2 African Background to Eurasian Prehistory: Out of Africa I and II

Ravi Korisettar

Introduction

Eurasia forms part of the old world which witnessed the early expansion of human ancestors who were tool makers, out of Africa. Their presence outside of Africa is evidenced by either stone tools or fossils or both occurring together at prehistoric sites. Eurasian prehistory can be best understood against the background of African prehistory, the region preserves the oldest remains of human ancestors and their cultural vestiges. The latter constitutes the archaeological record of the rise of human behaviour or culture.

Now human ancestors are generally referred to as hominins rather than hominids. The term hominid includes both humans and apes as they both share nearly 98% DNA. If people are found all over the globe it is because humans are a migratory species and they continue to occupy or colonize habitable geographical environments on the earth. Nowadays man is exploring the universe for habitable planets in the Solar system. The timing of hominin colonization of different parts of the old world is a complex issue dependent on the presence of securely datable contexts and the preservation of fossil and archaeological material in geological and archaeological strata.

2. Objectives

This chapter introduces to the human evolutionary scenarios in Africa and the processes leading to the colonization of distinctive geographical environments outside of Africa, the cradle of humankind. Prehistory of distinctive geographical environments across the globe therefore is governed by the timing of exit out of Africa and the suitability of dispersal routes and habitability of regional environments in terms of continuous availability of plant and animal food resources, perennial water bodies, and lithic raw material resources. Geochronology, palaeoanthropology, palaeoclimatology, archaeology and now ancient human genetics combined together provide us with an integrated picture of human bio-cultural evolution. Peopling of the planet is a fascinating saga of human progress towards the modern civilization.

Prehistoric human populations have been broadly divided into (a) ancients and (b) moderns, based on anatomical changes observed in the fossil record. Much of this record is continuous and well preserved in different parts of eastern and southern Africa. These two regions have well preserved geological contexts that have facilitated geochronology by the application of geochronometric methods. Transitional categories are referred to as archaic Homo. To date the oldest evidence of archaeological material, fossil remains and ancient mtDNA is only known from Africa, particularly eastern and southern Africa. Another important aspect of prehistory is the study of emergence of cognition in early humans and the rise of behavioural modernity embedded in the archaeological assemblages associated with human fossils and otherwise.

The presence of Pleistocene hominins in different parts of the world is evidenced by either fossils or lithic assemblages; the latter generally overwhelms the former. Oldowan, Acheulian, Levalloisian, Mousterian and Aurignacian are some of the typo-technological stages reflecting on bio-cultural evolution of Pleistocene hominins and their expansion out of Africa. Amongst these the Levalloisian is widespread in the old world, with its roots in the Late Acheulian of Africa. The emergence of Levalloisian technology marks the beginning of gradual transition from Lower to Middle Stone Age (also Middle Palaeolithic), when bifaces are replaced by flakes, points, blade artifacts, etc.

This chapter also outlines these developments in summary form and the reader is referred to relevant literature in the quadrant on further learning.

3. Timeline of Human Evolution

The fossil record of Africa belonging to the time period between 8 and 7 million years ago (Myr), of the Miocene epoch (25-5 Myr), has clearly established the African origins of humans as well as the fact that dispersal and colonization are as old as the human race itself. Archaeological, fossil and genetic footprints constitute indelible evidence of the human journey out of Africa. The timing of their entry into distinctive geographic areas and routes of dispersal are critical to our understanding patterns of colonization across the planet Earth.

While the archaeological evidence provides indisputable evidence of the human settlements and their antiquity, supported by the geochronological methods (fission rack, potassium–argon, OSL, etc.), the genetic (mtDNA) coalescence dates are not as yet considered conclusive. Complex natural and biological processes have been at play in the manner in which these sets of evidence are preserved. Obviously there are gaps in these two vital bodies (archaeological and genetic) of evidence leading both archaeologists and geneticists to an intense argument so as not to agree with each other. This is a hot topic today among archaeologists especially those working on anatomically modern humans (moderns) and not so much in regard to the early expansion out of Africa (out of Africa I) generally associated with Homo erectus/ergaster (ancients), the author of Acheulian techno-complex. Some of the European sites like Atapuerca in Spain and Dmanisi in Georgia stake claim for pre-Homo erectus epansion out of Africa. Both archaeologists and palaeoanthropologists are engaged in delineating processes leading to the peopling of the old and new worlds.

