scholarly journals Dental evolutionary rates and its implications for the Neanderthal–modern human divergence

2019 ◽  
Vol 5 (5) ◽  
pp. eaaw1268 ◽  
Author(s):  
Aida Gómez-Robles

The origin of Neanderthal and modern human lineages is a matter of intense debate. DNA analyses have generally indicated that both lineages diverged during the middle period of the Middle Pleistocene, an inferred time that has strongly influenced interpretations of the hominin fossil record. This divergence time, however, is not compatible with the anatomical and genetic Neanderthal affinities observed in Middle Pleistocene hominins from Sima de los Huesos (Spain), which are dated to 430 thousand years (ka) ago. Drawing on quantitative analyses of dental evolutionary rates and Bayesian analyses of hominin phylogenetic relationships, I show that any divergence time between Neanderthals and modern humans younger than 800 ka ago would have entailed unexpectedly rapid dental evolution in early Neanderthals from Sima de los Huesos. These results support a pre–800 ka last common ancestor for Neanderthals and modern humans unless hitherto unexplained mechanisms sped up dental evolution in early Neanderthals.

2010 ◽  
Vol 365 (1552) ◽  
pp. 2451-2457 ◽  
Author(s):  
Hie Lim Kim ◽  
Takeshi Igawa ◽  
Ayaka Kawashima ◽  
Yoko Satta ◽  
Naoyuki Takahata

Genomic DNA sequences are an irreplaceable source for reconstructing the vanished past of living organisms. Based on updated sequence data, this paper summarizes our studies on species divergence time, ancient population size and functional loss of genes in the primate lineage leading to modern humans ( Homo sapiens sapiens ). The inter- and intraspecific comparisons of DNA sequences suggest that the human lineage experienced a rather severe bottleneck in the Middle Pleistocene, throughout which period the subdivided African population played a predominant role in shaping the genetic architecture of modern humans. Also, published and newly identified human-specific pseudogenes (HSPs) are enumerated in order to infer their significance for human evolution. Of the 121 candidate genes obtained, authentic HSPs turn out to comprise only 25 olfactory receptor genes, four T cell receptor genes and nine other genes. The fixation of HSPs has been too rare over the past 6–7 Myr to account for species differences between humans and chimpanzees.


Author(s):  
Chris Stringer

This chapter provides an update on the speciation of modern Homo sapiens and the Out of Africa hypothesis. The majority of the fossil and genetic evidence favours an African origin for modern humans during the later part of the Middle Pleistocene (prior to 130,000 years ago), and one or more range expansions out of Africa after that date. However, a number of uncertainties remain. If there was a speciation event at the appearance of modern humans, what was its nature? Furthermore, did the evolution of modern human behaviour occur gradually or punctuationally? The discussion examines the difficulties faced in defining what is meant by ‘modern’ humans, and in reconstructing the morphological and behavioural origins of our species.


2015 ◽  
Vol 112 (37) ◽  
pp. 11524-11529 ◽  
Author(s):  
Juan Luis Arsuaga ◽  
José-Miguel Carretero ◽  
Carlos Lorenzo ◽  
Asier Gómez-Olivencia ◽  
Adrián Pablos ◽  
...  

Current knowledge of the evolution of the postcranial skeleton in the genus Homo is hampered by a geographically and chronologically scattered fossil record. Here we present a complete characterization of the postcranium of the middle Pleistocene paleodeme from the Sima de los Huesos (SH) and its paleobiological implications. The SH hominins show the following: (i) wide bodies, a plesiomorphic character in the genus Homo inherited from their early hominin ancestors; (ii) statures that can be found in modern human middle-latitude populations that first appeared 1.6–1.5 Mya; and (iii) large femoral heads in some individuals, a trait that first appeared during the middle Pleistocene in Africa and Europe. The intrapopulational size variation in SH shows that the level of dimorphism was similar to modern humans (MH), but the SH hominins were less encephalized than Neandertals. SH shares many postcranial anatomical features with Neandertals. Although most of these features appear to be either plesiomorphic retentions or are of uncertain phylogenetic polarity, a few represent Neandertal apomorphies. Nevertheless, the full suite of Neandertal-derived features is not yet present in the SH population. The postcranial evidence is consistent with the hypothesis based on the cranial morphology that the SH hominins are a sister group to the later Neandertals. Comparison of the SH postcranial skeleton to other hominins suggests that the evolution of the postcranium occurred in a mosaic mode, both at a general and at a detailed level.


