40 research outputs found
Diversité taxonomique des Hominidés fossiles en Asie : de nouvelles méthodes pour une vieille question
Les objectifs de cette Ă©tude sont de dĂ©terminer si les fossiles dâHominidĂ©s retrouvĂ©s en Asie du Sud-est reprĂ©sentent un ou plusieurs taxons, dâidentifier ceux-ci, de mesurer les distances entre ces taxons et de les comparer Ă celles existant entre des espĂšces et sous-espĂšces actuelles phylogĂ©nĂ©tiquement proches (grands singes). Pour cela, nous avons utilisĂ© les nouvelles mĂ©thodes de morphomĂ©trie gĂ©omĂ©trique. Vingt points repĂšres tridimensionnels ont Ă©tĂ© numĂ©risĂ©s sur un Ă©chantillon de 110 crĂąnes : 18 spĂ©cimens fossiles issus dâAsie et datĂ©s de 6 000 Ă 1 150 000 ans, 31 spĂ©cimens dâHomo sapiens actuels, 31 spĂ©cimens de chimpanzĂ©s et 30 spĂ©cimens de gorilles. La mĂ©thode Procruste a Ă©tĂ© appliquĂ©e afn de sĂ©parer la variable taille des variables de conformation. Nous avons utilisĂ© une nouvelle mĂ©thode originale en trois Ă©tapes, dans une dĂ©marche logique et objective. 1) La variabilitĂ© globale des quatre groupes a Ă©tĂ© explorĂ©e avec diffĂ©rents indices (variance, distances euclidiennes et de Manhattan). 2) Afin de sâaffranchir des regroupement arbitraires de fossiles dans des catĂ©gories taxonomiques prĂ©-Ă©tablies, des analyses en composantes principales (ACP) et de classification (Neighbor Joining et UPGMA) ont permis dâidentifier des sous-groupes au sein des quatre groupes (fossiles, H. sapiens, chimpanzĂ©s et gorilles). 3) Enfin, les distances de Mahalanobis entre ces diffĂ©rents sous-groupes ont Ă©tĂ© mesurĂ©es et comparĂ©es entre elles. Les rĂ©sultats montrent que la variabilitĂ© globale des fossiles est significativement supĂ©rieure Ă celle des H. sapiens. Elle est Ă©galement supĂ©rieure, mais de maniĂšre non significative, Ă celle des chimpanzĂ©s dâune part et des gorilles dâautre part. Les mĂ©thodes de classification et dâACP ont permis dâidentifier deux groupes au sein de lâĂ©chantillon des fossiles : un groupe dâaffinitĂ© H. erectus et un autre dâaffinitĂ© H. sapiens. La plus grande distance de Mahalanobis est observĂ©e entre les gorilles et les H. sapiens, puis entre les chimpanzĂ©s et les H. sapiens. Suit la distance entre les chimpanzĂ©s et les gorilles, qui est trĂšs proche de celle entre les H. sapiens actuels et les H. erectus. Cette derniĂšre est proche de la distance entre les H. sapiens fossiles et les H. erectus. En revanche, la distance entre les H. sapiens fossiles et actuels est nettement infĂ©rieure et est comparable aux distances observĂ©es entre les diffĂ©rents sous-groupes identifiĂ©s au sein des H. sapiens actuels, des chimpanzĂ©s et des gorilles. Cette nouvelle mĂ©thode originale a permis de conclure que les fossiles Ă©tudiĂ©s appartiennent bien Ă deux taxons diffĂ©rents. Le premier (les H. sapiens fossiles) peut ĂȘtre considĂ©rĂ© comme appartenant au mĂȘme taxon que celui des hommes actuels. Le deuxiĂšme appartient Ă un taxon diffĂ©rent.The  objectives  of  this  study  were  to  determine  whether  the  fossils  discovered  in Asia  belong  to  one  or  several taxa, to identify them and to compare the distances between them to the distances between actual groups and species of anthropoids. For  this purpose, we have used new geometric morphometric methods. Twenty  three dimensional  landmarks were digitized on 110  skulls: 18  fossils  from Asia dated between 1,150,000  years and 6,000 BC, 31 modern Homo sapiens, 31 chimpanzees and 30 gorillas. Landmarks were registered by Generalized Procruste Analysis. We used a  logical and objective method with  three steps. 1) The  taxa variabilities were explored by using several distance  indices  (variance, Euclidean and Manhattan distances). 2) We have  chosen not  to arbitrarily group  fossils  in established taxonomic categories: Principal component analysis (PCA) and hierarchical classification methods (UPGMA and NJ) were applied  to  identify subgroups  for each of  the  four  taxa. Finally, Mahalanobis distances between  identified groups and subgroups were calculated and compared between each other. The  overall  variability  was  larger  for  the  fossil  group  than  for  any  of  the  three  actual  species,  although  the difference was statistically significant only for the comparison to the modern H. sapiens. Classification and PCA analysis identified two subgroups within the fossil group: one with an H. sapiens affinity and the other with an H. erectus affinity. The Mahalanobis distances were ordered as  follows  (decreasing order): gorilla/modern H. sapiens, chimpanzee/modern H. sapiens, chimpanzee/gorilla which was very similar to the distance between modern H. sapiens and H. erectus. This last distance was similar to the one between fossil H. sapiens and H. erectus. Distances between modern and fossil H. sapiens and between subgroups of actual species were similar and less than the preceding ones. We finally concluded that the fossils belong to two different taxa. The first (fossil H. sapiens) belongs to the same taxon as modern H. sapiens and the second, H. erectus, is different
Small Size in the Philippine Human Fossil Record: Is It Meaningful for a Better Understanding of the Evolutionary History of the Negritos?
