Anthropology.net

There’s a very interesting new paper, through which prospective readers are free to roam and explore at will, by Alfonso Arribas et al, in which the site of Fonelas, Granada in southern Spain is described, where excavations have revealed that around 1.8 million years ago, a vast suite of mammalian fauna from Asia, Europe and Africa congregated, affording us a unique glimpse into a previously hidden corner of the world at a time when the first hominids are thought to have made their appearance on the European stage. Moreover, these findings will prompt a great deal of thought as to how and why large mammals from such discrete and distant geographical locations came to occupy an area known today as the Guadix Basin, part of the Betic Cordillera. By way of a more formal introduction, here’s the abstract:

Background

Over the last decades, there has been an increasing interest on the chronology, distribution and mammal taxonomy (including hominins) related with the faunal turnovers that took place around the Pliocene-Pleistocene transition [ca. 1.8 mega-annum (Ma)] in Europe. However, these turnovers are not fully understood due to: the precarious nature of the period’s fossil record; the “non-coexistence” in this record of many of the species involved; and the enormous geographical area encompassed. This palaeontological information gap can now be in part bridged with data from the Fonelas P-1 site (Granada, Spain), whose faunal composition and late Upper Pliocene date shed light on some of the problems concerning the timing and geography of the dispersals.

Methodology/Principal Findings

This rich fossil site yielded 32 species of mammals, among which autochthonous species of the European Upper Villafranchian coexist with canids (Canis), ovibovines (Praeovibos) and giraffids (Mitilanotherium) from Asia. Typical African species, such as the brown hyena (Hyaena brunnea) and the bush pig (Potamochoerus) are also present.

Conclusions/Significance

This assemblage is taxonomically and palaeobiogeographically unique, and suggests that fewer dispersal events than was previously thought (possibly only one close to 2.0 Ma) are responsible for the changes seen around 1.9–1.7 Ma ago in the fauna of the two continents.

The site at Fonelas itself has been described previously in 2006, (PDF), and this paper follows on from research published in 2007, reported at this very site, the BBC and elsewhere, whilst there is even a dedicated website, in Spanish, and the sheer number and density of the fossils found are in large part due to the scavenging activities of ancient hyena. However to bring us up to date, here’s another brief snippet from the opening paragraphs:

Lying within the western extreme of the Palaearctic, the Iberian Peninsula is known for palaeoenvironmental sites with evolutionary implications of paramount importance. Over long periods of geological time, this has been a land of transitions and physiographical heterogeneity, including the possible existence of islands in the Straits of Gibraltar (enabling exchanges with the African continent). Conceivably, throughout the Cenozoic, climatically influenced species turnover, invasions, and competitive exclusion combined with species survival produced unique associations of plant and animal species. Here, we report on the chronology and composition of the late Upper Pliocene Fonelas P-1 fossil assemblage. Analogous assemblages have not been documented in Eurasia and no other findings have been recovered in the Quaternary. This truly is a large mammal “Lost World”.

The finds seem to mostly date from 1.8 million years, a date traditionally ascribed to the Pliocene/Pleistocene boundary, also known as the Quaternary, (preceded by the Neogene) but as was reported recently, this boundary which describes the onset of global cooling which ushered in a series of intense glaciation episodes, has recently been officially re-dated some 800,000 years beforehand to 2.6 mya. This is because it was felt that the earlier date more accurately reflects the time when global cooling commenced, and moreover is opined to be of greater significance in the geological record.

The paper itself offers a graphic description of the site itself, of which only a tiny portion has thus far been excavated, and includes details of the various mammals which made their way to the Iberian peninsular,  in what the researchers believe was a single migration event. Of particular interest is how some of these mammals made their way from Africa, and owing to a lack of finds along the Levantine, they propose that the Strait of Gibraltar may have been a crossing point between the African and European continents.

Although there is speculation that island once existed there that would have allowed for such a crossing, there is no evidence that I could find in the geological record that any such islands existed  – presumably the mammals, including early Homo, would have swum between each of these putative islands, some heading north into Europe, others heading south into Africa, in a faunal (and floral) exchange.

