Anthropology.net

Hans-Peter Uerpmann of the University of Tubingen has lead a team excavating the Jebel Faya site in the United Arab Emirates, right near the Straits of Hormuz. They’ve found 125,000 year old stone tools that look like early modern human tools from East Africa around the same time. They’ve published their findings in today’s Science, under the title, “The Southern Route “Out of Africa”: Evidence for an Early Expansion of Modern Humans into Arabia.”

The current understanding is what we know as anatomically modern humans (AMH) originated in Africa about 250,000 years ago. The oldest Home sapiens, known as H. sapiens idaltu, was found to be 160,000 years old, found at the Middle Awash site in Ethiopia. Then between 80k-100k years ago, modern humans began appearing in the middle east, as remains from sites like the Qafzeh cave in Israel have yielded. Most agree that AMH stayed in Africa and about 140,000 years ago they began migrating out. There was an exception, a colonization remained or failed in Israel about 100,000 years ago.

One of the hand axes from Jebel Faya, UAE (Photograph courtesy Science/AAAS)

These hand axes, pictured above, show a pattern of flaking distinct from that made by Neandertals and also dissimilar to those by ~100,000 year old Israeli tools. They are two sided and very similar to stone tools seen only in early Africa.

What this means is early humans left Africa 20,000 years earlier than thought. Just how did they do it? 130,000 years ago, there was a window of climate change. They figured this out by using luminescence dating to determine the age of sand grains buried with the stone tools. Luminescence dating is a technique that measures naturally occurring radiation stored in the sand. The data showed that 130,000 years ago, the Arabian Peninsula was relatively more warm which caused more rainfall, turning it into a series of lush habitable land. During this period the southern Red Sea’s levels dropped and was only 2.5 miles or 4 km wide. This offered a brief window of time for humans to easily cross the sea and cross the Peninsula to opposing sites like Jebel Faya.

Does this study tell us that modern humans left Africa, into Arabia and out from there? It is most certainly a possibility. However, these axes could be of an abandoned migration like the site in Israel I’ve mentioned. I say that because no genetic clade, be it from mitochondrial, Y-chromosome, or somatic genome, shows an earlier divergence of modern humans from Africa earlier than 60,000 years ago. At the very minimum a find like this tells us humans left Africa a bit sooner than we thought, but does not really tell us that these were the humans that helped seed the Eurasia.

Armitage, S., Jasim, S., Marks, A., Parker, A., Usik, V., & Uerpmann, H. (2011). The Southern Route “Out of Africa”: Evidence for an Early Expansion of Modern Humans into Arabia Science, 331 (6016), 453-456 DOI: 10.1126/science.1199113

Razib has done rounded up a nice review of Dienekes‘ Dodecad data to answer some prelim questions on the genetic of Ethiopia. Ethiopia is a very interesting cultural and paleontological area of the world. I had the pleasure of being a part of a field group several years ago and had a wonderful time. A good summary of the ADMIXTURE analysis done by Dienekes, reorganized by Razib, is shown below:

I don’t have much to add to his post, other than to hand you over there and to check it out. You may also wanna read more about the Dodecad Ancestry Project in this Nature News piece.

The other day Dienekes pointed out a paper on ancestral human population dynamics within Africa before the out of Africa migrations. The paper is very similar to one I reviewed in April, which also focuses on the diversity of the mitochondrial haplogroup L — one of the oldest mtDNA haplogroups out there.

The new paper, “Bayesian coalescent inference of major human mitochondrial DNA haplogroup expansions in Africa,” published in the Proceedings of the Royal Society B, uses coalescent theory to investigate past population sizes of each of the four major African mtDNA haplogroups (L0-L3). 224 different mitochondrial genomes were analyzed and the comparison yielded some similar results to the previous paper I mentioned. But remember, the last paper investigated the time of the emergence of each haplogroup. This paper focuses on effective population sizes.

Anyways, for starters, the results show that three distinct demographic histories can be seen from the underlying the four haplogroups. Two of the oldest haplogroups, L0 and L1, show exponential growth from 213,000 to 156,000 years ago. The previous paper suggested that the L0 and L1 split about 200,000 years ago. Soon after this split, one of the the paleoafrican branches L0 established what we now consider sub-Saharan Khoisan peoples.