2020 ◽  
Author(s):  
Steven Samuel

Research and thinking into the cognitive aspects of language evolution has usually attempted to account for how the capacity for learning even one modern human language developed. Bilingualism has perhaps been thought of as something to think about only once the ‘real’ puzzle of monolingualism is solved, but this would assume in turn (and without evidence) that bilingualism evolved after monolingualism. All typically-developing children (and adults) are capable of learning multiple languages, and the majority of modern humans are at least bilingual. In this paper I ask whether by skipping bilingualism out of language evolution we have missed a trick. I propose that exposure to synonymous signs, such as food and alarm calls, are a necessary precondition for the abstracting away of sound from referent. In support of this possibility is evidence that modern day bilingual children are better at breaking this ‘word magic’ spell. More generally, language evolution should be viewed through the lens of bilingualism, as this is the end state we are attempting to explain.


2014 ◽  
Vol 100 (4) ◽  
pp. 297-309 ◽  
Author(s):  
Elena Santos ◽  
Nuria Garcia ◽  
Jose Miguel Carretero ◽  
Juan Luis Arsuaga ◽  
Evangelia Tsoukala

Nature ◽  
2021 ◽  
Vol 592 (7853) ◽  
pp. 253-257 ◽  
Author(s):  
Mateja Hajdinjak ◽  
Fabrizio Mafessoni ◽  
Laurits Skov ◽  
Benjamin Vernot ◽  
Alexander Hübner ◽  
...  

AbstractModern humans appeared in Europe by at least 45,000 years ago1–5, but the extent of their interactions with Neanderthals, who disappeared by about 40,000 years ago6, and their relationship to the broader expansion of modern humans outside Africa are poorly understood. Here we present genome-wide data from three individuals dated to between 45,930 and 42,580 years ago from Bacho Kiro Cave, Bulgaria1,2. They are the earliest Late Pleistocene modern humans known to have been recovered in Europe so far, and were found in association with an Initial Upper Palaeolithic artefact assemblage. Unlike two previously studied individuals of similar ages from Romania7 and Siberia8 who did not contribute detectably to later populations, these individuals are more closely related to present-day and ancient populations in East Asia and the Americas than to later west Eurasian populations. This indicates that they belonged to a modern human migration into Europe that was not previously known from the genetic record, and provides evidence that there was at least some continuity between the earliest modern humans in Europe and later people in Eurasia. Moreover, we find that all three individuals had Neanderthal ancestors a few generations back in their family history, confirming that the first European modern humans mixed with Neanderthals and suggesting that such mixing could have been common.


2003 ◽  
Vol 13 (2) ◽  
pp. 263-279 ◽  
Author(s):  
David Lewis-Williams ◽  
E. Thomas Lawson ◽  
Knut Helskog ◽  
David S. Whitley ◽  
Paul Mellars

