We hypothesize that as one of the most consequential events in evolution, primary endosymbiosis accelerates lineage divergence, a process we refer to as the endosymbiotic ratchet. Our proposal is supported by recent work on the photosynthetic amoeba, Paulinella, that underwent primary plastid endosymbiosis about 124 Mya. This amoeba model allows us to explore the early impacts of photosynthetic organelle (plastid) origin on the host lineage. The current data point to a central role for effective population size (Ne) in accelerating divergence (...) post‐endosymbiosis due to limits to dispersal and reproductive isolation that reduce Ne, leading to local adaptation. We posit that isolated populations exploit different strategies and behaviors and assort themselves in non‐overlapping niches to minimize competition during the early, rapid evolutionary phase of organelle integration. The endosymbiotic ratchet provides a general framework for interpreting post‐endosymbiosis lineage evolution that is driven by disruptive selection and demographic and population shifts. Also see the video abstract here: https://youtu.be/gYXrFM6Zz6Q. (shrink)

The article focuses on radiation dosimetry, which made use of the photographic film known as Type 2 Monitoring Film (Kodak) to detect and measure harmful ionizing radiation. It explores the implications of the demise of this technology in relation to Henri Van Lier's critique of photographic indexicality in his paper "Towards a Philosophy Instigated by Photography". It notes that the demise of indexical theories of photographic film can be aligned to the demise of the personal monitoring film. It states that (...) dosimetry reveals the limitation of energetic effects in a superabundant field. (shrink)

This article elaborates a theory of rhythm in relation to photography and, in particular, argues for the importance of rhythm in the theorization of photographic temporality. The approach taken breaks with a number of significant strands in contemporary photography theory, namely, Aristotelian-influenced modes of formalist criticism, dualistic formulations of representation and definitions of photographic temporality based on its difference to cinema. Through an interrogation of definitions of rhythm, the article examines, first, a formalist heritage from Aristotle to Lessing and evident (...) in Greenberg that assumes a naturalistic definition of rhythm based on linearity, regularity and anthropomorphic essentialism. The second strand is described through Frye's anticipation of a different rhythm, lyricism, that problematically compounds the subject as an entity defined in a dualistic paradigm. Against this background the article elaborates the possibilities inherent in Deleuze's notion of crystal time a rhythm of energetic intensity not dependent on linear temporality or subjectivism as a further, more credible, theorization of rhythmic temporality-as-texture. (shrink)