Arabian Peninsula Wet Periods - a note

 My last note discussed Marine isotype Stages (MIS). These provided a dated measurement of glacial (dry climate) and interglacial (wetter) periods over extended time periods. The most relevant time periods from our perspective are summarised below 

"MIS 4 – 71

MIS 5 – 130, usually sub-divided into a to e:

MIS 5a – 82 (peak of interglacial sub-stage)

MIS 5b – 87 (peak of glacial sub-stage)

MIS 5c – 96 (peak of interglacial sub-stage)

MIS 5d – 109 (peak of glacial sub-stage)

MIS 5e – 123 (peak of Last Interglacial, also known as the Eemian among other names)

MIS 6 – 191 (Penultimate Glacial Period, also called Illinoian glacial in North America, later Saalian in northern Europe and later Wolstonian in Britain)

MIS 7 – 243 (Aveley Interglacial in Britain)"

If the Aboriginal ancestors came out of Africa they would have had to travel through the Arabian Peninsula. But was that possible? The work of Abi Stone et al (2023) suggest that it was.

Abstract:

"Past environmental and climatic conditions within the Arabian Peninsula are key to understanding the setting for hominin dispersal across the Saharo-Arabian dryland belt. The tufa deposits within the volcanic harrats on the southwest coast of Saudi Arabia fill a significant spatial gap in the distribution of palaeoenvironmental records on the west coast of the Arabian Peninsula adjacent to the Red Sea. In the catchment of Wadi Dabsa in the Harrat Al Birk, there are widespread fossil palustrine to shallow-lacustrine tufa deposits with fluvial elements. Several phases of tufa accumulation, separated by fluvial downcutting, are observable within these powerful palaeoenvironmental proxies. U–Th dating of targeted dense, banded tufa facies, yield ages that are stratigraphically consistent at the landscape scale, and indicate that tufa accumulation occurred during distinct humid phases broadly coeval with the last two warm interglacial Marine Isotope Stages (MIS 7 and MIS 5). For the first time this shows humid intervals in southwest Arabia coincident with the southern coast. There is a similar pattern emerging further north in the Arabian Peninsula, The Sinai and Levant and further on into continental Europe. Furthermore, tufa δ18O ranges from −14.6 to −1.9‰, covering a range similar to those reported for tufa from north African oasis sites and speleothems elsewhere on the Arabian Peninsula and The Levant. The lowest δ18O values are derived from MIS 5e samples, a pattern in agreement with speleothems in Yemen and Oman, and consistent with an isotopic-enabled climate model simulation for this time slice. The δ13C and Sr isotopic compositions of dated tufa samples indicate deposition from shallow-circulating meteoric water, with no geothermal influence. This, along with the δ18O values, suggest a freshwater supply that was a potable water source in this landscape. The δ13C signatures at Wadi Dabsa are more negative than for parts of north Africa, suggesting Wadi Dabsa may have experienced comparatively higher biomass, thicker soils and wetter conditions with lower evaporative losses. This new record of tufa deposition during the middle and late Pleistocene, suggests for the first time that the west coast of Arabia experienced a similar history of humid phases over the past 250 ka as southern Arabia and the Nefud in the northern interior. These regional changes in hydroclimatic regime occur at timescales coincident with hominin dispersals." Abi Stone, Robyn H. Inglis, Ian Candy, Diana Sahy, Anne-Lise Jourdan, Dan N. Barfod, Abdullah M. Alsharekh, “Humid phases on the southwestern Arabian Peninsula are consistent with the last two interglacials”, Quaternary Science Reviews, Volume 319, 2023, https://doi.org/10.1016/j.quascirev.2023.108333 

Comment

The warmer wet periods suggested by the analysis do appear to fit with an out of Africa date of 72000 kya (MIS 5). An earlier date might also be possible to fit with MIS 7 should the present latest date for occupation within Sahul (c65,000 kya) be pushed back. 

 

Marine Isotype Stages - a note

 DNA analysis suggests that the descendants of Australia's Aboriginal peoples left Africa perhaps 72,000 years ago. To reach Australia they would have travelled through the Arabian Peninsula. This is a desert area today, difficult to traverse. But was this always so? Were there periods when  the Peninsula was green in whole or part, when the Aboriginal ancestors might have passed? 

A clue here might be provided by Marine isotype stages (MIS). The material that follows is drawn from Wikipedia. 

What are Marine isotype stages?

Quoting:

"Marine isotope stages (MIS), marine oxygen-isotope stages, or oxygen isotope stages (OIS), are alternating warm and cool periods in the Earth's paleoclimate, deduced from oxygen isotope data derived from deep sea core samples. Working backwards from the present, which is MIS 1 in the scale, stages with even numbers have high levels of oxygen-18 and represent cold glacial periods, while the odd-numbered stages are lows in the oxygen-18 figures, representing warm interglacial intervals. The data are derived from pollen and foraminifera (plankton) remains in drilled marine sediment cores, sapropels, and other data that reflect historic climate; these are called proxies."

 The Stages

The following represents the dates etc of some of the stages most relevant to my topic.

Quoting

"The following are the start dates (apart from MIS 5 sub-stages) of the most recent MIS (Lisiecki & Raymo 2005, LR04 Benthic Stack). The figures, in thousands of years ago, are from Lisiecki's website.[13] Numbers for substages in MIS 5 denote peaks of substages rather than boundaries.

MIS     Start date

MIS 1 – 14 kya, end of the Younger Dryas marks the start of the Holocene. The LR04 date of 14 kya had to accommodate less well studied time intervals, and the generally accepted date of 11.7 kya is to be preferred.[14]

MIS 2 – 29 (Last Glacial Maximum)

MIS 3 – 57[a] (MIS 2-4 is called the Last Glacial Period, Wisconsinan glaciation in North America, Weichselian glaciation in northern Europe)

MIS 4 – 71

MIS 5 – 130, usually sub-divided into a to e:

MIS 5a – 82 (peak of interglacial sub-stage)

MIS 5b – 87 (peak of glacial sub-stage)

MIS 5c – 96 (peak of interglacial sub-stage)

MIS 5d – 109 (peak of glacial sub-stage)

MIS 5e – 123 (peak of Last Interglacial, also known as the Eemian among other names)

MIS 6 – 191 (Penultimate Glacial Period, also called Illinoian glacial in North America, later Saalian in northern Europe and later Wolstonian in Britain)

MIS 7 – 243 (Aveley Interglacial in Britain)

MIS 8 – 300 (early Wolstonian in Britain)

MIS 9 – 337 (Purfleet Interglacial in Britain)[16]

MIS 10 – 374

MIS 11 – 424 (Hoxnian Interglacial in Britain, and Holstein Interglacial in Central Europe)"

Comment

If you look at the stages you will see that MIS 4 and 5 are the most relevant to our story. In my next note I will move from the broad stages to look at some of the research relating to the Arabian peninsula to check when the Aboriginal ancestors might have been able to come. 

