Tag Archives: Human diaspora

The Hofmeyr skull

For thoroughness sake I’m posting this piece on the Hofmeyr skull. Its the complete article, not just the abstract on the link.

Contrary to what I’ve seen in written a couple of sites, this isn’t a Caucasian skull. It’s got a mix of characteristics. Although Hofmeyr is similar in size to Eurasian UP crania, it differs from them in other respects (such as its broad nose and continuous supraorbital tori). that said, it does measure up closer to EUP crania than anything, as this twig diagram shows.

Late Pleistocene Human Skull from Hofmeyr, South Africa, and Modern Human Origins
F. E. Grine,1* R. M. Bailey,2 K. Harvati,3 R. P. Nathan,4 A. G. Morris,5 G. M. Henderson,6 I. Ribot,7 A. W. G. Pike8

The lack of Late Pleistocene human fossils from sub-Saharan Africa has limited paleontological testing of competing models of recent human evolution. We have dated a skull from Hofmeyr, South Africa, to 36.2 ± 3.3 thousand years ago through a combination of optically stimulated luminescence and uranium-series dating methods. The skull is morphologically modern overall but displays some archaic features. Its strongest morphometric affinities are with Upper Paleolithic (UP) Eurasians rather than recent, geographically proximate people. The Hofmeyr cranium is consistent with the hypothesis that UP Eurasians descended from a population that emigrated from sub- Saharan Africa in the Late Pleistocene.

I’m still having a think as to how this skull fits into the grand scheme of things. I’m going to take a look into sub Saharan DNA studies to see if there’s any indication of a migration from East Africa to South Africa at that time that could explain it’s presence.  From a little digging there may possibly have been a second movement out of Africa prior to 50k ago that might explain the similarities.

hofmeyr

 I should comment on the totally ridiculous date for the OOA exit (65k to 25k ago) since Aborigines seem to have arrived in Australia about 60,000 years ago, and the Eurasian M mt DNA clade is about 65,000 years old, as well as the remains in Israel being about 95k old. Its A failing in a lot of articles I see. They don’t seem to compare the dates of recent finds before typing up propsed exit dates.

A Libyan ‘Out of Africa’ route for ancient humans.

Is suggested in this recent article, kindly pointed out by Mr Mathilda a couple of days ago. Finally, I manage to pry my kids off the damn computer to post it.

The widely held belief that the Nile valley was the most likely route out of sub-Saharan Africa for early modern humans 120,000 year ago is challenged in a paper published this week in the Proceedings of the National Academy of Sciences. A team led by the University of Bristol shows that wetter conditions reached a lot further north than previously thought, providing a wet ‘corridor’ through Libya for early human migrations. The results also help explain inconsistencies between archaeological finds.

While it is widely accepted that modern humans originated in sub-Saharan Africa 150-200 thousand years ago, their route of dispersal across the hyper-arid Sahara remains controversial. The Sahara covers most of North Africa and to cross it on foot would be a serious undertaking, even today with the most advanced equipment.

Well-documented evidence shows there was increased rainfall across the southern part of the Sahara during the last interglacial period (130-170 thousand years ago). The Bristol University team, with collaborators from the universities of Southampton, Oxford, Hull and Tripoli (Libya), investigated whether these wetter conditions had reached a lot further north than previously thought.

Anne Osborne, lead author on the paper said: “Space-born radar images showed fossil river channels crossing the Sahara in Libya, flowing north from the central Saharan watershed all the way to the Mediterranean. Using geochemical analyses, we demonstrate that these channels were active during the last interglacial period. This provides an important water course across this otherwise arid region.” The critical ‘central Saharan watershed’ is a range of volcanic mountains formerly considered to be the limit of this wetter region.

The researchers measured the isotopic composition of snail shells taken from two sites in the fossil river channels and from the shells of planktonic microfossils in the Mediterranean. Despite being hundreds of kilometres from the volcanic rocks in the mountains of the Saharan watershed, these shells had a distinctly volcanic ‘signature’, very different from the other rocks surrounding the sites. Water flowing from these volcanic mountains is the only possible source of this signature.

Dr Derek Vance, senior author on the paper, added: “The study shows, for the first time, that monsoon rains fed rivers that extended from the Saharan watershed, across the northern Sahara, to the Mediterranean Sea. These corridors rivalled the Nile Valley as potential routes for early modern human migrations to the Mediterranean shores.”

The similarities between Middle Stone Age artefacts in places like Chad and the Sudan, with those of Libya, strongly support this theory. “We now need to focus archaeological fieldwork around the large drainage channels and palaeo-lakes to test these ideas” said Nick Barton, a contributor to the project from the University of Oxford.