L1 split up into the L2 and L3 branches sometime around 127,000 to 72,000 years ago, again consistent with the previous paper. The L2 and L3 branches show two exponential growth periods, one around 86,000 to 61,000 years ago and another around 20,000 to 12,000 years ago. The authors observed a distinct expansion of the L3 branch around 12,000 to 8,000 years ago. They suggest that,

“L3 did not simply spill over into Eurasia, but was driven as part of an expansion that had begun in sub-Saharan Africa thousands of years earlier.”

While this date is a bit later than the one suggested in the previous paper, both indicate that there were deep African migrations within Africa. The later expansions of L2 and L3, coincide with environmental and cultural changes, such as the greening of the Sahara and emergence of pastoralism. The authors write that,

“The timing of the L3 expansion-8-12kyr 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.”

Quentin D. Atkinson, Russell D. Gray, Alexei J. Drummond (2008). Bayesian coalescent inference of major human mitochondrial DNA haplogroup expansions in Africa Proceedings of the Royal Society B: Biological Sciences, -1 (-1), -1–1 DOI: 10.1098/rspb.2008.0785

In late May, Paul Sereno was in town to talk at the 2008 conference titled, ‘Integrating Evolution, Development, & Genomics.’ He was invited to also give a talk titled, “Living Lakeside in the Sahara: A Chronicle of Holocene Adaptation,” to the Primate Biology Group. I eagerly attended. Paul Sereno, if you don’t know, is primarily a dinosaur paleontologist and geologist. And a really well known one at that. He’s discovered around 10 or so new dinosaur species.

But, in 2000 while on a excavation for dinosaurs and giant crocodiles in Niger, National Geographic photographer, Mike Hettwer, stumbled upon a Neolithic graveyard. Sereno shifted his search for dinos to studying these bodies and the artifacts associated with them. He discussed his finds in his talk.

It was so inspiring to be there, and I’m not alone in sharing this sentiment. I was attending the talk with a couple of friends, and they also felt the same way. The clarity and enthusiasm with which Sereno explained the site and his work was impressive — I’ve rarely seen someone so excited to explain so much material. Sereno’s definitely got a reason to be enthusiastic — he has what is now most likely the largest collection of Early to Mid-Holocene bones ever discovered at a single site in Africa.

Gobero, a Neolithic Site in Niger.

After the talk, I got a chance to have a one and one with Sereno. He let me know about his time frame and publication plans. I’m happy to see that everything has come to fruition. Published today, in the open access journal PLoS One is Sereno et al.’s analysis of the site, “Lakeside Cemeteries in the Sahara: 5000 Years of Holocene Population and Environmental Change.”

In the paper, Sereno and team describe the paleoecology of the site and climatic change. They include their interpretation of the burials and associated artifacts. I’ll do my best summarizing the piece in this blog post, but I really recommend you read this gem for yourself. It is open access and well written — you don’t have really any excuse not too.

This site has been called Gobero, after the local Tuareg name for the area. About 10,000 years ago (7700–6200 B.C.E.), Gobero was a much less arid environment than it is now. In fact, it was actually a rather humid lake side hometown of sorts for a group of hunter-fisher-gatherers who not only lived their but also buried their dead there. How do we know they were fishing? Well, remains of large nile perch and harpoons were found dating to this time period.

Of the 67 burials excavated, five of them date to an occupation span from 9,750 to 9,500 years ago. That’s 250 years or so. Looking at photos of the field site, it is hard to believe these prehistoric people got comfortable in Gobero. They began making pottery and ritually burying their dead. One of these guys, G3B8, is a 2 meter tall dude (that’s like 6 feet 6 inches!). He’s pictured below, buried rather utilitarian, with hands covering his mouth and crossed feet, just as he was found:

G3B8, a 6 foot 6 individual from Gobero, Nigeria. Photo (c) Mike Hettwer, courtesy Project Exploration.