Immediate priorities in the writing of New England's history - Aboriginal New England to 1788: Origins

 My present first priority in completing my history of Australia's New England is the creation of a full working draft for the history of New England's Aboriginal peoples to 1788 starting with origins and journey.  Where and when did their ancestors come from? How did they get to Sahul? Who did they mix with on the way? When did they arrive in the area that I call New England? How did they get there?

I covered this material in my lecture series to Armidale U3A but now need to consolidate and update it. Power points are a real trap here. A set of summary power points does not a history make! I had become very dissatisfied with my work but then realised that was silly. I am presenting a story, really a series of hypotheses linked to create a synthesis. No matter how much time I spend there will always be errors of fact and interpretation. Better to get it out there so that it can be critiqued, recognising that the pace of new discoveries will quickly over-run my analysis.  

  

Introducing the Museum of Stone Tools - an invaluable resource

 

One of the challenges in teaching the history of Australia's New England over such a long period lies in the sheer range of topics and disciplines that need to be included. One example is the stone artifacts that formed key elements in Aboriginal toolkits. 

Uniface pebble chopper tools from the Seeland's dig, Clarence Valley

From these surviving physical manifestations we can deduce something about the changing patterns of life over time, about the relationship between the Aborigines and their environments, about trade and the relationships between Aboriginal groups.

I started with some base knowledge in this area. Back in the 1960s I was a student member of Isabel McBryde’s pioneering UNE prehistory group. My second paying job during University vacations was as a research assistant for Isabel sorting, classifying and recording stone tools. However, in 2020 when I came integrate Aboriginal tools into my story of Aboriginal New England to 1788, part of my broader course on New England’s history to 1788, the gaps in my knowledge quickly became clear. 

The 2020 course was badly affected by the covid epidemic. However, one plus of the epidemic and its shutdowns is that it led UNE’s Professor Mark Moore to begin the development of the on-line Museum of Stone Tools. Mark is one of Australia’s leading archaeologists and an expert in stone flaking techniques. 

Professor Mark Moore

The resulting museum provides examples of various stone tools from across the world supported by explanatory material. Central to it are 3D models that allow you to play with various implements rotating them as required. The overall analysis is simple and accessible designed for people of all ages. You do not need specialist knowledge to understand. 

I hope to run my course again in the second half of next year. I think that the museum will prove a real blessing. In the meantime, do have a browse.

The impact of periodic drought on Aboriginal life and history - a note

Interesting piece in The Conversation (6 October) by Kathryn Allen, Alison O'Donnell, Benjamin I. Cook, Jonathan Palmer and Pauline Grierson, "Megadroughts helped topple ancient empires. We’ve found their traces in Australia’s past, and expect more to come".  The article includes a link to a 2016 paper that I had not seen that attempts to construct  a 1013 year rainfall chart for the Williams River in the Hunter Valley - Carly R. Tozer, Tessa R. Vance, Jason L. Roberts, Anthony S. Kiem, Mark A. J. Curran and Andrew D. Moy, "An ice core derived 1013-year catchment-scale annual rainfall reconstruction in subtropical eastern Australia", Hydrol. Earth Syst. Sci., 20, 1703–1717, 2016, www.hydrol-earth-syst-sci.net/20/1703/2016/ doi:10.5194/hess-20-1703-2016.

Attempts to reconstruct Aboriginal history over the long period of human occupation of Sahul then the later Australian continent including my own for the broader New England tend to focus on broader trends such as the impact of the Last Glacial Maximum and the subsequent emergence of the Holocene. While this is inevitable,  it is easy to ignore the significant impact on Aboriginal life of major changes within periods including long mega droughts and subsequent wet periods. 

If we take the Murray River as an example, I'm working from memory here, Mulvaney notes the evidence of periodic malnutrition in skeletal remains. Here we have relatively small territories with substantial populations dependent upon drought exposed riverine resources. On New England's western slopes and plains the pattern of life seems clearly affected by periodic droughts. 

I haven't worked all this through. For the moment, this is just a note for further thought.  

Historical climate change on the Arabian peninsular, hominin occupation and the pattern of Aboriginal settlement of Sahul

The second lecture in my introductory course on the history of Australia's New England, the Tablelands and surrounding river valleys, traces the journey of the Aboriginal and Papuan ancestors from Africa until their arrival on the mega continent we now call Sahul. 

On 1 September 2021 an article by H S Groucutt et al was published in Nature that bears upon our story. The abstract including link to the paper follows. Comments follow the abstract.  

Pleistocene hominin dispersals out of, and back into, Africa necessarily involved traversing the diverse and often challenging environments of Southwest Asia. Archaeological and palaeontological records from the Levantine woodland zone document major biological and cultural shifts, such as alternating occupations by Homo sapiens and Neanderthals. However, Late Quaternary cultural, biological and environmental records from the vast arid zone that constitutes most of Southwest Asia remain scarce, limiting regional-scale insights into changes in hominin demography and behaviour. Here we report a series of dated palaeolake sequences, associated with stone tool assemblages and vertebrate fossils, from the Khall Amayshan 4 and Jubbah basins in the Nefud Desert. These findings, including the oldest dated hominin occupations in Arabia, reveal at least five hominin expansions into the Arabian interior, coinciding with brief ‘green’ windows of reduced aridity approximately 400, 300, 200, 130–75 and 55 thousand years ago. Each occupation phase is characterized by a distinct form of material culture, indicating colonization by diverse hominin groups, and a lack of long-term Southwest Asian population continuity. Within a general pattern of African and Eurasian hominin groups being separated by Pleistocene Saharo-Arabian aridity, our findings reveal the tempo and character of climatically modulated windows for dispersal and admixture.