Link

The widely held belief that it was the Nile? Generally I see the Gate of Tears pushed as the exit point, whenever I bang on about the Nile being the most likely exit route everyone ignores me. What really interested me is the 120,000 date. Very interesting. I think the 120k date is quite possible. I think the dates from the mt DNA and Y DNA don’t show any signs of accuracy. When I compared a couple they didn’t match the population expansions I knew of at all (in North Africa).

I’d like to point out that the Nile flows through the Sudan, then up into North Africa. Personally I think this theory is a bit weak, I’m still going with the Nile. I support 120k as a reasonable exit date, there was never any good evidence modern humans became extinct in the Levant when it’s climate changed.

The antiquity of M Mt DNA macrohaplogroup

Phylogeny and antiquity of M macrohaplogroup inferred from complete mt DNA sequence of Indian specific lineages
Revathi Rajkumar,1 Jheelam Banerjee,1 Hima Bindu Gunturi,1 R Trivedi,1 and VK Kashyap1. Pub 2005

Background
Analysis of human complete mitochondrial DNA sequences has largely contributed to resolve phylogenies and antiquity of different lineages belonging to the majorhaplogroups L, N and M (East-Asian lineages). In the absence of whole mtDNA sequence information of M lineages reported in India that exhibits highest diversity within the sub-continent, the present study was undertaken to provide a detailed analysis of this macrohaplogroup to precisely characterize and unravel the intricate phylogeny of the lineages and to establish the antiquity of M lineages in India.
Results
The phylogenetic tree constructed from sequencing information of twenty-four whole mtDNA genome revealed novel substitutions in the previously defined M2a and M6 lineages. The most striking feature of this phylogenetic tree is the recognition of two new lineages, M30 and M31, distinguished by transitions at 12007 and 5319, respectively. M30 comprises of M18 and identifies a potential new sub-lineage possessing substitution at 16223 and 16300. It further branches into M30a sub-lineage, defined by 15431 and 195A substitution. The age of M30 lineage was estimated at 33,042 YBP, indicating a more recent expansion time than M2 (49,686 YBP). The M31 branch encompasses the M6 lineage along with the previously defined M3 and M4 lineages. Contradictory to earlier reports, the M5 lineage does not always include a 12477 substitution, and is more appropriately defined by a transversion at 10986A. The phylogenetic tree also identifies a potential new lineage in the M* branch with HVSI sequence as 16223,16325. Substitutions in M25 were in concordance with previous reports.
Conclusion
This study describes five new basal mutations and recognizes two new lineages, M30 and M31 that substantially contribute to the present understanding of macrohaplogroup M. These two newly erected lineages include the previously independent lineages M18 and M6 as sub-lineages within them, respectively, suggesting that most mt DNA genomes might arise as limited offshoots of M trunk. Furthermore, this study supports the non existence of lineages such as M3 and M4 that are solely defined on the basis of fast mutating control region motifs and hence, establishes the importance of coding region markers for an accurate understanding of the phylogeny. The deep roots of M phylogeny clearly establish the antiquity of Indian lineages, especially M2, as compared to Ethiopian M1 lineage and hence, support an Asian origin of M major haplogroup.

They are going to have to redraw some of those migration pattern maps for the Mt DNA.

It seems that L3 was the OOA lineage, and both N and M arose in West Asia, about 63,500 and 65,000 years ago (although, personally I suspect the dates are a closer to the older edge of the possible range than the average, and are more like 80,000 years old for haplogroup M). This is the second study I’ve seen that places M as an Asian mutation.  I am uncertain as to the Gate of Tears (Red sea) as the exit route. I think the Nile still has a lot going for it as an exit point.

A possible 60,000 year old human presence in Australia

The rock shelter at Nauwalbila

Radiocarbon analysis of the early archaeological site of Nauwalabila I, Arnhem Land, Australia: implications for sample suitability and stratigraphicintegrity
Auteur(s) / Author(s)
BIRD M. I. ; TURNEY C. S. M. ; FIFIELD L. K. ; JONES R. ; AYLIFFE L. K. ; PALMER A. ; CRESSWELL R. ; ROBERTSON S. ;
Résumé / Abstract
This study presents the results of an extensive radiocarbon dating program at the Nauwalabila I site in northern Australia. The results show that the radiocarbon chronology at Nauwalabila is reliable to ∼130 cm depth, but below this depth coarse charcoal has been variably altered during a period in the early Holocene when an ephemeral groundwater table reached close to the ground surface of the time. Below ∼150 cm none of the radiocarbon ages can be considered to indicate reliably the age of deposition of the sediments. Luminescence dates near the surface and at 110 cm are concordant with the radiocarbon chronology in the upper part of the sequence, and hence the aberrant radiocarbon results below ∼ 150 cm do not constitute a reason to doubt the accuracy of the luminescence chronology deeper in the stratigraphy. A conservative estimate of the age of the sequence, based on extrapolation of results from that portion of the sequence where the radiocarbon chronology is considered to be reliable, is consistent with the chronology proposed previously from luminescence dating. Both chronologies therefore suggest occupation of the site before 50,000 years. Based on sediment characteristics and the distribution of quartz, chert, quartzite and quartz crystal’ artefacts, there is no evidence that there has been significant vertical displacement of artefacts relative to the surrounding sand matrix. Both chemical alteration and physical translocation of charcoal contributed to the aberrant ages at depth in the deposit. The results point to the need for careful assessment of the suitability of charcoal for radiocarbon dating prior to analysis and to the dangers of relying on a small number of radiocarbon dates in the development robust site chronologies. Strategies for screening samples for suitability include (i) microscopic examination, (ii) not analysing samples unless they survive the full ABOX pretreatment, (iii) not analysing samples unless the material is significantly larger than the sediment matrix, (iv) using CHN analysis on both untreated and pretreated material to check for organic contamination and (v) using stepped combustion to check for concordancy in the ages of carbon released at successively higher temperatures.