G3B8 is not alone in his stature and robustness. There other burials, both male and female, from this time frame are of similar height. These Early Holocene hunter-gathering fishermen also have characteristic skulls — long and low, with a unique occipital bun and broad nasals. These features aren’t restricted to only adults, in fact, juveniles as young as 4 years exhibit similar traits which are not shared by the later inhabitants of Gobero. These bodies were tightly bound when buried.

Around 6200 B.C.E (8,200 years ago) Gobero began to resemble what we see today. The paleolake dried up, and these tall, robust inhabitants hauled out. The youngest early-Holoecene burial dated to 6210 B.C.E. This regional climate change persisted for about 1,000 years, correlating to climatic deterioration across the Chad Basin and linked to the chilling of the North Atlantic.

The return of humid conditions came about immediately after this arid interruption. The lake refilled, and plants, animals and people moved back to Gobero. These favorable conditions persisted for much longer than the early Holocene occupation, roughly 2,700 years. The new settlers were anatomically much different from their predecessors. For starters, they are shorter. They’ve got tall, narrow skulls, with long faces. This guy, dubbed G1B11, is a mid-Holocene adult male dating to around 4,645 B.C.E. is a good example of the different morphology:

G1B11, an adult male from Gobero, Niger. Photo (c) Mike Hettwer, courtesy Project Exploration.

To better illustrate the differences between the robust, early occupants and the latter, gracile ones. Check out this comparison. On the left is a 9,500 years old skull of this mature male. The eye sockets are square, the cranium is low and check out those nasals! On the right is a 5,800 years old skull of a young adult. While not as mature as his 3,700 counter part, you can see the anatomical differences for yourself — a much taller cranium, look at the forehead.

Kiffian (9,500 year old) Skull vs Tenereian (5,800 year old) Skull from Gobero, Niger. Photo (c) Mike Hettwer, courtesy Project Exploration.

Tenerean Bracelet Girl. Photo (c) Mike Hettwer, courtesy Project Exploration.

7 of 35 burials excavated from the mid-Holocene occupation were buried with artifacts. I remember Sereno showing us a photograph of an individual buried with a turtle shell underneath him. I didn’t catch the specimen number at the time, and now found out that guy is G1B11 — pictured above. You can see in the middle image the carapace functioning as an eternal bed. The mid-Holocene occupants were much more symbolic than the early Holocene individuals. They buried their dead with more elaborate artifacts, such as this 11 year old girl (G1B2) who is wearing an upper-arm bracelet carved from the tusk of a hippo. She’s believed to have died around 4,835 years ago.

Why were these people burying their dead with beads, bracelets, and on turtle shells? Sereno et al. suggest that the latter occupants were more pastoralists and agriculturalists — because archaeological evidence for grain and remains of domesticated cattle are present in the midden from this time period. Their gracile frames support this lifestyle, as well. Additionally, curious looking fine-grained green rocks were used to make points, scrapers and adzes from this time period. This rock isn’t found in Gobero. Actually, this feldspar rock came from Alallaka — a prehistoric rock quarry about 160km north of Gobero. The relaxation from gathering and hunting for food allowed for people to develop new skills, such as jewelry making and symbolic burials — even trade their skills for green rocks from the north.

So who were these people?

Sereno et al. did a principal components analysis of craniofacial dimensions of the skulls from both periods and compared them to Late Pleistocene to mid-Holocene populations from the Maghreb and southern Sahara. The early Holocene occupants are similar to remains from Maghreb Capsian, Maghreb Iberomaurusian, Mali, Mauritania. The mid-Holocene occupants are unlike any other population tested. That doesn’t tell us much about who they were.

Kiffian Wavy Pottery. Photo (c) Mike Hettwer, courtesy Project Exploration.

So Elena Garcea, a specialist in African archaeology from this period, analyzed the material culture. She believes that the bone harpoon points and hooks, as well was the dotted wavy-line, zigzag ceramic exhibit attributes of the Kiffian people. Kevin MacDonald described the Kiffian technology, one that specialized in harpoons and microliths, in the text “Archaeology and Language.” Several other publication also support this claim. On Sereno’s website, there are more photos of the bone harpoons and pottery. I don’t have any examples of Kiffian artifacts to compare, so I’ll just trust that Garcea and Sereno got this identification.

