Category: Uncategorized

GRAVITROPISM. "It has to be noted that gravitropism, albeit it can be described as a purely synchronous orientation towards an extrinsic gravity vector, apparently involves lasting imprints of the environmental stimulus at least in some plant organs, although it is unclear whether this “memory” is accessed also under natural conditions, or only in some experimental setups." https://lnkd.in/dfsCv77 View in LinkedIn

Flowstone is the same calcite material that the mediaeval sculptors used to make their remarkable alabaster creations. View in LinkedIn

TWO OPTIONS. "For instance, light-driven morphogenesis of tree crowns, or exploration of patchy environment by foraging clonal plants, can be convincingly approximated by a model that only requires the individual branches or ramets to avoid collision with congeneric neighbors and to adjust their branching and runner production according to present light conditions." https://lnkd.in/dfsCv77 View in LinkedIn

STARTLING REALIZATION. "Thanks to the impressive models constructed, in particular, by P. Prusinkiewicz and co-workers, we have to accept the startling realization that history, if included in the model at all, takes often only the form of constraints carried by the environment (such as e.g., shading by branches or leaves of the developing plant) rather than memory of the developing individual itself." https://lnkd.in/dfsCv77 View in LinkedIn

DISCRIMINATING ASSESSMENT. "Not all seemingly convincing examples of “intelligent” plant behavior pass our memory model test. In particular, orientation towards extrinsic cues such as light or gravity can be often described by models that only require perception of, and reaction to, synchronous cues and stimuli, without any reference to the past." An impressive and discriminating assessment. https://lnkd.in/dfsCv77 View in LinkedIn

HABITUATION. "In addition to Mimosa, habituation has been found in the carnivorous plant Drosera (sundew). When sundew tentacles are repeatedly stimulated they stop curling toward the stimulus. In addition to sundew, Applewhite cites an experiment by Darwin reportedly showing habituation in the passion flower (Passiflora gracilis)." https://lnkd.in/dsHa-Px View in LinkedIn

STRESS VS HABITUATION. "These are quite different from habituated responses like the one shown by the Mimosa plants in this study, where an input to the gene may produce a behavioral output that operates as a negative regulator of the gene, imposing an inhibitory epigenetic marking which, in turn, leads to a smaller behavioral response when recurring stimulations of the same kind activate that gene [i.e. memory of inhibitory modifications and recall." https://lnkd.in/dH68RKn View in LinkedIn

FROM RADIAL TO BILATERAL SYMMETRY. "The chordate sagittal plane is perpendicular to the sagittal plane primitive for the bilaterally symmetrical metazoans (Bilateria). The earliest metazoans, when symmetrical at all, were probably radial in symmetry. The axis of symmetry was vertical and the mouth, when present, opened either upward or downward." https://lnkd.in/dXzuUmP View in LinkedIn

DELAYED PHENOTYPIC RESPONSE. "It should be cautiously noted here that these stress-induced changes in plant response resulting from previous experiences involve a priming input that modifies chromatin patterns but does not lead to an immediate phenotypic response [i.e. memory with delayed output." https://lnkd.in/dH68RKn View in LinkedIn

FRAGMENT FROM NATURE considers the question of the evolution of bilateral symmetry in animals. In our universe, symmetry is very important. Symmetry breaking in physics is critical for many phenomena. Quite why mirror imagery, and with it, balance, is so important is an interesting question. In biology, symmetry is a subject that has occupied scientists for a long time. During this weekend, we will touch on some of the highlights of their thinking. View in LinkedIn