A very old, but not impossibly old, date for Aborigines in Northern Australia. 65,000 isn’t an impossibility. I’ve had a look around and the thermoluminesence dates from the site seem to agree with the 50,000 date, as do dates from Malakunanja II

The case of Roberts et al. has been recently been significantly strengthened by their announcement of a similar age for the basal deposits of a second Arnhem Land site, Nauwalabila I, 65-70 km south of Malakunanja II. This site contains ‘securely stratified’ artefacts in a rubble base below the sand deposits dated by the related but different luminescence technique, optically-stimulated luminescence (OSL) (Jones 1993; 114; Roberts et al. 1993; Roberts et al. in press). At Nauwalabila I a sequence of five OSL dates are also in stratigraphic order The three oldest samples are 30,000+2400 years (OxODK166) from 1.70-1.75 m depth below surface; 53,400+5400 years (OxODK168) from 2.28-2.40 m; and 60,300+6,700 years (OxODK169) from 2.85-3.01 m. This latter date is below both the rubble layer and the lowest artefacts, while the date of 53,400+5400 years dates the sands immediately above the rubble layer.

 Implications

The central issue is whether Malakunanja II and Nauwalabila I are really >15,000 years older than any other known Australian site as these dates imply. Luminescence dates measure calendrical years and for that part of the radiocarbon range for which we can calibrate radiocarbon determinations against other dating techniques, uncalibrated radiocarbon determinations mainly underestimate calendrical years. Stuiver et al. (1991: 10) suggest this underestimation is c. 2000 at 14,000 years ago. Mazaud et al. (1991) propose a maximum underestimation of 3000 years between 18,000 years ago and 40,000 years ago and a negligible difference between 45,000 years ago and 50,000 years ago. Bard et al. (1993) indicate that a determination of 18,000 radiocarbon years represents almost 22,000 calendar years. Stuiver & Reimer (1993) use this last date as the oldest in their most recent calibration program. In western NSW, Bell (1991: 48) compared four paired radiocarbon determinations and thermoluminescence dates for separate hearths each c. 30,000 years old, where the TL dates were between 3500 and 5100 years older than radiocarbon determinations. However, substantial comparative sequences of radiocarbon determinations and dates produced by alternative radiometric techniques for the crucial period between 20,000 and 40,000 radiocarbon years are not yet available from anywhere in the world.

From this discussion of the dating of Australian sites. It’s entirely possible that humans were in Oz at this time, as there’s some evidence of contemporary occupation in Asia (Luijiang, at 68,000 years old). So a 60,000 year old entry date to Australia is completely possible.

When did humans first arrive in greater Australia and why is it important to know?
James F. O’Connell, Jim Allen
 
James O’Connell is Professor of Anthropology at the University of Utah. He has conducted ethnographic and archaeological fieldwork in central Australia, western North America and East Africa, and has published extensively on modern hunter-gatherer ecology, ethnoarchaeology, and Greater Australian and North American prehistory. Jim Allen is currently an Australian Research Council Senior Research Fellow in the Archaeology Department, La Trobe University, Melbourne. Prior to this he was the Foundation Professor of the same department. He has conducted extensive archaeological fieldwork in various parts of Australia and Tasmania and in Papua New Guinea since the mid-1960s. Since 1984 he has concentrated on the Pleistocene archaeology of those countries and published widely on that research.