Pygmy populations are recognized in several places over the world, especially in Western Africa and in Southeast Asia (Philippine negritos, for instance). Broadly defined as small-bodied Homo sapiens (compared with neighboring populations), their origins and the nature of the processes involved in the maintenance of their phenotype over time are highly debated. Major results have been recently obtained from population genetics on present-day negrito populations, but their evolutionary history remains largely unresolved. We present and discuss the Upper Pleistocene human remains recovered from Tabon Cave and Callao Cave in the Philippines, which are potentially highly relevant to these research questions. Human fossils have been recovered in large numbers from Tabon Cave (Palawan Island) but mainly from reworked and mixed sediments from several archaeological layers. We review and synthesize the long and meticulous collaborative work done on the archives left from the 1960s excavations and on the field. The results demonstrate the long history of human occupations in the cave, since at least ~30,000 BP. The examination of the Tabon human remains shows a large variability: large and robust for one part of the sample, and small and gracile for the other part. The latter would fit quite comfortably within the range of variation of Philippine negritos. Farther north, on Luzon Island, the human third metatarsal recently recovered from Callao Cave and dated to ~66,000 BP is now the oldest direct evidence of human presence in the Philippines. Previous data show that, compared with H. sapiens (including Philippine negritos), this bone presents a very small size and several unusual morphological characteristics. We present a new analytical approach using three-dimensional geometric morphometrics for comparing the Callao fossil to a wide array of extant Asian mammals, including nonhuman primates and H. sapiens. The results demonstrate that the shape of the Callao metatarsal is definitely closer to humans than to any other groups. The fossil clearly belongs to the genus Homo; however, it remains at the margin of the variation range of H. sapiens. Because of its great antiquity and the presence of another diminutive species of the genus Homo in the Wallace area during this time period (H. floresiensis), we discuss here in detail the affinities and potential relatedness of the Callao fossil with negritos that are found today on Luzon Island
Intégration polynésienne au Vanuatu (Mélanésie) : étude de cas sur les rapports entre société préexistante et individus migrants
Certaines sociĂ©tĂ©s humaines modernes de lâarchipel du Vanuatu (MĂ©lanĂ©sie) prĂ©sentent des traits culturels polynĂ©siens et parlent des langues polynĂ©siennes. Ces caractĂ©ristiques diffĂšrent de celles des autres sociĂ©tĂ©s prĂ©sentes dans lâarchipel qui sont apparentĂ©s aux influences mĂ©lanĂ©siennes rĂ©gionales. On suppose que des migrations polynĂ©siennes auraient particuliĂšrement contribuĂ© Ă la formation de ces sociĂ©tĂ©s « polynĂ©siennes » du Vanuatu lors du dernier millĂ©naire. Pourtant, les Ă©tudes arch..
