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Plagiognathops microlepis is an economic freshwater fish in the subfamily Xenocyprinae of Cyprinidae. It is widely distributed in the freshwater ecosystem of China, with moderate economic value and broad development prospects. However, the lack of genomic resources has limited our understanding on the genetic basis, phylogenetic status and adaptive evolution strategies of this fish. Here, we assembled a chromosome-level reference genome of P. microlepis by integrating Pacbio HiFi long-reads, Illumina short-reads and Hi-C sequencing data. The size of this genome is 1004.34 Mb with a contig N50 of 38.80 Mb. Using Hi-C sequencing data, 99.59% of the assembled sequences were further anchored to 24 chromosomes. A total of 578.91 Mb repeat sequences and 28,337 protein-coding genes were predicted in the current genome, of which, 26,929 genes were functionally annotated. This genome provides valuable information for investigating the phylogeny and evolutionary history of cyprinid fishes, as well as the genetic basis of adaptive strategies and special traits in P. microlepis. [ABSTRACT FROM AUTHOR]

Intense public interest in scientific claims about COVID-19, concerning its origins, modes of spread, evolution, and preventive and therapeutic strategies, has focused attention on the values to which scientists are assumed to be committed and the relationship between science and other public discourses. A much discussed claim, which has stimulated several inquiries and generated far-reaching political and economic consequences, has been that SARS-CoV-2 was deliberately engineered at the Wuhan Institute of Virology and then, either inadvertently or otherwise, released to the public by a laboratory worker. This has been pursued despite a clear refutation, through comprehensive genomic analysis, of the hypothesis that the virus was deliberately engineered and the failure of detailed investigations to identify any evidence in support of a laboratory leak. At the same time a substantial, established body of knowledge about the many factors underlying the emergence of novel zoonotic diseases has been largely ignored—including climate change and other mechanisms of environmental destruction, tourism, patterns of trade, and cultural influences. The existence and conduct of these debates have raised questions about the vulnerability of science to manipulation for political purposes. Scientific discourses are vulnerable because: (i) claims can be made with no more than probabilistic force; (ii) alleged "facts" are always subject to interpretation, which depends on social, ethical, and epistemological assumptions; and (iii) science and scientists are not inherently committed to any single set of values and historically have served diverse, and sometimes perverse, social and political interests. In the face of this complexity, the COVID-19 experience highlights the need for processes of ethical scrutiny of the scientific enterprise and its strategic deployment. To ensure reliability of truth claims and protection from corrupting influences robust ethical discourses are required that are independent of, and at times even contrary to, those of science itself. [ABSTRACT FROM AUTHOR]

The Ediacaran Period (~635–539 Ma) is marked by the emergence and diversification of complex metazoans linked to ocean redox changes, but the processes and mechanism of the redox evolution in the Ediacaran ocean are intensely debated. Here we use mercury isotope compositions from multiple black shale sections of the Doushantuo Formation in South China to reconstruct Ediacaran oceanic redox conditions. Mercury isotopes show compelling evidence for recurrent and spatially dynamic photic zone euxinia (PZE) on the continental margin of South China during time intervals coincident with previously identified ocean oxygenation events. We suggest that PZE was driven by increased availability of sulfate and nutrients from a transiently oxygenated ocean, but PZE may have also initiated negative feedbacks that inhibited oxygen production by promoting anoxygenic photosynthesis and limiting the habitable space for eukaryotes, hence abating the long-term rise of oxygen and restricting the Ediacaran expansion of macroscopic oxygen-demanding animals. Using Hg isotopes, the authors find that repeated invasion of toxic, H2S-rich water into the marine photic zone of the Ediacaran ocean may have inhibited the rise of oxygen and delayed the expansion of early animals. [ABSTRACT FROM AUTHOR]

How did Chinese scientific intellectuals react to the dispute over evolutionary mechanisms during the period of the "eclipse of Darwinism"? This is my focal question. To answer it, I survey the attitudes of three groups of people toward the debate in the early decades of the twentieth century: Chinese paleontologists and their general embrace of the anti-Darwinian position, a group of non-specialists (or semi-specialists) and their assertion of a "revival of Lamarckism," and the American-trained Chinese biologists and their typical agnostic stance toward the antagonism between Darwinism and the mutation theory. Different concerns or motivations underlay these three different stances. There were also interesting attempts by biologists like Chen Zhen to exploit some recreational breeding traditions like goldfish breeding peculiar to China to participate in the dispute more directly. [ABSTRACT FROM AUTHOR]