Oldest evidence for cooking in pots comes from Libya

Quickies

Kambiz Karami at Anthropology.net (a most interesting blog to follow) mentioned this week that Libyan pottery remains, maybe as old as 10,000 years ago, have provided the oldest evidence of vegetable cooking of we know of, at least in pots (see below for the disclaimer). The remains indicate cooking of vegetables and meat and are associated to pictures of people gathering plants, as well as grinding stones (hand mills) with remains of such provisions.

Ref. Nature Plants.

Oddly enough, just two days later, he contradicted himself, mentioning that the charred remains of nuts and seeds from Palestine, dated from 780,000 years ago, actually provide the oldest evidence of vegetable cooking, even if it's clearly a more primitive way of cuisine and not yet at all the "refined" stew of ancient Libyans, which won them three stars in the Paleo-Michelin Guide for Nomads and five pitchforks in Popular Mesolithic Cuisine. 

Ref. PNAS.



Update (Jan 4): origin of Libyan and West Asian pottery could be Sudan

Jm8 mentions it in the comments, referencing to Anthromadness. I would need more data to judge (the ref. paper is behind paywall) but  it does sounds as probably correct to me, being Sudan/Nubia one of the earliest Mesolithic areas in the Western half of the Old World, one that is way too often and unfairly neglected but that definitely influenced the Levant prior to the development of Neolithic proper (what should explain a lot of things both linguistic and genetic).

H. heidelbergensis is Neanderthal ancestor and not 'Denisovan' cousin

Quickies

The unprecedented sequencing of a small fraction of the autosomal DNA of Homo heidelbergensis from the Sima de los Huesos of Atapuerca proves that they are in direct ancestral line to H. neanderthalensis and not particularly related to Denisovans.

Matthias Meyer et al., Nuclear DNA sequences from the Middle Pleistocene Sima de los Huesos hominins. Nature 2015. Pay per view → LINK [doi:10.1038/nature17405]

Abstract

A unique assemblage of 28 hominin individuals, found in Sima de los Huesos in the Sierra de Atapuerca in Spain, has recently been dated to approximately 430,000 years ago¹. An interesting question is how these Middle Pleistocene hominins were related to those who lived in the Late Pleistocene epoch, in particular to Neanderthals in western Eurasia and to Denisovans, a sister group of Neanderthals so far known only from southern Siberia. While the Sima de los Huesos hominins share some derived morphological features with Neanderthals, the mitochondrial genome retrieved from one individual from Sima de los Huesos is more closely related to the mitochondrial DNA of Denisovans than to that of Neanderthals². However, since the mitochondrial DNA does not reveal the full picture of relationships among populations, we have investigated DNA preservation in several individuals found at Sima de los Huesos. Here we recover nuclear DNA sequences from two specimens, which show that the Sima de los Huesos hominins were related to Neanderthals rather than to Denisovans, indicating that the population divergence between Neanderthals and Denisovans predates 430,000 years ago. A mitochondrial DNA recovered from one of the specimens shares the previously described relationship to Denisovan mitochondrial DNAs, suggesting, among other possibilities, that the mitochondrial DNA gene pool of Neanderthals turned over later in their history.

Some articles that describe the findings:

→ at Nature News

→ at Público (in Spanish)

Matthieson also found that the Sima de los Huesos hominids were closer to Denisovans and Neanderthals in mtDNA two years ago. But this sequencing of their nuclear DNA puts them much closer to Neanderthals instead.

Prüffer et al. found in 2013 that Neanderthals form a cline with "Denisovans" in nuclear DNA but not in mtDNA, in which they are closer to us. This one is a very interesting read for background, as it explores in great detail the various possible scenarios.

That "Denisovans" could be closely related to H. erectus (a catch-all term for most archaic populations, particularly in Asia) has been considered as very possible before (Waddell et al. 2012) but there is no genetic confirmation so far, neither strong rejection. Getting DNA from such ancient specimens is considered a breakthrough and this partial sequencing of 400,000 years ago is believed to be within the very limits of absolute possibility.

[Conclusions edited on Mar 19th because I got it all wrong and don't wish to keep confusing anybody else. Instead I listed several relevant background studies, judge yourself].

An archaic human population surviving in SW China until at least 14,000 years ago

Quickies

Just a femur but looks like it. Homo heidelbergensis (Denisovan)?

Darren Curnoe, Xueping Li et al. A Hominin Femur with Archaic Affinities from the Late Pleistocene of Southwest China. PLoS ONE 2015. Open access → LINK [doi:10.1371/journal.pone.0143332]

Abstract

The number of Late Pleistocene hominin species and the timing of their extinction are issues receiving renewed attention following genomic evidence for interbreeding between the ancestors of some living humans and archaic taxa. Yet, major gaps in the fossil record and uncertainties surrounding the age of key fossils have meant that these questions remain poorly understood. Here we describe and compare a highly unusual femur from Late Pleistocene sediments at Maludong (Yunnan), Southwest China, recovered along with cranial remains that exhibit a mixture of anatomically modern human and archaic traits. Our studies show that the Maludong femur has affinities to archaic hominins, especially Lower Pleistocene femora. However, the scarcity of later Middle and Late Pleistocene archaic remains in East Asia makes an assessment of systematically relevant character states difficult, warranting caution in assigning the specimen to a species at this time. The Maludong fossil probably samples an archaic population that survived until around 14,000 years ago in the biogeographically complex region of Southwest China.

Neanderthals, Denisovans and everything else

A recent analysis of the nuclear DNA of a Neanderthal toe from Altai has caused widespread interest.

