Who were the Nataruk people? Mandibular morphology among late Pleistocene and early Holocene fisher-forager populations of West Turkana (Kenya)

Abstract

Africa is the birthplace of the species Homo sapiens, and Africans today are genetically more diverse than other populations of the world. However, the processes that underpinned the evolution of African 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 heterogene`ous 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 Holocene site (∼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 the phenotypic 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.

Biocultural diversity in Late Pleistocene/Early Holocene Africa: Olduvai Hominid 1 (Tanzania) biological affinity and intentional body modification

“…Unfortunately, significant use of shellac and glue obscures most surfaces, making the detailed microscopic examination of surfaces difficult. (Mounier et al, 2018). These results are like those in the present study, showing some overlap between Late Pleistocene and Early Holocene individuals, but much less overlap between the Late Pleistocene and recent modern human groups.…”

“…Human remains from MIS 2 and early MIS 1 are more common than fossils from the preceding MIS 6 to MIS 3 (Grine 2016), but the regional distribution of human remains are skewed by a few, large mortuary contexts from more recent periods in North Africa (e.g., Afalou-bou-Rhummel and Grotte des Pigeons [Taforalt]) and the Nile Valley (e.g., Jebel Sahaba, Wadi Halfa, Tushka, Al Khiday) (Arambourg, Boule, Vallois, & Verneau, 1934;Ferembach, Dastugue, & Poitrat-Targowla, 1962;Hachi, 1996;Humphrey, Bello, Turner, Bouzouggar, & Barton, 2012;Stojanowski, Carver, & Miller, 2014;Stojanowski, Johnson, Paul, & Carver, 2016;Usai et al, 2010;Wendorf, 1968). With so few human fossils dated to the Late Pleistocene and Early Holocene in Africa, and concomitant biases in regional representation, the ones that are available for detailed analyses are of great importance for understanding issues of human biocultural variation in African prehistory (Crevecoeur et al, 2016;Mounier et al, 2018;Sawchuk & Willoughby, 2015;Scerri et al, 2018). Cranial, dental, and postcranial analyses of Pleistocene and Holocene humans provide meaningful insights into population dynamics within Africa (Armelagos, Van Gerven, Martin, & Huss-Ashmore, 1984;Benoiston, Bayle, & Crevecoeur, 2018;Crevecoeur, 2008;Crevecoeur et al, 2016;Crevecoeur et al, 2009;Greene, Ewing, & Armelagos, 1967;Holliday, 2015;Irish, 2000Irish, , 2005Irish, Black, Sealy, & Ackermann, 2014;Irish & Guatelli-Steinberg, 2003;Irish & Konigsberg, 2007;Mounier et al, 2018;Pfeiffer & Harrington, 2018;Ponce de León et al, 2018;Sawchuk & Willoughby, 2015;St...…”

“…With so few human fossils dated to the Late Pleistocene and Early Holocene in Africa, and concomitant biases in regional representation, the ones that are available for detailed analyses are of great importance for understanding issues of human biocultural variation in African prehistory (Crevecoeur et al, 2016;Mounier et al, 2018;Sawchuk & Willoughby, 2015;Scerri et al, 2018). Cranial, dental, and postcranial analyses of Pleistocene and Holocene humans provide meaningful insights into population dynamics within Africa (Armelagos, Van Gerven, Martin, & Huss-Ashmore, 1984;Benoiston, Bayle, & Crevecoeur, 2018;Crevecoeur, 2008;Crevecoeur et al, 2016;Crevecoeur et al, 2009;Greene, Ewing, & Armelagos, 1967;Holliday, 2015;Irish, 2000Irish, , 2005Irish, Black, Sealy, & Ackermann, 2014;Irish & Guatelli-Steinberg, 2003;Irish & Konigsberg, 2007;Mounier et al, 2018;Pfeiffer & Harrington, 2018;Ponce de León et al, 2018;Sawchuk & Willoughby, 2015;Stojanowski, 2014;Warren, Hall, & Ackermann, 2015), but biocultural approaches emphasizing intentional body modification have also proven useful as markers of population movement, continuity, and replacement in African prehistory (Barton et al, 2008;De Groote & Humphrey, 2016;Finucane, Manning, & Touré, 2008;Humphrey & Bocaege, 2008;Irish, 2017;Mercader, Garralda, Pearson, & Bailey, 2001;Stojanowski et al, 2014Stojanowski et al, , 2016. Biocultural approaches also provide an additional level of information on human lifeways and social identities that may otherwise be ignored in pursuit of data on biological affinity alone.…”

Human burials at the Kisese II rockshelter, Tanzania

“…Our findings contribute to a growing body of evidence that suggests that human skeletal remains from the Late Pleistocene and early Holocene in eastern Africa exhibit relatively high amounts of morphological diversity (Crevecoeur et al, 2009; Crevecoeur et al, 2016; Grine et al, 2007; Mounier et al, 2018; Stojanowski, 2014). Compared to other eastern Africans, KNM‐KX 2 had a similar cranial breadth and length, but relatively small dentition, and a relatively large nasal aperture.…”

“…Previous research on Late Pleistocene LSA individuals indicates at least some populations exhibit patterns of morphological diversity distinct from recent sub‐Saharan Africans (Crevecoeur et al, 2009; Crevecoeur et al, 2016; Grine et al, 2007; Mounier et al, 2018; Reiner et al, 2017; Stojanowski, 2014; Tryon et al, 2015). This could reflect phenotypic variation since lost to genetic drift and other demographic processes (Lahr, 2016; Lahr & Foley, 1998; Manica et al, 2007).…”