It occurred to me that there may have been episodic freezing of the Strait, which would allow for a much neater and tidier fit than transient islands, or even a land bridge which would have had to be in existence long after the Messinian salinity crisis around 5.9 million years ago, the last time that the flow of water into and out of the Med from the Atlantic had been blocked. The result was that the Med evaporated in around 1,000 years, with the possible exception of a few briny lakes scattered across the abyssal floor.

However, the sheer volume of water flowing through the Strait in both directions would seem to dictate that the Strait would not have frozen, even on a more contrasted seasonal basis,  around the time of the glaciation in Europe around 1.8 million years ago – something would have needed to temporarily switch off the Atlantic current, whose reduced salinity would have been more prone to freezing. But these strong currents would also have been a major problem for terrestrial mammals attempting the crossing, with or without islands dotted here and there, and would therefore have presented a formidable obstacle.

However, I can find no evidence that even hints at the Strait freezing over at that time, or indeed ever, and although it might be possible that a very brief episode of (seasonal) freezing lasting only decades occurred around 1.8 mya, there might be no clues in the geologic records that could confirm or deny this. The southerly latitude of the Strait is far from the Alpine glaciation which occurred further north in Europe, and even in the recent glaciation, it is thought that icebergs were found no further south than the Bay of Biscay, which again would seem to argue against the southern Iberian peninsular being cold enough to freeze its coastal waters.

If there had been islands or a land bridge at the time, the flow of water from the Atlantic could have been severely restricted, possibly to the extent that sea levels in the Med would have fallen, as the outflow of rivers around the Med Basin isn’t enough to keep it topped up. But a thin ice sheet across the Strait of Gibraltar may have allowed enough water from the Atlantic to continue flowing into the Med without compromising the depth therein – allowing for this mysterious exchange of flora and fauna which later inhabited the ‘lost world’ of the Guadix Basin.

There’s plenty more in this paper worth checking out, most notably about how the dating was established, and the details of the impressive number of remains discovered, and it seems likely that future seasons of digging  and analysis will offer an even greater volume of data and further establish the Iberian peninsular as a unique location for establishing its importance in the search for ever clearer insights into the first archaic humans residents of Europe and the vast suite of mammalian fauna with whom they co-habited.

References: Arribas A, Garrido G, Viseras C, Soria JM, Pla S, et al. (2009) A Mammalian Lost World in Southwest Europe during the Late Pliocene. PLoS ONE 4(9): e7127. doi:10.1371/journal.pone.0007127

César Viserasa, Jesús M. Soriab, Juan J. Duránc, Sila Plaa, c, Guiomar Garridoc, Fernando García-Garcíad and Alfonso Arribasc (2006) A large-mammal site in a meandering fluvial context (Fonelas P-1, Late Pliocene, Guadix Basin, Spain) Sedimentological keys for its paleoenvironmental reconstruction (PDF)

Palaeogeography, Palaeoclimatology, Palaeoecology
Volume 242, Issues 3-4, 8 December 2006, Pages 139-168

doi:10.1016/j.palaeo.2006.05.013

The controversies over the hobbits or Homo floresiensis just refuse to end. It seems that the hobbits might not be a Homo after all. I guess they found the index and ring fingers of the hobbits (Sorry, inside joke. Read this post if you want).

Anyway, Peter Brown from the University of New England who first described Homo floresiensis said that he is considering of stripping the hobbits from the genus Homo. Brown and his colleague, Tomoko Maeda, said that the Homo floresiensis lineage possibly left Africa before the evolution of the genus Homo. Their paper had been accepted and will be published in an upcoming special Homo floresiensis edition of the Journal of Human Evolution.

I can’t wait for the paper to come out. In the meantime, you can read this article from The Australian.

Originally posted on The Prancing Papio.

That is what University of Liverpool’s Emma Nelson probably would have said if she were to meet our hominan ancestors in person. Known to hold true in anthropoids (humans, apes and monkeys), the index (second digit) to ring (fourth digit) fingers ratio or 2D:4D is an indication of how much an individual were exposed to androgen (such as testosterone) in the womb. The more androgen you are exposed to, the longer the ring fingers are (and the shorter the index fingers are compared to the index fingers).