Fossil and genetic evidence of human ancestors in Africa show agreement in placing hominin origins between 7 and 5 Myr. The earliest indisputable hominin ancestor has been placed in the Pliocene. Hominins have a short evolutionary history of about 2 million years during which period their biological evolution was marked by continuing trend towards encephalization and obligate bipedalism. These two factors, including a large body size, and the tool making ability of the hominin ancestors provided them greater adaptive capability over other apes and so they were widely distributed in Africa.

Archaeological, fossil and genetic footprints constitute indelible evidence of the hominins’ journey out of Africa. The timing of their entry into distinctive geographic areas and routes of dispersal are the moot questions. While the archaeological evidence provides indisputable evidence of the antiquity of hominin expansion, supported by the geochronological methods, the genetic coalescence dates betray limitations. Complex natural and biological processes have been at play in the manner in which these two sets of evidence are preserved. Obviously there are gaps that have lead both archaeologists and geneticists to an intense debate, as to the timing of exit of moderns out of Africa and which was their first stop outside of Africa.

3.1 The Hominin Family Tree

Around 2.5 Myr Homo habilis with Mode I tool kit was present in Eastern Africa where by around 1.8 Myr a new group of hominin, Homo erectus/ergaster appeared possessing more or else complete hominin characteristics, such as large body, larger brain, meat consumption and ability to range into newer geographical environments. Fossil remains of this group are found across Africa and beyond, including Caucasus, Indian subcontinent and Java. This widespread dispersal occurred between 2 and 1.5 Myr, while carrying with them the Acheulian techno-complex. Prior to the emergence of Homo the African fossil records places the hominin ancestry around 4.5 Myr. A series of skeletal fossils of Ar. ramidus, Au. anamensis, Au. afarensis and Au. garhi have been identified as antecedent bipedal hominins. They are not known to have produced stone tools and were not successors to one another. Each one of them seems to have reached their dead end during the course of time. Some of the Australopithecines and early Homo shared Eastern and Southern African habitats during the Early Pleistocene.

The Early Pleistocene environments across the old world favoured expansion of Homo erectus/ergaster out of Africa (Out of Africa I). Though some scholars argue for a pre-erectus expansion, overwhelming evidence is in favour of the larger brained bipedal erectus. Hominins colonized northern and southern parts of Africa (~1.8 Myr), the Indian subcontinent (2-1.5 Myr) Southeast Asia (1.8 Myr), East Asia (1 Myr) and Europe (1 Myr). Obviously by 1 Myr hominin populations were widely distributed across the old world and were well adapted to distinctive geographical Early Pleistocene environments and slightly later around 0.8 Myr hominins entered temperate Europe. This distribution also reveals that they were subject to regional differentiation in terms of species and populations, during the course of the one million years between 1.8 and 0.8 Myr. The short chronology for the first human colonization of Europe is challenged by a number of dated sites in Spain, Georgia and the Levant.

The Middle Pleistocene (0.8- 1.25 Myr) Europe, Africa, Southwestern Asia and much of South Asia witnessed the emergence of morphologically distinctive hominins and accompanying tool assemblages. Hominins’ morphology is devoid of erectus features but with increased body size and brain size. The morphological distinctiveness renders them a species status, Homo heidelbergensis, found at a number of sites in Europe and Africa. This species made its presence in Africa and Europe, was contemporary during the Middle Pleistocene, and is associated with the Late Acheulian (Mode II). From the European standpoint the spread of Homo heidelbergensis is considered out of Africa II. This species, or its descendent Homo helmi (according to some scholars), is considered the last common ancestor of both Neanderthals and anatomically modern humans (Homo sapiens) popularly referred to as AMHs. On the other hand this development is not observed in China and Java, where Homo erectus associated with simple tools survived till about 0.3 Myr, under conditions of long term isolation. Around 300 Kyr morphologically distinctive fossils of hominins appear alongside Homo erectus in China. Conventionally out of Africa II refers to the spread of AMHs leading to complete peopling of the world.