Kay Prüffer et al., The complete genome sequence of a Neanderthal from the Altai Mountains. Nature 2013. Pay per view → LINK [doi:10.1038/nature12886]

The story of a finger and a toe

Both the Denisovan and Neanderthal DNA sequences discussed in this paper come from small bones found at the same location: Denisova cave, Altai Republic. The Denisovan sequence that revolutionized human paleogenetics a few years ago corresponds to a finger phalanx bone of some 50,000 years ago. The less notorious Neanderthal sequence discussed in this study corresponds to a toe imal phalanx, which was found in a lower layer in the same gallery of the same cave, and hence should be older.

This is very interesting to underscore because it seems to imply that Neanderthals were in Altai and specifically in Denisova cave very early, at dates similar to those we find in West Asia (Tabun excepted) and they may even be older than Denisovans in the very cave that gave them their name.

The toe sequence was found in a previous study to have Neanderthal mtDNA, closely related to the lineages of European Neanderthals of various dates and sites. Instead the finger mtDNA (Denisovan) was derived from a more ancient branch of humankind than the very point of split between Neanderthals and modern humans (H. sapiens) and has been recently shown to be related to European H. heidelbergensis from Atapuerca. 

Notes in red are mine.

This study focuses on the autosomal DNA of both Neanderthals and Denisovans. Unlike mtDNA, whose phylogenetic position is simple and quite straightforward, autosomal or nuclear DNA (nDNA) is extremely much more complex to understand because of its recombining nature, requiring of statistical approaches, which may get extremely complex and potentially subject to premise biases. When comparing two individuals this gets largely simplified but it is a lot more complex when doing the same with larger samples.

And that is precisely what this study does: comparing one Denisovan, several Neanderthals and also several modern humans. Therefore it is a very complex paper and the authors necessarily assume some evaluation risks, which nevertheless are discussed in depth in the supplemental material, a methodology of the Pääbo team that we can't but greatly appreciate.

Age estimates

The study makes two age estimates, one based on a very conservative and truly unbelievable Pan-Homo split date of 6.5 Ma BP and the other based on observed per generation mutation rates, which happens to be perfectly coincident with a Pan-Homo split of 13 Ma BP, the oldest extreme of Langergraber's estimate. This coincidence alone is of enough relevance for all molecular clock approaches, because it effectively demands the doubling of all age estimates based on the ridiculously short 6.5 Ma Pan-Homo split supposition. 

Red outlines are mine. Click to enlarge.

It also produces a semi-reasonable San-West African age estimate of c. 86-130 Ka, although I would think it a bit older in fact or at the very least at the top end. This highlights the severe difficulties of such molecular clock estimates, because a 4 Ma divergence between the alleged introgressing mystery archaic in the Denisovan genome, seems out of the question according on the archaeological and paleontological record, which only documents Homo species since c. 2 Ma ago, half that time (within the estimate but clearly very far from the top end).

Altai Neanderthal inbreeding

An important finding of this study is that the studied individual was extremely inbred, with parents in effective relationship comparable to that of grandparent and grandchild or half siblings. This inbreeding tendency, even if extreme, is not so strange in populations that have experienced founder effect bottlenecks and small population sizes. The Denisovan and the modern human Karitiana people are not so extreme but range in the lower end of double first cousins level of genetic relationship between the parents. Other Native Americans like the Mixe are close to that range, while the other compared populations, Papuans and Sardinians, show much lower levels of inbreeding.

Whatever we may think of Altai Neanderthal inbreeding, their drift parameter is still very low when compared with European Neanderthals. This is not discussed in the paper but such extreme drift also seems to imply extreme inbreeding issues in European Neanderthals, even if these may have other causes such as an extremely strong founder effect or whatever.

Bonobo-specific segments were removed, so the bonobo position is not realistic.

Inferred population history

Both populations leading to the Altai Neanderthal and Denisovans, but not modern humans, appear to have gone through a strong decline in population size since hundreds of millennia ago. The Denisovan decline seems to begin c. 800 Ka ago while the Neanderthal one may have begun c. 500 Ka ago. While this is coincident with a general expansion of the H. sapiens branch (still undifferentiated in Africa), peaking around c. 250 Ka ago before differentiation and relative decline. In their words:

All genomes analysed show evidence of a reduction in population size that occurred sometime before 1.0 million years ago. Subsequently, the population ancestral to present-day humans increased in size,whereas the Altai and Denisovan ancestral populations decreased further in size. It is thus clear that the demographic histories of both archaic populations differ substantially from that of present-day humans.

Neanderthal and Denisovan admixture in modern humans

The new tests confirm in essence the previous findings: there is significant Neanderthal introgression in modern humans descending from the migrants out of Africa and there is also significant Denisovan one among Australasian populations.

Additionally and with some caution, the authors think that much lesser Denisovan introgression (of around 0.2%) is found among East Asians and that these, as well as Native Americans, show slightly more Neanderthal admixture than West Eurasians. In my understanding this may be caused by minor African flow to West Eurasia after the admixture event (and/or residual "First Arabian" persistence) and I would think that measuring South Asians would help to clarify this issue (because African admixture is negligible in the subcontinent but they are also distinct from East Asians).

These measurements are so weak that the authors agree to all kind of cautions about them in any case.

In addition to all this, the supplemental material (section 13) also detects tiny, almost homeopathic, amounts of Neanderthal gene flow to Yorubas (~0.02%), obviously mediated by H. sapiens backflow from Asia and Europe into parts of Africa, which eventually influenced other African populations. An even more diluted amount may also be present among the Mbuti Pygmies.



Altai Neanderthal admixture in Denisovans

This issue is not really explained in the paper as such, and we have to reach out to the Supplemental Information chapter 15 in order to grasp it.

It is clear that the Altai Neanderthals are closer to Denisovans than other Neanderthals are by approx. the following fractions (directly deduced from the raw affinities listed in fig. S6a.2):

• 2% more than Mezhmaiskaya
• 7% more than Vindija (avg.)
• 9% more than El Sidrón

Feldhofer appears closer instead but this sequence was not used by the authors in most tests because it has too dubious quality.

