Problems in the interpretation of Ramapithecus: with special reference to anterior tooth reduction

The dental proportions of Ramapithecus specimen FT 1271-2 (from Fort Ternan, Kenya) have been compared with undoubted fossil pongids from the Miocene of East Africa. Compared to its Miocene pongid contemporaries, Ramapithecus exhibits distinct anterior tooth reduction both in its incisor and canine dimensions. This distinction is most clearly seen in comparisons of Ramapithecus with pongids of similar cheek tooth size, i.e., Dryopithecus africanus and Pan paniscus. The differences in dental proportions between the phylogenetic lines of D. africanus to Pan and Ramapithecus to Homo are discussed in terms of various dietary hypotheses. The similarities in dental proportions of Gorilla and Ramapithecus illustrate their non-frugivorous dietary preferences, but have little or no value as far as the taxonomic assessment of Ramapithecus is concerned.     

The nature of the transition in the dental mechanism from pongids to hominids

Many recent discoveries of Ramapithecus, and of probably ground-living dryopithecines, Dryopithecus (subgenus Sivapithecus), clarify the nature of the transition of the dental mechanism from that of pongids to the hominid stage with reduced canines and flattened cheek teeth with thick enamel.Faunal correlation with potassium/argon dated sites indicates that Sivapithecus and Ramapithecus appeared in the Old World about the same time, approximately 13 million years ago. The thickened molar enamel of these hominoids suggests a terrestrial adaptation in both groups, probably resulting from climatic changes. This adaptation was not necessarily a unique event in the ancestry of the two genera, for species of the two seem to have been different sizes when the change was made.New Ramapithecus finds come from Pyrgos, near Athens, from Çandir in Anatolia, and from Rudabánya, Hungary. At the latter site various specimens preserve all upper and lower teeth in place, while the Çandir and Pyrgos mandibles give important new information about symphyseal structure and orientation, as well as about arcade arrangement. The Rudabánya finds confirm, as do the others, marked facial foreshortening, relatively orthal incisors, anteriorly abbreviated mandible and canine reduction in Ramapithecus. The dental mechanics of Ramapithecus suggested from earlier described finds recovered in the Siwalik deposits of India and Pakistan, as well as at Fort Ternan, Kenya are clarified by the finds from Athens, Anatolia, and Hungary. Like Australopithecus, Ramapithecus mandibles have well-developed double transverse, shallow but transversely thick horizontal rami and anteriorly shifted, vertically oriented, deep ascending branches. These addes resemblances increase the probability that Ramapithecus is in or near the ancestry of Australopithecus and other hominids.     

Notes on Ramapithecus, the earliest known hominid, and Dryopithecus

Recent paleontological analysis of the Higher Primate subfamily Dryopithecinae shows that fossils in this group can be referred to two genera, Ramapithecus and Dryopithecus. Ramapithecus is known from India and East Africa in Late Miocene or Early Pliocene time (about 14 m. years ago). The remains of Ramapithecus resemble closely the equivalent parts of the later Hominidae and contrast with those of the Pongidae. It is concluded that Ramapithecus is the earliest known hominid, some 5 or 6 times older than the oldest Pleistocene hominids. Dryopithecus is a pongid and contains as subgenera (Dryopithecus), (Proconsul), and (Sivapithecus). Probably part of (Proconsul) is ancestral to the chimpanzee and part to the gorilla, while part of (Sivapithecus) is ancestral to the orang-utan.     

Les primates hominoides du Vallésien de Macédoine (Grèce). Étude de la machoire inférieure

The locality of the Ravine of the Rain is located in Lower Macedonia (Greece); it has yielded an important mammalian fauna of Vallesian age (Upper Miocene). An hominoid Primate is present with a lot of well preserved jaws. It is one of the better set of specimens never found in the same locality. His features and caracters are described and compared with those of the others tertiary Hominoids. This is a species which is near of Sivapithecus, Bodvapithecus and Ramapithecus and also it is very near of the ancestry of Gigantopithecus. All these Primates have had a particular ecology and this is probably the set in which we shall find the root of the plio-pleistocen Hominids.     

Observations on mid-tertiary hominoids Sivapithecus and Ramapithecus

Detailed palaeontological analyses of the hominoids of the Miocene indicate the occurrence of forms belonging to Pongidae and Hominidae. Of these, Sivapithecus (Pongidae) with three contained species and Ramapithecus (Hominidae) with two distinct species can be recognized. These two families Pongidae and Hominidae were sufficiently well defined and distinct by the late Miocene about 14 million years ago. The author has discussed in brief the status of a few interesting finds of Sivapithecus and Ramapithecus based on the study of the originals preserved in India and America.     