The mid-Holocene occupants are believed to be Tenereans. Their affinity for green feldspar and the small projectile points as well as the disc knives characterize the Tenerean material culture. An example of Tenerean style projectile points from Gobero is below: IMAGE REMOVED AS PER MIKE HETTWER’S REQUEST.

Tenerean Triple Burial, from Gobero, Niger. Photo (c) Mike Hettwer, courtesy Project Exploration.

If you’re not completely floored by the wealth of archaeological and anatomical material from Gobero, let me share with you the Tenerean triple burial. The triple burial includes a female, presumably the mother, laid to rest on her right side who died somewhere around 5,300 years ago. Facing her are two children (ages 8 & 5 years old) and buried on their left side, interpreted as her children. These people were buried with their arms and legs around each other and holding hands. Abundance of pollen residues underneath them suggest they were buried on a bed of flowers. Multiple burials like this, and in this condition are rare. Furthermore, this is first triple burial ever discovered on Africa.

Sereno did not excavate these individuals like a normal archaeologist would. Instead, being a dinosaur specialist, he jacketed the remains.

Gasp!

You’re probably thinking, “Sacrilegious technique! He shoulda used brushes and dental picks, removing each bone and shipping them off for study in the lab.” But had he not done so, burials like the triple burial would have not survived excavation — the extreme heat of the Sahara has made the bones exceptionally fragile. That’s why having a multidisciplinary approach to doing this sorta fieldwork works. And I commend Sereno for taking these measures to preserve the bodies and site.

This publication has shown us very eloquently how important Gobero is to our understanding of climate change and prehistoric peoples and archaeology of the Sahara. As more and more of Gobero becomes exposed and weathered, more and more of it will be lost to time if we do not support Sereno’s research. Hettwer has documented the impact 5 years has made on one such exposed skeleton:

Weathering of an exposed skeleton at Gobero, Niger. Photo (c) Mike Hettwer, courtesy Project Exploration.

I’ve mentioned before only 67 burials were excavated. There are at least 182. Gobero needs to be preserved, for its wealth of evidence and the cultural heritage it provides Niger.

Sereno, P.C., Garcea, E.A., Jousse, H., Stojanowski, C.M., Saliège, J., Maga, A., Ide, O.A., Knudson, K.J., Mercuri, A.M., Stafford, T.W., Kaye, T.G., Giraudi, C., N’siala, I.M., Cocca, E., Moots, H.M., Dutheil, D.B., Stivers, J.P., Harpending, H. (2008). Lakeside Cemeteries in the Sahara: 5000 Years of Holocene Population and Environmental Change. PLoS ONE, 3(8), e2995. DOI: 10.1371/journal.pone.0002995

According to this press release, a new paper reports on the discovery of a 10,000 year old SNP on the Y-chromosomes of men from Tanzania and southern Africa. It will be appearing in PNAS‘ online early edition tomorrow (DOI: 10.1073/pnas.0801184105). The SNP is thought to have originated in eastern Africa,

“The team analyzed Y chromosomes from men in 13 populations in Tanzania in eastern Africa and in the Namibia-Botswana-Angola border region of southern Africa. They discovered a novel mutation shared by some men in both locations, which implied those men had a common ancestor. Further analysis showed the novel mutation arose in eastern Africa about 10,000 years ago and was carried by migration to southern Africa about 2,000 years ago. The mutation was not found in Bantu-speakers, suggesting that a different group – Nilotic-language speakers – first brought herds of animals to southern Africa before the Bantu migration.

This new genetic evidence correlates well with pottery, rock art and animal remains that suggest pastoralists – herders who migrated to new pasture with their flocks – first tended sheep and cattle in southern Africa around 2,000 years ago. The genetic finding also helps explain linguistic similarities between peoples in the two regions.”

You may know that previous research based upon archaeology, skeletal morphology, linguistics and mtDNA has suggested that prehistoric people in eastern and southern Africa were virtually isolated between 30,000 and 1,500 years ago, with only two known migrations between the regions during that time frame. One of the authors of this paper, Brenna Henn, acknowledges this over at the Spitton. She writes,

“Our new genetic study, while still supporting the archaeological record for the timing and place of the origins of pastoralism in sub-Saharan Africa, puts a new twist on the current thinking. It suggests that a small group of men actually migrated into southern Africa about 2,000 years ago. These men probably married into local hunter-gatherer populations, contributing their livestock and cultural knowledge of pastoralism.”