In section 15 of the supplementary material, using complex methodology and lamenting the lack of a second Denisovan sample which would be most useful, they estimate a minimal 0.5% (Altai) Neanderthal introgression in Denisovans, with strong warnings that this could well be quite higher. I don't know why they are not even considering a more direct approach, but I would dare to guesstimate the introgression to be close to 8% from the above raw data, assuming that there are no further complexities at play, such as other Heidelbergensis introgression in European Neanderthals, etc. The drift parameter (see above) does not seem to be one such complexity because Mezhmaiskaya is almost as drifted as Vindija yet it is consistently much closer, as it seems to correspond to its specific relatedness to Altai Neanderthals in mtDNA (and possibly also in nDNA if it is admixture what causes their pseudo-tree positioning closer to the root, what would be typical).

Note in blue is mine.

Mystery archaic genetic flow into Denisovans

The authors find that some 0.5-8% of the Denisovan genome appears to come from another hominin, which split from the human trunk even earlier.

We caution that these analyses make several simplifying assumptions. Despite these limitations, we show that the Denisova genome harbors a component that derives from a population that lived before the separation of Neanderthals, Denisovans and modern humans. This component may be present due to gene flow, or to a more complex population history such as ancient population structure maintaining a larger proportion of ancestral alleles in the ancestors of Denisovans over hundreds of thousands of years.

Later in the discussion section they ponder further the implications of this finding:

The evidence suggestive of gene flow into Denisovans from an unknown hominin is interesting. The estimated age of 0.9 to 4 million years for the population split of this unknown hominin from the modern human lineage is compatible with a model where this unknown hominin contributed its mtDNA to Denisovans since the Denisovan mtDNA diverged from the mtDNA of the other hominins about 0.7–1.3 million years ago⁴¹. The estimated population split time is also compatible with the possibility that this unknown hominin was what is known from the fossil record as Homo erectus. This group started to spread out of Africa around 1.8 million years ago⁴², but Asian and African H. erectus populations may have become finally separated only about one million years ago⁴³. However, further work is necessary to establish if and how this gene flow event occurred.

Going to the detail of the matter (i.e. supplemental material sections 16a and 16b), one of the key details is that present-day Africans share more derived alleles with Neanderthals than with Denisovans. This can only be explained because Denisovans have other archaic ancestry prior to their apparent divergence from Neanderthals or (what is about the same) because Denisovans diverged themselves prior to the Neanderthal-Sapiens split, what is what the mtDNA (unlike the nDNA) suggests. However the difference, even if consistent across comparisons, is too small (a few percentage points) to be attributed to the later scenario.

This means that Denisovans appear to be at nDNA level some sort of an independent branch of proto-Neanderthals with some other but minor archaic admixture. Instead at mtDNA level they appear to be unrelated to Neanderthals and related instead to H. heidelbergensis (a detail not discussed in this paper because it is a too recent independent discovery).

There are still many details to explore but, in principle, it would seem that the Denisovan branch appears to be a divergent proto-Neanderthal one (maybe related to the Hathnora hominin, which looks very much Neanderthal) with lesser other archaic (H. heidelbergensis?) admixture, which nevertheless remained prominent in their mtDNA for whatever accidental reason.

Whether the H. heidelbergensis population of Atapuerca responds to this same profile (i.e. they were Denisovans too) or belongs instead to the "other archaic" population which introgressed in the Denisovan genome remains to be solved. So far we only know the mitochondrial lineage and this one may be misleading, as seems to be the case with the Denisova hominin.

Note in red is mine

Modern human genetic evolution

Benefiting from the high quality of the archaic genomes of Altai, the authors cataloged a long list of simple mutations exclusive to our species: 31,389 single nucleotide substitutions and 4,113 short insertions and deletions (indels). Additionally they found other 105,757 substitutions and 3,900 indels shared by 90% of their modern human sample of 1094 individuals.

They suggest some lines for future research in this regard, maybe focusing on genes known to influence brain development or regions that could show signs of positive selection. These preliminary lines of research are explored in SI-20, noticing potential selection in genes that affect the ventricular zone of the brain and cell proliferation in fetal brain development.

Echoes from the past (May 17 2013)

Some interesting news I cannot dedicate much effort to:


Human intelligence not really linked to frontal lobe.

New research highlights that the human frontal lobe is not oversized in comparison with other animals. Instead the human intelligence seems to be distributed through all the brain, being the network what really matters → Science Daily. 

Ref. Robert A. Barton and Chris Venditti. Human frontal lobes are not relatively large. PNAS, May 13, 2013 DOI: 10.1073/pnas.1215723110
 

Early hominin ear bones found together in South Africa.

The three bones, dated to c. 1.9 Ma show intermediate features between modern humans and apes → PhysOrg.

New hominin site in Hunan (China).

The sediments of Fuyan cave, in which five human teeth (Homo erectus?) were found, along with plenty of animal ones, are dated to 141,700 (±12,100) years ago. → IVPP - Chinese Academy of Sciences.

The five human teeth

Neanderthal workshop found in Poland.

In Pietrowice Wielkie (Silesia), which is at the end of a major natural corridor from the Danubian basin → PAP.


Ancient Eastern Europeans ritually killed their pets to become warriors.

In the Bronze Age site of Krasnosamarkskoe (Volga region, Russia) more than 50 ritually pieced skulls of dogs have puzzled archaeologists, who have reached the conclusion, after researching Indoeuropean accounts from India, that the animals may have been killed in adulthood rituals: the boys who were to become warriors had to kill their most beloved pet in order to be accepted as such, and did so in a precise and macabre ritual → National Geographic.


Ancient log boat found in Ireland.

