scholarly journals Using hominin introgression to trace modern human dispersals

2019 ◽  
Vol 116 (31) ◽  
pp. 15327-15332 ◽  
Author(s):  
João C. Teixeira ◽  
Alan Cooper

The dispersal of anatomically modern human populations out of Africa and across much of the rest of the world around 55 to 50 thousand years before present (ka) is recorded genetically by the multiple hominin groups they met and interbred with along the way, including the Neandertals and Denisovans. The signatures of these introgression events remain preserved in the genomes of modern-day populations, and provide a powerful record of the sequence and timing of these early migrations, with Asia proving a particularly complex area. At least 3 different hominin groups appear to have been involved in Asia, of which only the Denisovans are currently known. Several interbreeding events are inferred to have taken place east of Wallace’s Line, consistent with archaeological evidence of widespread and early hominin presence in the area. However, archaeological and fossil evidence indicates archaic hominins had not spread as far as the Sahul continent (New Guinea, Australia, and Tasmania), where recent genetic evidence remains enigmatic.

1992 ◽  
Vol 337 (1280) ◽  
pp. 225-234 ◽  

The transition from anatomically ‘archaic’ to ‘modern’ populations would seem to have occurred in most regions of Europe broadly between ca.40 and 30 ka ago: much later than in most other areas of the world. The archaeological evidence supports the view that this transition was associated with the dispersal of new human populations into Europe, equipped with a new technology (‘Aurignacian’) and a range of radical behavioural and cultural innovations which collectively define the ‘Middle-Upper Palaeolithic transition'. In several regions of Europe there is archaeological evidence for a chronological overlap between these populations and the final Neanderthal populations and, apparently, for various forms of contact, interaction and, apparently, ‘acculturation’ between these two populations. The fundamental behavioural adaptations implicit in the ‘Upper Palaeolithic Revolution’ (possibly including language) are thought to have been responsible for this rapid dispersal of human populations over the ecologically demanding environments of last-glacial Europe.


Hereditas ◽  
2021 ◽  
Vol 158 (1) ◽  
Author(s):  
Úlfur Árnason

Abstract Background The Out of Africa hypothesis, OOAH, was challenged recently in an extended mtDNA analysis, PPA (Progressive Phylogenetic Analysis), that identified the African human populations as paraphyletic, a finding that contradicted the common OOAH understanding that Hss had originated in Africa and invaded Eurasia from there. The results were consistent with the molecular Out of Eurasia hypothesis, OOEH, and Eurasian palaeontology, a subject that has been largely disregarded in the discussion of OOAH. Results In the present study the mtDNA tree, a phylogeny based on maternal inheritance, was compared to the nuclear DNA tree of the paternally transmitted Y-chromosome haplotypes, Y-DNAs. The comparison showed full phylogenetic coherence between these two separate sets of data. The results were consistent with potentially four translocations of modern humans from Eurasia into Africa, the earliest taking place ≈ 250,000 years before present, YBP. The results were in accordance with the postulates behind OOEH at the same time as they lent no support to the OOAH. Conclusions The conformity between the mtDNA and Y-DNA phylogenies of Hss is consistent with the understanding that Eurasia was the donor and not the receiver in human evolution. The evolutionary problems related to OOAH became similarly exposed by the mtDNA introgression that took place from Hss into Neanderthals ≈ 500,000 YBP, a circumstance that demonstrated the early coexistence of the two lineages in Eurasia.


Zootaxa ◽  
2020 ◽  
Vol 4852 (2) ◽  
pp. 203-210
Author(s):  
ZI-WEI YIN ◽  
PETER HLAVÁČ

The monospecific genus Syrraphesina Raffray, 1903 contains a single species distributed in eastern New Guinea. In this paper a second species from Lombok Island, S. agostii Yin & Hlaváč, sp. nov., is described, figured, and compared to S. pliciventris Raffray, 1903. A revised diagnosis of Syrraphesina is provided. The distribution of Clavigerini through the islands of the world is briefly discussed. 


Antiquity ◽  
2003 ◽  
Vol 77 (298) ◽  
pp. 671-684 ◽  
Author(s):  
Michael D. Petraglia ◽  
Abdullah Alsharekh

The Middle Palaeolithic record of the Arabian Peninsula can provide crucial evidence for understanding human dispersal. The authors summarise the archaeological evidence and suggest some of the routes taken by the earliest humans coming out of Africa, including one implying the use of boats. Early populations adapted to a hospitable environment, but had later to adapt to the advance of the desert.


2018 ◽  
Vol 4 (9) ◽  
pp. eaat6925 ◽  
Author(s):  
James Hansford ◽  
Patricia C. Wright ◽  
Armand Rasoamiaramanana ◽  
Ventura R. Pérez ◽  
Laurie R. Godfrey ◽  
...  