The fossil record across the old world after 0.5 Myr reveals the presence of four distinctive morphologically divergent lineages between Africa, Europe and Asia: Homo sapiens in Africa, Homo neanderthalensis in Europe, Denisovans in inner Asia (Siberia) and Homo erectus in China. The Neanderthals were fully evolved with classic features between 190 and 130 Kyr that were well suited for adapting to cold conditions of the Middle Pleistocene. This lineage is the best represented of all the contemporary ones, as many 500 fossil specimens have been documented. Both Neanderthals and AMH co-existed in Southwest Asia for a long period of time. The excavations at Skhul and Qafzeh caves have yielded AMHs remains dating between 120 Kyr and 90 Kyr, and Neanderthal remains have been recovered from Kebara Cave (c. 60 Kyr) and Amuda Cave (50 Kyr) and in western Europe Neanderthals survived till about 40 Kyr. They also possessed comparable cognitive capabilities and behavioural similarities, but appears to have differing growth rates.

3.2 Homo floresiensis

The Late Pleistocene palaeoanthropological record of skeletal fossils, named Homo floresiensis, from excavation of the cave of Ling Bua on the island of Flores (Indonesia) has given rise to a challenging time to evolutionary palaeoanthropologists, especially finding them a place in the hominin phylogenetic tree. This small bodied assemblage of skeletal remains dated to from 97 to 12 Kyr were of individuals 1 m tall and with a endocranial volume of 380 cc and were associated with fauna (some with cut marks) and stone tools, including points, blades and perforators. Discussions on its origins and the reasons for dwarfism have continued till date, whether it descended from the native Homo erectus or it represents a new species, or it belonged to a pre-erectus that left Africa before 1.8 Myr. Genetic studies are being invoked to resolve these issues. However, on the basis of a geometric and morphometric comparative analysis of floresiensis and pathological human samples, which included pathological conditions such as microcephaly, myxoedematous endemic hypothyroidism and Laron syndrome have concluded that Flores cranium is most comparable with H. erectus, particularly with early Eurasian H. erectus, and belongs to a distinct taxon, H. floresiensis a possible descendant of local H. erectus and rule out the role of pathological conditions as the cause of LB1 neurocranial phenotype.

3.3 The Denisovans

Excavations at the Denisova Cave in the Altai Mountains of southern Siberia yielded a distal phalanx bone of an archaic hominin young female in 2010, and a tooth from layer 11.1. This is a reference site for the Middle and Upper Palaeolithic of the region, where human occupation goes back to 280 Kyr. The fossil bone comes from layer 11 dated to 50-30 Kyr. It is associated with stone artefacts of Middle Palaeolithic type (including scrapers and Levallois blanks) microblades and objects of body adornment of the Upper Palaeolithic time period. The genetic material extracted from this bone indicated that it belonged to an unknown type of hominin and designated it as Denisovans, considered a sister group of Neanderthals that had diverged before Neanderthals shared genes with AMHs. The Denisovans’s DNA is found in modern Melanesians, with implications for two waves of settlement of Southeast Asia and Oceania: the early settlement of Australia prior to 60 Kyr and later around 38 Kyr. The genetic history of the Denisovans stands distinct and the individual “belonged to a hominin group that shares common ancestor with Neanderthals’ and ‘show that on the Eurasian mainland there existed at least two forms of archaic hominins in the Upper Pleistocene: a western Eurasian form with morphological features that are commonly used to define them as Neanderthals, and an eastern for to which the Denisova individuals belong’.

Homo erectus, Homo sapiens, Homo neanderthalensis, Homo floresiensis and Denisovans inhabiting distinctive environments came under selective pressure posed by the evolutionary environments, such as increased aridity in Africa and extreme cold conditions in Europe and northern Asia, underwent morphological changes as a means of biological adaptation, experienced differential growth rates and island dwarfism in case of Homo floresiensis.