In the Boyne river, which was in the past a major artery of the island. Not yet dated: it could be from prehistoric times or the 18th century. → Irish Times.

An infant's milk tooth from Orce is the earliest known human remain in West Europe

The discovery was made in 2002 but is only to be published in a formal paper now, at the Journal of Human Evolution (not yet published, it seems). The molar from a young child of, possibly, Homo erectus, habilis or, if you wish, georgicus was found in the Cave of Orce (Granada province, Andalusia) and dated to c. 1.4 million years ago, being therefore the most ancient human inhabitant known in Western Europe. 

This finding correspond to Oldowan findings by Catalan archaeologist Josep Gibert, which he dated to c. 1.5-1.8 Ma ago but that other scholars prefer to date somewhat more recently (1.2 Ma ago?) The Gibert dates in any case correlate well with the recent discovery of H. georgicus and the general estimate for the first migrations out of Africa by H. habilis/erectus, dated also to c. 1.8 Ma ago. 

"Orce Man" scapula

It would also add some support to the claim by Gibert of a bone found in that same cave in 1983 being part of the skull of an archaic human, the so-called Orce Man, which he dated to 1.3 Ma. Back in the day the finding was strongly contested and even claimed to be an equid's scapula, however the debate has not yet settled and it seems that these days only creationists are heavily opposed to Orce Man being real, while the scientific establishment remains divided. 

Whatever the case, if Orce Man was real, this kid could well have been his direct ancestor.

Sources[es/cat]: Pileta (incl. videos); Catalan Institute of Human Paleontology (IPHES) → blog (many photos), press release; 20 Minutos.


Update:

The son of Josep Gibert, Luis, laments in interview by press agency EFE (published today at Diario Vasco, for example) that some people (in direct reference to IPHES' director) still discredit his father's work but he feels happy about the tooth finding.

He argues that it cannot be the scapula of a ruminant among other reasons because these animals have a much thicker skull than us humans.

He also feels personally affected because he had hoped that his team could have obtained a license to work in the Orce area but the Andalusian authorities have only produced one single license for one single team.

(Via Pileta again).


Update (Mar 23): Gibert controversy delays publication

Publication of the relevant paper has been delayed after Luis Gibert asked the Journal of Human Evolution why a tooth fragment, dated to 1.25 Ma., published by his father Josep in Human Evolution 1999 (now extinct), is not even mentioned. Other works by Josep Gibert on Olduwayan tools found in the very same site of Barranco de León with dates as old as 1.5 Ma. are also ignored in the study's text and bibliography. For these reasons Elsevier has decided to provisionally pull back the publication until these works are cited.

Paul Palmqvist, one of the members of the team currently digging at Orce, laments the decision on the grounds that the tooth fragment found by Gibert is not at all conclusively human.

It is a fragment of tooth enamel that in my opinion belonged to a hippopotamus, he said.

Luis Gibert claims that the humanity of the tooth was confirmed to his father in a telephone conversation by reputed archaeologist José María Bermúdez de Castro, however this one denies such thing ever happening and the humanity of the Gibert molar fragment. He also attacked the defunct publication Human Evolution as a third tier magazine, a parochial flier in which everything was allowed.

Source: Paleorama en Red[es].


Update (Mar 25):

Ama Ata dedicates today an entry to a documentary (in Spanish, 1hr long, split in four videos) titled Orce Man, homage to Josep Gibert. It is interesting to realize that many scientists are supportive of the position of Gibert, very notably Yves Coppens, discoverer of famous australopitecine Lucy, who says that Josep died too young (in 2007) because otherwise he might have lived to see the triumph of his theories.

The real issue seems to be that in the early 80s, there was a widespread belief in the Academic establishment on Europe had not being inhabited by any kind of humans until some 500,000 years ago. This finding did not only more than double those dates (something now widely accepted) but Gibert was even suggesting that they might have arrived by crossing the Strait of Gibraltar, something that even today some find hard to believe for Homo erectus.

However the skull fragment was widely accepted initially as real. But then a small "occipital crest" was found in it, what led Lumbley to argue that it was a horse instead. Gibert lamented that instead of communicating this to him or otherwise debating cleanly, the French leaked this to the press surreptitiously and pulled strings within the circles of power of the Academia, a similar method of pseudoscientific disqualification by established "armchair scientists" to calumniate the findings of Iruña-Veleia.

Million years old human remains from Eritrea

Fragments of a human skull dated to some one million years ago have been found at Muhuli Amo, Eritrea. They are probably correlated with a previous finding of hundreds of Acheulean tools. 

The skull fragments found

Sources: The Archaeology Network, Pileta, Noticias de Prehistoria[es].

Technological revolution in African Acheulean some 800,000 years ago

Well, maybe the title is a bit of a hype but something like that seems to be the most relevant finding on the Acheulean of Konso (SNPP region, Ethiopia): that the technique stood the same for a million years and then, some 800,000 years ago, became more refined in which was apparently one of the first technological leaps of archaic Humankind. Specifically it is the edges of the handaxes (the archetypal Acheulean finding, which may have been more a knife of sorts than a true axe) which became more refined and apt for its cutting purpose.