Anterior tooth reductions inRamapithecus

A metric study comparing the maxillary dentition ofRamapithecus to modern hominoids is undertaken. From such a study, one can determine whether the criterion of relative anterior tooth reduction is significant enough to support the placement ofRamapithecus in the hominid line of evolution. As it turns out, the anterior dental reduction is not significant and thus this particular criterion cannot be used for this purpose.     

Determination of intracellular osmotic volume and sodium concentration in dunaliella

A new method to measure intracellular volume in Dunaliella was developed, where lithium ions are used as monitors of the extracellular volume. Li⁺ is shown to be impenetrable to the intracellular volume, insignificantly absorbed to the algae, and is rapidly and evenly distributed within the extracellular volume. The method is suggested to be free of several limitations and consistent errors present in several previously employed techniques.

Using the new technique it is shown that both Dunaliella salina and Dunaliella bardawil adjust to a constant cellular volume when grown in a medium containing salt concentrations ranging from 0.5 molar to 4 molar NaCl. That volume is 90 femtoliter per cell for D. salina and 600 femtoliter per cell for D. bardawil. Nonosmotic volume accounts for about 10% of the total cell volume.

The intracellular sodium concentration, as determined with the new technique, was under all experimental conditions tested below 100 millimolar. This was true both for cells grown on 0.5 to 4 molar NaCl, and during the osmoregulatory process. It is thus concluded that intracellular NaCl is a minor contributor to the overall intracellular osmotic pressure in Dunaliella.

     

Unique Dental Morphology of Homo floresiensis and Its Evolutionary Implications

Homo floresiensis is an extinct, diminutive hominin species discovered in the Late Pleistocene deposits of Liang Bua cave, Flores, eastern Indonesia. The nature and evolutionary origins of H. floresiensis’ unique physical characters have been intensively debated. Based on extensive comparisons using linear metric analyses, crown contour analyses, and other trait-by-trait morphological comparisons, we report here that the dental remains from multiple individuals indicate that H. floresiensis had primitive canine-premolar and advanced molar morphologies, a combination of dental traits unknown in any other hominin species. The primitive aspects are comparable to H. erectus from the Early Pleistocene, whereas some of the molar morphologies are more progressive even compared to those of modern humans. This evidence contradicts the earlier claim of an entirely modern human-like dental morphology of H. floresiensis, while at the same time does not support the hypothesis that H. floresiensis originated from a much older H. habilis or Australopithecus-like small-brained hominin species currently unknown in the Asian fossil record. These results are however consistent with the alternative hypothesis that H. floresiensis derived from an earlier Asian Homo erectus population and experienced substantial body and brain size dwarfism in an isolated insular setting. The dentition of H. floresiensis is not a simple, scaled-down version of earlier hominins.     

Partial analysis of the bands seen in circular dichroism spectra of green and blue-green algal cells and thylakoids

A comparison was made of the circular dichroism (C.D.) spectra of Chlorella, Euglena, and Anacystis cells and thylakoids. Analyses of the spectra reveal that these C.D. bands are similar to those observed previously in whole spinach choloroplasts and subchloroplast particles. C.D. spectra of Euglena chloroplasts show bands at longer wavelengths than previously reported. From comparisons of circular dichroism spectra and fine structure, it was concluded that: (a) bands seen in circular dichroism spectra were not the result of light scattering from thylakoid membranes; and (b) bands seen in the C.D. spectra of nonmembranous systems (previously reported) could account for circular dichroism of algae. We also concluded that comparisons would have to be made with model systems in order to correct for effects of absorption flattening, concentration obscuring, and differential light scattering of membranous systems.     

Proteomic Analysis of Gastrocnemius Muscle in Rats with Streptozotocin-Induced Diabetes and Chronically Exposed to Fluoride

