Arts et pensée dans l’évolution humaine

Myth and beauty come together to transmit original stories. Music transmits emotion and is found worldwide; it has always been present. Performances of rhythm and dance unite the group and accompany ceremonies. Art also includes anatomy, enabling the body to be harmonised and integrated within social codes. Images use the play of morphemes (elements of the form) and they result from the combination of support and graphical illusion. The icon (representation) turns into schemas while preserving its original meaning. The secondary variations of the forms of images indicate the way in which the worldview is maintained in each community. Symbols have contingent meanings, but their regularity and permanence also demonstrate the universal force that they occupy in the human spirit. Signs and images maintain continuous structural components, such as the elements of a tale. In all of these forms, art participates in the realisation of rituals that punctuate religious life. The logical structure of the figured scenes shows that they illustrate mythical tales.     

Des gènes à la culture : introduction

Human thought participates in cosmic matter, which it extends. Bipedalism favored the use of tools, their conception and utilization, as a stimulant for the development of thinking. Fire acted as a weapon, both physically and metaphysically, against natural constraints. It was the symbol and attribute of such conquest, and humankind defied the gods. The forms created by the tools were extracted out of a void and then given to humanity to forge their destiny. The flexibility acquired by the preparation of flakes and by the use of hafts evidences the planning capacities and total autonomy achieved in the modes of existence. The first “machines”, such as the bow, gave the mind the conviction of absolute power, extending in distance and speed, the attribute of kings and gods. The ways of life combined between animals, nature and humans offer infinitely varied means of subsistence, autonomous from natural determinism, imposed by each component considered separately. The intimate relationship between human thought and animal behavior takes on the strength of a tradition, similarities between customs and genes require a reciprocal approach that is still in its infancy today.     

Des steppes aux déserts, à l’Aurignacien. Les hommes modernes venus d’Asie

From east to west, Aurignacian populations and civilizations moved into Europe during dry and cold climatic conditions. The zones of origin in the Middle East at that time had a steppic environment with large fauna that were rich caloric resources. Alongside many other examples, this new cultural unit has strict parallels that are clearly evidenced at Jabrud (Syria) and Yafteh (Iran). Now a desert region, during the Aurignacian this vast geographic and ethnic region extended on both sides of the Central Zagros Mountains, towards Central Asia where immense steppes seem having formed the epicenter.     

Detecting selected haplotype blocks in evolve and resequence experiments

Shifting from the analysis of single nucleotide polymorphisms to the reconstruction of selected haplotypes greatly facilitates the interpretation of evolve and resequence (E&R) experiments. Merging highly correlated hitchhiker SNPs into haplotype blocks reduces thousands of candidates to few selected regions. Current methods of haplotype reconstruction from Pool‐seq data need a variety of data‐specific parameters that are typically defined ad hoc and require haplotype sequences for validation. Here, we introduce haplovalidate, a tool which detects selected haplotypes in Pool‐seq time series data without the need for sequenced haplotypes. Haplovalidate makes data‐driven choices of two key parameters for the clustering procedure, the minimum correlation between SNPs constituting a cluster and the window size. Applying haplovalidate to simulated E&R data reliably detects selected haplotype blocks with low false discovery rates. Importantly, our analyses identified a restriction of the haplotype block‐based approach to describe the genomic architecture of adaptation. We detected a substantial fraction of haplotypes containing multiple selection targets. These blocks were considered as one region of selection and therefore led to underestimation of the number of selection targets. We demonstrate that the separate analysis of earlier time points can significantly increase the separation of selection targets into individual haplotype blocks. We conclude that the analysis of selected haplotype blocks has great potential for the characterization of the adaptive architecture with E&R experiments.     

Protein kinase C isozymes have distinct roles in neural induction and competence in Xenopus.

The restricted ability of embryonic tissue to respond to inductive signals is controlled by a poorly understood phenomenon, termed competence. In Xenopus, dorsal ectoderm is more competent than ventral ectoderm to become induced to neural tissue. We tested whether the Xenopus protein kinase C (PKC) isozymes alpha and beta have a role in neural induction and competence. We found that PKC alpha is predominantly localized in dorsal ectoderm, whereas PKC beta is uniformly distributed. Overexpression of PKC beta conveys a higher propensity for neural differentiation to both dorsal and ventral ectoderm, but their difference in competence remains. However, ectopic expression of PKC alpha elevates the level of neural competence of ventral ectoderm to that of dorsal ectoderm. These data indicate that different PKC isozymes have distinct roles in mediating both neural induction and competence.