Yoyas Beyene et al., The characteristics and chronology of the earliest Acheulean at Konso, Ethiopia. PNAS 2013. Open access → LINK [doi:10.1073/pnas.1221285110]

Abstract

The Acheulean technological tradition, characterized by a large (>10 cm) flake-based component, represents a significant technological advance over the Oldowan. Although stone tool assemblages attributed to the Acheulean have been reported from as early as circa 1.6–1.75 Ma, the characteristics of these earliest occurrences and comparisons with later assemblages have not been reported in detail. Here, we provide a newly established chronometric calibration for the Acheulean assemblages of the Konso Formation, southern Ethiopia, which span the time period ∼1.75 to <1.0 Ma. The earliest Konso Acheulean is chronologically indistinguishable from the assemblage recently published as the world’s earliest with an age of ∼1.75 Ma at Kokiselei, west of Lake Turkana, Kenya. This Konso assemblage is characterized by a combination of large picks and crude bifaces/unifaces made predominantly on large flake blanks. An increase in the number of flake scars was observed within the Konso Formation handaxe assemblages through time, but this was less so with picks. The Konso evidence suggests that both picks and handaxes were essential components of the Acheulean from its initial stages and that the two probably differed in function. The temporal refinement seen, especially in the handaxe forms at Konso, implies enhanced function through time, perhaps in processing carcasses with long and stable cutting edges. The documentation of the earliest Acheulean at ∼1.75 Ma in both northern Kenya and southern Ethiopia suggests that behavioral novelties were being established in a regional scale at that time, paralleling the emergence of Homo erectus-like hominid morphology.

Fig. 4. Handaxe refinement through time. Upper, dorsal; Lower, ventral.
From left to right, two each are shown from KGA6-A1 (∼1.75 Ma), KGA4-A2 (∼1.6 Ma), KGA12-A1 (∼1.25 Ma), and KGA20 (∼0.85 Ma). In each pair of handaxes from the respective sites, near-unifacial (left) and more extensively bifacial (right) examples are shown (except with the KGA20 handaxes, which are both well worked bifacially).

I am a bit intrigued by the all-covering work style of the last handaxes, which remind somewhat to the later MSA technology, which belongs already to Homo sapiens. Our species may have also evolved in that very area of the Nile Basin, with the oldest specimen known being from nearby Omo River.

Of course that there are hundreds of thousands of years in between and of course that the peculiar orography of the Rift Valley is susceptible of offering archaeological findings from old much more easily than other areas but still...

Other sources: Pileta, NBC News.



Update: much more than just the edges but a whole technological paradigm change:

I was not really appreciating the whole extent of the technological revolution implicit in these changes. I just took note (reading too fast, too many things to do) of the edge refinement but Va_Highlander has correctly called my attention on that it was a much more ample and complex change in the whole technology of stone flaking and not just the edges, maybe even a whole jump in our mental capacities:

In contradistinction to the >1.2-Ma assemblages, the younger ∼0.85-Ma Konso Acheulean is characterized by considerably refined handaxes. Some of these handaxes are refined to the extent that they would qualify as approaching “three-dimensional symmetry” (i.e., symmetric not only in plan view but also in cross-section form) (Fig. 4 and Fig. S2). Some suggest that manufacturing 3D symmetric tools is possible only with advanced mental imaging capacities and that such tools might have emerged in association with advanced spatial and navigational cognition, perhaps related to an enhanced mode of hunting adaptation. It has been pointed out that purposeful thinning of large bifacial tools is technologically difficult, even in modern human ethnographic settings. In modern humans, acquisition and transmission of such skills occur within a complex social context that enables sustained motivation during long-term (>5 y) practice and learning.
 
In light of the above information, it is of interest that our metric analysis shows that there may be a fundamental difference between the handaxe technologies of >1.2 and ∼0.85 Ma. Whereas refinement of handaxe shape did occur from ∼1.6 to ∼1.2 Ma, this refinement did not result in tool thinning and advanced 3D symmetry.

Asian Homo erectus may have used fire and clothes

That is what a media news is claiming on this New Year's night: that Peking man, an early member of a long diverged branch of Humankind (understood as the genus Homo in full) may have already used artificial fire and leather clothing.

While this may seem quite necessary for any kind of people living as far North as Beijing (roughly the latitude of Philadelphia) the possibility that our cousin's adaption to cold was biological, by means of retaining ancestral fur instead of our techno-cultural way, was open.

Now some researchers from the Chinese Academic of Science's Institute of Palaeoanthropology and the University of Toronto think that they have some evidence that could support the use of fire and clothing.

As far as I can tell no study has been published yet, so I'm telling from the media alone.

Sources: Live Science, MSBCN - h/t Unreported Heritage News.

PS - Happy 2013 to all. 

The Paleolithic of the Three Gorges region of China

The controversial construction of the Three Gorges Dam served at least to make some extensive and intensive archaeological research in the area, evidencing human presence in much of the last million years. 

Pei Shuwen et al., Middle to Late Pleistocene hominin occupation in the Three Gorges region, South China. Quaternary International (2012). Pre-publication free access → LINK (PDF) [doi:10.1016/j.quaint.2012.04.016]

Abstract

The contributions of the Chinese Paleolithic record to broader ranging paleoanthropological debates have long been difficult to decipher. The primary problem that hinders many contributions that include or focus on the Chinese record is that relatively few regions outside of the main flagship sites/basins (e.g., Zhoukoudian, Nihewan Basin, Bose Basin) have been intensively researched. Fortunately, systematic archaeological survey and excavations in the Three Gorges region, South China over the past two decades has led to the discovery of a number of important hominin fossils and Paleolithic stone artifact assemblages that have contributed to rethinking of ideas about hominin adaptations in Pleistocene China. This paper provides a detailed review of the results of recent paleoanthropological, particularly Paleolithic archaeological, research from this region.