Groucutt, H.S., White, T.S., Scerri, E.M.L. et al. Multiple hominin dispersals into Southwest Asia over the past 400,000 years. Nature (2021). https://doi.org/10.1038/s41586-021-03863-y

Comment

To the best of our present knowledge, the ancestors of the Aboriginal and Papuan peoples came out of Africa arriving in Sahul perhaps 65,000 years ago. This was during the Pleistocene, a period marked by ice ages separated by warmer periods. 

Today, Saudi Arabia is marked by arid deserts. This study suggests that the Arabian Peninsula experienced wetter green periods approximately 400, 300, 200, 130–75 and 55 thousand years ago. Each period was marked by different hominin occupations, with people withdrawing and reoccupying as the climate changed. 

From our viewpoint, the green period from 130-75,000 years ago would appear to fit with Aboriginal migration patterns given the present earliest indicated occupation date of c65,000 years ago.  

Postscript 

 An article in the Conversation  provides more commentary. Research reveals humans ventured out of Africa repeatedly as early as 400,000 years ago, to visit the rolling grasslands of Arabia  

The early Aboriginal peopling of Australia's New England

Neanderthal cousins: Artists reconstruction of a Denisovan girl based on the combination of skeletal and DNA evidence.

In April, I began a sort series of Armidale Express columns on the history of the Aboriginal peopling of New England. Drawn from the introductory course I was running on the history of New England, the columns told in short form the story of the journey to and arrival on the mega-continent now known as Sahul, the spread across Sahul and arrival in New England followed by the challenge of the Last Glacial Maximum.

Aboriginal settlement of Sahul: by 40,000 years ago, the ancestors of Australia's Aboriginal peoples had occupied the entire continent known as Sahul.

In a later series I will carry the story forward through the Holocene and the golden age that came to an end with the arrival of the Europeans in 1788.

I have now posted all the columns to this blog. This post allows you to follow the whole series through from the first post. 

• Wednesday, April 01, 2020 The peopling of New England - the mysterious Denisovans
• Wednesday, April 08, 2020 The peopling of New England - Mysteries of migration
• Wednesday, April 15, 2020 The peopling of New England - Aboriginal peoples' arrival in New England
• Wednesday, April 22, 2020 The Aboriginal peopling of New England - What did Aboriginal life look like in New England 40,000 years ago?
• Wednesday, April 29, 2020 The Aboriginal peopling of New England. How the New England landscape went through dramatic changes
• Wednesday, May 06, 2020 The Aboriginal peopling of New England. Reoccupation following the ending of the Last Glacial Maximum

The Aboriginal peopling of New England. Reoccupation following the ending of the Last Glacial Maximum

Stuart’s Point today, the site of the oldest known Aboriginal occupation in New England following the end of the Last Glacial Maximum This is the sixth and final in a series on the Aboriginal peopling of New England drawn from the introductory course I have been running on New England's history. I will continue the story of the Holocene period in a later series.   

In my last column I discussed the likely impact of the Last Glacial Maximum (LGM), a cold dry windy period running from around 12,000 to 15,000 years ago, on New England’s Aboriginal peoples.

Faced with persistent drought and temperatures up to 8C below present, New England’s Aboriginal peoples were forced to retreat to refuge areas where food as well as protection from the elements was still available. Whole groups may have been wiped out.

Around 15,000 years ago, the LGM began to ease. From around 12,000 years ago, the period now described as the Holocene began. Average temperatures rose, rainfall increased. Deserts retreated westwards, while plants, animals and humans began to reoccupy the landscape.

This process took time, while its effects varied from place to place.

Down on our coastal strip, sea levels rose by 130 metres rushing inland past the coastline we know today. If you were standing where Kempsey is now, you would be on the coast. Shelters, camping grounds, ceremonial sites and food resources were submerged by the rising waters.

Slowly, the silt laden rivers swollen by higher Tablelands’ rainfall pushed back, joined by sea currents depositing sand, creating the current coastal dunes and backing estuaries.

This process took time. The coast as we know it today finally emerged about 6,000 years ago.

Even before this date, new habitats emerged favourable to human occupation.

In 1975 excavations at Stuarts Point, a very large oyster and cockle midden on the inner barrier north of the present estuary of the Macleay, revealed an occupation date of 9320 ± 160 BP (Before Present). Prior to that result, the earliest coastal date had been 6444 ± 74 BP for the basal levels of the Seelands dig in the Clarence about 12 kilometres northwest of Grafton.

On the Western Slopes and Plains, the earliest certain occupation date we have is much later than the coast, with an uncalibrated age of 5450 ± 100 years BP at Graman near Inverell.

On the Tableland, the earliest certain occupation date that we presently have is an uncalibrated age of 4300 years ago from Bendemeer. However, analysis done by Wendy Beck suggests that the resource base would have allowed targeted visits from at least the start of the Holocene, with permanent settlement possible from perhaps 6,000 years.

It is frustrating that we cannot sketch out the story in more detail. What we can say with a degree of certainty is that New England’s Aboriginal peoples were entering a golden age that would last to European invasion.

I will tell you this story in a later series of columns.

This post was prepared as a column for the on-line edition of the Armidale Express. I am repeating the columns here with a lag because they are not all on line outside subscription. You can see all the Belshaw World and History Revisited/History Matters columns by clicking here for 2009, here for 2010, here for 2011, here for 2012, here for 2013, here for 2014, here for 2015,  here for 2016, here  2017, here 2018, here 2019, here 2020 

The Aboriginal peopling of New England. How the New England landscape went through dramatic changes

The Byron landslip scar. This is the fifth in a series on the Aboriginal peopling of New England drawn from the introductory course I have been running on New England's history.

Aboriginal oral tradition records memories of great floods as the sea rushed in. These are usually attributed to large scale sea level rises as the icy conditions of the Last Glacial Maximum (21,000 to 15,000 years ago) eased and sea levels rose.

I suspect that’s broadly true, but they may also included memories of submarine landslide induced tsunamis, many of which occurred over the last 25,000 years along the Southern Queensland and Northern NSW coasts.

