Alex Wilshaw
I recently finished my doctorate on the Late Stone Age of the central Kenyan Rift Valley (Title: An Investigation into the LSA of the Nakuru-Naivasha Basin and surround, Central Rift Valley, Kenya: Technological Classifications and Population Considerations) and am beginning a post-doctoral position with the In Africa Project, based at the Leverhulme Centre for Human Evolutionary Studies (LCHES). Alongside this, I also hold a teaching fellowship in Biological Anthropology at St. John's College, Cambridge.
Over the past seven years I have been involved in archaeological and palaeoanthropological projects concerning the prehistory of Fezzan, Libya, the Nakuru-Naivasha Basin, Kenya and Western Turkana, Kenya.
I am trained in lithic analysis (with a specialisation in East African microlithic industries), cranial and post-cranial human anatomy with a good working knowledge of palaeopathologies and am a competent illustrator of lithic Modes 1-5, bone tool technologies, pottery and beads (to publication standard). I am also interested in developing new methods and techniques within artefact illustration to create images with greater artistic appeal that , at the same time, still convey technical information to the observer.
Supervisors: Dr Marta Mirazon Lahr
Address: St. John's College
Cambridge
CB2 1TP
UK
Over the past seven years I have been involved in archaeological and palaeoanthropological projects concerning the prehistory of Fezzan, Libya, the Nakuru-Naivasha Basin, Kenya and Western Turkana, Kenya.
I am trained in lithic analysis (with a specialisation in East African microlithic industries), cranial and post-cranial human anatomy with a good working knowledge of palaeopathologies and am a competent illustrator of lithic Modes 1-5, bone tool technologies, pottery and beads (to publication standard). I am also interested in developing new methods and techniques within artefact illustration to create images with greater artistic appeal that , at the same time, still convey technical information to the observer.
Supervisors: Dr Marta Mirazon Lahr
Address: St. John's College
Cambridge
CB2 1TP
UK
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"The Late Stone Age (LSA) of East Africa is a diverse period of recent human prehistory. Despite the temporal proximity to today, these prehistoric people and their technological traditions are still poorly described and little understood. The Nakuru-Naivasha Basin, Kenya, has the best documented examples of the East African LSA (Eburran, nee Kenya Capsian), the diversity of which is manifested in an abundance of archaeological sites that show a confusing complexity of unexplained technological variation. Research stagnated at the end of the 1980's, after the Kenya Capsian classification system (phases A-E) was replaced with the Eburran (phases I-V) which confined the Nakuru-Naivasha industry to within 25 km of Mount Eburru. Modern research techniques within a novel research paradigm are applied to revitalise the study of this important prehistoric period. Firstly, historically collected evidence which lacks vital research information is modernised using archival investigation and mapping software. Secondly, the temporal and spatial variation of lithic artefacts and sites (12.5-2.5 kya) are described using univariate statistical analyses of attributes taken from a diverse sample of 36 LSA occurrences from 30 sites (2200 lithic tools and 220 cores); 6 further sites are included as a comparative framework of other localised technological traditions (SPN, Elmenteitan and Lukenya Hill). Thirdly, the relationship between the LSA technology and the shifting Holocene palaeo-environment is examined using multivariate statistics. Finally, technological characteristics that exhibit little ecological plasticity are used in a cultural cladistic analysis to infer information about prehistoric populations. Geometric microlith and core sizes show high levels of environmental plasticity (72.7% and 80.4%), and should not be used to define industrial boundaries in this area; as a result, the Eburran classification system is challenged. Likewise, the industry extends outside of the imposed 25 km boundary. It is argued that the original name of Kenya Capsian should be reinstated for this LSA industry, but not the phases defined within it. Instead, a clade based system is suggested, which is able to cope with the variation exhibited by the technology until a comprehensive classification system can be created; this will only be possible with greater research investment and novel evidence. Ultimately, the prehistoric people of the Kenya Capsian exhibit similar population patterns to the tribal system in Kenya today, which would explain why the LSA is so beautifully diverse and complex in this area.""
populations remain largely obscure. Only a handful of late Pleistocene African fossils (~50-12 Ka) are known, while the more numerous sites with human fossils of early Holocene age are patchily distributed.
