32 research outputs found
Food Sharing across Borders
Evolutionary models consider hunting and food sharing to be milestones that paved the way from primate to human societies. Because fossil evidence is scarce, hominoid primates serve as referential models to assess our common ancestors’ capacity in terms of communal use of resources, food sharing, and other forms of cooperation. Whereas chimpanzees form male-male bonds exhibiting resource-defense polygyny with intolerance and aggression toward nonresidents, bonobos form male-female and female-female bonds resulting in relaxed relations with neighboring groups. Here we report the first known case of meat sharing between members of two bonobo communities, revealing a new dimension of social tolerance in this species. This observation testifies to the behavioral plasticity that exists in the two Pan species and contributes to scenarios concerning the traits of the last common ancestor of Pan and Homo. It also contributes to the discussion of physiological triggers of in-group/out-group behavior and allows reconsideration of the emergence of social norms in prehuman societies
The evolution of the upright posture and gait—a review and a new synthesis
During the last century, approximately 30 hypotheses have been constructed to explain the evolution of the human upright posture and locomotion. The most important and recent ones are discussed here. Meanwhile, it has been established that all main hypotheses published until the last decade of the past century are outdated, at least with respect to some of their main ideas: Firstly, they were focused on only one cause for the evolution of bipedality, whereas the evolutionary process was much more complex. Secondly, they were all placed into a savannah scenario. During the 1990s, the fossil record allowed the reconstruction of emerging bipedalism more precisely in a forested habitat (e.g., as reported by Clarke and Tobias (Science 269:521–524, 1995) and WoldeGabriel et al. (Nature 412:175–178, 2001)). Moreover, the fossil remains revealed increasing evidence that this part of human evolution took place in a more humid environment than previously assumed. The Amphibian Generalist Theory, presented first in the year 2000, suggests that bipedalism began in a wooded habitat. The forests were not far from a shore, where our early ancestor, along with its arboreal habits, walked and waded in shallow water finding rich food with little investment. In contrast to all other theories, wading behaviour not only triggers an upright posture, but also forces the individual to maintain this position and to walk bipedally. So far, this is the only scenario suitable to overcome the considerable anatomical and functional threshold from quadrupedalism to bipedalism. This is consistent with paleoanthropological findings and with functional anatomy as well as with energetic calculations, and not least, with evolutionary psychology. The new synthesis presented here is able to harmonise many of the hitherto competing theories
Strategies for the Use of Fallback Foods in Apes
Researchers have suggested that fallback foods (FBFs) shape primate food processing adaptations, whereas preferred foods drive harvesting adaptations, and that the dietary importance of FBFs is central in determining the expression of a variety of traits. We examine these hypotheses in extant apes. First, we compare the nature and dietary importance of FBFs used by each taxon. FBF importance appears greatest in gorillas, followed by chimpanzees and siamangs, and least in orangutans and gibbons (bonobos are difficult to place). Next, we compare 20 traits among taxa to assess whether the relative expression of traits expected for consumption of FBFs matches their observed dietary importance. Trait manifestation generally conforms to predictions based on dietary importance of FBFs. However, some departures from predictions exist, particularly for orang-utans, which express relatively more food harvesting and processing traits predicted for consuming large amounts of FBFs than expected based on observed dietary importance. This is probably due to the chemical, mechanical, and phenological properties of the apes’ main FBFs, in particular high importance of figs for chimpanzees and hylobatids, compared to use of bark and leaves—plus figs in at least some Sumatran populations—by orang-utans. This may have permitted more specialized harvesting adaptations in chimpanzees and hylobatids, and required enhanced processing adaptations in orang-utans. Possible intercontinental differences in the availability and quality of preferred and FBFs may also be important. Our analysis supports previous hypotheses suggesting a critical influence of the dietary importance and quality of FBFs on ape ecology and, consequently, evolution
Grouping patterns of wild pygmy chimpanzees (Pan paniscus) observed at a marsh grassland amidst the tropical rain forest of Yalosidi, Republic of Zaïre
MicroRNA signatures in malignant pleural mesothelioma effusions
Introduction/Aim
Malignant pleural mesothelioma (MPM) is an incurable cancer of the pleura that can be difficult to diagnose. Biomarkers for an earlier and/or easier diagnosis are urgently needed. The powerful gene regulators microRNA, have become popular diagnostic targets due to their stable expression within the body. Studies have examined microRNA in MPM and control samples, however it is still unclear which microRNA are potential biomarkers for MPM. Approximately 90% of patients develop pleural effusions which are an ideal source of diagnostic targets as sample collection is minimally invasive. The biomarker potential of microRNA in MPM frozen/fresh effusions is yet to be determined. We hypothesise that microRNA expressed in effusions are potential biomarkers for MPM.