The Three Gorges region is located in the transitional zone between the upper and middle reaches of the Yangtze River (Changjiang River). Vertebrate paleontological studies indicate that the faunas from this region belong primarily to the AiluropodaeStegodon faunal complex, a group of taxa representative of a subtropical forest environment. Systematic field surveys identified sixteen Paleolithic sites in caves and along the fluvial terraces of the Yangtze River. Based on geomorphology, biostratigraphy, and geochronology studies, these sites were formed during the Middle to Late Pleistocene. Follow up excavations at these sites led to the discovery of a large number of Paleolithic stone artifacts, Pleistocene mammal fossils, as well as some hominin fossils. Analysis of these materials has provided the opportunity to reconstruct hominin technological and mobility patterning in a restricted spatial point. The Paleolithic technology from the Three Gorges region is essentially an Oldowan-like industry (i.e., Mode 1 core and flake technologies) comprised of casual cores, whole flakes, fragments, and chunks as well as a low percentage of retouched pieces. The utilized stone raw material is primarily high sphericity cobbles and limestone, which were locally available along the ancient river bed and surrounding terraces. Most of the artifacts are fairly large in size. All flaking is by direct hard hammer in a single direction without core preparation. Unifacial choppers are the predominant core category, with fewer bifacial choppers, sporadic discoids, polyhedrons, and bifaces. The flake types demonstrate that the first stage of core reduction is represented by a low percentage of Type III and VI flakes. Some flakes are retouched unifacially by direct hard hammer percussion on the dorsal surface of the blanks. Archaic Homo sapiens and modern H. sapiens identified from some of the cave deposits are likely the hominins responsible for the production of the stone artifacts. Implications for Oldowan-like technological patterning in South China are discussed.

There is rather high detail in this paper in spite of the stone tools of East Asia tending almost invariably to simple flake forms hard to classify, arguably caused by the lack of good quality materials. But I guess that the most relevant of all is this chronology:

Of great interest are no doubt the human (or hominin) fossils found in these and previous digs. If my recollection is correct these are:

• Xinlong cave (Wushan Co., c. 118-154 Ka): Four hominin permanent teeth were recovered during the 2001 excavation field season (Fig. 2). These hominin fossils have been tentatively assigned to archaic H. sapiens, though more detailed morphometric analysis is warranted.
• Leiping cave (Wushan Co., middle or late Pleistocene): Hominin fossils including one occipital, some fragments of skull, and a frontal bone of one juvenile, and one upper incisor were collected from the sediments and tentatively assigned to archaic H. sapiens...
• Migong cave (Wushan Co., c. 13,100 BP): The hominin fossils are two fragments of parietal bones which belong to one individual (Fig. 2) and can be assigned to modern H. sapiens.
• An archaic jaw bone was also found in the 1950s without context.

It is not clear if by archaic Homo sapiens the authors mean Homo sapiens with debatable archaic features or, using obsolete terminology, other species of Homo such as Homo erectus. I'm guessing that the latter but no idea.

Folic acid deficiency detected in Olduway c. 1.5 Ma ago

The headlines and even contents in commercial media and blogs alike are all about meat eating (much of which must be blamed on the lead researcher himself, who seems to have a bias) but it does not need to be the reason at all and rather reflects an ideological bias. 

All that paleoanthroplogists have detected is a folate deficiency in a fragment of a skull of what is probably an Homo erectus/ergaster young child (est. 2 y.o. or less) from East Africa. There is no dietary isotope research that can confirm or deny the meat hypothesis.

Manuel Domínguez-Rodrigo et al., Earliest Porotic Hyperostosis on a 1.5-Million-Year-Old Hominin, Olduvai Gorge, Tanzania. PLoS ONE 2012. Open access ··> LINK [doi:10.1371/journal.pone.0046414]

The authors found exactly this:

Figure 3. Ectocranial (top right) and endocranial (top left) close-up views of the OH 81 fossil, accompanied by magnifications of the porotic hyperostosis paleopathology as observed ectocranially (lower left) and edge-on at the diploic-table junction (lower right).

Scale = 1 mm.

They conclude that this porosity of the bone, known as porotic hyperostosis, should indicate folate deficiency (in which vitamins B9 and B12 are involved) caused by malnutrition. They also argue that weaning may have been a cause because, at least in other contexts, it is a key period for nutritional illnesses, often implying B12 deficiency. 

The archaeo-environmental context (persistent drought) may have contributed to this illness and death as well.

Still the emphasis in meat eating, even if possibly correct, strikes me as very ideological:

The presence of anemia-induced porotic hypertostosis on the 1.5 Ma OH 81 hominin parietal, indicates indirectly that by at least the early Pleistocene meat had become so essential to proper hominin functioning that its paucity or lack led to deleterious pathological conditions. 

Were do we get that from, Dr. Domínguez? Some sort of nutritional lack seems obvious but there are many reasons why folate deficiency can develop; for example excess of solar radiation (it has been proposed that the ancestral dark skin of humans serves to prevent folate loss, rather than cancer, which only develops in the long term). Was this child an albino maybe? 

Or had it celiac disease (another possible cause of malabsorption)?

And (update), as the Subersive Archaeologist discusses rather emotionally, the maybe simplest explanation: that malaria could be the cause is dismissed in the paper without satisfactory explanation.

Sure thing that lack of sufficient animal protein intake is a plausible cause but by no means demonstrated. An isotopic analysis could support or reject this hypothesis, although I am uncertain if it is possible to perform on this particular bone.


See also labels Paleolithic food, human evolution and pigmentation in this blog.


Update (Oct 10): I just got to know that there is a formal criticism by two anthropologists, J.J. Crandall and D.L. Martin, roughly in the same line as mentioned here. Read it here.

Update (Oct 16): Domínguez at al.  replied to the previous criticism here. However their only argument against a malaria-caused PH is:

PH still occurs in much lower frequencies on skeletons in this earlier transitional period than is observed in more recent skeletal populations from the sedentary, agrarian Neolithic.

... what fails to be conclusive.

Evolving bigger brains everywhere?

Peking Man (CC by Mutt)

New craniometric research on the NE Asian Homo erectus (also known as Peking Man or Homo erectus pekinensis) seems to confirm that the population grew bigger brains with limited external input. If correct, this may mean that the pressure towards bigger brains has been a generalized tendency in all Homo sp. populations. 