These tsunamis came about because of land collapses along the steeply sloping continental shelf. These collapses sent great blocks of rock and sediment plunging down the steeply sloping shelf out to sea over distances up too 100km and depths of 3,000m. You can imagine the effects on sea levels.

While spectacular, these changes were only a small part of the challenges faced by Australia’s Aboriginal peoples.

In my last column, I discussed what the Aboriginal occupation of New England might have looked like perhaps 40,000 years ago.

The Aborigines had arrived on the ancient content called Sahul at a time when the climate was colder but damper.

From perhaps 25,000 years ago, the environment deteriorated significantly.

Globally, the ice spread. As it did, the climate became colder and drier, deserts spread and trees retreated. This climatic regime peaked during the Last Glacial Maximum 21,000 to 15,000 years ago.

Sahul became very dry, both intensely hot and intensely cold. Sea levels fell by 60+ metres to perhaps 130 metres below current levels. Sea temperatures fell to 2-4 degrees C below those of today.

The effects across New England were dramatic. In the west, there were cold arid conditions. The deserts expanded eastwards. Stream flow was reduced. Trees and animals retreated.. In the east, the falling sea levels revealed a rugged inhospitable shore. While the coastal areas remained relatively well watered, food resources would have been reduced.

On the New England Tablelands, average temperatures fell by perhaps 8 degrees C. The Tablelands marked the start of a region of cold steppe and scattered sub-alpine woodland sweeping down through the southern Snowy Mountains into Tasmania, making it an inhospitable region for human habitation.

Faced with these changing conditions, the Aborigines would have been forced to retreat to refuge areas where food was still available. Some groups would have perished.

Better conditions lay ahead, but challenges had to be surmounted first.

This post appeared as a column in the on-line edition of the Armidale Express on 23 April 2020. I am repeating the columns here with a lag because they are not all on line outside subscription. You can see all the Belshaw World and History Revisited/History Matters columns by clicking here for 2009, here for 2010, here for 2011, here for 2012, here for 2013, here for 2014, here for 2015,  here for 2016, here  2017, here 2018, here 2019, here 2020 

The Aboriginal peopling of New England - What did Aboriginal life look like in New England 40,000 years ago?

Over c48,000 years, Tableland lagoons such as Little Llangothlin have provided a potential resource for Aboriginal people. This is the fourth in a series on the Aboriginal peopling of New England drawn from the introductory course I have been running on New England's history.

In my last column I suggested that while we had no direct archaeological evidence, the pattern of archaeological dates across Sahul suggested that first Aboriginal occupation of the broader New England may have taken place around 40,000 years ago.

Given the present absence of archaeological evidence, what might this occupation have looked like? To start answering this question, we need to start with New England’s geography.

In the east, the coastline as we know it today with its rich estuarine and marine resources did not exist and would not do so for another 34,000 years.

Sea levels were 60 metres lower than present. Because the continental shelf in this part of Australia is generally relatively narrow and steep sloping, the land revealed by the lower waters was often rugged, falling away to the then coastline,

The rivers from the Tablelands that now meander to the sea would have been faster flowing, their courses straighter with smaller estuaries. However, while the coastal environment was not as rich as it would later be, the combination of coastal, riverine and land environments would have been sufficient to support human occupation.

Inland, the Western Slopes and Plains would have been relatively well watered and potentially rich in resources. Again, it seems unlikely that the area was left vacant.

Further force is provided to this tentative conclusion in that in moving south whether by the inland or coastal routes, the advancing Aborigines would have passed through the broader New England. 

But what about that bit in the middle, the New England Tablelands? This was a less rich area in food terms, making occupation less likely.

In the absence of early dates, Wendy Beck, Robert Hayworth and John Appleton examined what resources might have been available to the Aborigines on the New England in the lagoons that run along the spine of the Tablelands.

The lagoons and especially Little Llangothlin have been studied because their long existence (c48,000 years) provides a useful record of change over time. They concluded that the combination of megafauna with lagoon resources could have provided a base for at least seasonal visits.

All this is surmise based on circumstantial evidence. We may never know because of the scale of changes that have taken place over the last forty thousand years. On the coast, for example, changing sea levels mean that many potential occupation sites have been buried under water or later silt deposits.

Despite such problems, I do believe that we can learn more through the type of studies pioneered by Wendy and her colleagues.

Note to readers: This post appeared as a column in the on-line edition of the Armidale Express Extra on 17 April 2020. I am repeating the columns here with a lag because they are not all on line outside subscription. You can see all the Belshaw World and History Revisited/History Matters columns by clicking here for 2009, here for 2010, here for 2011, here for 2012, here for 2013, here for 2014, here for 2015,  here for 2016, here  2017, here 2018, here 2019, here 2020 

The peopling of New England - Aboriginal people's arrival in New England

Aboriginal settlement of Sahul: by 40,000 years ago, the ancestors of Australias Aboriginal peoples had occupied the entire continent known as Sahul. This is the third in a series on the Aboriginal peopling of New England drawn from the introductory course I have been running on New England's history.

If the ancestors of Australia’s Aboriginal peoples reached the large continent known as Sahul perhaps 65,000 years ago, how and when did they reach the broader New England?

To start answering this question, consider the illustration to this column from Alana Coper et al. It shows the land boundaries of the mega-continent of Sahul during the Last Glacial maximum when sea levels were much lower.

The red lines suggest possible settlement paths; the black dates archaeological dates where kya stands for a thousand years. Ignore the other elements.

The Aboriginal ancestors arrived in Sahul during the Pleistocene, a period of repeated ice ages broken by warmer periods. They arrived at a benign time with relatively comfortable temperatures and a higher rainfall sufficient to fill the lakes and rivers.

The archeological dates shown in black suggest that by 40,000 years ago the descendents of those first settlers had occupied the entire continent of Sahul from Papua and surrounding islands in the north to Tasmania in the far south.

The migration paths are subject to some dispute. One school of thought is that migration went down the east coast.

I disagree. I think that it is most likely that migration proceeded down the western slopes and immediate western plains where there was water and easier immigration paths.

