scholarly journals The bears from Dmanisi and the first dispersal of early Homo out of Africa

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Tsegai Medin ◽  
Bienvenido Martínez-Navarro ◽  
Joan Madurell-Malapeira ◽  
Borja Figueirido ◽  
Giorgi Kopaliani ◽  
...  
Keyword(s):  
Systematic Position ◽  
Early Pleistocene ◽  
Substantial Contribution ◽  
Tooth Size ◽  
Forest Patches ◽  
Early Homo ◽  
Morphometric Analyses ◽  
Coefficients Of Variation ◽  
Out Of Africa ◽  
New Evidence

AbstractWe report on the taxonomy and paleodiet of the bear population that inhabited the emblematic palaeoanthropological Early Pleistocene (1.8 Ma) site of Dmanisi (Georgia), based on a dual approach combining morphometrics and microwear of upper and lower teeth. Given that the teeth of Ursus etruscus Cuvier, 1823 from Dmanisi show considerable size variability, their systematic position has been debated. However, a comparative study of the coefficients of variation for tooth size measurements in several modern bear species shows that the variability in tooth size of the ursid population from Dmanisi could result from sexual dimorphism. The analysis of tooth microwear indicates that these bears inhabited a mixed environment of open plain with forest patches, where they had a browsing diet with a substantial contribution of meat and/or fish. Comparative tooth morphometric analyses of modern ursids and fossil U. etruscus indicate that this extinct species had an omnivorous behavior similar to that of extant brown bears. The ecological interactions of the Dmanisi bears with other members of the large mammals community, including the first hominins that dispersed out of Africa, are discussed in the light of this new evidence.

Inference of Diets of Early Hominins from Primate Molar Form and Microwear

2019 ◽  
Vol 98 (4) ◽  
pp. 398-405 ◽  
Author(s):  
P.S. Ungar
Keyword(s):  
Food Preferences ◽  
Tooth Wear ◽  
Early Pleistocene ◽  
Dental Microwear ◽  
Dietary Specialization ◽  
The Past ◽  
Early Homo ◽  
Occlusal Surfaces ◽  
Adaptive Nature ◽  
Fossil Hominin

Paleontologists use fossil teeth to reconstruct the diets of early hominins and other extinct species. Some evidence is adaptive: nature selects for tooth size, shape, and structure best suited to specific food types. Other evidence includes traces left by actual foods eaten, such as microscopic tooth wear. This critical review considers how molars work, how they are used, and how occlusal topography and dental microwear can be used to infer diet and food preferences in the past, particularly for hominins of the Pliocene and early Pleistocene. Understanding that cheek teeth function as guides for chewing and tools for fracturing allows us to characterize aspects of occlusal form that reflect mechanical properties of foods to which a species is adapted. Living primates that often eat leaves, for example, have longer crests and more sloping occlusal surfaces than those that prefer hard foods. Studies of feeding ecology have shown, however, that tooth shape does not always correspond to preferred food items. It often follows mechanically challenging foods whether eaten often or rarely. Other lines of evidence that reflect actual tooth use are required to work out food preferences. Microwear textures, for example, reflect foods eaten by individuals in the past such that hard seeds and bone tend to leave complex, pitted surface textures, whereas tough leaves and meat more often leave anisotropic ones covered in long, parallel scratches. The study of fossil hominin molars shows how these various attributes are combined to infer diet and food preference in the past. A trend in occlusal morphology suggests decreased dietary specialization from Australopithecus to early Homo, and increasing dispersion in microwear complexity values is consistent with this. On the other hand, occlusal morphology may suggest dietary specialization in Paranthropus, although different species of this genus have different microwear texture patterns despite similar craniodental adaptations.

A giant early Pleistocene bird from eastern Europe: unexpected component of terrestrial faunas at the time of early Homo arrival

2019 ◽  
Vol 39 (2) ◽  
pp. e1605521 ◽  
Author(s):  
Nikita V. Zelenkov ◽  
Alexander V. Lavrov ◽  
Dmitry B. Startsev ◽  
Innessa A. Vislobokova ◽  
Alexey V. Lopatin
Keyword(s):  
Eastern Europe ◽  
Early Pleistocene ◽  
Early Homo

Molecular evidence for the systematic positions of two enigmatic mosses: Pterogonidium pulchellum (Sematophyllaceae, Musci) and Piloecium pseudorufescens (Myuriaceae, Musci)

2006 ◽  
Vol 84 (3) ◽  
pp. 501-507
Author(s):  
Ying Chang ◽  
Chan Woon Khiong ◽  
Sean W. Graham ◽  
Benito C. Tan
Keyword(s):  
Bayesian Inference ◽  
Maximum Likelihood ◽  
Maximum Parsimony ◽  
Phylogenetic Analyses ◽  
Systematic Position ◽  
Molecular Evidence ◽  
Rbcl Gene ◽  
Branch Support ◽  
New Evidence ◽  
Rbcl Gene Sequences

