see, this is where human stupidity reigns in most issues.
Most Europeans felt they were descendants of evolved Neanderthals. This has long been used as ammo by Africans to demean White Supremacists and call them, "White cave men" and "sub-human." Then Europeans change their mind citing they hold no link to Neanderthals and are modern humans. The problem with that is being a modern human you must accept African roots. Everyone in the United States of America has African genetics, and we know how diverse we are. Now that Europeans have to accept that fact, they try anything to make it seem like they hold no African roots going anything from saying they're Neanderthals or something more ridiculous.
Why can't we just accept the fact we're all brothers and sisters? Like damn, we're human beings not monkeys ffs but by how we act like it I'm not so sure that's true anymore. (Not insulting monkeys, they seem to be smarter than us as of late).
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Post by djoser-xyyman on Jul 23, 2010 7:47:34 GMT -5
Determination of optimal rehydration, fixation and staining methods for histological and immunohistochemical analysis of mummified soft tissues A-M Mekota1, M Vermehren2 Department of Biology I, Biodiversity Research/Anthropology1and Department of Veterinary Anatomy II2, Ludwig-Maximilians University Munich, Germany Submitted January 8, 2002; revised May 4, 2004; accepted August 12, 2004 Abstract During an excavation headed by the German Institute for Archaeology, Cairo, at the tombs of the nobles in Thebes-West, Upper Egypt, three types of tissues from different mummies were sampled to compare 13 well known rehydration methods for mummified tissue with three newly developed methods. Furthermore, three fixatives were tested with each of the rehydration fluids. Meniscus (fibrocartilage), skin, and a placenta were used for this study. The rehydration and fixation procedures were uniform for all methods. The stains used were standard hematoxylin and eosin, elastica van Gieson, periodic acid-Schiff, and Grocott, and five commercially obtained immunohistochemical stains including pancytokeratin, vimentin, alpha-smooth-muscle-actin, basement membrane collagen type IV, and S-100 protein. The sections were examined by transmitted light microscopy. Our study showed that preservation of the tissue is dependent on the quality and effectiveness of the combination of the rehydration and fixation solutions, and that the quality of the histological and histochemical stains is dependent on the tissue quality. In addition, preservation of the antigens in the tissues is dependent on tissue quality, and fungal permeation had no influence on the tissue. Finally, the results are tissue specific. For placenta the best solution combination was Sandison and solution III (both fixed with formaldehyde) while results for skin were best with Ruffer I (using formaldehyde and Schaffer as fixatives), Grupe et al. (using formaldehyde as a fixative) and solution III (in combination with formaldehyde and Bouin fixatives). Ruffer II (using formaldehyde as a fixative) and solution III (in combination with Schaffer fixative) gave the best results for fibrocartilage.
Mummification, whether spontaneous or artificial, has provided soft tissue materials that allow insight into ancient cultures as well as diseases afflicting earlier populations. Palaeohistology is the study of histological structures found in prehistoric skeletal remains and mummified tissues. Unfortunately, dehydration and time have rendered the mummified tissues hard, brittle, and difficult to manage. Therefore, it is crucial to use optimal rehydration and fixation procedures to optimize morphological detail. Previous studies have employed a variety of fluids to reconstitute this material, but a systematic comparison to determine the optimal procedure has not been made.