Homo luzonensisâŻ: principales caractĂ©ristiques et implications pour lâhistoire Ă©volutionnaire du genre
La nouvelle espĂšce Homo luzonensis a Ă©tĂ© dĂ©crite en 2019 Ă partir dâun assemblage constituĂ© de treize Ă©lĂ©ments fossiles dĂ©couverts dans la grotte de Callao (Ăźle de Luzon, Philippines) en 2007, 2011 et 2015. La datation directe de deux de ces fossiles par les sĂ©ries de lâuranium indique des Ăąges minimums respectifs de 50 000 et 67 000 ans. Dans cette prĂ©sentation, nous montrons que ces spĂ©cimens prĂ©sentent une combinaison de caractĂ©ristiques morphologiques primitives (i.e. ressemblant Ă Austra..
Homo sapiens, Homo luzonensis et contemporains : du terrain Ă lâanalyse des variations de forme
Sur les premiers peuplements du Pacifique sud
Le Pacifique sud regroupe l\u27Australie et les Ăźles du Pacifique : MĂ©lanĂ©sie, MicronĂ©sie, PolynĂ©sie. Quelles populations les ont peuplĂ©es ? Quand, pourquoi et comment ? D\u27oĂč venaient-elles ? L\u27environnement a-t-il conditionnĂ© leurs dĂ©placements ? Une discussion exhaustive de ces vastes problĂ©matiques ne saurait ĂȘtre entreprise rigoureusement dans le cadre de ce court article. Nous proposons donc plutĂŽt de discuter ici certains points trĂšs prĂ©cis, apportant un Ă©clairage nouveau sur les premiers peuplements du Pacifique sud. Si l\u27on se rĂ©fĂšre aux sites archĂ©ologiques les plus anciens d\u27Australie, l\u27arrivĂ©e des premiers Homo sapiens dans la rĂ©gion a pu se produire il y a au moins 40 000 ans, voire dĂšs 50 Ă 60 ka BP. D\u27un point de vue palĂ©oanthropologique, un dĂ©bat existe depuis plusieurs annĂ©es sur l\u27origine de ces hommes anatomiquement modernes : sont-ils issus d\u27une migration hors d\u27Afrique relativement rĂ©cente (hypothĂšse de l\u27 Out of Africa) ou bien sont-ils les descendants directs des derniers Homo erectus indonĂ©siens (hypothĂšse « multirĂ©gionale ») ? Plusieurs points fondamentaux opposent les partisans de ces deux hypothĂšses, en particulier l\u27interprĂ©tation de ressemblances morphomĂ©triques entre les H. erectus indonĂ©siens les plus rĂ©cents et les H. sapiens fossiles australiens dits « robustes » de Kow Swamp et Cohuna. L\u27application de mĂ©thodes de morphomĂ©trie gĂ©omĂ©trique en 3D (analyses Procruste) permet d\u27aborder cette problĂ©matique sous un angle nouveau. Les conformations de ces deux ensembles d\u27hominidĂ©s fossiles sont trĂšs clairement distinctes, permettant de mettre en doute l\u27hypothĂšse d\u27une filiation locale directe. Pour ces peuplements humains anciens et les migrations ultĂ©rieures, la confrontation et la comparaison des donnĂ©es palĂ©oenvironnementales, archĂ©ologiques, palĂ©oanthropologiques, gĂ©nĂ©tiques et linguistiques permettent de reconstituer petit Ă petit les grandes lignes de l\u27histoire des premiers peuplements humains de ces rĂ©gions. Climat et environnement ont interagi avec ces dĂ©placements de populations. Le tout premier exemple en est la formation de ponts terrestres entre le continent Asiatique et l\u27archipel IndonĂ©sien lors des glaciations quaternaires, qui ont permis le passage des hommes et de la faune. C\u27est peut-ĂȘtre aussi Ă l\u27occasion de l\u27abaissement du niveau des mers, que la dispersion d\u27Ăźles en Ăźles a pu ĂȘtre favorisĂ©e. Vents et courants, directement liĂ©s au climat et Ă ses variations sont Ă©galement intervenus dans le peuplement du Pacifique. L\u27environnement naturel, qui s\u27appauvrit d\u27ouest en est, a Ă©tĂ© enrichi des animaux et des plantes que les hommes transportaient avec eux. En fonction de leur mode de vie, mais aussi des ressources disponibles, ils ont occupĂ©, dans un premier temps, la zone littorale (sites Lapita), puis, trĂšs vite, l\u27intĂ©rieur des terres, comme l\u27ont montrĂ©, entre autres, des fouilles rĂ©alisĂ©es en Nouvelle-CalĂ©donie, dans le Nord de la Grande Terre.South Pacific includes Australia and the Pacific Islands: Melanesia, Micronesia, Polynesia. Which human populations settled them? When, why and how? Where did they come from? Did environment influence these migrations? An exhaustive discussion of these vast questions could not be undertaken rigorously within the framework of this short article. We thus propose to discuss here very precise points that could bring a new lighting on the first settlements of South Pacific. According to the oldest archaeological sites of