The systematic position of Pterogonidium pulchellum (W.J. Hooker) Muell. Hal. in the Sematophyllaceae and Piloecium pseudorufescens (Hampe) Muell. Hal. in the Myuriaceae is reexamined with new evidence derived from rbcL gene sequences. A total of 18 taxa from Sematophyllaceae, Hypnaceae, Myuriaceae, and Hookeriaceae were included, 11 of which were newly sequenced for the rbcL gene. Analyses were done using maximum parsimony, maximum likelihood (TrN + Γ + I model and GTR + Γ + I model), and Bayesian inference (GTR + Γ + I model). The results show that Pterogonidium pulchellum has a closer relationship with members of Hypnaceae than with Sematophyllaceae, while Piloecium pseudorufescens forms a clade with the Sematophyllaceae in all phylogenetic analyses, with robust branch support. Two SOWH tests were carried out and the results show that it is not appropriate to classify Pterogonidium pulchellum in Sematophyllaceae and it is also not appropriate to classify Piloecium pseudorufescens in Myuriaceae.

New evidence for the systematic position of Gundelia L. with notes on delimitation of Arctoteae ( Asteraceae )

Taxon ◽  
2001 ◽  
Vol 50 (1) ◽  
pp. 105-114 ◽  
Author(s):  
Per Ola Karis ◽  
Pia Eldenäs ◽  
Mari Källersjö
Keyword(s):  
Systematic Position ◽  
New Evidence

scholarly journals Historical biogeography of the leopard (Panthera pardus) and its extinct Eurasian populations

2018 ◽  
Author(s):  
Johanna L.A. Paijmans ◽  
Axel Barlow ◽  
Daniel W. Förster ◽  
Kirstin Henneberger ◽  
Matthias Meyer ◽  
...  
Keyword(s):  
Late Pleistocene ◽  
Dna Sequences ◽  
Sister Group ◽  
Historical Biogeography ◽  
Early Pleistocene ◽  
Middle Pleistocene ◽  
Recent Common Ancestor ◽  
Panthera Pardus ◽  
Phylogenetic Placement ◽  
Out Of Africa

AbstractBackgroundResolving the historical biogeography of the leopard(Panthera pardus)is a complex issue, because patterns inferred from fossils and from molecular data lack congruence. Fossil evidence supports an African origin, and suggests that leopards were already present in Eurasia during the Early Pleistocene. Analysis of DNA sequences however, suggests a more recent, Middle Pleistocene shared ancestry of Asian and African leopards. These contrasting patterns led researchers to propose a two-stage hypothesis of leopard dispersal out of Africa: an initial Early Pleistocene colonisation of Asia and a subsequent replacement by a second colonisation wave during the Middle Pleistocene. The status of Late Pleistocene European leopards within this scenario is unclear: were these populations remnants of the first dispersal, or do the last surviving European leopards share more recent ancestry with their African counterparts?ResultsIn this study, we generate and analyse mitogenome sequences from historical samples that span the entire modern leopard distribution, as well as from Late Pleistocene remains. We find a deep bifurcation between African and Eurasian mitochondrial lineages (∼710 Ka), with the European ancient samples as sister to all Asian lineages (∼483 Ka). The modern and historical mainland Asian lineages share a relatively recent common ancestor (∼122 Ka), and we find one Javan sample nested within these.ConclusionsThe phylogenetic placement of the ancient European leopard as sister group to Asian leopards suggests that these populations originate from the same out-of-Africa dispersal which founded the Asian lineages. The coalescence time found for the mitochondrial lineages aligns well with the earliest undisputed fossils in Eurasia, and thus encourages a re-evaluation of the identification of the much older putative leopard fossils from the region. The relatively recent ancestry of all mainland Asian leopard lineages suggests that these populations underwent a severe population bottleneck during the Pleistocene. Finally, although only based on a single sample, the unexpected phylogenetic placement of the Javan leopard could be interpreted as evidence for exchange of mitochondrial lineages between Java and mainland Asia, calling for further investigation into the evolutionary history of this subspecies.