Late H. erectus pekinensis had cranial capacities above 1000 cc., in some cases bordering our own averages and certainly within our range. 

This research highlights that there is no apparent evolution in the shape of the head while the size did grow along time. However craniometry is a very inexact science.

Source: Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences.

Denisovan and Neanderthal proviral DNA

A provirus is a strand of autosomal DNA that was inserted by a virus once upon a time and got lost in our genome as junk DNA, not being anymore active (would it remain active it'd be a retrovirus). Such insertions are thought to be unique phylogenetic events. 

New research has identified a provirus* (HERV-K-Ne1 = HERV-K-De6, inserted in Chromosome 5) shared by Neanderthals and Denisovans but not Homo sapiens. This is consistent with the previous data that placed their autosomal DNA closer to each other than to Homo sapiens.

Lorenzo Agoni et al., Neandertal and Denisovan retroviruses. Current Biology, 2012. Freely accessible (letter with supplementary material) at the time of writing this.

It must be noted however the mitochondrial DNA, inherited by pure matrilineage, is much closer among our species and Neanderthals than either one with Denisovans, what to me suggest that Denisovans are no new species but a hybrid of Neanderthal and Homo erectus. A theory not yet fully testable for lack of DNA from Asian Homo erectus.

Interestingly Denisovans have also several proviruses not found in Neanderthals, what could well support my theory of hybridization. The detected provirus could hence have migrated from Neanderthals to Denisovans in the hybridization episode (along with lots of other autosomal DNA), while the rest could have been retained from the H. erectus ancestors by the maternal line. 

However as the article is both very technical and succinct, I can't be sure right now of how strongly or weakly can this info support the hybridization model (founded opinions welcome). 

In total the researchers detected three Neanderthal proviruses and 12 Denisovan ones, one of which is shared between both nominal species. It is convenient to remind that while the Denisovan genome was very well preserved and sequenced almost completely, the Neanderthal genome is only known in fragmentary form, amounting to about 60% of the actual genome.

Acheulean use of fire confirmed

That is what Francesco Berna and colleagues argue in a new paper:

F. Berna et al., Microstratigraphic evidence of in situ fire in the Acheulean strata of Wonderwerk Cave, Northern Cape province, South Africa. PNAS 2012. Open access.

The findings are dated to at least one million years ago and correspond to the Acheulean period, characterized by bifacial axes and generally attributed to Homo erectus or H. ergaster.

Partly charred bone from Wonderwerk

As the authors explain, previous claims of fire use in this period in East Africa,  the Levant or China have been plagued with controversy. In most cases the controversy stems from the relatively low resolution of the research and the possibility of the fires being natural occurrences. In the case of Zhoukoudian, near Beijing, what was once claimed as product of fire ended being sedimentary deposits. 

This research actually continues the findings of Peter B. Beaumont last year, who claimed (JSTOR, pay-per-view) that the South African cave hosted evidence of fire dated to c. 1.7 Ma.

The evidence included charred vegetal remains and animal bones, these last not completely calcinated, meaning that combustion was under 700 °C. Also remains of ironstone brought intently to the cave and worked in situ (main material of artifacts) show signs of manipulation under heat above 500 °C.

Apparently the fires were produced almost exclusively with light materials such as dry grasses and leaves. While it is not impossible that they might have used wood and then the evidence got lost, the data from bones indicates combustion under 700 °C, what is compatible with fire produced with lighter materials exclusively.

See also: Boston University's site, BU Today.

Anomalous Paleolithic skull from South China

This is sure going to cause some heated debates:

Darren Curnoe et al., Human Remains from the Pleistocene-Holocene Transition of Southwest China Suggest a Complex Evolutionary History for East Asians. PLoS ONE 2012. Open access.

See also the press release (Eureka Alert) and a photo gallery (Live Science).

And this is what is all about:

It's not the skull of Darth Vader, although I know you thought so as soon as you saw it, but actually that of a person living some 14,000 years ago at Longling cave, known as Longlin 1.

The authors of the paper argue on craniometric grounds that the specimen may not be a modern human, however in all PC analysis the skull falls (oddly enough) within or very close to modern human clusters. Only in the PC3 some differences show up. 

In fact the closest among those skulls analyzed in fig. 8 is Mai Da Nuoc[PDF], an Early Hoabinhian skull from nearby Vietnam, which is claimed to be Australoid (but does not look at all like the Australian skulls I'm familiar with, normally quite broader).

In fact I have been searching and I found at least one skull that looks a lot like Longlin 1: Peñón woman from Mexico:

(Source)

She's one of a number of Paleoindian skulls that have puzzled prehistorians because they are not quite like most modern Native American skulls. However to my eyes, the Peñuelas skull (Chile) skull is not that different, even if it is also more like modern Native American ones.

Also to my eyes, those very marked cheek bones (regardless of whether they may have been produced by mastication) remind me of one of the most characteristic traits of the so-called Mongoloid type (which is quite unreal and plural in fact): prominent cheekbones that give the face a flat appearance.

But I'll leave that to the experts. Not worth bumping heads for something that may well be partly epigenetic/environmental for all I know.

What I do not see is any ground for the claims of the authors that it could be a newly found species. They even have worked a fancy reconstruction that makes Longlin 1 to look like a well-known reconstruction (by the same author) of the notorious Hobbit (when the skulls do not look at all similar):

Credit: Peter Schouten (info)

Notice please how any trait that could make him look Mongoloid (East Asian or Native American) has been scrapped from the reconstruction: he has dark brown skin, beard (which could well have been shaven by a professional just yesterday) and a hairy body, a very broad nose that does not fit at all with the small triangular orifice, absolute lack of epicanthic fold - plus very small ears that make him look odd. 