In particular, late Pleistocene and early Holocene human diversity in Eastern Africa remains little studied, precluding any analysis of the potential factors that shaped human diversity in the region, and more
broadly throughout the continent. These periods include the Last Glacial Maximum (LGM), a moment of extreme aridity in Africa that caused the fragmentation of population ranges and localised extinctions, as well as the ‘African Humid Period’, a moment of abrupt climate change and enhanced connectivity throughout Africa. East Africa, with its range of environments, may have acted as a refugium during the LGM, and may have played a critical biogeographic role during the heterogeneous environmental recovery that followed. This environmental context raises a number of questions about the relationships among early Holocene African populations, and about the role played by East Africa in shaping late hunter-gatherer biological diversity. Here, we describe eight mandibles from Nataruk, an early Holocenesite (~10 Ka) in West Turkana, offering the opportunity of exploring population diversity in Africa at the height of the ‘African Humid Period’. We use 3D geometric morphometric techniques to analyze thephenotypic variation of a large mandibular sample. Our results show that (i) the Nataruk mandibles are most similar to other African hunter-fisher-gatherer populations, especially to the fossils from Lothagam,another West Turkana locality, and to other early Holocene fossils from the Central Rift Valley (Kenya); and (ii) a phylogenetic connection may have existed between these Eastern African populations and some Nile Valley and Maghrebian groups, who lived at a time when a Green Sahara may have allowed substantial contact, and potential gene flow, across a vast expanse of Northern and Eastern Africa.
Figure 1. Map showing the location of Aliel in context with pillar/platform sites and pastoral sites in the area. After Hildebrand et al. (2011) and Hildebrand and Grillo (2012).
communities, economies and traditions expanding into East Africa during the mid-Holocene, and holds crucial information for understanding the changes in population history and settlement dynamics at the time. The site of Aliel is well placed both temporally and geographically to yield further insights into this period of prehistory.
relations among prehistoric hunter-gatherers.
remain relevant today, others have become misunderstood
relics of an old classification system that hinders current research. This is particularly evident in the classification of a Later Stone Age (LSA) culture – the Kenya (East African) Aurignacian, later known as Kenya (East African) Capsian. Although this cultural entity was redressed during the 1970s and 1980s and redefined as the Eburran industry, there is still mystique surrounding the current status of the Kenya Capsian, its original scope and definition, the relationship with the Eburran and its position within a modern understanding of the
East African LSA. This is largely due to paradigmatic shifts in researcher attitudes, leading to the use of the Eburran as a false proxy. It is necessary now to completely remove the term Kenya Capsian as an indication of similarity among the different LSA technologies. However, there also needs to be less emphasis on
the importance of the Eburran and recognition that it is just one example of a multitude of diverse localised LSA industries. This will open the way for future research into the LSA and facilitate our greater understanding of recent prehistory in East Africa.
"The Late Stone Age (LSA) of East Africa is a diverse period of recent human prehistory. Despite the temporal proximity to today, these prehistoric people and their technological traditions are still poorly described and little understood. The Nakuru-Naivasha Basin, Kenya, has the best documented examples of the East African LSA (Eburran, nee Kenya Capsian), the diversity of which is manifested in an abundance of archaeological sites that show a confusing complexity of unexplained technological variation. Research stagnated at the end of the 1980's, after the Kenya Capsian classification system (phases A-E) was replaced with the Eburran (phases I-V) which confined the Nakuru-Naivasha industry to within 25 km of Mount Eburru. Modern research techniques within a novel research paradigm are applied to revitalise the study of this important prehistoric period. Firstly, historically collected evidence which lacks vital research information is modernised using archival investigation and mapping software. Secondly, the temporal and spatial variation of lithic artefacts and sites (12.5-2.5 kya) are described using univariate statistical analyses of attributes taken from a diverse sample of 36 LSA occurrences from 30 sites (2200 lithic tools and 220 cores); 6 further sites are included as a comparative framework of other localised technological traditions (SPN, Elmenteitan and Lukenya Hill). Thirdly, the relationship between the LSA technology and the shifting Holocene palaeo-environment is examined using multivariate statistics. Finally, technological characteristics that exhibit little ecological plasticity are used in a cultural cladistic analysis to infer information about prehistoric populations. Geometric microlith and core sizes show high levels of environmental plasticity (72.7% and 80.4%), and should not be used to define industrial boundaries in this area; as a result, the Eburran classification system is challenged. Likewise, the industry extends outside of the imposed 25 km boundary. It is argued that the original name of Kenya Capsian should be reinstated for this LSA industry, but not the phases defined within it. Instead, a clade based system is suggested, which is able to cope with the variation exhibited by the technology until a comprehensive classification system can be created; this will only be possible with greater research investment and novel evidence. Ultimately, the prehistoric people of the Kenya Capsian exhibit similar population patterns to the tribal system in Kenya today, which would explain why the LSA is so beautifully diverse and complex in this area.""
populations remain largely obscure. Only a handful of late Pleistocene African fossils (~50-12 Ka) are known, while the more numerous sites with human fossils of early Holocene age are patchily distributed.