Nelson et al. believe that a high ratio (longer index finger, shorter ring finger) suggests monogamy (or pair-bonded) while a low ratio (shorter index finger, longer ring finger) suggests polygamy (or non pair-bonded). Simply put, individuals with high androgen level is likely to be non pair-bonded and the telltale sign is in the index and ring fingers. Also, some controversial studies had suggested that both men and women who receive high levels of androgen in the womb are more likely to be stronger, faster, and more sexually competitive.

Nelson and her researchers recently looked at the fossils of two Neandertals and one Australopithecus afarensis with complete index and ring fingers to determine their 2D:4D. They found that Neandertals had long ring fingers, suggesting that they were polygamous just like modern day primates that live in groups. A. afarensis on the other hand, had long index fingers. Nelson is puzzled by this discovery. “These were small creatures that probably lived in groups and were being eaten by predators. How do you keep from mating with different members of the group?”, she said.

Indeed it does not make sense for A. afarensis to be monogamous if they live in groups. Notice that Nelson et al. only used one A. afarensis fossil to get the 2D:4D. Perhaps it is not their fault that only one A. afarensis specimen had complete index and ring fingers but such are the dilemma of using fossil specimens to generalize a whole species.The result might just be a statistical outlier. However, I can’t speculate the result or the implications but anyone that are familiar with statistical data knows that a small sample size leads to a higher sampling error. Also what would a 2D:4D = 1 (same index and ring finger length) be?

Interesting enough, John Hawks at John Hawk’s Weblog mentioned the correlation of 2D:4D with male homosexuality (Robinson and Manning, 2000). I would know about this. In fact, my 2D:4D is indeed low.  Robinson and Manning predicted right! Maybe …

I do find both Nelson et al. and Robinson and Manning (2000) research interesting but I would like to stress that the results are mere predictors and correlations. Take it with a grain of salt. Don’t go measuring 2D:4D of your future spouse, boyfriend or girlfriend and accuse them of not being monogamous or a homosexual.

Emma Nelson and her team presented their research at this year’s Society for Vertebrate Paleontology meeting held in Bristol, United Kingdom. Read more about Emma Nelson’s research.

References:

Reilly M. 2009. Human Ancestors Conflicted on Monogamy. Discovery News. Retrieved September 25, 2009, from http://dsc.discovery.com/news/2009/09/24/human-monogamy.html

Robinson SJ. Manning JT. 2000. The ratio of 2nd to 4th digit length and male homosexuality. Evolution and Human Behavior 21(5): 333-345. [doi:10.1016/S1090-5138(00)00052-0]

Originally posted on The Prancing Papio

There’s water on the Moon, and even at lower than expected latitudes on Mars, not to mention a monstrous lightning storm on Saturn that has been on the go since mid-January. But none of that concerns us here, as we Earthlings possess a force of nature of our own which is much nearer to home, specifically a fortnightly anthropology blog carnival called Four Stone Hearth, which this time round is hosted over at Afarensis.

This 76th edition is a great mix of recent discoveries that have made the headlines of late, as well as a few contemplative posts, which amongst all else question not only what we see but how we interpret and process different types of information that are presented to us; there’s even a movie to watch, courtesy of the Archaeology Channel, plus a load of free papers from PNAS. None of these articles require expensive multi-spectrum telescopes, robotic space missions or teams of dauntingly bright astrophysicists to enlighten us further, as an ability to read is quite sufficient; so just head on over to Afarensis to check out the latest cluster of posts to have been plucked from their orbital paths around the blogosphere.

The next edition of 4SH is due out on October 7th, but as yet there are no hosts slated, so if you’re keen on embarking on a one-person mission to stage the 77th edition, just head over to the Four Stone Hearth base, where instructions for hosting and submitting await.

The latest issue of the Proceedings from the National Academy of Science journal hosts a Out of Africa: Modern Human Origins special feature for free online. I recommend you check it out.