Into the Woods Early Homo sapiens and Tropical Forest Colonization

2019 ◽  
Author(s):  
Patrick Roberts
Keyword(s):  
Tropical Forests ◽  
Late Pleistocene ◽  
Homo Sapiens ◽  
Homo Erectus ◽  
Rapid Expansion ◽  
Early Pleistocene ◽  
Human Populations ◽  
Tropical Regions ◽  
Early Homo ◽  
Middle And Late Pleistocene

Popular philosophical associations of tropical forests, and forests in general, with an inherent ancestral state, away from the stresses, pollution, and technosphere of modern life, are nicely summarized by Murakami’s quote above (2002). Given the probable origins of the hominin clade in tropical forests, this quote is also apt from an evolutionary standpoint. Yet, somewhat surprisingly, tropical forests have frequently been considered impenetrable barriers to the global migration of Homo sapiens (Gamble, 1993; Finlayson, 2014). As was the case with the focus on ‘savannastan’ in facilitating the Early Pleistocene expansion of Homo erectus discussed in Chapter 3 (Dennell and Roebroeks, 2005), the movement of H. sapiens into tropical regions such as South Asia, Southeast Asia, and Australia has tended to be linked to Late Pleistocene periods when forests contracted and grasslands expanded (Bird et al., 2005; Boivin et al., 2013). Alternative narratives have focused on the importance of coastal adaptations as providing a rich source of protein and driving cultural and technological complexity, as well as mobility, in human populations during the Middle and Late Pleistocene (Mellars, 2006; Marean, 2016). The evidence of early art and symbolism at coastal cave sites such as Blombos in South Africa (Henshilwood et al., 2002, 2011; Vanhaeren et al., 2013) and Taforalt in North Africa (Bouzouggar et al., 2007) is often used to emphasize the role of marine habitats in the earliest cultural emergence of our species. Indeed, for the last decade, the pursuit of rich marine resources (Mellars, 2005, 2006) has been a popular explanation for the supposed rapidity of the ‘southern dispersal route’, whereby humans left Africa 60 ka, based on genetic information (e.g., Macaulay et al., 2005), to reach the Pleistocene landmass that connected Australia and New Guinea (Sahul) by c. 65 ka (Clarkson et al., 2017). In both of these cases, the coast or expanses of grassland have been seen as homogeneous corridors, facilitating rapid expansion without novel adaptation.

scholarly journals New evidence of bone tool use by Early Pleistocene hominins from Cooper’s D, Bloubank Valley, South Africa

2021 ◽  
Vol 39 ◽  
pp. 103129
Author(s):  
Raphaël Hanon ◽  
Francesco d'Errico ◽  
Lucinda Backwell ◽  
Sandrine Prat ◽  
Stéphane Péan ◽  
...  
Keyword(s):  
South Africa ◽  
Tool Use ◽  
Early Pleistocene ◽  
New Evidence ◽  
Bone Tool

Docosapentaenoic acid monoacylglyceride reduces inflammation and vascular remodeling in experimental pulmonary hypertension

2014 ◽  
Vol 307 (4) ◽  
pp. H574-H586 ◽  
Author(s):  
Caroline Morin ◽  
Roddy Hiram ◽  
Eric Rousseau ◽  
Pierre U. Blier ◽  
Samuel Fortin
Keyword(s):  
Pulmonary Hypertension ◽  
Lipid Analysis ◽  
Pulmonary Inflammation ◽  
Docosapentaenoic Acid ◽  
Ki 67 ◽  
Tissue Samples ◽  
Morphometric Analyses ◽  
Tissue Homogenates ◽  
Consistent Increase ◽  
New Evidence

n-3 Polyunsaturated fatty acids (n-3 PUFA) have been shown to reduce inflammation and proliferation of pulmonary artery smooth muscle cells under pathophysiological conditions. However, the anti-inflammatory effect of the newly synthesized docosapentaenoic acid monoacylglyceride (MAG-DPA) on key signaling pathways in pulmonary hypertension (PH) pathogenesis has yet to be assessed. The aim of the present study was to determine the effects of MAG-DPA on pulmonary inflammation and remodeling occurring in a rat model of PH, induced by a single injection of monocrotaline (MCT: 60 mg/kg). Our results demonstrate that MAG-DPA treatment for 3 wk following MCT injection resulted in a significant improvement of right ventricular hypertrophy (RVH) and a reduction in Fulton's Index (FI). Morphometric analyses revealed that the wall thickness of pulmonary arterioles was significantly lower in MCT + MAG-DPA-treated rats compared with controls. This result was further correlated with a decrease in Ki-67 immunostaining. Following MAG-DPA treatments, lipid analysis showed a consistent increase in DPA together with lower levels of arachidonic acid (AA), as measured in blood and tissue samples. Furthermore, in MCT-treated rats, oral administration of MAG-DPA decreased NF-κB and p38 MAPK activation, leading to a reduction in MMP-2, MMP-9, and VEGF expression levels in lung tissue homogenates. Altogether, these data provide new evidence regarding the mode of action of MAG-DPA in the prevention of pulmonary hypertension induced by MCT.

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