The aim of our study was to test the quality of 13 well known methods of rehydration for mummified tissue (Fulcheri et al. 1985, Giacometti and Chiarelli 1968, Gordon and Bradbury 1977, Graf 1949, Grupe et al. 1997, Kleiss and Simonsberger 1984, Piepenbrink and Herrmann 1988, Ruffer 1921, Sandison 1955, Turner and Holtom 1981,Wiest et al. 1994,Wilder 1904) and to compare these with three newly developed techniques (Table 1). Furthermore, three fixation fluids were tested with each rehydration solution. Each procedure was assessed for degree of tissue conservation, histological and histochemical staining properties, and specificity of immunohistochemical staining methods. Materials and methods In 1997, the German Institute for Archaeology headed an excavation of the tombs of the nobles in Thebes-West, Upper Egypt. At this time, three types of tissues were sampled from different mummies: meniscus (fibrocartilage), skin, and placenta. Archaeological findings suggest that the mummies dated from the New Kingdom (approximately 1550/1080 BC). Three adjacent samples, approximately 0.5 cm3, taken from each organ were placed in 100 ml of each rehydration fluid and left on a rotary mixer for a specific amount of time depending on the hardness and density of the tissue to be examined. Softening placenta samples required 24 h, skin samples required 36 h and meniscus samples required 48 h. After rehydration, samples of each tissue were taken from each rehydration solution and immersed in each of the following three fixatives for an additional 24 h: 4% formaldehyde, modified Schaffer solution (2:1 80% ethanol: 36% aqueous formaldehyde), or Bouin solution (15:15:1 saturated picric acid: 30% aqueous formaldehyde: concentrated acetic acid). After the samples were embedded in blocks of paraffin wax, they were cut with a microtome (Microm, HM440E) into both cross and longitudinal sections 4 mm thick. To ensure standard conditions for comparison, rehydration, fixation, embedding and staining procedures were kept uniform. The following histochemical stains were applied to the three tissues: hematoxylin and eosin (H & E; nuclei blue, cytoplasm pink), elastica van Gieson (EvG; elastic tissue black, connective tissue red), periodic acid-Schiff (PAS; nuclei blue, glycoproteins red) and Grocott (fungi black, cytoplasm green) (Bo¨ck 1989).
Table 1. Methods and ingredients of rehydration solutions Method Ingredients Fulcheri et al. (1985) undiluted, inactivated human blood serum at 48 C Giacometti and Chiarelli (1968) 0.9% sodium chloride Gordon and Bradbury (1979) 70 ml ethanol (70%), 30 ml glycerin, 1g dithionite Graf (1949) 5 parts glycerin, 5 parts 10% acetic acid Grupe et al. (1997) 5% DMSO in Tris buffer, pH 7.6 Kleiss and Simonsberger (1984) 2% aqueous sodium carbonate Piepenbrink and Herrmann (1988) 15% glucose solution Ruffer I (1921) 5 parts distilled water, 3 parts absolute ethanol, 2 parts 5% aqueous sodium carbonate Ruffer II (1921) 97 parts tap water, 2 parts 5% aqueous sodium carbonate, 1 part 4% formaldehyde Sandison (1955) 5 parts 1% aqueous formaldehyde, 3 parts 96% ethanol, 2 parts 5% aqueous sodium carbonate Turner and Holtom (1981) 0.2% solution of "Comfort" fabric softer (Lever Bros.) in normal saline Wiest et al. (1994) 9.5 parts formaldehyde (2%), 0.5 parts Brij† solution Wilder (1904) 1% solution of caustic potash Solution I 4 parts undiluted inactivated human blood serum at 48 C, 1 part 5% sodium carbonate Solution II 5 parts distilled water, 3 parts 15% saccharose solution, 2 parts 2% sodium carbonate Solution III 8 parts 0.2% solution of "Comfort" fabric softer (Lever Bros.) in 5% sodium carbonate, 2 parts aqueous formaldehyde (4%)
Five commercially obtained immunohistochemical markers also were applied to the three tissues: pancytokeratin (Progen Biotechnik GmbH, Heidelberg, Germany); vimentin (DAKO); alpha-smoothmuscle- actin (Boehringer Mannheim GmbH, Mannheim, Germany); basement membrane collagen type IV (Labo Nova, Giessen, Germany); and S-100 protein (DAKO). Immunohistochemistry was performed using enzymatic pre-digestion (pepsin) or heat-induced epitope retrieval in citrate buffer, pH 6.0, for enhancement of immunoreactivity, application of primary antibodies, and visualization by labeled-streptavidin-biotin (LSAB)/horseradish peroxidase (DAKO) followed by DAB (DAKO). Simultaneously, control experiments were performed with corresponding modern tissues. All sections were prepared in the Pathological Institute of the Ludwig-Maximilians-Universita¨t, Mu¨ nchen, Germany. The sections were inspected by transmitted light microscopy. Acknowledgments This research was funded by a Ph.D. grant from the Ludwig-Maximilians-Universita¨t Mu¨ nchen. Technical assistance was provided through a grant by the German Science Foundation. We are deeply grateful to Prof Dr G. Grupe for making this paper possible.