Whatever the exact path, it seems clear that by 40,000 years ago Sahul was occupied. Herein lies a problem, for the dates we have for the broader New England are all later.

The Cuddie Springs site near Brewarrina suggests occupation as long ago as 35,000 years BP. However, dates here have been subject to considerable dispute.

Excluding Cuddie Springs, we have a date of greater than 20,200 years BP (Before Present) from a hearth at Glennies Creek 35 kilometres north of Branxton in the Hunter, while a site on a former terrace of Wollombi Brook near Singleton suggested a date range of 18,000-30,000 years BP. At Moffats Swamp near Raymond Terrace, a date of 17,000 years BP was obtained.

On the Liverpool Plains, Aboriginal occupation has been dated to at least 19,000 years BP. Further north in South-East Queensland, the Wallen Wallen Creek site on what is now North Stradbroke Island shows continuous occupation from about 20,000 years ago.

While these dates are all later, Aboriginal peoples moving south must have passed through the broader New England, so we can reasonably assume some Aboriginal occupation by at least 40,000 years ago, probably earlier.

In my next column, I will discuss what that occupation might have looked like. 

Note to readers: This post appeared as a column in the Armidale Express Extra on 8 April 2020. I am repeating the columns here with a lag because they are not all on line outside subscription. You can see all the Belshaw World and History Revisited/History Matters columns by clicking here for 2009, here for 2010, here for 2011, here for 2012, here for 2013, here for 2014, here for 2015,  here for 2016, here  2017, here 2018, here 2019, here 2020 

The peopling of New England - Mysteries of migration

Digging deep: Evidence from the Madjedbebe rock shelter suggests early occupation from 65,000 years ago plus or minus 5,000 years.This is the second in a series on the Aboriginal peopling of New England drawn from the introductory course I have been running on New England's history.

In my last column, I spoke of the mysterious Denisovans, a new hominid species only discovered in 2010. They are significant to Australian history because it is clear that the ancestors of both the Papuans and Australia’s Aboriginal peoples met and mated with them on their journey to Sahul, the name given to the continent of which both Australia and Papua New Guinea were once part.

Over the next few columns I will tell you a little of the remarkable story of Aboriginal occupation of Sahul, including New England. It’s a story still shrouded in mystery and uncertainty, but we know enough now to at least paint a broad picture.

We do not know exactly when the ancestors of Australia’s Aboriginal peoples arrived on Sahul. The earliest date we have comes from excavations at the Madjedbebe rock shelter in Kakadu near Jabiru. There earliest occupation was dated to 65,000 years plus or minus 5,000 years.

There have been some suggestions of earlier possible dates based on circumstantial evidence such as fire patterns. Most recently, an excavation at Moyjil Port Ritchie near Warnambool identified a possible hearth dating to 120,000 years ago. However, the team was cautious in their conclusions in the absence of any associated artefacts.

The evidence from Madjedbebe also suggests a sophisticated material culture from an early date. This is consistent with an emerging body of evidence that suggests that earlier hominin species including anatomically modern humans were far more advanced and at an earlier period than previously realized.

This bears upon the question of just how the ancestors of the Aboriginal and Papuan peoples reached Sahul.

The old view based upon then perceptions of “primitiveness” saw the original settlers almost as castaways, small groups who came by accident. This now seems highly unlikely and for two reasons.   

The first is that we now know that earlier peoples were far more capable of crossing open water than previously realized. The great voyages from East Asia into Polynesia are a later and very dramatic example.

The second reason is that population analysis suggests that the survival and then expansion of the early human occupants of Sahul required a minimum foundation population measured in at least the low thousands. To my mind, there are likely to have been a number of movements spaced over time, possibly using different paths.

We don’t know what caused these migrations.

It may have been because of population pressures on existing ranges or because of pressures created by in-migration from other groups. There may have been natural disasters or, perhaps, just the normal human spirit wishing to explore new territories.

We may never know the answers here. However, we do more about what happened once the Aboriginal ancestors reached Sahul.

Note to readers: This post appeared as a column in the Armidale Express Extra on 1 April 2020. I am repeating the columns here with a lag because they are not all on line outside subscription. You can see all the Belshaw World and History Revisited/History Matters columns by clicking here for 2009, here for 2010, here for 2011, here for 2012, here for 2013, here for 2014, here for 2015,  here for 2016, here  2017, here 2018, here 2019, here 2020 

The peopling of New England - the mysterious Denisovans

Neanderthal cousins: Artists reconstruction of a Denisovan girl based on the combination of skeletal and DNA evidence.This is the first in a series on the Aboriginal peopling of New England drawn from the introductory course I have been running on New England's history.

We all carry our ancestry within us, imprinted in our DNA. We all know this in part because it provides the base for the increasingly popular ancestry DNA tests. What is perhaps less recognised is the way in which the science of genomics has totally transformed our knowledge of the deep human past. 

Genomics, an interdisciplinary field of biology, focuses on the structure, function, evolution, mapping, and editing of genomes. A genome is an organism's complete set of DNA, including all of its genes.

Genomics allows us to map and compare DNA from even ancient specimens. It allows us to map changes over time, and to estimate when certain changes might have taken place. This has resulted in a knowledge explosion.

The mysterious Denisovans are a case in point.

Denisova Cave lies in the Altai Mountains in south-central Siberia near the border with Kazakhstan, China and Mongolia.

In 2010, a Russian team announced that the DNA analysis of a juvenile female finger bone from the site had revealed a new hominin species that they named the Denisovans after the cave. The Denisovans were cousins to the European based Neanderthals, but had separated from them several hundred thousand years before.

This was remarkable enough, but more was to follow. DNA analysis of other remains and of modern human populations suggested that the Denisovans were widely spread across Asia with two distinct lines, one in East Asia, a second in South East Asia.

Further, the results show that the Denisovans overlapped with the Neanderthals at Denisova and with both Homo Erectus and anatomically modern humans in East and South East. The widespread nature of the Denisovan trace in dispersed anatomically modern human populations suggests extensive interbreeding with multiple Denisovan populations.

The DNA analysis also revealed that in their long journey out of Africa to the ancient continent called Sahul, the ancestors of the Papuans and Australian Aborigines had met and mated with the Denisovans.