Abstract
Until recently, archeologists have generally agreed that modern humans arrived on Australia and its continental islands, New Guinea and Tasmania (collectively, Greater Australia), about 35,000 to 40,000 years ago,1 a time range that is consistent with evidence of their first appearance elsewhere in the Old World well outside Africa.2,3 Over the past decade, however, this consensus has been eroded, first by dates of 50,000 to 60,000 years from two sites in Arnhem Land and then, dramatically, by dates of 116,000 to 176,000 years from a third site on the eastern margin of the nearby Kimberley region. If accurate, these dates require significant changes in current ideas, not just about the initial colonization of Australia, but about the entire chronology of human evolution in the late Middle and early Upper Pleistocene. Either fully modern humans were present well outside Africa at a surprisingly early date or the behavioral capabilities long thought to be uniquely theirs were also associated, at least to some degree, with other hominids. Deciding whether these dates are accurate and associated with definite evidence of human activity thus becomes critically important. We think there are good reasons to be skeptical, not only on the basis of the dates and their alleged associations, but because of their mismatch with established sequences, both in Greater Australia and elsewhere. Until these issues are resolved, adjusting the broader global picture to accommodate these early dates is premature. © 1998 Wiley-Liss, Inc.

However, I’m suspicious of a date over 100,000 years. I think it’s rather more likely there was another hominid group (Erectus) in that locale, and Mungo man agrees with me.

The 60,000 year old exit from Africa…that makes no sense at all.

It’s claimed to be about 60,000 years ago from the Horn of Africa..

Let me just say I’m with Stephen Oppenheimer on this one. That ‘60,000 years ago’ exit date is pretty impossible, for several reasons…

  • The age of the haplotype M mutation, occuring in the Pakistan? area is dated to 64,000 years ago at least.
  • There’s a modern human skull in Luijiang China 68,000 years old (at least) and quite likely older.
  • There’s evidence of modern humans under the mount Toba explosion 74,000 years old in the Malay peninsula
  • There’s evidence of modern humans on top of the Toba Ash, suggesting the population didn’t die out in East Asia
  • The age of Y chromosome Adam in Africa is estimated to be 60,000 BP 4,000 years after the date of the M mtDNA mutation in South Asia. There were also people in Far East Asia by then. They must have some men not descended from Y chromsome Adam to keep going, but they are not present now.  If that isn’t proof of selection in Y chromosmes I don’t know what is.

A good look at the Mt DNA of Pakistan and India shows some L haplotypes present in Asia, so it seems a good amount of lead time can be added to the 64,000 years date, as haplotype L ‘s seems to have got there a while before. Also, In an age that great for the estimated date of a MtDNA haplotype, even a minor percentage error can add up to ten thousand years and more.

After reading some of his articles, it seems Oppenheimer is behind the colonisation of Australia at the low tide date of 65,000 years. He then worked out that you’d need at least 10,000 years to reach there from Africa.

Add this 10,000 years to the 74,000 date (Toba date) and this gives you at least 85,000 years BP from the Gate of Tears (Red sea).

So essentially, you are looking at an exit date of at least 85,000 years and probably a lot older.

There’s also the issue of ‘was there really one exit ?’ To my knowledge the Nile has always flowed into the Mediterranean, making a permanent route to the Mahgreb. There does seem to be an early seperation of Mt DNA haplotype N and M, one swinging North into central Asia (from a Nile exit?) and the other following the coastal route into Australia.

This brings me to the issue of modern humans in North Africa, in Jebel Irhoud, dated to 160,000 years years ago. If modern humans were in North africa then, how did they first exit sub Saharan Africa 100,000 years later? Another seeming impossiblity. There still seems to have been a human population there 82,000 years ago, they left bones and beads.

This all leads me to question the validity of ‘one recent exit by the Gate of Tears’ quite deeply. Thismistrust of it is made stronger by a couple of studies that have concluded mt DNA is subject to natural selection, and is not a neutral marker, so it’s entirely possible for less successful lineages to die out (there’s evidence climate affects what lineages thrive).

One DNA study I’ve seen based on other DNA markers dated the split from the East African population at 120,000 BP, and the European split from Asians at about 40,000 BP. This would roughly fit the presence of modern humans in Israel at Skhul, at 125,000 BP. It also matches roughly the date at which Europeans started moving into Neanderthal territory, so I’m inclined to support this, and assume that the MtDNA dates are very wrong, for the older clades at least.

Then there’s the issue of Mungo man, mt DNA from him showed he wasn’t descended from mitochondrial Eve.

It has to be remembered that the world wasn’t empty of people at this time. Asia was full of Homo Erectus, and from Europe into Siberia there were Neanderthals. This wasn’t just a case of expanding into an empty territory, they had two subspecies (or races, the jury is out on that one) to wipe out. This would add to the time it took to get from A to B.

This also raises the point ‘were we ever really genetically isolated from Neanderthals and Homo Erectus?’, as AMH’s seem to have been mooching around in North Africa nearly the whole time before we officially exited Africa. The fact that the Jebel Irhoud remains were initially misidentified as Neanderthal should be a clue to the answer

The out of Africa theory makes no sense at all. Beats me how it remains the accepted paradigm.