Previous research suggests that people first arrived on Madagascar by ~2500 years before present (years B.P.). This hypothesis is consistent with butchery marks on extinct lemur bones from ~2400 years B.P. and perhaps with archaeological evidence of human presence from ~4000 years B.P. We report >10,500-year-old human-modified bones for the extinct elephant birdsAepyornisandMullerornis, which show perimortem chop marks, cut marks, and depression fractures consistent with immobilization and dismemberment. Our evidence for anthropogenic perimortem modification of directly dated bones represents the earliest indication of humans in Madagascar, predating all other archaeological and genetic evidence by >6000 years and changing our understanding of the history of human colonization of Madagascar. This revision of Madagascar’s prehistory suggests prolonged human-faunal coexistence with limited biodiversity loss.


2012 ◽  
Vol 367 (1590) ◽  
pp. 850-859 ◽  
Author(s):  
Sebastien Gagneux

Tuberculosis (TB) is a disease of antiquity. Yet TB today still causes more adult deaths than any other single infectious disease. Recent studies show that contrary to the common view postulating an animal origin for TB, Mycobacterium tuberculosis complex (MTBC), the causative agent of TB, emerged as a human pathogen in Africa and colonized the world accompanying the Out-of-Africa migrations of modern humans. More recently, evolutionarily ‘modern’ lineages of MTBC expanded as a consequence of the global human population increase, and spread throughout the world following waves of exploration, trade and conquest. While epidemiological data suggest that the different phylogenetic lineages of MTBC might have adapted to different human populations, overall, the phylogenetically ‘modern’ MTBC lineages are more successful in terms of their geographical spread compared with the ‘ancient’ lineages. Interestingly, the global success of ‘modern’ MTBC correlates with a hypo-inflammatory phenotype in macrophages, possibly reflecting higher virulence, and a shorter latency in humans. Finally, various human genetic variants have been associated with different MTBC lineages, suggesting an interaction between human genetic diversity and MTBC variation. In summary, the biology and the epidemiology of human TB have been shaped by the long-standing association between MTBC and its human host.


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 ◽  
Author(s):  
Pengfei Qin ◽  
Mark Stoneking

Although initial studies suggested that Denisovan ancestry was found only in modern human populations from island Southeast Asia and Oceania, more recent studies have suggested that Denisovan ancestry may be more widespread. However, the geographic extent of Denisovan ancestry has not been determined, and moreover the relationship between the Denisovan ancestry in Oceania and that elsewhere has not been studied. Here we analyze genome-wide SNP data from 2493 individuals from 221 worldwide populations, and show that there is a widespread signal of a very low level of Denisovan ancestry across Eastern Eurasian and Native American (EE/NA) populations. We also verify a higher level of Denisovan ancestry in Oceania than that in EE/NA; the Denisovan ancestry in Oceania is correlated with the amount of New Guinea ancestry, but not the amount of Australian ancestry, indicating that recent gene flow from New Guinea likely accounts for signals of Denisovan ancestry across Oceania. However, Denisovan ancestry in EE/NA populations is equally correlated with their New Guinea or their Australian ancestry, suggesting a common source for the Denisovan ancestry in EE/NA and Oceanian populations. Our results suggest that Denisovan ancestry in EE/NA is derived either from common ancestry with, or gene flow from, the common ancestor of New Guineans and Australians, indicating a more complex history involving East Eurasians and Oceanians than previously suspected.


2018 ◽  
Vol 14 (2) ◽  
pp. 20-37 ◽  
Author(s):  
Alison S. Chiu ◽  
Denise Donlon

The utilization of odontometric variation as a discriminator between modern human groups continues to decline, despite its value in both anthropological and forensic contexts. Traditional odontometric methods, coupled with advanced statistical methods, are applied to illustrate the continuing usefulness of these techniques. The ability to discriminate between the major population groups (Caucasoid and Mongoloid) in the Sydney region of Australia, absed on dental dimensions, is extremely valuable in the forensic identification of individuals. Furthermore, metric variation in the dentition of these contemporary populations is poorly understood in this region of the world. The utility of variation in tooth dimensions in discriminating between these two groups is explored. Dental stone casts of the permanent maxillary and mandibular dentition of 198 individuals were made, and mesiodistal and buccolingual crown diameters were recorded for each tooth. Both univariate and multivariate analyses were used to investigate differences in linear and areal dimensions, as well as the predictive value of these measures in a forensic contect, using discriminant function analysis (DFA). DFA produced separation of Caucasoids and Mongoloids with a success rate of 93.9% on the basis of these measurements. Separation of the groups was most apparent in the mesiodistal and buccolingual dimensions of the maxillary first premolar (P1), the mesiodistal diameter of the maxillary second premolar (P2), and the mesiodistal dimension of the mandibular first premolar (P1). The results from this study further highlight the usefulness of dental metrics in forensic applications and contribute to our knowledge of the variation of these features in contemporary human populations.


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