This mating probably took place in what is now South East Asia close to Sahul. However, the trace is so strong among Papuans that it raises the possibility that the Denisovans may have lived in Papua or nearby islands until as recently 30,000 years ago.

This date is well within the period of Aboriginal occupation of Sahul. It raises an intriguing question: if the Denisovans were in Papua, then the northern extension of Sahul, did they penetrate further south into what is now the Australian continent?

Note to readers: This post appeared as a column in the Armidale Express Extra on 25 March 2020. I am repeating the columns here with a lag because they are not all on line outside subscription. You can see all the Belshaw World and History Revisited/History Matters columns by clicking here for 2009, here for 2010, here for 2011, here for 2012, here for 2013, here for 2014, here for 2015,  here for 2016, here  2017, here 2018, here 2019, here 2020 

A note on cave art in Borneo

Twelve months ago, 7 November 2018, a team of researchers published a letter in Nature outlining new discoveries in cave art in Borneo. I missed it at the time. hat tip to Iain Davidson who posted a link on the UNE Archaeology Society Facebook page.

The piece adds to our understanding of the early world the Australian Aborigines travelled through to reach Sahul.

Abstract

Figurative cave paintings from the Indonesian island of Sulawesi date to at least 35,000 years ago (ka) and hand-stencil art from the same region has a minimum date of 40 ka1. Here we show that similar rock art was created during essentially the same time period on the adjacent island of Borneo. Uranium-series analysis of calcium carbonate deposits that overlie a large reddish-orange figurative painting of an animal at Lubang Jeriji Saléh—a limestone cave in East Kalimantan, Indonesian Borneo—yielded a minimum date of 40 ka, which to our knowledge is currently the oldest date for figurative artwork from anywhere in the world. In addition, two reddish-orange-coloured hand stencils from the same site each yielded a minimum uranium-series date of 37.2 ka, and a third hand stencil of the same hue has a maximum date of 51.8 ka. We also obtained uranium-series determinations for cave art motifs from Lubang Jeriji Saléh and three other East Kalimantan karst caves, which enable us to constrain the chronology of a distinct younger phase of Pleistocene rock art production in this region. Dark-purple hand stencils, some of which are decorated with intricate motifs, date to about 21–20 ka and a rare Pleistocene depiction of a human figure—also coloured dark purple—has a minimum date of 13.6 ka. Our findings show that cave painting appeared in eastern Borneo between 52 and 40 ka and that a new style of parietal art arose during the Last Glacial Maximum. It is now evident that a major Palaeolithic cave art province existed in the eastern extremity of continental Eurasia and in adjacent Wallacea from at least 40 ka until the Last Glacial Maximum, which has implications for understanding how early rock art traditions emerged, developed and spread in Pleistocene Southeast Asia and further afield.
M. Aubert, P. Setiawan, A. A. Oktaviana, A. Brumm, P. H. Sulistyarto, E. W. Saptomo, B. Istiawan, T. A. Ma’rifat, V. N. Wahyuono, F. T. Atmoko, J.-X. Zhao, J. Huntley, P. S. C. Taçon, D. L. Howard & H. E. A. Brand, Palaeolithic cave art in Borneo,  Nature 564, 254–257 (2018) doi:10.1038/s41586-018-0679-9

Homo luzonensis, Denisovans, Papuans and the the Australian Aborigines - more evidence from the deep past

Because of issues associated with my move to Armidale, it is some considerable time since I last reported on the continuing research into the deep human past, research that affects our understanding of Aboriginal history.

While I have been relatively off-line, regular commenter John B has been emailing me material. It now seems an appropriate point to bring that material on line. The long post that follows reports on three recent studies, concluding with a short discussion. My continued indebtedness to John B will be apparent.

Homo Luzonensis 

In April 2019, a group of researchers reported on the results of exploration at Calloa Cave in the Philippines, suggesting the discover of another hominin species that they named Homo luzonensis, dating to about 67,000 years ago.

The map from the paper is shown, including land that would have been revealed at various sea levels below the present. The abstract from the paper is set out below. 

"A hominin third metatarsal discovered in 2007 in Callao Cave (Northern Luzon, the Philippines) and dated to 67 thousand years ago provided the earliest direct evidence of a human presence in the Philippines. Analysis of this foot bone suggested that it belonged to the genus Homo, but to which species was unclear. Here we report the discovery of twelve additional hominin elements that represent at least three individuals that were found in the same stratigraphic layer of Callao Cave as the previously discovered metatarsal. These specimens display a combination of primitive and derived morphological features that is different from the combination of features found in other species in the genus Homo (including Homo floresiensis and Homo sapiens) and warrants their attribution to a new species, which we name Homo luzonensis. The presence of another and previously unknown hominin species east of the Wallace Line during the Late Pleistocene epoch underscores the importance of island Southeast Asia in the evolution of the genus Homo."
Florent Détroit, Armand Salvador Mijares, Julien Corny, Guillaume Daver, Clément Zanolli, Eusebio Dizon, Emil Robles, Rainer Grün & Philip J. Piper, A new species of Homo from the Late Pleistocene of the Philippines, Nature volume 568, pages 181–186 (2019) Published on-line 10 April 2019, accessed 22 October 2019 

That same day (10 April), BBC Science Paul Rincon provided a useful popular summary in Homo luzonensis: New human species found in Philippines.The article included this chart derived from the Smithsonian which I thought provided a useful graphic.

The BBC article as well as other commentary quotes Professor Chris Stringer, from London's Natural History Museum. For those who follow Twitter, Professor Stringer is an active tweeter - @ChrisStringer65.

John kindly sent me a press release apparently issued by Professor Stringer at the time. This is set out below. I have not been able to find a link to the original but have included it in full because of the overview it provides.

"Homo Luzonensis -  a new human species from island south east Asia

After the remarkable finds of the diminutive Homo floriensis were published in 2004, I said that the experiment in human evolution conducted on Flores could have been repeated on many of the other islands in the region. That speculation has seemingly been confirmed on the island of Luzon in the Philippines, nearly 3,000 km away. 13 fossil human remains - teeth, hand and foot bones, and part of a femur from at least 3 adults and immature individuals have been recovered from excavations at Callao Cave since 2007. They have been dated to at least 50,000 years old, are small in size, particularly the teeth, and they show a distinctive combination of primitive and and derived traits sufficient for the authors of the paper in Nature to create a new human species for them: Homo luzonensis. They suggest that some of the hand and foot bones show features also present in much more ancient australopiths ("southern apes") found in Africa, and interpreted as adaptations for life in the trees.