Results We devised a grading system to compare and to rate each procedure for its degree of tissue conservation, histological and histochemical staining properties, the specificity of immunohistochemical staining methods, and the degree of fungal penetration into the tissue. Skin Skin sections showed particularly good tissue preservation, although cellular outlines were never distinct. Although much of the epidermis had already separated from the dermis, the remaining epidermis often was preserved well (Fig. 1). The basal epithelial cells were packed with melanin as expected for specimens of Negroid origin. In the dermis, the hair follicles, hair, and sebaceous and sweat glands were readily apparent (Fig. 2). Blood vessels, but no red blood cells, and small peripheral nerves were identified unambiguously (Fig. 3). The subcutaneous layer showed loose connective tissue fibers attached to the dermis, and fat cell remnants were observed. To evaluate the influence of postmortum tissue decay by micro-organisms, the samples were tested for the presence of fungi using silver staining. Fungi were observed in some samples and were widespread in both epidermis and dermis. The molecular preservation of the antigen determinants, due to tissue preservation, determines the accuracy of the immunohistological stains. Depending on the rehydration
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Post by djoser-xyyman on Jul 23, 2010 8:29:43 GMT -5
www.sciencedirect.com/science?_ob=MImg&_imagekey=B6WM8-4VCRNRF-6-1&_cdi=6928&_user=73941&_pii=S0190962281700033&_orig=search&_coverDate=01%2F31%2F1981&_sk=999959998&view=c&wchp=dGLzVzb-zSkzV&md5=44037378529e1279af5a6a01b3b1cdfd&ie=/sdarticle.pdfHistologic findings in mummified skin Thomas A. Chapel, M.D., Amir H. Mehregan, M.D., and Theodore A. Reyman, M.D. Detroit, MJ Skin specimens from five mummies were examined histologically. The specimens ranged in age from 2,000 to 3,200 years . Material from two mummies had carbonized and showed only amorphous debris. The histology of the three remaining skin fragments retained surprising histologic architectural detail. One specimen obtained from the sole of the foot was compatible with a callus. (J AM ACAD DERMATOL 4:27-30 , 1981.) ==== Egyptian mummies were prepared by chemical dehydration, and the skin was covered with plant resin or mineral pitch prior to elaborate wrapping. Despite these factors, many areas of the skin of these mummies have been well preserved. The dehydration procedures and the passage of centuries have made the skin hard, brittle, and virtually water-free. However, following rehydration and histologic processing, surprising morphologic detail often remains . This report describes the histologic findings of skin fragments from five Egyptian mummies, although experience of one of us (T. A . R.) suggests that the changes in the Aleutian and North and South American mummies are similar. ===== The specimens ranged in age from 2 ,000 to 3,200 years . The first four specimens were random skin sections, while the one from the Royal Ontario Museum mummy consisted of one of two contiguous papules, 0.3 to 0.5 em, from the sole of the right foot in the area of the second and third metatarsal heads ===== Fig. 1. Tissue from the nape of the neck shows a deeply pigmented epidermis. Occasional clear cells (arrow) are recognized at the dermoepidermal junction. In the papillary connective tissue are nuclei of fibroblasts. (Hematoxylin-eosin stain; X60.) ===== Fig. 2. In the deep dermis is an acutely curved hair follicle suggesting formation of a kinky hair shaft. (Hematoxylin-eosin stain; x60.)