Administration of high doses of fluoride (F) can alter glucose homeostasis and lead to insulin resistance (IR). This study determined the profile of protein expression in the gastrocnemius muscle of rats with streptozotocin-induced diabetes that were chronically exposed to F. Male Wistar rats (60 days old) were randomly distributed into two groups of 18 animals. In one group, diabetes was induced through the administration of streptozotocin. Each group (D-diabetic and ND-non-diabetic) was further divided into 3 subgroups each of which was exposed to a different F concentration via drinking water (0 ppm, 10 ppm or 50 ppm F, as NaF). After 22 days of treatment, the gastrocnemius muscle was collected and submitted to proteomic analysis (2D-PAGE followed by LC-MS/MS). Protein functions were classified by the GO biological process (ClueGO v2.0.7+Clupedia v1.0.8) and protein-protein interaction networks were constructed (PSICQUIC, Cytoscape). Quantitative intensity analysis of the proteomic data revealed differential expression of 75 spots for ND0 vs. D0, 76 for ND10 vs.D10, 58 spots for ND50 vs. D50, 52 spots for D0 vs. D10 and 38 spots for D0 vs. D50. The GO annotations with the most significant terms in the comparisons of ND0 vs. D0, ND10 vs. D10, ND50 vs. D50, D0 vs. D10 and D0 vs. D50, were muscle contraction, carbohydrate catabolic processes, generation of precursor metabolites and energy, NAD metabolic processes and gluconeogenesis, respectively. Analysis of subnetworks revealed that, in all comparisons, proteins with fold changes interacted with GLUT4. GLUT4 interacting proteins, such as MDH and the stress proteins HSPB8 and GRP78, exhibited decreased expression when D animals were exposed to F. The presence of the two stress proteins indicates an increase in IR, which might worsen diabetes. Future studies should evaluate whether diabetic animals treated with F have increased IR, as well as which molecular mechanisms are involved.     

Adaptation to hard-object feeding in sea otters and hominins

The large, bunodont postcanine teeth in living sea otters (Enhydra lutris) have been likened to those of certain fossil hominins, particularly the ’robust’ australopiths (genus Paranthropus). We examine this evolutionary convergence by conducting fracture experiments on extracted molar teeth of sea otters and modern humans (Homo sapiens) to determine how load-bearing capacity relates to tooth morphology and enamel material properties. In situ optical microscopy and x-ray imaging during simulated occlusal loading reveal the nature of the fracture patterns. Explicit fracture relations are used to analyze the data and to extrapolate the results from humans to earlier hominins. It is shown that the molar teeth of sea otters have considerably thinner enamel than those of humans, making sea otter molars more susceptible to certain kinds of fractures. At the same time, the base diameter of sea otter first molars is larger, diminishing the fracture susceptibility in a compensatory manner. We also conduct nanoindentation tests to map out elastic modulus and hardness of sea otter and human molars through a section thickness, and microindentation tests to measure toughness. We find that while sea otter enamel is just as stiff elastically as human enamel, it is a little softer and tougher. The role of these material factors in the capacity of dentition to resist fracture and deformation is considered. From such comparisons, we argue that early hominin species like Paranthropus most likely consumed hard food objects with substantially higher biting forces than those exerted by modern humans.     

Chemometric Methods to Quantify 1D and 2D NMR Spectral Differences Among Similar Protein Therapeutics

NMR spectroscopy is an emerging analytical tool for measuring complex drug product qualities, e.g., protein higher order structure (HOS) or heparin chemical composition. Most drug NMR spectra have been visually analyzed; however, NMR spectra are inherently quantitative and multivariate and thus suitable for chemometric analysis. Therefore, quantitative measurements derived from chemometric comparisons between spectra could be a key step in establishing acceptance criteria for a new generic drug or a new batch after manufacture change. To measure the capability of chemometric methods to differentiate comparator NMR spectra, we calculated inter-spectra difference metrics on 1D/2D spectra of two insulin drugs, Humulin R® and Novolin R®, from different manufacturers. Both insulin drugs have an identical drug substance but differ in formulation. Chemometric methods (i.e., principal component analysis (PCA), 3-way Tucker3 or graph invariant (GI)) were performed to calculate Mahalanobis distance (D _M) between the two brands (inter-brand) and distance ratio (D _R) among the different lots (intra-brand). The PCA on 1D inter-brand spectral comparison yielded a D _M value of 213. In comparing 2D spectra, the Tucker3 analysis yielded the highest differentiability value (D _M = 305) in the comparisons made followed by PCA (D _M = 255) then the GI method (D _M = 40). In conclusion, drug quality comparisons among different lots might benefit from PCA on 1D spectra for rapidly comparing many samples, while higher resolution but more time-consuming 2D-NMR-data-based comparisons using Tucker3 analysis or PCA provide a greater level of assurance for drug structural similarity evaluation between drug brands.     