3.4 Homo naledi

Assigned to the genus Homo, Homo naledi fossils were first discovered by recreational cavers Rick Hunter and Steven Tucker in 2013 in South Africa’s Gauteng province, in the Dinaledi chamber (“chamber of stars”) in the Rising Star Cave system. They were first described in 2015 by a 47-member international team of authors led by American and South African paleoanthropologist Lee Berger of the University of the Witwatersrand. Fossils of at least fifteen individuals – old, young and infants amounting to 1550 specimens have been excavated. Disarticulated and articulated skulls, jaws, ribs, teeth, bones of an almost complete foot, of a hand, and of an inner ear were found lying on the cave floor or buried in shallow sediment The species is characterized by a body mass and stature similar to small-bodied human populations, a smaller endocranial volume similar to Australopithecus (Four skulls were discovered, thought to be two females and two males, with a cranial volume of 560 cm3 for the males and 465 cm 3 for females), and a skull shape similar to early Homo species. Bipedal adult males stood around 150 cm tall and weighed around 45 kg, while females were a little shorter and weighed a little less. Three dating methods have been tried with inconclusive results although there are various suggestions ranging from 2.8 to 1 Myr. It is also believed that the individuals may have been deliberately placed in the cave near the time of their death indicating some funerary ritual/belief.

3.5 The Neanderthals

There is competition among scholars of the Middle Palaeolithic and the origins of behavioural modernity, while one school asserts that AMHs gave rise to behavioural modernity in Africa the other school documents evidence from Neanderthal burials and other related objects to attest behavioural modernity in Neanderthals as a parallel development in western Eurasia and that both were culturally modern. The Neanderthals biogeographic area extended from Europe to Central and Western Asia.

Nearly 500 fossil remains of Neanderthal individuals have been documented from different parts of Western Eurasia (Europe, Middle East and Central Asia) their principal biogeography, so far known. The distribution of their fossil remains in Asia lies between the Taurus and Zagros mountains. The Levallois-Mousterian industries that are credited to the Neanderthals are typical of the European Middle Palaeolithic, including the northwestern parts of the Indian Subcontinent as indicated by the typical Levallois-Mousterian industries. Distinctive Levallois assemblages occurring in north and northeastern Africa were made by the Middle Stone Age anatomically modern humans. The material culture of the Neanderthals is represented by Mousterian complexes with varying percentage of Levallois technology.

The fossil specimens range in time from 400 to 25 Kyr, the upper time mark has been revised to 40 Kyr. The Neanderthals are considered to have emerged from the Non-African or the Eurasian Homo heidelbergensis, around 500-400 Kyr. Owing to their widespread occurrence, attempts have been made to understand their adaptive capability to a wide variety of environments across the region of their occurrence. Morphologically Neanderthal specimens reveal negligible difference in the body mass index (BMI) between Neanderthals and AMHs. The genetic analyses of Neanderthal DNA and Y-chromosome not only reveal spatio-temporal variation among the Neanderthals but also the fact that both Neanderthals and modern human’s genetic similarity up to 4% and that the Neanderthals could not be excluded from genetic heritage of modern human populations across Eurasia. The implication of this is that interbreeding occurred between the African AMH and European Neanderthals during their co-existence. Against this background it has been argued that both belong to the same species Homo sapiens.

Given the vast geographical dimensions of the Indian subcontinent, the documented evidence of fossil hominins is rare, and if present, is widely scattered in time and space. Thus it is rendered difficult to affirm the presence of either the AMHs or Neanderthals. The latter’s presence is suggested by the Levallois-Mousterian assemblages in the Pakistan part of the subcontinent. Although it is generally difficult to distinguish the lithic assemblages as sound markers of either the Neanderthals or early modern humans.

4. How modern were Neanderthals?

Considerable debate is witnessed among scholars regarding behavioural modernity centering on the Neanderthal burials, whether intentional or accidental; the cognitive capability; innovative and complex technologies; symbolic culture; etc. That the Neanderthals were either replaced by AMHs, or assimilated into AMHs populations, or suffered extinction is considered as evidence of lack of behavioural modernity or lack of complex technologies. Even if they possessed these, their presence has been attributed to borrowing from incoming Homo sapiens and that the Neanderthals lacked an environmental stimulus that could have triggered intellectual and cognitive abilities that are said to have existed in Africa around 80 Kyr. However, it should be noted that such arguments were based on insufficient archaeological data and that both these populations possessed similar lithic technologies.

