Secondary defences

2018 ◽  
Author(s):  
Graeme D. Ruxton ◽  
William L. Allen ◽  
Thomas N. Sherratt ◽  
Michael P. Speed
Keyword(s):  
Life History ◽  
Social Interaction ◽  
Tree Of Life ◽  
Evolutionary Mechanisms ◽  
Predator Prey ◽  
Chemical Defences ◽  
Selection Of

In this chapter we consider defences that are usually deployed during, or just before, contact between a prey and its predator: so-called ‘secondary’ defences. Secondary defences are found right across the tree of life and therefore come in very many forms, including: 1.) chemical defences; 2.) mechanical defences; and 3.) behavioural defences. Here we review selected examples that provide useful illustrations of the ecological and evolutionary characteristics associated with secondary defences. We discuss costs of secondary defences, placing emphasis on the consequences of such costs, especially as they relate to forms of social interaction. We show also that the acquisition of secondary defences may modify niche, life history, and habitat range of prey animals and review a well-known and significant study of predator–prey co-evolution of defensive toxins of prey and resistance to those toxins in predators. We include a small selection of examples and ideas from the plant and microbe defence literature where we think a broader perspective is helpful. We begin the chapter by considering the evolutionary mechanisms that favour secondary defence evolution.

Identify This…

2009 ◽  
Vol 2 (2) ◽  
pp. 209-228 ◽  
Author(s):  
Leslie Rebecca Bloom ◽  
Amanda Reynolds ◽  
Rosemary Amore ◽  
Angela Beaman ◽  
Gatenipa Kate Chantem ◽  
...  
Keyword(s):  
Higher Education ◽  
Life History ◽  
Graduate Students ◽  
Women's Studies ◽  
Essential Elements ◽  
Women's Voices ◽  
Readers Theater ◽  
Creative Pedagogy ◽  
And Gender ◽  
Selection Of

Readers theater productions are meaningful expressions of creative pedagogy in higher education. This article presents the script of a readers theater called Identify This… A Readers Theater of Women's Voices, which was researched, written, and produced by undergraduate and graduate students in a women's studies class called Intersections of Race, Class, and Gender. Section one of the article reproduces the script of Identify This that was based on life history interviews with a diverse selection of women to illustrate intersectional identities. Section two briefly describes the essential elements of the process we used to create and perform Identify This.

scholarly journals Untangling the environmental from the dietary: dust does not matter

2016 ◽  
Vol 283 (1838) ◽  
pp. 20161032 ◽  
Author(s):  
Gildas Merceron ◽  
Anusha Ramdarshan ◽  
Cécile Blondel ◽  
Jean-Renaud Boisserie ◽  
Noël Brunetiere ◽  
...  
Keyword(s):  
Critical Role ◽  
Tooth Wear ◽  
Textural Analysis ◽  
Significant Determinant ◽  
Intrinsic Properties ◽  
Dental Microwear ◽  
Natural Conditions ◽  
Evolutionary Mechanisms ◽  
Food Items ◽  
Selection Of

Both dust and silica phytoliths have been shown to contribute to reducing tooth volume during chewing. However, the way and the extent to which they individually contribute to tooth wear in natural conditions is unknown. There is still debate as to whether dental microwear represents a dietary or an environmental signal, with far-reaching implications on evolutionary mechanisms that promote dental phenotypes, such as molar hypsodonty in ruminants, molar lengthening in suids or enamel thickening in human ancestors. By combining controlled-food trials simulating natural conditions and dental microwear textural analysis on sheep, we show that the presence of dust on food items does not overwhelm the dietary signal. Our dataset explores variations in dental microwear textures between ewes fed on dust-free and dust-laden grass or browse fodders. Browsing diets with a dust supplement simulating Harmattan windswept environments contain more silica than dust-free grazing diets. Yet browsers given a dust supplement differ from dust-free grazers. Regardless of the presence or the absence of dust, sheep with different diets yield significantly different dental microwear textures. Dust appears a less significant determinant of dental microwear signatures than the intrinsic properties of ingested foods, implying that diet plays a critical role in driving the natural selection of dental innovations.

Electrical Emissions in Gymnotus Carapo and Their Relation To Social Behavior

Behaviour ◽  
1970 ◽  
Vol 37 (1-2) ◽  
pp. 1-14 ◽  
Author(s):  
J.A. Valone
Keyword(s):  
Life History ◽  
Social Interaction ◽  
Social Behavior ◽  
Social Interactions ◽  
Physical Contact ◽  
Postural Responses ◽  
The Social ◽  
History Of ◽  
Electrical Stimuli

Abstract1. The relation between the social behavior and the electrical emissions of Gymnotus carapo is examined. 2. Members of the species Gymnotus carapo approach certain sources of electrical stimuli and, in a statistically significant number of instances, assume a stance parallel to the plane from which the stimuli originate. 3. The approach and postural responses elicited by electrical cues resemble those observed when two fish, placed in the same tank, interact socially. 4. Electrical cues therefore appear to facilitate certain social interactions in Gymnotus carapo. 5. The character of electrical emission in Gymnotus carapo appears to change as a function of certain social interaction: a. Interaction resembling aggression is accompanied by brief increases in the frequency of emission. b. The increases in frequency appear to be linked to thrusting movements. c. Fish interacting with one another appear to lock into a common frequency more often than fish that are not in physical contact with one another. d. During social interaction, one of the two fish is occasionally observed to halt emissions altogether. 6. The exact significance of the social behavior observed in the context of the life history of Gymnotus carapo is unknown.