September 22nd, 2009 Cover of the PNAS Out of Africa: Modern Human Origins Special

• Editorial by Richard G. Klein, “Darwin and the recent African origin of modern humans.”
• Perspective by Ian Tattersall, “Human origins: Out of Africa.”
• Perspective by Timothy D. Weaver, “The meaning of Neandertal skeletal morphology.”
• Research Article by J. J. Hublin, “The origin of Neandertals.”
• Research Article by Michael P. Richards and Erik Trinkaus, “Isotopic evidence for the diets of European Neanderthals and early modern humans.”
• Research Article by John F. Hoffecker, “The spread of modern humans in Europe.”
• Research Article by G. Philip Rightmire, “Middle and later Pleistocene hominins in Africa and Southwest Asia.”
• Research Article by Francesco d’Errico, et al., “Additional evidence on the use of personal ornaments in the Middle Paleolithic of North Africa.”
• Research Article by Michael DeGiorgio, et al.,”Explaining worldwide patterns of human genetic variation using a coalescent-based serial founder model of migration outward from Africa.”

Unfortunately, I have not yet had the time to read any of these papers but they I reckon they should be somewhat enlightening.

Julien at A Very Remote Period Indeed has posted a brief note on what looks to be a very important discovery from southern Spain, where archaeologists investigating Neanderthal occupation levels at a Mousterian site called El Salt, dating back at least 60,000 years, have discovered and analysed fat residues and other remains that indicate Neanderthals were not only cooking animals such as wild goat and deer, but quite possibly fish and vegetable matter too. Should the results be confirmed, the site of El Salt, Alcoy in Alicante would represent far earlier evidence for the dietary complexity of Neanderthals than those who occupied Gorham’s Cave, Gibraltar, and who were thought to have been eating mussels and dolphin around 25,000 years ago, after cooked remains were discovered in situ.

The difference between the two sites is that the latter dates to a time when the very last Neanderthals were thought to have been alive, c.24,500 years ago. It’s been suggested that the Neanderthals living on coastal Gibraltar had been pushed to the very edges of Europe by incoming anatomically modern humans (AMH), and that marine food was likely to have been eaten of necessity rather than choice, because by this time the harried Neanderthals were supposedly unable to acquire sufficient fresh meat on the hoof to cater for their daily needs.

However, this new study from El Salt puts Neanderthals in Mediterranean Europe 25,000 years beforehand, at a time when there were very few  – if any – AMH present to act as competition for food resources, indicating that if the El Salt Neanderthals were eating fish and possibly cooking or heating plant or vegetable products in addition to deer and goat, they were probably doing so from gastronomic choice alone.

From another report on the same site, news comes of a previous discovery of what appear to be semi-circular walls constructed of stones, that appear to have been built by Neanderthals inside the cave, although no specific date is given. As we see from this (Spanish) report in Noticias Alcoy…

Por otra parte, el equipo de arqueólogos, capitaneados por Bertila Galván, catedrática de la Universidad de La Laguna, ha encontrado unos pequeños muros de forma semicircular en la cara exterior del yacimiento.

All of which makes it seem as though we’re dealing with some pretty sophisticated customers in these Neanderthals – I think walls have been found in other Palaeolithic caves, but why in this instance they were semicircular isn’t clear, and hopefully a detailed plan and layout of the cave will be illustrated at a later date.

Back to the main story, and those fish and plant remains – although there is no specific link to the research therein, I tracked down this paper, (PDF) again in Spanish, which I think refers to the published news article, but may instead refer to another recent excavation at the same site. Very broadly speaking, it details how the researchers went about analysing through organic chemistry the remains found in and around the hearths at specific layers, and for which this is the rather modest abstract:

Se presenta un estudio químico preliminar de los alcanos y de los ácidos grasos saturados aislados en muestras sedimentarias procedentes de distintos testimonios de combustión del yacimiento musteriense de El Salt, reconociéndose importantes diferencias entre ellos, lo que refleja distintos orígenes y la complejidad funcional del yacimiento.

(We present a preliminary chemical study of alkanes and saturated fatty acids isolated from sedimentary samples from different evidences of combustion in the Mousterian site of El Salt. Important differences are recognized between them, which reflects different origins and the functional complexity of the site.)