In the context of rise of behavioural modernity among late Pleistocene populations distributed across the old world: Homo sapiens in Africa; Neanderthals in western Eurasia; Denisovans in northern Asia; archaic hominins in southern, eastern and south eastern Asia, the African hominins are considered the supreme forerunners with ability to innovate complex technologies and invent symbols. Many scholars emphasize that both Homo sapiens and the Upper Palaeolithic revolution (behavioural modernity) originated in Africa (Sub-Saharan Africa) and the latter in particular was a response to environmental stimulus. In support of this the Neanderthals in western Eurasia have been classified as weaker hominins possessing a weaker lithic repertoire making them incapable of facing the AMHs ‘invasion’ who carried with them the Aurignacian technology. Inherent contradictions in this argument are revealed by existence of comparable lithic technologies among the Homo sapiens and Neanderthals distributed across northern Africa and western Eurasia, covering the time periods between Middle Stone Age and Middle Palaeolithic of Africa and Eurasia respectively. Striking similarity is seen in the presence of projectile technology among all the late Middle Pleistocene populations within and outside Africa. Despite lack of sustainable argument, the European model of AMHs expansion, ushering the Upper Palaeolithic revolution, emphasizes that Homo sapiens, endowed with advanced cognitive and symbolic attributes as responsible for replacement of Neanderthals by AMHs. The African Homo sapiens are credited to have invented art and other elements of symbolic culture.

Revised radiocarbon chronology of the Neanderthal fossils has clearly revealed that both these populations lived together for several thousands of years; this provided plenty of opportunities for cultural interaction as well as interbreeding; the estimated time of overlap between them is about 5,400 years (in parts of southern Europe) and has revised the date of last appearance of the Neanderthal to 40 Kyr. The genetic analysis reveals interbreeding between the autochthonous and allochthonous populations and gradual disappearance of the former. However, the emergence of Uluzzian industry in southern Italy and the shell beads and stone tools of the Chatelperronian in France, around 45 Kyr, attributed to the Neanderthals, are considered a product of contact between AMHs and Neanderthals. Such conclusions are challenged by other scholars and pose a question if other contemporary populations, including Neanderthals, did not possess cognitive and intellectual capabilities? It is now clear that traits that cumulatively represent behavioural modernity did not appear at once and that it was possible that such capabilities arose at different times in different environments and archaic populations distributed across the old world, be it Homo sapiens in Africa or Neanderthals in Eurasia and that the ‘development of symbolic culture cannot be linked to specific human populations’ and perhaps to specific environmental stimulus. Current literature reveals undue emphasis on undermining the cognitive and intellectual capabilities of Neanderthals and that the Neanderthals became extinct soon after the arrival of Homo sapiens into Europe, despite clear evidence of negligible differences between AMHs and Neanderthals physical characteristics. The average body mass, average height and BMI are close to each other, though Neanderthals were slightly more massive and shorter.

The Neanderthal burials have also been subject to reexamination and scrutiny of their mortuary practices and to examine if the Neanderthals were at par with Homo sapiens’ modern behaviour. Although these investigations have not produced unequivocal evidence in respect of behavioural modernity, a great deal of diversity in Neanderthal burials have been documented, some containing grave goods such as pigments and animal bones. However, doubts have prevailed regarding the intent and ritual context of the burials. There is evidence of use of red pigment by the Neanderthals as early as 200 Kyr, from a Neanderthal cave in the Netherlands. Its use is considered a good example of religious rituals in the Middle Palaeolithic period of Eurasia. The Neanderthals hunted the same way as the AMHs; hunted large animals and ate diverse and healthy diet. Despite these bits of evidence the antiquity of modern human culture is traced to the Middle Stone Age of Africa, perhaps prior to Neanderthals exodus from Africa. Ongoing discussion whether Neanderthals possessed modern human behaviour, while successfully adapting to changing continental glacial and interglacial conditions, has not conclusively assigned them inferior status.