I caught this Smithsonian review of the evolution of modern humans from Peter Frost’s blog post last night. I got some time to read the piece on the bus this morning, and wanted to briefly share my thoughts of it with you. The piece is written by science writer Guy Gugliotta, he has covered other anthropological topics such as the rise and fall of the Maya and the genetic diversity of early human settlers of the Americas for other sources before.

Guy got a lot of big names in paleoanthropology and archaeology to comment on his latest Smithsonian piece, “The Great Human Migration.” You may recognize Tim White and Ofer Bar-Yosef among the many he’s interviewed. Guy summarizes some major sites and recent finds, such as the artistic and symbolic nature of early Homo sapiens seen in the 164,000 years old artifacts from Pinnacle Point, South Africa and the 77,000 year old shell beads Blombos Cave, also in South Africa. Guy also offers up a physical comparison of Homo sapiens to other hominids, such as Neandertals. He reviews both older and current genetic evidence on the evolution of humans.

You should read it if you don’t know much about paleoanthropology and other disciplines related to the evolution of modern humans and are interested in the subject. Guy synthesizes many different fields, from archaeology to paleontology to genetics, and offers up a pretty succint and clear review of what know about how modern humans got to where we are now.

Dienekes, Blaine, Razib, and Simon have all chimed in introducing us to a new paper from the American Journal of Human Genetics. It seems like a really interesting one, one that takes mtDNA to construct a phylogeny used to investigate what was happening to early Homo sapiens genetic diversity and populations within Africa. This study focuses on what was going on before the migrations out of Africa. The paper is titled, “The Dawn of Human Matrilineal Diversity,” and is open access. The research has already made it all the way onto some of my favorite news sources, such as Digg and Slashdot, but the big timers like CNN, BBC, the Economist, and the AFP are also carrying word.

The researchers constructed a mitochondrial phylogeny of 624 sub-Saharan individuals. They paid close attention to what’s going on with the phylogeny of the Khoisan, because previous research like Knight et al.‘s study on another loci, the Y-chromosome has shown that the Khoisan are carriers of oldest-diverging Y haplogroup, the Y-haplogroup A, indicating they may represent the deepest clade of modern humans. Recent research identified that the pygmy Khoisan populations share an ancestral and indigenous lineage of mtDNA with a neighboring population, the Bantu and this new study confirmed this.

The phylogenetic tree in this newer study is really informative. I’ve included it to the right. The researchers honed in on the mitochondrial haplogroup L, which is one of the oldest mtDNA haplogroups out there. The tree shows that early humans split into two small groups, demarcated by the L0 branch splitting from the L1’5 branch around 140,000 years ago. Based upon these two branches, the researchers were able to identify that one group was concentrated around eastern Africa (the L1’5 branch), while the other, the Khoisan’s L0 branch, in southern Africa. The sub-branches within the L1’5 clade represent all of the other L haplotypes in the entire remainder of humanity, including haplogroups of those that left Africa… further suggesting east Africa peoples were the main migrators out of Africa.

How could this happen? As populations of early humans migrated within Africa and reached southern Africa, they were cut off from the eastern African populations for a significant period of isolation to diverge into two separate clades. From ScienceDaily,

“Recent paleoclimatological data suggests that Eastern Africa went through a series of massive droughts between 135,000-90,000 years ago. It is possible that this climatological shift contributed to the population splits.”

The press is suggesting that this phenomenon indicated humans “started down the path of evolving into two separate species.” But that’s not true, they missed the part of the paper where populations came back together as a single, pan-African population about 40,000 years ago.

But, something is a little fishy, because as I already indicated, the coalescence calculations in this new paper indicate the Khoisan matrilineal ancestry diverged from the rest of the human mtDNA pool about 140,000 years ago. At that time, the five additional, currently extant maternal lineages (Haplogroups L1’5) existed in Eastern Africa, before the emergence of L0 branch. Looking at the phylogenetic tree, these haplogroups are more ancestral to the haplogroup L0 branch by at around 40,000 years, implying that the Khoisan may not be the deepest clade of living humans alive. This doesn’t match the Y-chromosome data, but we know already that mtDNA and Y-chromosome coalescent times aren’t the same… but this doesn’t match scores of other studies that indicate the Khoisan are a basal group of humans based off of their linguistic and cultural traits.