They go on to relate how they went about identifying the long and short chain fatty acids, which varied considerably from layer to layer at the site, with some at the lowest, Z6 (image at right) indicating animal fats not altered by heat processes, which may have been faeces with others above, X6 that had been altered by heat, indicating cooking. As far as I can tell, the authors speculate that level V6 contains traces of plant fatty acids, which were also modified by heat processes, indicating that a site originally thought to have been a seasonal hunting camp, was used for different purposes over the period of its occupation. The presence of Pinus nigra was noted as being predominant,

This was gleaned from the conclusions at the end of the paper, but there is a great deal more detail of the specific chemical processes and analyses involved, and it may well be the case that I’ve omitted some important details from earlier in the paper. The presence of mammoth and salmon is also suggested, but I don’t think these are as yet conclusively proven – the more recent find of fish bones may confirm the salmon theory, which I surmise would mean such fish were sourced from a river rather than the sea.

Comparison with the samples from the excavations was made with some nearby lichen, but the chemical signatures seemed to indicate that lichen wasn’t represented in the archaeological layers.

All a bit vague I’m afraid, but overall this story and related paper definitely hint at some quite sophisticated behaviour by Late Middle Palaeolithic Neanderthals, underscored by the likely presence of constructed Mousterian stone walls within the confines of the cave itself, and hopefully further reports from this unusual site will appear in due course.

image at top from Noticias Alcoy

Reference: Tras El Fuego de los Neandertales: Química Orgánica Aplicada al Estudio de las Estructuras de Combustión del Yacimiento Musteriense de El Salt (Alcoy, Alicante)* (PDF)

R.J. MARCH, R. DORTA PÉREZ, A. SISTIAGA GUTIÉRREZ, B. GALVÁN SANTOS, C.M. HERNÁNDEZ GÓMEZ, 2009(?)

* Este trabajo se realiza en el marco del proyecto I+D: HUM2004-01427/HIST “Tras las Huellas de Los Neandertales. El origen del poblamiento humano en los valles alcoyanos” y con la autorización de la Dirección General de Patrimonio Cultural Valenciano y Museos (Consejería de Cultura, Educación y Deportes, Generalitat Valenciana).

Congreso Iberico papers from the same conference – this paper is listed as ’2′.

Mundo Neandertal

Antigua y Medieval

Volume 50, Number 5 of Current Anthropology takes as its theme the continuing debate surrounding one of the most important cultural and technological innovations of modern humans, the mass production and storage of plant foods beginning in earnest after the Natufian era, which has ultimately given rise to what we currently refer to as modern civilisation. Recent archaeological research, and especially advances in the field of genetics, promise to offer much clearer and more accurate insights into the origins of agriculture and its effects on people, animals and plants following the  abandonment  of the fluid forager lifestyle for something altogether more rigid and sedentary. Here’s an extract from the introductory note by CA editor Mark Aldenderfer:

Much recent research on the domestication process has focused upon the identification of more reliable and robust indicators of domestication. A good example of this approach is a collection of papers titled Documenting Domestication: New Genetic and Archaeological Paradigms (University of California Press, 2006), edited by Melinda Zeder, Daniel Bradley, Eve Emshwiller, and Bruce Smith. Although specialists continue to refine traditional indicators of domestication, such as the increase in seed size of plants or the decrease in body size of animals undergoing domestication, the search for robust indicators is undergoing its own revolution—the increasingly sophisticated analysis of the genetics of the process.

As it has with understanding the evolutionary history of our own species, the analysis of the DNA of plants and animals has created a wealth of new insights into the domestication process of many species. Genetic analysis has been particularly important in helping to resolve a perennial question of the domestication process of many species—whether there was a single region from which a species emerged or multiple, independent loci of domestication. The resolution of this question can help to better define the causal factors of the process and may well show that the same species was domesticated under very different conditions in different places. If nothing else, genetic analysis can create testable hypotheses of the domestication process that could not have been envisioned only a few decades ago.

As will be clear from reading through the submissions, there is a wide range of opinion as to exactly what caused humankind to adopt such a radically different set of behaviours from those that had served perfectly adequately up until the Late Upper Palaeolithic, and I hope to cover some of the ongoing discussions in due course. Of particular interest is the adoption of feasting practices and the extent to which they may – or not – have mitigated and facilitated new societal dynamics, and why despite the poorer health and lower life-expectancy experienced by the first farmers, agriculture nevertheless persisted throughout the Neolithic world.