Fossil Hominin Record of the Indian Subcontinent

The year 1964 marks the beginning of systematic archaeo-anthropology (also palaeo-anthropology) in South Asia. An integration of archaeological and bio-anthropological methods and their application to skeletal series from a number of prehistoric sites in South Asia has helped address issues relating to biological anthropology of South Asian skeletal record from the Palaeolithic to Iron Age, including the Harappan Civilization. This has resulted in delineating demographic structure, age at death, nutritional status and human behaviour in particular contexts and environments of the Holocene populations in the subcontinent.

The best known Pleistocene fossil hominin discoveries are from Sri Lanka. Detailed bio-cultural analysis of the Sri Lankan hominins antedate the rise of ongoing vigorous debate on when and how the modern human expansion out of Africa took place. This study also revealed the continuity of Late Pleistocene populations into modern times not only in Sri Lanka but also other parts of South India. The Pleistocene fossil hominin record of India is inadequate for placing the Indian subcontinent at the centre of ongoing debate on eastward expansion of Homo sapiens out of Africa, eventually colonizing Australia around 60 Kyr. However, the application of new dating techniques to archaeological contexts has facilitated in substantiating colonization events (out of Africa I and II) and they could now be traced and placed on a timescale that clearly moved the Indian subcontinent from the periphery to the centre of eastward expansions out of Africa.

Table 1: Later Pleistocene fossil hominin evidence from the Indian subcontinent and border lands, arranged in order of their ages.

Given the vast dimensions of the Indian subcontinent and the proportionate number of documented Palaeolithic sites the above table (Table 1) reveals glaring inadequacy of fossil hominin sites. Similarly there is a dearth of securely dated Palaeolithic contexts in the region, especially in a region so enormously rich in prehistoric sites. Yet, the recent absolute dates for the Lower and Middle Paleolithic and microlithic sites are in conformity with the earlier dating of Paleolithic contexts in Pakistan, Sri Lanka and western India. These developments provide excellent opportunities to South Asian archaeologists for initiating intensive investigations on the Early and Middle Palaeolithic and the transition from Middle to Upper Palaeolithic. The early dates of the Lower and Middle Palaeolithic are a pointer to place Pleistocene and Palaeolithic research in the forefront. These dating results have pushed the earliest colonization of the subcontinent to Lower Pleistocene on the one hand and the presence of AMHs to around 80 Kyr (or even during MIS5) on the other. Similar results from Arabia stand in support of this changed situation in the subcontinent. The Lower Pleistocene presence of Homo erectus/Acheulian in the subcontinent attests that emigrant population moved eastwards of Southwest Asia and colonized the Indian subcontinent much earlier than entering temperate Europe. This is the key to understanding the differential dispersal events associated with the colonization of the rest of the old world and that euro-centric models are not necessarily applicable to other parts of the old world.

6. The Indian Palaeolithic Record: the antiquity of hominin settlement

Although Palaeolithic research in the Indian subcontinent has a long history of more than 150 years the research emphasis was largely focused on the Lower Palaeolithic and on filling the gaps in the Palaeolithic succession that was comparable to the European. Issues relating to preservation of hominid/hominin fossils, chronology, terminology and hominin behaviour were periodically addressed alongside excavation of Lower and Upper Palaeolithic sites. Despite increasing intensity of research on the Late Pleistocene origin and spread of modern humans and behavioural modernity, during the last three decades and despite the recognition of the Middle Palaeolithic as a distinctive phase in Indian prehistory greater emphasis was laid more on a typo-technological study of lithic assemblages and inter-regional comparison within the Subcontinent and less on detailed technological comparisons and comparability with the African stone industries.

The sporadic nature of documentation of Late Pleistocene microlithic assemblages from a number of sites in central and peninsular south India, the presence of dated contexts of microliths in Sri Lanka and India (e.g. Patne) and modern hominin remains in Sri Lanka and Pakistan, this body of data was considered peripheral to the debate on dispersal of modern humans out of Africa. The emergence of Southern Dispersal model entailed a thorough scrutiny of the Indian evidence and the geographical importance of the peninsular coast that might have facilitated a rapid expansion from out of Africa to Australia. Such research designs began to address questions relating to the significance of microlithic and symbolic artefacts from the later Pleistocene contexts. During the last ten years the application of new dating methods in the Palaeolithic archaeology of southern India has new insights to our understanding of the presence of modern humans and their behavioural spectrum in India and that the Indian lithic industries have closer affinity with Africa. Now the subcontinent figures prominently in the out of Africa debates.