David Lewis-Williams is well-known in rock-art circles as the author of a series of articles drawing on ethnographic material and shamanism (notably connected with the San rock art of southern Africa) to gain new insights into the Palaeolithic cave art of western Europe. Some 15 years ago, with Thomas Dowson, he proposed that Palaeolithic art owed its inspiration at least in part to trance experiences (altered states of consciousness) associated with shamanistic practices. Since that article appeared, the shamanistic hypothesis has both been widely adopted and developed in the study of different rock-art traditions, and has become the subject of lively and sometimes heated controversy. In the present volume, Lewis-Williams takes the argument further, and combines the shamanistic hypothesis with an interpretation of the development of human consciousness. He thus enters another contentious area of archaeological debate, seeking to understand west European cave art in the context of (and as a marker of) the new intellectual capacities of anatomically modern humans. Radiocarbon dates for the earliest west European cave art now place it contemporary with the demise of the Neanderthals around 30,000 years ago, and cave art, along with carved or decorated portable items, appears to announce the arrival and denote the success of modern humans in this region. Lewis-Williams argues that such cave art would have been beyond the capabilities of Neanderthals, and that this kind of artistic ability is unique to anatomically modern humans. Furthermore, he concludes that the development of the new ability cannot have been the product of hundreds of thousands of years of gradual hominid evolution, but must have arisen much more abruptly, within the novel neurological structure of anatomically modern humans. The Mind in the Cave is thus the product of two hypotheses, both of them contentious — the shamanistic interpretation of west European Upper Palaeolithic cave art, and the cognitive separation of modern humans and Neanderthals. But is it as simple as that? Was cave art the hallmark of a new cognitive ability and social consciousness that were beyond the reach of previous hominids? And is shamanism an outgrowth of the hard-wired structure of the modern human brain? We begin this Review Feature with a brief summary by David Lewis-Williams of the book's principal arguments. There follows a series of comments addressing both the meaning of the west European cave art, and its wider relevance for the understanding of the Neanderthal/modern human transition.


2004 ◽  
Vol 125 (3) ◽  
pp. 220-231 ◽  
Author(s):  
E. Cunha ◽  
F. Ramirez Rozzi ◽  
J.M. Bermúdez De Castro ◽  
M. Martinón-Torres ◽  
S.N. Wasterlain ◽  
...  

2014 ◽  
Vol 112 (2) ◽  
pp. 366-371 ◽  
Author(s):  
Habiba Chirchir ◽  
Tracy L. Kivell ◽  
Christopher B. Ruff ◽  
Jean-Jacques Hublin ◽  
Kristian J. Carlson ◽  
...  

Humans are unique, compared with our closest living relatives (chimpanzees) and early fossil hominins, in having an enlarged body size and lower limb joint surfaces in combination with a relatively gracile skeleton (i.e., lower bone mass for our body size). Some analyses have observed that in at least a few anatomical regions modern humans today appear to have relatively low trabecular density, but little is known about how that density varies throughout the human skeleton and across species or how and when the present trabecular patterns emerged over the course of human evolution. Here, we test the hypotheses that (i) recent modern humans have low trabecular density throughout the upper and lower limbs compared with other primate taxa and (ii) the reduction in trabecular density first occurred in early Homo erectus, consistent with the shift toward a modern human locomotor anatomy, or more recently in concert with diaphyseal gracilization in Holocene humans. We used peripheral quantitative CT and microtomography to measure trabecular bone of limb epiphyses (long bone articular ends) in modern humans and chimpanzees and in fossil hominins attributed to Australopithecus africanus, Paranthropus robustus/early Homo from Swartkrans, Homo neanderthalensis, and early Homo sapiens. Results show that only recent modern humans have low trabecular density throughout the limb joints. Extinct hominins, including pre-Holocene Homo sapiens, retain the high levels seen in nonhuman primates. Thus, the low trabecular density of the recent modern human skeleton evolved late in our evolutionary history, potentially resulting from increased sedentism and reliance on technological and cultural innovations.


Science ◽  
2021 ◽  
Vol 372 (6549) ◽  
pp. 1424-1428
Author(s):  
Israel Hershkovitz ◽  
Hila May ◽  
Rachel Sarig ◽  
Ariel Pokhojaev ◽  
Dominique Grimaud-Hervé ◽  
...  

It has long been believed that Neanderthals originated and flourished on the European continent. However, recent morphological and genetic studies have suggested that they may have received a genetic contribution from a yet unknown non-European group. Here we report on the recent discovery of archaic Homo fossils from the site of Nesher Ramla, Israel, which we dated to 140,000 to 120,000 years ago. Comprehensive qualitative and quantitative analyses of the parietal bones, mandible, and lower second molar revealed that this Homo group presents a distinctive combination of Neanderthal and archaic features. We suggest that these specimens represent the late survivors of a Levantine Middle Pleistocene paleodeme that was most likely involved in the evolution of the Middle Pleistocene Homo in Europe and East Asia.


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