In particular, late Pleistocene and early Holocene human diversity in Eastern Africa remains little studied, precluding any analysis of the potential factors that shaped human diversity in the region, and more
broadly throughout the continent. These periods include the Last Glacial Maximum (LGM), a moment of extreme aridity in Africa that caused the fragmentation of population ranges and localised extinctions, as well as the ‘African Humid Period’, a moment of abrupt climate change and enhanced connectivity throughout Africa. East Africa, with its range of environments, may have acted as a refugium during the LGM, and may have played a critical biogeographic role during the heterogeneous environmental recovery that followed. This environmental context raises a number of questions about the relationships among early Holocene African populations, and about the role played by East Africa in shaping late hunter-gatherer biological diversity. Here, we describe eight mandibles from Nataruk, an early Holocenesite (~10 Ka) in West Turkana, offering the opportunity of exploring population diversity in Africa at the height of the ‘African Humid Period’. We use 3D geometric morphometric techniques to analyze thephenotypic variation of a large mandibular sample. Our results show that (i) the Nataruk mandibles are most similar to other African hunter-fisher-gatherer populations, especially to the fossils from Lothagam,another West Turkana locality, and to other early Holocene fossils from the Central Rift Valley (Kenya); and (ii) a phylogenetic connection may have existed between these Eastern African populations and some Nile Valley and Maghrebian groups, who lived at a time when a Green Sahara may have allowed substantial contact, and potential gene flow, across a vast expanse of Northern and Eastern Africa.
Figure 1. Map showing the location of Aliel in context with pillar/platform sites and pastoral sites in the area. After Hildebrand et al. (2011) and Hildebrand and Grillo (2012).
communities, economies and traditions expanding into East Africa during the mid-Holocene, and holds crucial information for understanding the changes in population history and settlement dynamics at the time. The site of Aliel is well placed both temporally and geographically to yield further insights into this period of prehistory.
relations among prehistoric hunter-gatherers.
remain relevant today, others have become misunderstood
relics of an old classification system that hinders current research. This is particularly evident in the classification of a Later Stone Age (LSA) culture – the Kenya (East African) Aurignacian, later known as Kenya (East African) Capsian. Although this cultural entity was redressed during the 1970s and 1980s and redefined as the Eburran industry, there is still mystique surrounding the current status of the Kenya Capsian, its original scope and definition, the relationship with the Eburran and its position within a modern understanding of the
East African LSA. This is largely due to paradigmatic shifts in researcher attitudes, leading to the use of the Eburran as a false proxy. It is necessary now to completely remove the term Kenya Capsian as an indication of similarity among the different LSA technologies. However, there also needs to be less emphasis on
the importance of the Eburran and recognition that it is just one example of a multitude of diverse localised LSA industries. This will open the way for future research into the LSA and facilitate our greater understanding of recent prehistory in East Africa.
An investigation into the size and morphology of all available cores, as a proxy for the treatment of raw material, was carried out for 32 mode 5 Holocene sites (Late Stone Age and Pastoral Neolithic) with the distance to raw material sources ranging from 1km to 100km distance. Multiple Regression and General Linear Models were used to investigate the effects of raw material source proximity on core variables including the formality of core preparation and utilisation and the volume of discarded cores, whilst also correcting for other potential influences. A group of sites exhibiting non-obsidian cores was used as a control.
There was an inverse relationship between site proximity to a raw material source and the level of formality of the cores discarded there; distant sites show higher frequencies of formally prepared cylindrical and pyramidical cores and a reduction in the number of informal chunk and cobble cores compared to sites with greater proximity to raw material sources. The distance of a site from obsidian source accounted for 82.2% of the variation in core volume. Specifically, there was no pattern to core volumes when a site was within 5 km of an obsidian source, volume declined steadily from 30 cm3 to 7 cm3 at sites 5-20 km from a source and at sites over 20 km from a source core volume stabilised at a mean of 6 cm3. The control group of non-obsidian cores showed no difference in formality or volume in relation to obsidian source proximity, and consistently showed mean discard volumes of ~10 cm3.
The patterns shown by obsidian core volume are suggested to be related to planning and acquisition strategies based on logistical and caching radii; this supports conclusions drawn from previous studies on hunter-gatherer foraging patterns with critical distances of around 5 km for caching and between 10 km and 24 km for foraging (Hayden et al., 1987:282, Stein Mandryk, 1993:42). Increased core formality is also the result of planning, indicating that the quality and workability of obsidian is tested prior to acquisition. The formalisation of cores would improve the efficiency of flake removal, therefore conserving raw material. This would ultimately reduce the number of trips needed to acquire raw materials within a given time period and therefore reduce the risk to the individual and group. The stabilisation of mean core volumes at 6 cm3 after 20 km indicates that this volume is the limit of viability for an obsidian core.