Application of new dating methods has established the presence of Lower Palaeolithic hominins in the Early Pleistocene and Middle Palaeolithic hominins in the Late Middle Pleistocene/early Late Pleistocene (pre-Toba – 74 Kyr), and post-Toba continuity of population. In addition the new dates have contributed to opening new pathways of hominin expansion out of Africa: whether Homo sapiens exited Africa during the Middle or Upper Palaeolithic periods. This is now the most debated hot topic among archaeologists working in South Asia. This has also necessitated a detailed technological analysis of recently excavated lithic assemblages to be able to systematically compare the Indian evidence with the African as well as with the sites further east of the subcontinent. The current absolute dates for the Middle Palaeolithic in central and southern India range in time from 80 Ka to 40 Kyr and the oldest microlithic sites are about 40 Kyr.

Despite systematic survey and excavation at potential sites for locating fossil hominin remains the result has been frustrating. However the new dates for the Middle and Upper Palaeolithic assemblages and associated material remains show a late development of symbolic thought and behaviour. At present showing a wide time gap between the first appearance of behavioural modernity in Africa and India does not fit into the single rapid southern dispersal model, i.e. distinctly associated with the microlithic Upper Palaeolithic exit out of Africa. It is also suggested that the coastal route facilitated faster dispersal, at the rate of 1 km per year. In an estimated time of about 10-15,000 years modern humans are said to have moved from their African homeland to Australian via the southern coast, by taking into account combined DNA and lithic evidence. The appearance of typical Upper Palaeolithic microliths and symbolic artefacts have been dated to 45 Kyr at Mehtakheri, to >34 Kyr at Jwalapuram (JWP9)and to 27 yr at Patne. The microlithic technology has been documented that shows a development from late Middle Palaeolithic. At Blombos in South Africa symbolic behaviour dates back to 100 Kyr. These assemblages clearly show a gap of 50-60 Kyr between Africa and India and much less between India and Australia. Therefore a much earlier expansion of modern humans into South Asia is being advocated.

Recent advances in the Middle and Upper Palaeolithic archaeology of Arabia and India have revealed fresh evidence suggesting arid regions opened corridors during interglacial phases and that the Middle Palaeolithic expansion in Arabia represents the first out of Africa stop of modern humans. A large number of sites have been investigated in the inland valleys of Arabia.

Environmental and ecological analyses of coastal routes contradicts the feasibility of the coastal routes given the rapid fluctuation of sea levels, consistent occurrence of high quality lithic resources, fresh water springs during lowered sea levels, terrain characteristics, existence of barriers along the path, etc. For instance the Laterite (fossil soil) along the western coast of India could have been a big barrier: the major part of the west coast (including the continental shelf and the upland Western Ghats) is highly lateritised, the upper part of which is highly indurated ferruginous duricrust (of the order of several meters in thickness). It is basically iron stone out of which blocks are cut into bricks and sun dried, largely used for construction today. It mantles the exposed surfaces all over the western sea board except the steeper sides of the valleys and escarpments. In fact the earliest settlements along the west coast do not go earlier than the Iron Age. Surely for hunter-gatherers this region would have been a greater barrier, with rock outcrops concealed underneath it. In fact, years of search for Palaeolithic settlements along the coast of Maharashtra and Karnataka have been frustrating. The above being the possible explanation for the absence of sites. Similarly the mouth of the Indus and the Ranns of Kachchh in Western India were barriers. The entire western coast and the southeastern coast of India are devoid of any evidence of Later Pleistocene sites. The known coastal adaptations are in the time range of Terminal Pleistocene to Holocene.