Improving the spatial orientation of human teeth using a virtual 3D approach

Since teeth are resistant to decomposition processes, they provide important and at times unique sources of information about fossil humans. Fortunately, dental remains reflect significant evolutionary changes. These changes make a very important and often exclusive contribution to the definition of new taxa or the attribution of fossil specimens to existing taxa.The traditional approach to dental morphometric analyses usually focuses on the recording of several measures of the tooth with calipers, especially the two basic crown diameters (buccolingual and mesiodistal). However, since these measures do not adequately represent the complex morphology of the tooth, 2D images and 3D digital models of dental morphology have been used. For both types of analysis, the possibility of correctly comparing homologous teeth depends on the adoption of a common orientation system. The lack of such a system makes it difficult to compare the results of different studies.Here we describe a new method for orienting teeth specifically devised for the upper and lower first molar (M1). Samples of unworn maxillary (n = 15) and mandibular (n = 15) first molars of modern humans were scanned with a Roland Picza 3D digitizer. The 3D virtual models were used to compare our new orientation method with those proposed in the literature. The new orientation system, which meets a geometric criterion, is based on three points identified on the cervical line and ensures acceptable repeatability of the spatial positioning and orientation independent of the shape and wear of the first molar under investigation. This orientation system is a first step toward the creation of a virtual set of hominid and fossil human first molars, which will allow us to make comparisons via a sophisticated and noninvasive approach. This pilot study also provides guidelines to extend the new methodology to the other types of teeth.     

A new species of Pliopithecus from the Indian S̀ivaliks

This paper gives a detailed account of an isolated upper third molar of a gibbon-like primate, the first of its kind ever found from the S?ivalik hills. The tooth comes from the Nagri beds comparable to the Middle Miocene Formations. This tooth has been assigned to a new species of Pliopithecus, namely P. krishnaii, on the basis of morphological and metrical comparisons with the fossil gibbon-like primates and living gibbons.     

Stomatal Ultrastructure, Molecular Phylogeny, and Description of Parasitodiplogaster laevigata n. sp. (Nematoda: Diplogastridae), a Parasite of Fig Wasps

Parasitodiplogaster comprises a potentially large radiation of nematode species that appear to be parasitically bound to their Agaonid fig wasp hosts, which are mutualistically associated in the syconia (figs) of the diverse plant genus Ficus. Parasitodiplogaster laevigata n. sp. is described and illustrated as an associate of the fig wasp, Pegoscapus sp. from Ficus laevigata from southern Florida. It is the first species of Parasitodiplogaster reported from North America and is closest to P. trigonema from F. trigonata from Panama. Parasitodiplogaster laevigata n. sp. can be differentiated from all described species of Parasitodiplogaster based on stomatal morphology (presence of a large dorsal and a right subventral tooth) in the adults of both sexes, molecular comparisons of two expansion segments (D2,D3) of the large subunit (LSU) rRNAgene, and fig-fig wasp host affinities. The ultrastructure of P. laevigata n. sp. was elucidated using TEM and SEM for comparisons with other species of Parasitodiplogaster. The stoma of P. laevigata n. sp. possesses a nonsegmented cheilostomal ring that connects to the longitudinal body musculature per- and interradially, a claw-like dorsal tooth, a right subventral tooth, and telostegostomatal apodemes arising from the dorsal side of each subventral sector. The unification of the pro-, meso-, and metastegostom with the gymnostom in P. laevigata n. sp. and further simplification in other described species may be due to derived adaptations associated with the internal parasitism of fig wasps.     

Assessing the impact of comparative genomic sequence data on the functional annotation of the Drosophila genome

Background

It is widely accepted that comparative sequence data can aid the functional annotation of genome sequences; however, the most informative species and features of genome evolution for comparison remain to be determined.

Results

We analyzed conservation in eight genomic regions (apterous, even-skipped, fushi tarazu, twist, and Rhodopsins 1, 2, 3 and 4) from four Drosophila species (D. erecta, D. pseudoobscura, D. willistoni, and D. littoralis) covering more than 500 kb of the D. melanogaster genome. All D. melanogaster genes (and 78-82% of coding exons) identified in divergent species such as D. pseudoobscura show evidence of functional constraint. Addition of a third species can reveal functional constraint in otherwise non-significant pairwise exon comparisons. Microsynteny is largely conserved, with rearrangement breakpoints, novel transposable element insertions, and gene transpositions occurring in similar numbers. Rates of amino-acid substitution are higher in uncharacterized genes relative to genes that have previously been studied. Conserved non-coding sequences (CNCSs) tend to be spatially clustered with conserved spacing between CNCSs, and clusters of CNCSs can be used to predict enhancer sequences.

Conclusions

Our results provide the basis for choosing species whose genome sequences would be most useful in aiding the functional annotation of coding and cis-regulatory sequences in Drosophila. Furthermore, this work shows how decoding the spatial organization of conserved sequences, such as the clustering of CNCSs, can complement efforts to annotate eukaryotic genomes on the basis of sequence conservation alone.     