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Post by djoser-xyyman on Jul 26, 2010 9:25:46 GMT -5
Full study uploaded Determination of optimal rehydration, fixation and staining methods for histological and immunohistochemical analysis of mummified soft tissues A-M Mekota1, M Vermehren2 Department of Biology I, Biodiversity Research/Anthropology1and Department of Veterinary Anatomy II2, Ludwig-Maximilians University Munich, Germany Submitted January 8, 2002; revised May 4, 2004; accepted August 12, 2004 Abstract During an excavation headed by the German Institute for Archaeology, Cairo, at the tombs of the nobles in Thebes-West, Upper Egypt, three types of tissues from different mummies were sampled to compare 13 well known rehydration methods for mummified tissue with three newly developed methods. Furthermore, three fixatives were tested with each of the rehydration fluids. Meniscus (fibrocartilage), skin, and a placenta were used for this study. The rehydration and fixation procedures were uniform for all methods. The stains used were standard hematoxylin and eosin, elastica van Gieson, periodic acid-Schiff, and Grocott, and five commercially obtained immunohistochemical stains including pancytokeratin, vimentin, alpha-smooth-muscle-actin, basement membrane collagen type IV, and S-100 protein. The sections were examined by transmitted light microscopy. Our study showed that preservation of the tissue is dependent on the quality and effectiveness of the combination of the rehydration and fixation solutions, and that the quality of the histological and histochemical stains is dependent on the tissue quality. In addition, preservation of the antigens in the tissues is dependent on tissue quality, and fungal permeation had no influence on the tissue. Finally, the results are tissue specific. For placenta the best solution combination was Sandison and solution III (both fixed with formaldehyde) while results for skin were best with Ruffer I (using formaldehyde and Schaffer as fixatives), Grupe et al. (using formaldehyde as a fixative) and solution III (in combination with formaldehyde and Bouin fixatives). Ruffer II (using formaldehyde as a fixative) and solution III (in combination with Schaffer fixative) gave the best results for fibrocartilage. Attachments:
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Post by djoser-xyyman on Jul 26, 2010 9:28:29 GMT -5
Full study uploaded Histologic findings in mummified skin Thomas A. Chapel, M.D., Amir H. Mehregan, M.D., and Theodore A. Reyman, M.D. Detroit, MJ Skin specimens from five mummies were examined histologically. The specimens ranged in age from 2,000 to 3,200 years . Material from two mummies had carbonized and showed only amorphous debris. The histology of the three remaining skin fragments retained surprising histologic architectural detail. One specimen obtained from the sole of the foot was compatible with a callus. (J AM ACAD DERMATOL 4:27-30 , 1981.) Attachments:
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Post by scv on Sept 2, 2010 13:09:59 GMT -5
That is why “Caucasoid” has no scientific base. Where does Negroid end and Caucasoid begin. After all, up to about 4kya Europeans were “Negroid”. The so called Caucasoid or modern European “features” did not appear until about Neolithic times. Cro-magnon and Grimaldi were termed Negroid. And these were the ancestors of modern European. So I ask again – where does Negroid end and Caucasoid begin. In other words can a father be a Negroid and the son a Caucasoid. Totally irrational. Caucasoid begin when that phenotype appeared in the Caucasus(where the word "Caucasoid"comes from)but it just a phenotype change, not a big change, is like the phenotypical difference you can see between an West African and an Central African. If the sons was born in the Caucasus, then he is caucasoid, because that is a name after a region.
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Post by anansi on Jun 6, 2011 8:05:43 GMT -5
Some Pdf info passed to me Investigative Geneticswww.investigativegenetics.com/content/pdf/2041-2223-2-12.pdfGenetic variation of 15 autosomal STR loci in Upper (Southern) Egyptians download.journals.elsevierhealth.com/pdfs/journals/1872-4973/PIIS1872497308000859.pdfArchaeogenetic Evidence of Ancient Nubian Barley Evolution from Six to Two-Row Indicates Local AdaptationAbstract Background: Archaeobotanical samples of barley (Hordeum vulgare L.) found at Qasr Ibrim display a two-row phenotype that is unique to the region of archaeological sites upriver of the first cataract of the Nile, characterised by the development of distinctive lateral bracts. The phenotype occurs throughout all strata at Qasr Ibrim, which range in age from 3000 to a few hundred years. Methodology and Findings: We extracted ancient DNA from barley samples from the entire range of occupancy of the site, and studied the Vrs1 gene responsible for row number in extant barley. Surprisingly, we found a discord between the genotype and phenotype in all samples; all the barley had a genotype consistent with the six-row condition. These results indicate a six-row ancestry for the Qasr Ibrim barley, followed by a reassertion of the two-row condition. Modelling demonstrates that this sequence of evolutionary events requires a strong selection pressure. Conclusions: The two-row phenotype at Qasr Ibrim is caused by a different mechanism to that in extant barley. The strength of selection required for this mechanism to prevail indicates that the barley became locally adapted in the region in response to a local selection pressure. The consistency of the genotype/phenotype discord over time supports a scenario of adoption of this barley type by successive cultures, rather than the importation of new barley varieties associated with individual cultures. www.plosone.org/article/fetchObjectAttachment.action?uri=info%3Adoi%2F10.1371%2Fjournal.pone.0006301&representation=PDF
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