What this ultimately indicates is that eastern Africa may have truly been the cradle of humanity, at least the maternal cradle of modern humans. Which matches the fossil record, since some of the oldest remains of early human remains are also found in Eastern Africa, such as BOU-VP-16/1 and Omo 1 from Ethiopia.

BEHAR, D., VILLEMS, R., SOODYALL, H., BLUESMITH, J., PEREIRA, L., METSPALU, E., SCOZZARI, R., MAKKAN, H., TZUR, S., COMAS, D. (2008). The Dawn of Human Matrilineal Diversity. The American Journal of Human Genetics DOI: 10.1016/j.ajhg.2008.04.002

KNIGHT, A. (2003). African Y Chromosome and mtDNA Divergence Provides Insight into the History of Click Languages. Current Biology, 13(6), 464-473. DOI: 10.1016/S0960-9822(03)00130-1

Quintana-Murci, L., Quach, H., Harmant, C., Luca, F., Massonnet, B., Patin, E., Sica, L., Mouguiama-Daouda, P., Comas, D., Tzur, S., Balanovsky, O., Kidd, K.K., Kidd, J.R., van der Veen, L., Hombert, J., Gessain, A., Verdu, P., Froment, A., Bahuchet, S., Heyer, E., Dausset, J., Salas, A., Behar, D.M. (2008). Maternal traces of deep common ancestry and asymmetric gene flow between Pygmy hunter-gatherers and Bantu-speaking farmers. Proceedings of the National Academy of Sciences, 105(5), 1596-1601. DOI: 10.1073/pnas.0711467105

About two weeks ago, I blogged on how variation mtDNA was used to reconstruct an idea of Pleistocene population growth. That study was very remarkable because illuminated a large 5 fold increase in South Asian populations about 50,000 years ago. But we haven’t been able to use polymorphisms in autosomal loci to the same. A new paper in Molecular Biology and Evolution tries to figure out a way to overcome this limitation, by testing to see whether or not mitochondrial and Y chromosomal DNA show similarities in the spread of polymorphisms in populations that have experienced a recent increase in effective population size.

The paper, “Contrasting Signatures of Population Growth for Mitochondrial DNA and Y Chromosomes among Human Populations in Africa,” honed in a large sequence from the Y-chromosome and the cytochrome c gene in the mtDNA from 172 males from 5 African populations. Four different statistical tests were applied to test for population expansion: Fu’s Fs statistic, the R2 statistic, coalescent simulations, and the mismatch distribution.

The authors find,

“…Patterns of mtDNA polymorphism better fit a model of constant population size for food-gathering populations and a model of population expansion for food-producing populations. In contrast, none of the tests reveal evidence of Y chromosome growth for either food-gatherers or food-producers. The distinct mtDNA and Y chromosome polymorphism patterns most likely reflect sex-biased demographic processes in the recent history of African populations. We hypothesize that males experienced smaller effective population sizes and/or lower rates of migration during the Bantu expansion, which occurred over the last 5,000 years.”

Pilkington, M.M., Wilder, J.A., Mendez, F.L., Cox, M.P., Woerner, A., Angui, T., Kingan, S., Mobasher, Z., Batini, C., Destro-Bisol, G., Soodyall, H., Strassmann, B.I., Hammer, M.F. (2008). Contrasting Signatures of Population Growth for Mitochondrial DNA and Y Chromosomes among Human Populations in Africa. Molecular Biology and Evolution, 25(3), 517-525. DOI: 10.1093/molbev/msm279

The Neolithic revolution is a really important transition in human prehistory, one that is identified by an increase in technology. During this time people became skilled agriculturalists, adopted more sedentary lifestyles that revolved around more complex, structured city-state societies.