Methods
Taqman OpenArray profiling and real-time quantitative PCR were used to analyse microRNA in a cohort (Cohort 1) of 48 effusion cell and supernatant samples from MPM, lung adenocarcinoma and benign pleural disease patients. The potential microRNA biomarkers were then analysed in a second cohort (Cohort 2) of 60 MPM and lung adenocarcinoma samples.
Statistics
MicroRNA expression was determined to be significantly different between diseases on a volcano plot with a 2 or more-fold change and a p< 0.05. MicroRNA combinations were analysed using logistic regression and diagnostic efficiency was assessed using receiver operating characteristic curves.
Results
An effusion cell signature based on the combination of miR-143, miR-210 and miR-200c for the diagnosis of MPM was identified in Cohort 1 (AUC – 0.92) and validated in Cohort 2 (AUC – 0.71).
Conclusion
MicroRNA expressed in effusion cells are potential biomarkers for differentiating MPM from lung adenocarcinoma.
Grant Support: This work was supported by grants from Dust Diseases Board N.S.W, Maurice Blackburn and Sir Charles Gairdner Hospital Research Committee. S Mutsaers was supported on a Cancer Council WA Research Fellowship
MicroRNA signatures in malignant pleural mesothelioma effusions
Malignant pleural mesothelioma (MPM) is an incurable cancer of the pleura that can be difficult to diagnose. Biomarkers for an easier and/or earlier diagnosis are needed. Approximately 90% of MPM patients develop a pleural effusion (PE). PEs are ideal sources of biomarkers as the fluid would almost always require drainage for diagnostic and/or therapeutic reasons. However, differentiating MPM PE from PE caused by other diseases can be challenging. MicroRNAs are popular biomarkers given their stable expression in tissue and fluid. MicroRNAs have been analysed in PE cytology samples for the diagnosis of MPM but have not been measured in frozen/fresh PE. We hypothesise that microRNAs expressed in PE are biomarkers for MPM. TaqMan OpenArray was used to analyse over 700 microRNAs in PE cells and supernatants from 26 MPMs and 21 other PE-causing diseases. In PE cells, combining miR-143, miR-210, and miR-200c could differentiate MPM with an area under the curve (AUC) of 0.92. The three-microRNA signature could also discriminate MPM from a further 40 adenocarcinomas with an AUC of 0.9887. These results suggest that the expression of miR-143, miR-210, and miR-200c in PE cells might provide a signature for diagnosing MPM
Observations on the meat-eating behavior of wild bonobos (Pan paniscus) at Wamba, Republic of Zaire
Increased circulating miR-625-3p
INTRODUCTION:
We investigated the ability of cell-free microRNAs (miRNAs) in plasma and serum to serve as a biomarker for malignant mesothelioma (MM).
METHODS:
Using miRNA microarrays, we profiled plasma samples from MM patients and healthy controls. miRNAs with significantly different abundance between cases and controls were validated in a larger series of MM patients and in an independent series of MM patients using quantitative real-time polymerase chain reaction. Levels of candidate miRNAs were also quantified in MM tumor samples.
RESULTS:
We compared cell-free miRNA profiles in plasma from MM patients with healthy controls. Reviewing 90 miRNAs previously reported to be associated with MM, we found that the levels of two miRNAs, miR-29c* and miR-92a, were elevated in plasma samples from MM patients. In addition, we identified 15 novel miRNAs present at significantly higher levels in the plasma of MM patients. Further analysis of candidate miRNAs by real time-quantitative polymerase chain reaction confirmed that one of them, miR-625-3p, was present in significantly higher concentration in plasma/serum from MM patients and was able to discriminate between cases and controls, in both the original and the independent series of patients. MiR-625-3p was also found to be up-regulated in tumor specimens from a group of 18 MM patients, who underwent extrapleural pneumonectomy.
CONCLUSION:
Our data confirm the potential of miR-29c* and miR-92a as candidate tumor markers and reveal that miR-625-3p is a promising novel diagnostic marker for MM