Australia, first arrivals of Homo sapiens in the area occurred at least 40 000 years ago, and possibly as early as 50 to 60 ka BP. From a palaeoanthropological point of view, the question of the origin of these anatomically modern H. sapiens is under debate for several years: did they come from a relatively recent âout of Africaâ migration (Out-of-Africa hypothesis) or did they evolve locally from the last Indonesian H. erectus (multiregional hypothesis)? Partisans of these two models disagree on several fundamental points, and particularly on the interpretation of certain morphometric affinities between the most recent Indonesian H. erectus and the ârobustâ Australian fossil H. sapiens from Kow Swamp and Cohuna. The application of 3D geometric morphometrics (Procrustes analysis) makes it possible to approach this question under a new angle. The shapes of these two sets of fossil hominids are clearly distinct, questioning seriously the assumption of a local direct evolution. For these oldest human settlements as well as for later migrations, multidisciplinary studies (archaeology, palaeoenvironment, palaeoanthropology, genetic, and linguistic) allow us to reconstruct the outlines of the first human settlements of these areas. Climate and environment interacted with these migrations of populations. The very first example is the formation of land bridges between Asian mainland and the Indonesian archipelago during Quaternary glaciations allowing the passage of humans and fauna. And periods of lower sea levels possibly also favoured dispersion from islands to islands. Winds and sea currents, directly related with climate and its variations, also intervened in the settlement of the Pacific. Natural environment, which is impoverished eastward, has been enriched by animals and plants transported by humans. In relation to their way of life as well as to available resources, peoples initially settled littoral zones (Lapita sites), then moved inland very quickly, as demonstrated by excavations carried out in the North of Grande Terre, New Caledonia.</p
Unité et diversité préhistorique entre Java et Sumatra
Prehistoric Unity and Diversity of Java and Sumatra
The comparison of the archaeological records of Java and Sumatra allows to present a preliminary assessment defining future researches to be implemented in order to address major questions such as the origin of the â Austronesiansâ. The geographical fates of both islands are different for modern humans and obviously played an important role, shared or separated, in the history and prehistory of Indonesia. From 20 000 to 5 000 BP, Java is marked by a technical heterogeneity in produced stone tools. In the meantime, Sumatra shows more homogenous technical choices, with a unifacial pebble shaping which still belongs to the Hoabinhian tradition. Recent palaeoanthropological data from Java indicate a large variability in funerary practices as well. Different types of burials, partial cremations and other mortuary practices are documented diachronically and synchronically. Consistent data related to funerary practices are still needed regarding Sumatra.La comparaison des donnĂ©es archĂ©ologiques de Java et Sumatra permet de prĂ©senter une Ă©valuation prĂ©liminaire dĂ©finissant les recherches futures Ă lancer Ă propos de questions fondamentales telles que lâorigine des «AustronĂ©siens » . Les destins gĂ©ographiques des deux Ăźles sont diffĂ©rents pour les humains modernes et ont manifestement jouĂ© un rĂŽle important, partagĂ© ou sĂ©parĂ©, dans lâhistoire et la prĂ©histoire de lâIndonĂ©sie. De 20 000 Ă 5 000 BP, Java est marquĂ© par une hĂ©tĂ©rogĂ©nĂ©itĂ© technique en outils lithiques fabriquĂ©s. Ă la mĂȘme Ă©poque, Sumatra montre des choix techniques plus homogĂšnes, avec un façonnement unifacial sur galet appartenant Ă la tradition hoabinhienne. De rĂ©centes donnĂ©es palĂ©oanthropologiques de Java indiquent Ă©galement une grande variabilitĂ© des pratiques funĂ©raires. DiffĂ©rents types dâinhumations, crĂ©mations et autres pratiques mortuaires sont documentĂ©s diachroniquement et synchroniquement. Les donnĂ©es funĂ©raires fiables concernant les pratiques funĂ©raires Ă Sumatra restent insuffisantes.Forestier Hubert, Simanjuntak Truman, DĂ©troit Florent, Zeitoun ValĂ©ry. UnitĂ© et diversitĂ© prĂ©historique entre Java et Sumatra. In: Archipel, volume 80, 2010. pp. 19-44