Spider vs. Guns: Expectancy and Attention Biases to Phylogenetic Threat Do Not Extend to Ontogenetic Threat
0
Citation
0
Reference
10
Related Paper
Abstract:
Attention bias plays an important role in specific fears and phobias. Previous studies revealed that a-priori expectancies affect attention toward neutral stimuli (e.g., birds), but not threatening stimuli (e.g., spiders). The aim of the current study was to test whether this selective influence of expectancies on attention is specific to phylogenetic threat (i.e., spiders) or whether it can be generalized to ontogenetic threat (i.e., guns). Correspondingly, we directly compared expectancy effects on attentional allocation to phylogenetically vs. ontogenetically threatening stimuli. To this aim, expectancies were manipulated by presenting a cue indicating the likelihood of the appearance of a deviant picture in a visual search array. The array included eight distractors and one neutral (phone/bird) or threatening (gun/spider) deviant picture. In a comprehensive design, we examined the effects of stimulus type (phylogenetic/ontogenetic) and visual background (white and sterile/complex and ecological). Individual differences such intolerance of uncertainty and spider fear were also measured. Results showed that attention bias toward spiders does not extend to threatening ontogenetic stimuli (i.e., guns). Our previous findings on attention bias toward spiders were replicated and a correlation was found between attention bias toward spiders and pre-existing fear of spider levels. Additionally, a correlation was found between fear of spiders and intolerance of uncertainty. Together, these results suggest that expectancy and attentional processes may differ between ontogenetic and phylogenetic threat. Importantly, the effects of expectancy on attentional allocation depend on an interaction between the type of threat (ontogenetic/phylogenetic), visual factors, and individual differences.Comparisons of macromolecular sequences offer the greatest potential for inferring phylogenetic relationships spanning the diversity of extant life (Zuckerkandl and Pauling 1965). In addition, molecular comparisons promise to provide insights into the character of the most recent common ancestor of present-day species and the evolution of various metabolic abilities.
Ancestor
Phylogenetic diversity
Cite
Citations (241)
The primary function of a spider’s web is to capture prey.The structure of a web can reflect the foraging investment and strategy the spider has taken.In this study,we examined webs from different sized spiders.Results indicate that among spiders under 200 mg,there exists a positive relation between the spider’s mass and the capture thread length,capture spiral space,and capture area.This relationship was not seen in spiders larger than 200 mg.The stabilimentum was only found among spiders above a certain weight (in our study,the smallest spider having a stabilimentum was 22.7 mg) and total stabilimentum area was related to the spider’s mass.Furthermore,there was a negative relationship between the radius of the web and the spider’s mass.In spiders under 200 mg,there was a negative relationship between spider mass and the ratio of the upper capture thread length to lower the capture thread length.These results are consistent with our hypothesis that changes in web structure reflect the foraging investments and strategies of different sized spiders.
Cite
Citations (1)
Life span
Cite
Citations (11)
Stegodyphus sarasinorum Karsch is a Sri Lankan social spider that exhibits communal predation and feeding. A spider's feeding time is dependent on its position in the feeding sequence, with early feeders feeding longer than those arriving later. Feeding time per spider does not decrease with increasing group size when compared with a given feeding position, temporally speaking. The first spider to feed is the only individual whose feeding time is not shortened by conspecifics.
Cite
Citations (20)
Once there was a kuia who made mats and baskets. In the corner of her kitchen lived a spider who made webs. Since its publication in 1981, Patricia Grace and Robyn Kahukiwa's The Kuia and the Spider has become a New Zealand classic.
Cite
Citations (11)
In this short paper, we report the predation of an orb-weaving spider Neoscona sp. (Araneae: Araneidae) by a corinnid sac spider Corinnomma severum (Araneae: Corinnidae) from Thailand. To the best of our knowledge, this is the first report of predation of web-building spider by a spider of the genus Corinnomma observed in the field.
Orb (optics)
Weaving
Cite
Citations (1)
Cite
Citations (0)
We propose an approach for identifying microinversions across different species and show that microinversions provide a source of low-homoplasy evolutionary characters. These characters may be used as “certificates” to verify different branches in a phylogenetic tree, turning the challenging problem of phylogeny reconstruction into a relatively simple algorithmic problem. We estimate that there exist hundreds of thousands of microinversions in genomes of mammals from comparative sequencing projects, an untapped source of new phylogenetic characters.
Tree (set theory)
Cite
Citations (45)
Abstract Many species of spiders move from one location to another using a remarkable aerial dispersal “ballooning”. By ballooning, spiders can reach distances as far as 3200 km and heights of up to 5 km. Though a large number of observations of spider ballooning have been reported, it remains a mysterious phenomenon due to the limited scientific observation of spider ballooning in the field, high uncertainties of the meteorological conditions and insufficient controlled laboratory experiments. Most of the ballooning spiders are spiderlings and spiders under 3 mm in length and 0.2 to 2 mg in mass with a few exceptions of large spiders (over 3 mm in length, over 5 mg in mass). What physical mechanism dominates the three stages of spider ballooning — take-off, flight, and settling? Many factors have been identified to influence the physical mechanism, including a spider’s mass, morphology, posture, the silken dragline properties, and local meteorological conditions (e.g., turbulence level, temperature and humidity). A thorough understanding of the roles of key parameters is not only of ecological significance but also critical to advanced bio-inspired technologies of airborne robotic devices. This work aims to determine how the dragline length and spider mass affect the interaction of the spider-dragline system in the free-fall scenario. Experiments using a thread of different lengths and a sphere of different masses to mimic the spider-dragline were carried out. The first sets of tests focused on the spider-dragline system, rather than the fluid flow. High-speed images of a spider-dragline falling in a closed container of air were recorded with 1500 frames per second at Reynolds numbers of several thousand, based on the spider dragline and the local relative velocity. Image data allow for tracking the vertical velocities and acceleration of the spider-dragline, as well as the drag force acting on the spider-dragline. Terminal velocities in the settling stage are compared with estimates using various fluid dynamics models in previous work. Such results under controlled laboratory conditions are expected to shed lights on the intriguing flow physics of spider ballooning at the settling stage and to inform future experiments and numerical models.
Ballooning
Cite
Citations (2)