To view the list of contents just click here – to gain full access a subscription is required, which in this case is only $38.00 for a year’s electronic access to the new issues, as well as an extensive archive.

The 75th edition of the anthropology blog carnival named above is now online at Ad Hominin, and as is customary for 4SH, a wide variety of topics are covered by various bloggers, whose recent posts and essays have been compiled into a coherent whole, making this an ideal way to catch up on some informative and thoughtful writing, whilst saving yourself the trouble of wading through the Sunday newspapers in search of something vaguely interesting to read.

The next host will be Afarensis on September 23rd, after which there a free hosting slots up for grabs, and details of how to bring 4SH to your own blog can be found at the dedicated carnival site.

News of an exciting and illuminating discovery in Georgia, which has revealed that people living 34,000 years ago had mastered the art of making materials from processed wild flax, prompting speculation that such items as ropes, containers and even clothes and shoes were routinely manufactured by anatomically modern humans.

Back in July I wrote a brief post concerning the origins of basketry, and the impact such technologies may have had had on our prehistoric ancestors dating at least far back as the Palaeolithic, and this week comes apparent confirmation of the idea that although at the time the oldest known traces of textile date back 26,000 years ago, there was the distinct possibility that people living at least 10,000 years earlier may also have manufactured items from plant materials, when and where such were available.

The recent paper, ’30,000-Year-Old Wild Flax Fibers’ reports on recent research conducted by Ofer Bar-Yosef et al in the Upper Palaeolithic levels of Dzudzuana Cave, explained briefly in the abstract:

A unique finding of wild flax fibers from a series of Upper Paleolithic layers at Dzudzuana Cave, located in the foothills of the Caucasus, Georgia, indicates that prehistoric hunter-gatherers were making cords for hafting stone tools, weaving baskets, or sewing garments. Radiocarbon dates demonstrate that the cave was inhabited intermittently during several periods dated to 32 to 26 thousand years before the present (kyr B.P.), 23 to 19 kyr B.P., and 13 to 11 kyr B.P. Spun, dyed, and knotted flax fibers are common. Apparently, climatic fluctuations recorded in the cave’s deposits did not affect the growth of the plants because a certain level of humidity was sustained.

The story is taken up by PhysOrg, where we see that the flax fibres were discovered following examination of clay extracted from the cave deposits, leading the archaeologists to speculate that they were the remains of manufactured items which have long since disintegrated:

Some of the fibers were twisted, indicating they were used to make ropes or strings. Others had been dyed. Early humans used the plants in the area to color the fabric or threads made from the flax.

The items created with these fibers increased early humans chances of survival and mobility in the harsh conditions of this hilly region. The flax fibers could have been used to sew hides together for clothing and shoes, to create the warmth necessary to endure cold weather. They might have also been used to make packs for carrying essentials, which would have increased and eased mobility, offering a great advantage to a hunter-gatherer society…

“This was a critical invention for early humans. They might have used this fiber to create parts of clothing, ropes, or baskets—for items that were mainly used for domestic activities,” says Bar-Yosef. “We know that this is wild flax that grew in the vicinity of the cave and was exploited intensively or extensively by modern humans.”

The items created with these fibers increased early humans chances of survival and mobility in the harsh conditions of this hilly region. The flax fibers could have been used to sew hides together for clothing and shoes, to create the warmth necessary to endure cold weather. They might have also been used to make packs for carrying essentials, which would have increased and eased mobility, offering a great advantage to a hunter-gatherer society.

As we saw earlier in the year when Nicholas Conard and others found the remains of Aurignacian flutes at Hohle Fels, their search was made all the easier because they had made similar discoveries years earlier, and so knew what to look for – there was speculation at the time that similar artefacts in other caves may have been missed simply because no-one suspected their presence, and any fragmentary remains of other flutes may have been mistakenly discarded without further consideration.

The dating of 34,000 years for the Georgian fibres corresponds to the European Aurignacian, so it will be interesting to see if further research reveals similar traces of fibres at other locations across in northwestern Europe or Iberia, and crucially, the earliest times they date to.