"
Here, uni- and multi-variate statistics are used firstly to explore the variation of the LSA in this area, and secondly to investigate spatial, temporal and palaeo-environmental factors that may have influenced the composition and nature of the assemblages. This is followed by discriminant and cladistic analyses, which build data-driven hypotheses about the prehistoric people of the area and the population processes that may have led to the complex patterns of variation evident in their lithic technologies.
The results strongly suggest that certain assemblage and artefact attributes exhibit high levels of environmentally determined variation or plasticity (for example, geometric microlith length, multiple regression, F7,20=7.987, p<0.001, adjusted R2=0.727). These environmental effects often transcend the boundaries between industrial classifications, suggesting that artefacts exhibiting such plasticity have greater cohesion with the environment within which they were produced than they do with their respective technologies, traditions or adaptive strategies. Assemblage characteristics or stone tool data that exhibit such associations are therefore inappropriate for forming hypotheses about the interactions of ‘makers’ of stone tool technologies, which also has implications regarding the variables upon which the classificatory phases of these specific industries have been based in the past.
Overall, accounting for environmental influence on technological variation, ideas about population fragmentation during the late-Pleistocene and early-Holocene are supported, with patterns in lithic technological variation suggesting a prehistoric population structure with interactions similar to the groups or tribes seen in Eastern Africa today. However, this study may have wider methodological implications regarding the way in which stone tool attributes are used to delineate stone tool technologies globally. The Nakuru-Naivasha Basin exhibits a specific series of microenvironments, and thus the patterning identified in this study may not be a good example or guide to techno-environmental interaction effects elsewhere, but until such assessment is carried out on a greater diversity of geographic areas and across different modes of technology, the full potential impact of these effects for archaeological classification and human evolutionary patterns in general, remain a mystery.
REFERENCES
[1] Dewey, H., Hobley, C.W., 1925. 51. Some Obsidian Implements from Kenya Colony. Man 25, 88-92.
[2] Leakey, L.S.B., 1931. The Stone Age Cultures of Kenya Colony, First ed. Cambridge University Press, Cambridge.
[3] Ambrose, S.H., 1984. Holocene Environments and Human Adaptations in the Central Rift Valley, Kenya., Anthropology. University of California, Berkeley.
[4] Phillipson, D.W., 2005. African Archaeology, Third Edition ed. Cambridge University Press, Cambridge.
An investigation was carried out on the lithic technologies of 32 Holocene sites (Later Stone Age and Pastoral Neolithic) with distances to raw material sources ranging from 1km to 100km. The morphology of flakes and shaped tools did not vary in relation to obsidian source proximity, however, the morphology of cores did. Multiple regression and General Linear Models were used to investigate these variations whilst also correcting for other potentially influential factors. The effects of obsidian source proximity were particularly evident in relation to the formality of core preparation and utilisation, and the volume of a core at discard.
There exists an inverse relationship between a site's proximity to a raw material source and the level of formality of the cores discarded there; distant sites show higher frequencies of formally prepared cores and a reduction in the number of informal cores compared to sites with greater proximity to raw material sources. The distance of a site from an obsidian source accounted for 82.2% of the variation in core volume at the point of discard. Specifically, there was no pattern to core volumes when a site was within 5 km of an obsidian source, volume declined steadily from 30cm3 to 7cm3 at sites 5-20km from a source and at sites over 20km from a source core volume stabilised at a mean of 6cm3. A control group of sites exhibiting non-obsidian cores showed no difference in formality or volume in relation to obsidian source proximity, and consistently showed mean discard volumes of ~10cm3.
The patterns shown in obsidian core volume are suggested to relate to planning and acquisition strategies based on logistical and caching radii; this supports conclusions drawn from previous studies on hunter-gatherer foraging patterns with critical distances of around 5km for caching and between 10km and 24km for foraging. Increased core formality indicates that the quality and workability of the obsidian was tested prior to acquisition. The formalisation of cores improves the efficiency of flake removal, therefore conserving raw material. This ultimately reduces the frequency of forays that prehistoric people would have needed to make in order to acquire raw material and therefore would have reduced the risk that long distance travel posed to individuals and groups. Sites further than 20km from an obsidian source consistently exhibit a mean core volume of 6cm3, which is likely the limit of viability and therefore can be used as an indication of complete obsidian core exhaustion for this area.
The illustrations are of artefacts from the ongoing field project in Kenya.
Please note, this guide is not exhaustive, and is deliberately written in a simplified form so that non-specialists can understand it.
It is also designed to fill a gap in teaching, about which many students have complained to me - essentially, that many supervisors expect work to be correctly referenced yet do not teach students, many of whom have never encountered academic referencing before, how to do so properly.