7. Offshore Archaeology: The suitability of coastal habitats

Offshore and submarine surveys along the western sea board of India has yet not produced evidence of prehistoric past. Existence of neither caves nor rock shelter has been noticed, the known ones are onshore along the eastern seaboard. Till now artefacts of Holocene antiquity have only been reported in the form of ceramic sherds, though unidentifiable, known from the shelf off the Gulf of Khambat, with vast majority of submarine recovery related to ship wrecks. Quartzite, chert and other forms high quality siliceous rocks are restricted to some geological zones along the western shelf region. Although Paleolithic occurrences are known in Gujarat littoral (adjacent to the Makran coast of Pakistan), they are associated with regressive phases of the sea. Although periodic increase in continentally, particularly in the Late Quaternary, and the shelf was exposed offshore up to about 150 Km, in response to glacial and interglacial fluctuations. Whether this region facilitated the formation of refuge areas for hominin expansion is not clear from the marine archaeological surveys. The extent to which the shelf exposure occurs depends on the offshore bathymetry and the habitability is governed not only by coastal marine food resources but also the geological substrates with suitable lithic raw materials. On the contrary, expansion of hominin populations to the coastal regions is ascribed to periods of forest expansion and higher sea levels. Coastal land surveys along the Arabian Sea have found it difficult to find Paleolithic artifacts ranging from Early to Upper Palaeolithic, and the known microlithic occurrences are associated with the coastal promontories and rocky outcrops, largely belonging to Late Holocene hunter-fisher and gatherer communities, generally identified as Mesolithic. However, these sites are not everywhere and they tend to be restricted to certain environments. As yet there is no microlithic context onshore dating to Late Pleistocene or at least to the Last Glacial Maximum of 27-18 Kyr. Details of bathymetry along the west coast, in particular, are wanting. Although it is suggested that drying up of continental interior during glacial period, owing to lowered sea levels and decreased SW monsoon, the exposed coastal shelf could have served as refuge areas. It is interesting to note that palaeoclimate records of Late Quaternary witnessed higher intensity of NE monsoon that covered the major part of inland peninsular Indian. This means that inland basins remained perennial habitats, as evidenced by uninterrupted Paleolithic occupations. At present in order to present a persuasive argument in favor of coastal habitability during low sea levels, one needs clear understanding of the nature of bathymetry and the resources that could attract hominin expansion. The archaeological record from the western coast of Indian is inconsistent and patchy and is unlikely to mark the early arrival humans along a coastal route. In the light of this situation global dispersal of humans needs to be viewed as a prolonged involving complex processes and multiple migrations as opposed to single rapid dispersal of modern humans out of Africa around 60 Kyr. The Indian subcontinent had been previously colonized by archaic populations and had established a dispersal pattern that led to colonization of inland regions of the subcontinent. Invoking a new route of dispersal to suit the convenience of an argument that the coastal tracts maintained an uniform set of resources that did not put pressure on the dispersing hominins, appears an over emphasis.According to the evidence documented by Italian archaeologists working in Pakistan it has been suggested that Neanderthals/modern humans might have dispersed out of Africa along two possible routes to reach southern Eurasia and the Indian subcontinent; (a) along the northern Black Sea corridor during the OIS3 and (b) along the bridge connecting Balkans with Anatolia. The Indian subcontinent could be reached through Mesopotamia or along the exposed landmass along the Makran coast.

During the Early Pleistocene the route across the Bosphorus and around Black Sea was used by various species of Asian and African macro mammals to enter Europe. And during the major part of Quaternary, the Black Sea was periodically carried fresh water that implied the existence of land bridge between Asia and Europe and that early hominins could move westwards through the Danube valley or along the coast.

8. Summary

It should clear to us that humans have been living in Africa longer than any part of the world. The hominin origins is well documented from Africa and is placed in a firm chronological framework. The oldest stone tools are also recorded from Africa. We have also obtained a fairly good idea of the present state of information on human bio-cultural evolution in time and space. The new discoveries of hominin fossils have also added to our knowledge of the great diversity of hominin ancestors living in Africa during the Pliocene Period. Archaeological evidence from the Indian subcontinent is briefly presented here, details will follow in the individual modules on various phases of the Indian Palaeolithic. The next module will present information on the dispersal patterns across the old and new world and explain how the people came to be where they are.

Bibliography

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