In Biological Theory’s 17(4), December issue, Pierrick Bourrat presents a new approach for identifying cohesive wholes upon which natural selection can occur, and relatedly, whether a level of description pertains to units of selection. For these purposes he proposes the concepts of “functional nonadditivity” and “compositional stability” and discusses their applications to evolutionary transitions in individuality.

In a pair of related papers, Walter Veit explores the origins of consciousness, using a Darwinian approach to work towards an understanding of how the complex phenomenon may have arisen. In the first, he describes how the five-component categorization of Birch et al. (Trends Cog. Sci.; 2020): self-consciousness, synchronic experience diachronic experience, sensory experience, and evaluative experience, can be compared and measured in different species. In the second article, Veit interprets the life histories of nonhuman animals, specifically gastropods and arthropods, in relation to the five components and his own “pathological complexity thesis” (expounded in a forthcoming target article in BT).

In an essay proposing creation of a field of imagination studies that bridges the sciences and humanities, Stephen Asma argues that imagination is the “core operating system or cognitive capacity for humans… ground[ing] all our sense-making activities.” December’s issue also includes our second “Critical Concepts in Biological Theory” piece, by Ehud Lamm and Sophie Julia Veigl, describing the new centering of chromatin organization for the understanding of eukaryotic gene expression induced by the findings of the “Encyclopedia of DNA Elements” (ENCODE) project, and an article by Ron Aharoni taking a brief look at  Darwin’s insights into the functional-anatomical bases of what the author terms antithetical emotional expressions.

Also in December, Vidyanand Nanjundiah, R. Geeta, and Valentin Suslov contribute a new essay to the “Classics in Biological Theory” collection. They discuss the 1922 paper “The Law of Homologous Series in Variation” by N.I. Vavilov, one of the major figures of pre-Revolutionary and early Soviet biology, who later became a victim of Stalinist-Lysenkoist suppression. Vavilov’s paper raised the question, still a burning one in evolutionary developmental biology, of how much of the morphological similarities in disparate lineages can be attributed to parallel adaptive evolution, and how much to shared generic determination by chemistry and physics.

The issue closes with a list of referees from the past year, thanking them and all the scholars who provide reviews to the journal for their tremendous help.