Genetics and Evolution of the Salmonella Galactose-Initiated Set of O Antigens

This paper covers eight Salmonella serogroups, that are defined by O antigens with related structures and gene clusters. They include the serovars that are now most frequently isolated. Serogroups A, B1, B2, C2-C3, D1, D2, D3 and E have O antigens that are distinguished by having galactose as first sugar, and not N-acetyl glucosamine or N-acetyl galactosamine as in the other 38 serogroups, and indeed in most Enterobacteriaceae. The gene clusters for these galactose-initiated appear to have entered S. enterica since its divergence from E. coli, but sequence comparisons show that much of the diversification occurred long before this. We conclude that the gene clusters must have entered S. enterica in a series of parallel events. The individual gene clusters are discussed, followed by analysis of the divergence for those genes shared by two or more gene clusters, and a putative phylogenic tree for the gene clusters is presented. This set of O antigens provides a rare case where it is possible to examine in detail the relationships of a significant number of O antigens. In contrast the more common pattern of O-antigen diversity within a species is for there to be only a few cases of strains having related gene clusters, suggesting that diversity arose through gain of individual O-antigen gene clusters by lateral gene transfer, and under these circumstances the evolution of the diversity is not accessible. This paper on the galactose-initiated set of gene clusters gives new insights into the origins of O-antigen diversity generally.     

Computer analyses reveal a hobo-like element in the nematode Caenorhabditis elegans,which presents a conserved transposase domain common with the Tc1-Mariner transposon family

The present report describes the use of computer analyses to reveal a hobo-like element in the genome of Caenorhabditis elegans. This hobo-like sequence is 3039 bp long, contains two inverted terminal repeats of 25–27 bp and probably does not encoded a functional transposase. Sequence comparisons suggest that each transposase of hobo elements probably has a D(D/S)E motif. Thus the transposases of the hAT superfamily of transposons appear to be close to the other transposases and intregrases.     

Uniquely derived upper molar morphology of Eocene Amphipithecidae (Primates: Anthropoidea): Homology and phylogeny

The extinct Southeast Asian primate family Amphipithecidae is regularly cited in discussions of anthropoid origins, but its phylogenetic position remains controversial. In part, the lack of consensus regarding amphipithecid relationships can be attributed to uncertainty regarding the homology of upper molar structures in this group. Here, we describe a virtually pristine upper molar of Pondaungia cotteri from the late middle Eocene Pondaung Formation of Myanmar, which is the first example of a relatively unworn and well-preserved amphipithecid upper molar ever recovered. The distolingual upper molar cusp in this new specimen of Pondaungia appears to be a lingually displaced and enlarged metaconule, rather than a hypocone or pseudohypocone as previous workers have thought. Reassessment of the upper molar morphology of other amphipithecids and putative amphipithecids reveals a very similar pattern in Siamopithecus, Myanmarpithecus and Ganlea, all of which are interpreted as having upper molars showing many of the same derived features apparent in Pondaungia. In contrast, the upper molar morphology of Bugtipithecus diverges radically from that of undoubted amphipithecids, and the latter taxon is excluded from Amphipithecidae on this basis. Phylogenetic analyses of several character–taxon matrices culled from the recent literature and updated to reflect the new information on amphipithecid upper molar morphology yield similar results. Consensus tree topologies derived from these analyses support amphipithecid monophyly and stable relationships within Amphipithecidae. Amphipithecids appear to be stem members of the anthropoid clade.     

Invasion history, distribution, and relative abundances of Dreissena bugensis in the old world: a synthesis of data

We examined trends in expansion patterns and relative abundances of Dreissena bugensis in reservoirs and major river systems in eastern Europe. Based on our own data and data from the literature, it is apparent that trends were variable across river basins and not easily related to environmental conditions. In some cases these did not conform to the patterns typically found for dreissenids. In the early period of expansion beyond its native range in the Dnieper-Bug delta and estuary, D. bugensis rapidly replaced Dreissena polymorpha in the upper Dnieper River system, but increased only gradually and over time became less abundant relative to D. polymorpha in the Don-Manych River system. Contrary to the Dnieper and Don River systems, in the Volga River system considerable spatial variability in relative abundances was apparent, particularly in northern reservoirs. Moreover, even though D. bugensis usually displaces D. polymorpha as the dominant dreissenid, the latter can remain dominant in certain types of habitats where conditions are less favourable for the former. Suggested factors that may be responsible for differences in invasion patterns in the river systems may include differential responses to temperature, or to some other factor(s) associated with geographical latitude, the level of water mineralization, and selective predation by molluscivorous fish. In particular, the northward expansion of D. bugensis seems to be limited by temperature. The lack of long-term data on appropriate scales precludes linking these differences to specific features within the environment, but our comparisons indicate that the expansion of D. bugensis relative to D. polymorpha is more complex than previously believed.