Biology subjects

Wilkins, L.

Publications and source records attributed to Wilkins, L..

4 recordsLinked to original sources

bioRxiv2022

Decision-making strategies of a coral reef fish given changing visual signal reliability

Making informed decisions is fundamental to intelligent life and is crucial to survival. The problem many organisms face, is how to make optimal decisions in the face of incomplete, unreliable, or conflicting information. In many aquatic environments, fish use visual information to guide key behaviours, but the environment itself can alter or mask the very signals they rely on. Here, we asked how a highly visual species, Rhinecanthus aculeatus, responds to a learned discrimination task as signal reliability decreases, and whether probabilistic information gained during previous experience can be incorporated into their decision strategy. Fish were first trained to select a target (dark grey circle) from three distractors (light grey circles). In the first experiment, the target was more likely to appear in one of four possible stimulus positions. In the second experiment, the target appeared in all positions equally. In a series of trials, the difference in brightness between the target and distractors was reduced until all four stimuli were identical. We found that target selection accuracy decreased with decreasing target and distractor disparity. However, in Experiment 1 where the target was more likely to be in one position, fish increasingly selected stimuli in the biased position as target selection accuracy decreased, but not in Experiment 2. These results demonstrate 1) that fish learned more than a simple select/avoid rule based on stimulus brightness, but also integrated information (stimulus position) that could be considered ancillary to the primary task. 2) Fish can learn probability distributions and apply this knowledge as uncertainty increases, ultimately increasing the overall frequency of correct choices. Our results reveal that probabilistic decision rules can be used by fish when visual information is unreliable, indicating a possible mechanism for decision making given the inherent noise in incoming sensory information.

animal behavior and cognition↗

bioRxiv2019

The Statistical Foundations of Colour Space

The idea of a colour space where distance corresponds to discriminability has been fundamental to colour vision research since the 19th century. Despite their long-standing success there is a contradiction between the geometric framework that is typically used in these spaces (a particular application of Riemannian geometry) and a view of the transduction of sensory information as the result of a stochastic process. When this is made explicit, a subtly different approach is suggested which turns out to provide a general, and more complete framework for colour space. It is argued further that not only is a contradiction avoided, but that this framework is both intuitive and of real practical value, in particular for researchers interested in the visual behaviour and ecology of animals.

animal behavior and cognition↗

bioRxiv2019

Object Colours, Material Properties and Animal Signals

Colour is commonly regarded as an absolute measure of object properties, but most work on visual communication signals is concerned with colour differences, typically scaled by just noticeable differences (JNDs). Object colour solids represent the colour gamut of reflective materials for an eye. The geometry of colour solids reveals general relationships between colours and object properties which can explain why certain colours are significant to animals and evolve as signals. We define a measure of colour vividness, such that points on the surface are maximally vivid and the grey centre is minimally vivid. We show that a vivid colour for one animal is likely to vivid for others, and highly vivid colours are less easily mimicked than less vivid colours. Further, vivid colours such as black, white, red, blue and light, unsaturated shades are produced pure or orderly materials. This kind of material needs to created and maintained against entropic processes that would otherwise degrade or destroy them. Vivid coloration is therefore indicative of ecological affordance or biological function, so that it is valuable to have attentional biases towards these colours regardless of any specific significance.

animal behavior and cognition↗

bioRxiv2018

There and back again: metagenome-assembled genomes provide new insights into two thermal pools in Kamchatka, Russia

Culture-independent methods have contributed substantially to our understanding of global microbial diversity. Recently developed algorithms to construct whole genomes from environmental samples have further refined, corrected and revolutionized the tree of life. Here, we assembled draft metagenome-assembled genomes (MAGs) from environmental DNA extracted from two hot springs within an active volcanic ecosystem on the Kamchatka peninsula, Russia. This hydrothermal system has been intensively studied previously with regard to geochemistry, chemoautotrophy, microbial isolation, and microbial diversity. Using a shotgun metagenomics approach, we assembled population-level genomes of bacteria and archaea from two pools using DNA that had previously been characterized via 16S rRNA gene clone libraries. We recovered 36 MAGs, 29 of medium to high quality, and placed them in the context of the current microbial tree of life. We highlight MAGs representing previously underrepresented archaeal phyla (Korarchaeota, Bathyarchaeota and Aciduliprofundum) and one potentially new species within the bacterial genus Sulfurihydrogenibium. Putative functions in both pools were compared and are discussed in the context of their diverging geochemistry. This study can be considered complementary to foregoing studies in the same ecosystem as it adds more comprehensive information about phylogenetic diversity and functional potential within this highly selective habitat.

microbiology↗