Another analyzed skull from the same area is Maludong 1704, of which only the vault remains. This one overlaps in the analysis (fig. 9) with Crô-Magnon 1, however when more samples are added (fig. 10) some archaic skulls (H. erectus) also show up close, as do again CM1, early African H. sapiens and Nazlet Khater 2. 

For me, with due caution, modern proto-Mongoloid H. sapiens (anomalous) but your call: the debate is served.


Update (Mar 17): I must mention that the excellent anthropological artist Zaender (which I have mentioned before) has also produced his own versions of the Maludong people without most of the exotic fancy of Schouten's reconstruction:

Credit Zaender

He has another example at his blog: Regional Ancestry Bands.

The ears still look small to me and the nose and lips unnecessarily too wide but it is probably more correct re. eyes and hair.

In any case it makes evident that it's very difficult to actually reconstruct a face from just a skull when all the expressiveness and even most ethnic traits are in the flesh and skin, being impossible to discern from a mere skull.


Update (Mar 30):

Another interesting reconstruction by Zaender (he drew the nose smaller on my suggestion):

Credit: Zaender

See the discussion below and at his blog.

Also very interesting and surely important is the argumentation by Biological Anthropologist A.P. Van Arsdale that the main diveregent measure is the zygomatic bone but this one is fractured in several points, what may distort the results singnificantly:

Otherwise the skull fits quite well with modern East Asian metrics.

Extremely ancient introgression in Papuans

Melanesians

Neanderfollia mentions today[cat] new genetic research that has found unusual diversity in gene OAS1 among Papuans. They contend that this is caused by extremely old introgression that they estimate in more than three million years (more than the age of the genus Homo).

Fernando L. Méndez et al., Global genetic variation at OAS1 provides evidence of archaic admixture in Melanesian populations. Molecular Biology and Evolution 2012. Pay per view.

Abstract

Recent analysis of DNA extracted from two Eurasian forms of archaic human show that more genetic variants are shared with humans currently living in Eurasia than with anatomically modern humans in sub-Saharan Africa. While these genome-wide average measures of genetic similarity are consistent with the hypothesis of archaic admixture in Eurasia, analyses of individual loci exhibiting the signal of archaic introgression are needed to test alternative hypotheses and investigate the admixture process. Here, we provide a detailed sequence analysis of the innate immune gene, OAS1, a locus with a divergent Melanesian haplotype that is very similar to the Denisova sequence from the Altai region of Siberia. We re-sequenced a 7 kb region encompassing the OAS1 gene in 88 individuals from 6 Old World populations (San, Biaka, Mandenka, French Basque, Han Chinese, and Papua New Guineans) and discovered previously unknown and ancient genetic variation. The 5' region of this gene has unusual patterns of diversity, including 1) higher levels of nucleotide diversity in Papuans than in sub-Saharan Africans, 2) very deep ancestry with an estimated time to the most recent common ancestor of >3 million years, and 3) a basal branching pattern with Papuan individuals on either side of the rooted network. A global geographic survey of >1500 individuals showed that the divergent Papuan haplotype is nearly restricted to populations from eastern Indonesia and Melanesia. Polymorphic sites within this haplotype are shared with the draft Denisova genome over a span of ∼90 kb and are associated with an extended block of linkage disequilibrium, supporting the hypothesis that this haplotype introgressed from an archaic source that likely lived in Eurasia.

This is what I have been arguing since December 2010: "denisovan" admixture in Australasian and SE Asian aborigines stems from Homo erectus (diverged from our line at least 1.8 Ma ago) or even maybe a most distant cousin (maybe H. floresiensis, argued by some to be more archaic than H. erectus in key elements like the wrist or toes). 

Yet I am a bit skeptic of the age estimate, because, unless the H. floresiensis australopithecine hypothesis could be confirmed, the date is out of bounds for Humankind proper and creates many conceptual challenges, which are admittedly hard to swallow. While the "australopithecine hobbit" hypothesis would fit this scenario, it remains hard to swallow that the two genus would still be inter-fertile just a few dozen millennia ago and then again, why would archaic admixture come from this remote relative and not the much closer H. erectus, which we know lived in East Asia until rather recently. 

Finally I am in general very skeptic of age estimates as such and their ability to be able to inform more than they confuse. Normally I find them too recent but the opposite (too ancient) can also happen, I imagine. They are in any case just estimates: educated guesses and nothing else.


Update:

Got a copy of the paper (thanks again) and I would say that these two figures are of special interest:

Fig. 2 - Median joining network of OAS 1 haplotypes

Fig. 3 Geographic distribution of the deep lineage in A) Old World populations and B)
South East Asians and Oceanians.

I find particularly notable that the haplotype has been found at very low frequencies in South Asia and nowhere else West of Wallace Line. It can be backflow but may also be indicator about the possible location of the admixture event.

Certainly nothing seems to suggests in these or other maps (1, 2) of "Denisovan" admixture that the episode could have happened in Altai or nearby areas as some readers, stubborn proponents of obsolete migration models, have insisted on. Instead all the evidence suggests that the admixture episode happened in SE or otherwise Tropical Asia, whether deep in Indonesia or more towards the mainland is debatable indeed.


See also:

• Neanderthal gene flow found in modern humans (on Green 2010)
• Exploring the Neanderthal admixture episode (version 1)
• Denisova hominins, Neanderthals, Melanesians and so on... (on Reich 2010)
• Explaining 'Denisovan' and also 'Neanderthal' admixture: the simplest scenario (where I first hypothesize that H. erectus and also maybe a relative of Neanderthals like the Hathnora hominin, could be the actual culprits).
• Is X-DNA lineage Neanderthal?
• Denisovan admixture widespread beyond Wallace Line, non-existent elsewhere - but then:
• Minimal Denisovan admixture in SE Asians.
• 'Denisovan' admixture may actually be from H. erectus.