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<jats:p>Sibert and Rubin (Reports, 4 June 2021, p. 1105) report an early Miocene extinction in pelagic sharks based on the loss of shark denticle diversity in two widely separated deep-sea sediment cores. We assert that the pattern observed is not a consequence of extinction but results from shifting species ranges induced by global current reorganization.</jats:p>

<jats:p> Naylor <jats:italic>et al</jats:italic> . argue that the existence of multiple denticle types within a single species precludes the use of this metric as a measure of the decline of multiple shark species. We show that species-level shark diversity would have to decrease by &gt;90% to account for the observed &gt;70% denticle extinction, implying that the early Miocene shark extinction was larger than previously recognized. </jats:p>

<jats:title>Surveying brain interneuron development</jats:title> <jats:p> As transient structures in early brain development, the ganglionic eminences generate dozens of different types of interneurons that go on to migrate throughout and weave together the developing brain. Shi <jats:italic>et al</jats:italic> . analyzed human fetal ganglionic eminences. Single-cell transcriptomics revealed unexpected diversity in the types of progenitor cells involved. The human ganglionic eminence depends more heavily on intermediate progenitor cells as workhorses than does the developing neocortex, with its greater reliance on radial glial cells. —PJH </jats:p>

<jats:title>Deep learning for protein interactions</jats:title> <jats:p> The use of deep learning has revolutionized the field of protein modeling. Humphreys <jats:italic>et al</jats:italic> . combined this approach with proteome-wide, coevolution-guided protein interaction identification to conduct a large-scale screen of protein-protein interactions in yeast (see the Perspective by Pereira and Schwede). The authors generated predicted interactions and accurate structures for complexes spanning key biological processes in <jats:italic>Saccharomyces cerevisiae</jats:italic> . The complexes include larger protein assemblies such as trimers, tetramers, and pentamers and provide insights into biological function. —VV </jats:p>

<jats:title>ESCRTing lenses away from senescence</jats:title> <jats:p> ESCRT proteins control membrane fusion in various key cellular processes, but the mechanisms involved are still incompletely understood. Gulluni <jats:italic>et al</jats:italic> . report that ESCRT recruitment at the cytokinetic bridge is mediated by the binding of an ESCRT-II subunit to the signaling lipid phosphatidylinositol 3,4-bisphosphate (see the Perspective by Brill and Wilde). This pathway acts in parallel to a known cascade driven by a protein called ALIX, but its failure is sufficient to lead to premature senescence in the lens of fish, mouse, and human eyes, where ALIX is expressed at lower levels. These results point to an evolutionarily conserved pathway for the cell-specific control of cytokinesis that serves to protect from senescence and the early onset of cataracts. —SMH </jats:p>

<jats:p>Academic freedom is under fire across the world—from Hong Kong, where the Chinese government’s crackdown on open discussion has spurred an exodus of scholars from universities, to the United States, where there is a rising tide of anti-intellectualism and assaults on free inquiry. The effort to undermine this cornerstone of American democracy has been driven by former President Trump and his administration, members of Congress, state governors, and legislators. Alas, it also comes from faculty and students on the ideological right and left, and even from some presidents of the country’s research universities. These are powerful forces that must be overcome.</jats:p>

<jats:p>Institutions of higher education are valued by democracies because of their civic goal—to foster in the next generation of citizens a regard for individual freedoms and rights, principled debates, and tolerance for opposing opinions. The leaders of these institutions are expected to demonstrate their commitment to these values by supporting academic freedom—the ability of faculty, staff, and students to challenge wisdom, explore new ideas, and advance knowledge through free inquiry. But lately, some university administrators have been responding to the ever more polarized political climate by giving lip service to academic freedom while playing politics—either ignoring or playing both sides of conflicts that threaten to undermine the very tradition of free and diverse thinking and discourse.</jats:p>

<jats:p>New variant appears to evade immunity and shows signs of spreading more rapidly</jats:p>