At the end of the Palaeozoic Era, most species on Earth disappeared completely and the global sedimentary environment and biology changed dramatically. The Permian–Triassic boundary (PTB) was studied in three sections of the middle Upper Yangtze Platform, SW China: Xingwen well and Zhijin and Shangsi sections. These sections are characterized by carbonate-platform, toe-of-slope and basin facies, respectively. Detailed analysis of 100 closely spaced thin-sections revealed a total of 24 microfacies and 11 microfacies associations based on the dominant carbonate grain size and the skeletal material (type and proportion). Six bioassemblages are documented for the first time, spanning c. 1 Ma across the boundary succession, including normal, resurrected and miniaturized Permian biota, and cyanobacteria-dominated, survival post-crisis and neonatal Triassic biota. The Xingwen well indicated sedimentary evolution from a rimmed carbonate platform to a homoclinal carbonate ramp, as well as a sharp fall in sea level just prior to the PTB in the study area. The Zhijin section revealed a slope setting, in which toe-of-slope and middle-ramp microfacies are identified. The Shangsi section showed a complete evolution of basin and outer-ramp microfacies and bioassemblages. Fossil evidence showed that the Permian biota (trilobites, gastropods and phylloid algae) occurred in the uppermost Changhsingian stage and was overlain by biomicrites with miniaturized ostracods (< 0.2 mm in size). This indicated that the major extinction horizon is located up to 14 cm below the PTB, which lies in the middle–lower segments of the miniaturized ostracod layer.

In this paper we consider a scenario in which Carl Sagan's Copernican principle is more likely than its negation. Thus, assuming that the existence of an extraterrestrial intelligence (ETI) is reasonably likely, the paper considers the possibility of an ETI that is unable to recognize humans as intelligent beings. The paper presents the rationale for such an assumption. It also discusses the possible consequences for humanity of such a scenario. In this paper, we argue why the scenario under discussion is actually more positive for humanity than a scenario in which ETI would be capable of recognizing humanity as an intelligent species. We also point to feminist approaches to SETI issues exposing the role played by the specific evolutionary and developmental context of potential ETI.

We live in the epoch of explosive development of astrobiology, a novel interdisciplinary field dealing with the origin, evolution and the future of life. The relationship between cosmology and astrobiology is much deeper than it is usually assumed – besides a similarity in the historical model of development of these two disciplines, there is an increasing number of crossover problems and thematic areas which stem from considerations of Copernicanism and observation selection effects. Such a crossover area is both visualized and heuristically strengthened by introduction of the astrobiological landscape, describing complexity of life in the most general context. We argue that this abstract landscape-like structure in the space of astrobiological parameters is a concept capable of unifying different strands of thought and research, a working concept and not only a metaphor. By analogy with phase spaces of complex physical systems, we can understand the astrobiological landscape as a set of viable evolutionary histories of life in a particular region of space. It is a notion complementary to the classical concept of biological morphological space, underscoring the fact that modern astrobiology offers a prospect of both foundational support and vast extension of the domain of applicability of the Darwinian biological evolution. Such a perspective would strengthen foundations upon which various numerical models can be built; the lack of such quantitative models has often been cited as the chief weakness of the entire astrobiological enterprise.