So, do these finds really represent a new species, and what do they add to the story of human evolution? Given the small size of the sample, some scientists will question the wisdom of creating a new species based on such limited material, while others such as me wonder whether Luzon find might eventually turn out to be a variant of the already known Homo floresiensis, despite some clear differences. And we know that island isolation can be a catalyst for some odd evolutionary changes, including reversion to apparently primitive states. Nevertheless, for the moment, it is probably reasonable to accept the new species, at least provisionally, while awaiting more finds.

As for its origins and fate, they remain mysterious. As with floresiensis, expert opinion will probably be divided. Some will argue that the primitive features of luzonensis are evidence of a pre- Homo erectus dispersal out of Africa, perhaps more than 2 million years ago. floresiensis and luzonensis would represent some of the last survivors of that early wave, lingering on at the fringes of the inhabited world. Others would prefer to regard these island forms as descendants of Homo erectus, subject to isolation and island dwarfing over a considerable period of time. And given two such populations in the remote islands of south east Asia, others like me might consider they represent remnants of a dispersal of an original floresiensis or luzonensis -like founder lineage that originated somewhere like the island of Sulawesi. As for the fate of luzonensis, it is too early to say whether the spread of Homo sapiens into the region at least 50,000 years ago might have been factor in its disappearance, as has been suggested for floresiensis.

An extra layer of complexity in the region has been added by recent research on the Denisovans, an archaic population of humans originally identified from ancient DNA recovered from human fossils in Denisova Cave, Siberia. The additional existence of late Denisovan-like populations in south east Asia had been inferred from the presence of related DNA in extant Asian and Oceanian people, but recent research indicates at least three separate and varied Denisovan-like sources, at least one of which probably lived in the same wide biogeographic zone as floresiensis and luzonensis. We are currently far from establishing which fossils in the region might represent such populations, but it is probable that the spread of Denisovan-like people into the region was a separate and much later event than those involving floresiensis and luzonensis." Ends

Another who commented on the Luzon discoveries was Professor John Hawks. His New species of hominin from Luzon appeared on  his blog on 10 April 2019 and in the online journal Sapiens at the same time. It covers some of the same ground as Professor Stringer's comment, but with more focus on the details of the evidence.

Multiple Deeply Divergent Denisovan-related ancestries in Papuans 

 At the same time as the Luzonensis results were reported,  another paper was released in Cell entitled Multiple Deeply Divergent Denisovan-related ancestries in Papuans. 

The abstract reads:

"Genome sequences are known for two archaic hominins-Neanderthals and Denisovans-which interbred with anatomically modern humans as they dispersed out of Africa. We identified high-confidence archaic haplotypes in 161 new genomes spanning 14 island groups in Island Southeast Asia and New Guinea and found large stretches of DNA that are inconsistent with a single introgressing Denisovan origin. Instead, modern Papuans carry hundreds of gene variants from two deeply divergent Denisovan lineages that separated over 350 thousand years ago. Spatial and temporal structure among these lineages suggest that introgression from one of these Denisovan groups predominantly took place east of the Wallace line and continued until near the end of the Pleistocene. A third Denisovan lineage occurs in modern East Asians. This regional mosaic suggests considerable complexity in archaic contact, with modern humans interbreeding with multiple Denisovan groups that were geographically isolated from each other over deep evolutionary time."
Jacobs GS, Hudjashov G, Saag L, Kusuma P, Darusallam CC, Lawson D, Mondal M, Pagani L, Ricaut FX, Stoneking M, Metspalu M, Sudoyo H, Lansing JS, Cox MP, Multiple Deeply Divergent Denisovan-related ancestries in Papuans, Cell. 2019 May 2;177(4):1010-1021.e32. doi: 10.1016/j.cell.2019.02.035. Epub 2019 Apr 11.Accessed 23 October 2019

On 11 April, EuekaAlert carried a press release from the Max Planck Institute for Evolutionary Anthropology. I have set this out below in full because it provides another perspective.

"Multiple Denisovan-related ancestries in Papuans 
 DNA sequences from Indonesia and New Guinea reveal new branches of the Denisovan family tree

   The findings are based on a new study led by Murray Cox from Massey University in New Zealand and made possible by sampling efforts led by Herawati Sudoyo from the Eijkman Institute for Molecular Biology in Jakarta, Indonesia. The data were collected and analyzed by an international team of researchers, including Mark Stoneking from the Max Planck Institute for Evolutionary Anthropology. Taken together with previous work - which has pointed to a third Denisovan lineage in the genomes of modern Siberians, Native Americans, and East Asians - the evidence "suggests that modern humans interbred with multiple Denisovan populations, which were geographically isolated from each other over deep evolutionary time," the researchers write.

The new evidence also unexpectedly shows extra mixing between Papuans and one of the two Denisovan groups, suggesting that this group actually lived in New Guinea or its adjacent islands. Moreover, Denisovans may have lived in the area until as recently as 30,000 years ago, making them one of the last surviving groups of archaic hominins. "People used to think that Denisovans lived on the Asian mainland and far to the north," says Cox. "Our work instead shows that the center of archaic diversity was not in Europe or the frozen north, but instead in tropical Asia." Stoneking adds, "Moreover, this archaic diversity seems to have persisted much longer in Island Southeast Asia and New Guinea than elsewhere in the world."

It had already been clear that Island Southeast Asia and New Guinea was a special place, with individuals there carrying more archaic hominin DNA than anywhere else on Earth. The region was also recognized as key to the early evolution of Homo sapiens outside Africa. But there were gaps in the story.

Divergent Denisovan lineages

To help fill those gaps, the team identified stretches of archaic DNA from 161 new genomes spanning 14 island groups in Island Southeast Asia and New Guinea. Their analyses uncovered large stretches of DNA that did not jibe with a single introgression of genes from Denisovans into humans in the region. Instead, they report, modern Papuans carry hundreds of gene variants from two deeply divergent Denisovan lineages. In fact, they estimate that those two groups of Denisovans had been separated from one another for 350,000 years.