And we have also seen recently that the use of pierced shell beads, some of which were covered in pigment, and used for body decoration, have been found at various locations in Africa dating back tens of thousands of years earlier, a behavioural trait described as modern, that appears to have begun and mysteriously ended a good 30,000 years before the European Upper Palaeolithic. Whether people in Africa living 70,000 to 100,000 years ago had also exploited plant materials in the same way as the Upper Palaeolithic Georgians hasn’t yet been demonstrated, but on the circumstantial evidence so far, cannot be entirely discounted, as they would surely have had the cognitive ability and manual dexterity to spin, twist and dye plant fibres to their will.

A strong case has been made to suggest that the European Aurignacian was a behavioural innovation of anatomically modern humans, with little or no Neanderthal input from the end of the Middle Palaeolithic, with the further implication that Neanderthals weren’t cognitively advanced enough to create or even have any use for such items as musical instruments. However, we know nothing of how Neanderthals chose to dress themselves, but despite this gap in the knowledge they are frequently depicted wearing little more than ill-fitting attire tailored from animal hides, utterly useless in chilly weather, for keeping warm at night, and probably not much help in attracting prospective partners either.

It remains to be seen whether any such fibres will turn up in Neanderthal occupation sites, and I’m not even sure whether past researchers would have even considered even searching for such materials, assuming of course that  there were suitable conditions for their preservation, as has been the case at Dzudzuana Cave.

image of Dzudzuana Cave from Professor Anna Belfer-Cohen, one of the authors of the study.

Reference: 30,000-Year-Old Wild Flax Fibers Eliso Kvavadze, Ofer Bar-Yosef, Anna Belfer-Cohen, Elisabetta Boaretto, Nino Jakeli, Zinovi Matskevich, and Tengiz Meshveliani (11 September 2009)     Science 325 (5946), 1359. [DOI: 10.1126/science.1175404] Dyed flax fibers from 30,000 years ago show that humans in the Caucasus were making colored twine at that time.

Here’s a link to a newly published paper at PLoS Genetics, and although my knowledge of centromeres is scant, it seems clear that the authors are confident that their research can effectively demonstrate  the timing of past waves of primate evolution going back as far as 35 million years, including periods of heightened activity, as explained here in the abstract:

Alpha satellite domains that currently function as centromeres of human chromosomes are flanked by layers of older alpha satellite, thought to contain dead centromeres of primate progenitors, which lost their function and the ability to homogenize satellite repeats, upon appearance of a new centromere. Using cladistic analysis of alpha satellite monomers, we elucidated complete layer patterns on chromosomes 8, 17, and X and related them to each other and to primate alpha satellites. We show that discrete and chronologically ordered alpha satellite layers are partially symmetrical around an active centromere and their succession is partially shared in non-homologous chromosomes. The layer structure forms a visual representation of the human evolutionary lineage with layers corresponding to ancestors of living primates and to entirely fossil taxa.

Surprisingly, phylogenetic comparisons suggest that alpha satellite arrays went through periods of unusual hypermutability after they became “dead” centromeres. The layer structure supports a model of centromere evolution where new variants of a satellite repeat expanded periodically in the genome by rounds of inter-chromosomal transfer/amplification. Each wave of expansion covered all or many chromosomes and corresponded to a new primate taxon.

Complete elucidation of the alpha satellite phylogenetic record would give a unique opportunity to number and locate the positions of major extinct taxa in relation to human ancestors shared with extant primates. If applicable to other satellites in non-primate taxa, analysis of centromeric layers could become an invaluable tool for phylogenetic studies.

The research seems to promise much for the future, particularly for those attempting to shed light on our distant primate ancestors, whose fossils are vanishingly rare, making it much harder for us to trace the exact sequence of evolutionary events that led to our own sweet selves appearing on the scene – being able to track the chronology and timing of pulses and sequences of evolution is interesting enough in itself, but it might be a while before an understanding of what caused these evolutionary events in ancestral primates can be firmly established, and whether or not any kind of punctuated equilibrium can be said to exist.

Reference: Shepelev VA, Alexandrov AA, Yurov YB, Alexandrov IA (2009) The Evolutionary Origin of Man Can Be Traced in the Layers of Defunct Ancestral Alpha Satellites Flanking the Active Centromeres of Human Chromosomes. PLoS Genet 5(9): e1000641. doi:10.1371/journal.pgen.1000641