Not every area of the world experienced the Neolithic at the same time. It is believed that the Neolithic revolution began about 12,000 years ago in Levant, a region of the world we know now as the area occupied by Syria, Lebanon, Israel, and Jordan. As the Neolithic lifestyle radiated, we see it emerge in large settlements like, Çatalhöyük in Anatolia (modern day Turkey), by 10,000 years ago. After this moment, the Neolithic rapidly spread into Europe and Asia.

But, for some odd reason, the Neolithic isn’t seen in Africa until much later, about 4,500 years ago. It really doesn’t make sense that we haven’t seen the Neolithic earlier in Africa, given the fact that the Neolithic originated in the Near East which is in close proximity to Africa. Furthermore, the Neolithic is also seen to begin in the Americas at about 4,500 years ago!

A new discovery in Sudan, “the oldest proof of human sacrifice in Africa,” pushes back the date of the Neolithic in Africa to at least 5,500 years ago,

“The tomb of a 5,500-year-old man surrounded by three sacrificed humans, two dogs and exquisite ceramics were exhumed north of Khartoum by Neolithic expert Jacques Reinhold and his 66-year-old Austrian wife.

“This is the oldest proof of human sacrifice in Sudan, in Egypt, in Africa,” Reinhold told reporters next to the remains in El Kadada village, a three-hour drive north of the Sudanese capital.

“I don’t know of another example in Africa at this level… We don’t have anything as strong in other excavations in other countries,” said Reinhold.”

Reinhold also reported on finding “urns, materials used to grind wheat into flour, beeds and bracelets” at the El Kadada site. Tim, of Remote Central, also covered this news too.

The Pygmy hunter–gatherers of central Africa are an amalgamation of various groups of people that are on average about 4 feet tall. Some genetic and linguistic evidence point to them being direct descendants of hunter-gatherers from the late Stone Age. But that’s about it, there’s not much archaeological evidence to corroborate with this observation.

Most modern day Pygmy populations live in the rain forest alongside Bantu-speaking farmers. It is one of the few places in the world were we see cohabitation of hunter-gatherers with farmers. These two groups have very different lifestyles and a new multidisciplinary study sought to determine to what extent social, cultural and demographic factors have influenced the genetic heritage of these two populations.

The open access paper, “Maternal traces of deep common ancestry and asymmetric gene flow between Pygmy hunter–gatherers and Bantu-speaking farmers,” is published in PNAS. The authors analyzed the variation in mtDNA of 1,404 individuals from 20 Bantu farming populations and 9 Pygmy populations. They were able to identify a sing ancestral and indigenous lineage of mtDNA that was formerly shared by Pygmies and Bantu people. The Pygmy lineage diverged from the ancestral population about 70,000 years ago, at which point they began to be isolated and when the short phenotype began to differentiate. Pygmy variability is much more weak compared to the variability observed in Bantu populations which tells us that modern Pygmies came from a small common ancestor population.

And since they were comparing mtDNA, starting 40,000 years ago, the researchers were able to identify that female Pygmies were reproducing with Bantu males. Subsequently, the mtDNA gene pool of the Pygmies was not enriched by external gene influxes. The Bantu farmer gene pool, however, was enriched during the so-called “Bantu expansions”, an event corresponding to technological, demographic and linguistic advances in the late Stone Age.

The authors write that they wanna expand their study to Y-chromosomal relationships between these two groups and also to study the relationships between the genome and the populations’ vulnerability or resistance to pathogens. Why do they wanna do this? Well, as Razib has written often, the transition into sedentary lifestyle is often accompanied with a shakeup on populations, pathogens, and selection.

Quintana-Murci, L., Quach, H., Harmant, C., Luca, F., Massonnet, B., Patin, E., Sica, L., Mouguiama-Daouda, P., Comas, D., Tzur, S., Balanovsky, O., Kidd, K.K., Kidd, J.R., van der Veen, L., Hombert, J., Gessain, A., Verdu, P., Froment, A., Bahuchet, S., Heyer, E., Dausset, J., Salas, A., Behar, D.M. (2008). Maternal traces of deep common ancestry and asymmetric gene flow between Pygmy hunter-gatherers and Bantu-speaking farmers. Proceedings of the National Academy of Sciences, 105(5), 1596-1601. DOI: 10.1073/pnas.0711467105