The new findings highlight how "incredibly understudied" this part of the world has been, the researchers say. To put it in context, many of the study's participants live in Indonesia, a country the size of Europe that is the 4th largest country in the world based on population size. And yet, apart from a handful of genome sequences reported in a global survey of genomic diversity in 2016, the new paper reports the first Indonesian genome sequences. There also has been a strong bias in studies of archaic hominins toward Europe and northern Eurasia, because DNA collected from ancient bones survives best in the cold north.

Missing data bias scientific interpretation

This lack of global representation in both ancient and modern genome data is well noted, the researchers say. "However, we don't think that people have really grasped just how much of a bias this puts on scientific interpretations - such as, here, the geographical distribution of archaic hominin populations," Cox says.

As fascinating as these new findings are, the researchers say their primary aim is to use this new genomic data to help improve healthcare for people in Island Southeast Asia. They say this first genome survey in the region now offers the baseline information needed to set that work in motion." Ends

Adaptive archaic introgression of copy number variants and the discovery of previously unknown human genes    

On 18 October 2019, Science published another study under the catchy (!) title Adaptive archaic introgression of copy number variants and the discovery of previously unknown human genes. The above graphic reproduced from the article provides an effective schematic.

In this case, I am not providing the full abstract (you will find it here) because of length as well as complexity. However, a short extract follows:

"Copy number variants (CNVs) are subject to stronger selective pressure than single-nucleotide variants, but their roles in archaic introgression and adaptation have not been systematically investigated. We show that stratified CNVs are significantly associated with signatures of positive selection in Melanesians and provide evidence for adaptive introgression of large CNVs at chromosomes 16p11.2 and 8p21.3 from Denisovans and Neanderthals, respectively. Using long-read sequence data, we reconstruct the structure and complex evolutionary history of these polymorphisms and show that both encode positively selected genes absent from most human populations. Our results collectively suggest that large CNVs originating in archaic hominins and introgressed into modern humans have played an important role in local population adaptation and represent an insufficiently studied source of large-scale genetic variation."
PingHsun Hsieh, Mitchell R. Vollger, Vy Dang, David Porubsky, Carl Baker, Stuart Cantsilieris, Kendra Hoekzema1, Alexandra P. Lewis, Katherine M. Munson, Melanie Sorensen, Zev N. Kronenberg, Shwetha Murali, Bradley J. Nelson1, Giorgia Chiatante, Flavia Angela Maria Maggiolini, Hélène Blanché, Jason G. Underwood, Francesca Antonacci, Jean-François Deleuze, Evan E. Eichler, Adaptive archaic introgression of copy number variants and the discovery of previously unknown human genes, Science  18 Oct 2019:Vol. 366, Issue 6463, eaax2083 DOI: 10.1126/science.aax2083, accessed 22 October 2019

Discussion

In sending me material, John B commented (24 April 2019): "It is increasingly looking likely Jim that the Aboriginals who first colonised Australia were locals to the region and not in transit through it, my suspicions of the original Out of Africa single origin hypothesis, replacement hypothesis, or recent African origin model continue to be confirmed. Archaic diversity, I do like that descriptor and the picture it conveys."

John and I have been talking about these issues now for a number of years. Over that time, new research discoveries have added to our understanding, but also created an unexpectedly complex and uncertain  picture. 

In 2017, reports of results from the excavations at the Madjedbebe rock shelter, The lessons and questions from Madjedbebe, pushed back the date of human occupation of Northern Australia to perhaps 65,000. I was going to write Aboriginal occupation but, while it seems probable, we don't actually know that the continent of Sahul was first occupied by the descendants of today's Aboriginal Australians.

In October 2016 in a paper entitled A genomic history of Aboriginal Australia, by Anna-Sapfo Malvinas, Michael C Westerway et all, the authors concluded that:

• Aboriginal Australians and Papuans diverged from Eurasians and estimate 51–72 kya, following a single out-of-Africa dispersal, and subsequently admixed with archaic populations
• Papuan and Aboriginal Australian ancestors diversified 25–40 thousand years ago (kya), suggesting pre-Holocene population structure in the ancient continent of Sahul (Australia, New Guinea and Tasmania). However, all of the studied Aboriginal Australians descend from a single founding population that differentiated ~10–32 kya
• We infer a population expansion in northeast Australia during the Holocene epoch (past 10,000 years) associated with limited gene flow from this region to the rest of Australia, consistent with the spread of the Pama–Nyungan languages.   

I will leave aside the last conclusion for it raises another set of issues that is important to the history of Aboriginal Australia but is outside the scope of this post.

At the time, the estimate of 51–72 kya for divergence from Eurasians following a single out-of-Africa dispersal made me uncomfortable because the archaeological evidence was already suggesting possible early dates for human occupation of Sahul that might possibly conflict with these time lines. The Madjedbebe results added to this discomfort: the suggested 65,000 years was remarkably close to the suggested 72kya out of Africa date.

Before going on, I note that all the dating techniques involve statistical analysis with confidence intervals. Apparent differences and inconsistencies may reflect no more than this.

 The latest discoveries covered in this blog post suggest that:

• Earlier hominum species were in South East Asia long before modern humans
• Those species had come in different waves and had diversified 
• Those species had crossed the Wallace Line, overcoming sea barriers. They may even have reached Sahul
• Those species and modern humans overlapped far more than previously realised, co-existing in various forms of relationships including inter-breeding
• Aboriginal and Papuan groups that formed the basis of later population may have lived in what is now SE Asian for extended periods before moving on, not just passing through.

In writing to me, John also noted:

"I have just been reading a Geology paper that mentioned the super volcano Toba eruption as the largest single event of its type so far known. It struck me that this could have been the event to precipitate human migration into Australia. We now understand that the arrival of H.sapiens into Oz occurred most likely as a bulk entry over a very short period then nobody else over millennia. Could Toba have been the push factor ?"

I am not convinced that there was a single pulse and am generally sceptical of attributions to volcanic eruptions. But still. As dates get pushed back, the possibility that the Toba eruption played a role in the movement of and ending of human species becomes more plausible!