scholarly journals Changes in group size during resource shifts reveal drivers of sociality across the tree of life

2020 ◽  
Author(s):  
Albert B. Kao ◽  
Amanda K. Hund ◽  
Fernando P. Santos ◽  
Jean-Gabriel Young ◽  
Deepak Bhat ◽  
...  
Keyword(s):  
Group Size ◽  
Social Benefit ◽  
Tree Of Life ◽  
Strong Indication ◽  
Evolutionary Mechanisms ◽  
Resource Abundance ◽  
Dominant Mechanism ◽  
Individual Fitness ◽  
Model Predictions ◽  
Optimal Group Size

ABSTRACTFrom biofilms to whale pods, organisms have repeatedly converged on sociality as a strategy to improve individual fitness. Yet, it remains challenging to identify the most important drivers—and by extension, the evolutionary mechanisms—of sociality for particular species. Here, we present a conceptual framework, literature review, and model demonstrating that the direction and magnitude of the response of group size to sudden resource shifts provides a strong indication of the underlying drivers of sociality. We catalog six functionally distinct mechanisms related to the acquisition of resources, and we model these mechanisms’ effects on the survival of individuals foraging in groups. We find that whether, and to what degree, optimal group size increases, decreases, or remains constant when resource abundance declines depends strongly on the dominant mechanism. Existing empirical data support our model predictions, and we demonstrate how our framework can be used to predict the dominant social benefit for particular species. Together, our framework and results show that a single easily measurable characteristic, namely, group size under different resource abundances, can illuminate the potential drivers of sociality across the tree of life.

Life on the edge: the ecology and life history of the tropidurine iguanid lizard Uranoscodon superciliosum

1990 ◽  
Vol 68 (7) ◽  
pp. 1366-1373 ◽  
Author(s):  
Jeffrey M. Howland ◽  
Laurie J. Vitt ◽  
Pamela T. Lopez
Keyword(s):  
Life History ◽  
Social Interaction ◽  
Sexual Dimorphism ◽  
Small Diameter ◽  
Habitat Specialization ◽  
Large Size ◽  
Tropical Wet Forest ◽  
History Of ◽  
Forest Streams ◽  
Small Forest

An Amazonian population of the iguanid lizard Uranoscodon superciliosum was studied in lowland tropical wet forest in central Pará, Brazil. These nonheliothermic lizards are restricted to densely vegetated habitats near (often over) water, particularly riverbanks and small forest streams, where they utilize small-diameter perches and feed on a wide variety of invertebrates, apparently at the water's edge. They mature at moderate to large size at an age of about 1.5 years. Production of moderate-sized clutches of eggs is seasonal, and reproduction and fat storage both cycle in association with rainfall and flooding. Although they occur in fairly high densities, social interaction is uncommon and sexual dimorphism is not pronounced. The ecology and life history of this lizard seem to be strongly influenced by the unusual habitat specialization.

Pattern Dynamics in a Spatial Predator–Prey Model with Nonmonotonic Response Function

2018 ◽  
Vol 28 (06) ◽  
pp. 1850077 ◽  
Author(s):  
Xiaoling Li ◽  
Guangping Hu ◽  
Zhaosheng Feng
Keyword(s):  
Response Function ◽  
Turing Instability ◽  
Spatiotemporal Pattern ◽  
Weakly Nonlinear ◽  
Predator Prey ◽  
Predator Prey Model ◽  
Pattern Dynamics ◽  
Spatial Systems ◽  
Different Types ◽  
Selection Of

In this paper, we study a diffusive predator–prey system with the nonmonotonic response function. The conditions on Hopf bifurcation and Turing instability of spatial systems are obtained. Near the Turing bifurcation point we apply the weakly nonlinear analysis to derive the amplitude equations of stationary pattern, to investigate the selection of spatiotemporal pattern. It shows that different types of patterns will occur in the model under various conditions. Numerical simulations agree well with our theoretical analysis when control parameters are in the Turing space. This study may provide some deep insights into the formation and selection of patterns for diffusive predator–prey systems.

scholarly journals Evolution in interacting species alters predator life-history traits, behaviour and morphology in experimental microbial communities

2020 ◽  
Vol 287 (1928) ◽  
pp. 20200652
Author(s):  
Johannes Cairns ◽  
Felix Moerman ◽  
Emanuel A. Fronhofer ◽  
Florian Altermatt ◽  
Teppo Hiltunen
Keyword(s):  
Life History ◽  
Prey Species ◽  
Rapid Evolution ◽  
Prey Type ◽  
Automated Image Analysis ◽  
Foraging Efficiency ◽  
Predator Prey ◽  
Evolving Systems ◽  
Interacting Species ◽  
Evolutionary Response

Predator–prey interactions heavily influence the dynamics of many ecosystems. An increasing body of evidence suggests that rapid evolution and coevolution can alter these interactions, with important ecological implications, by acting on traits determining fitness, including reproduction, anti-predatory defence and foraging efficiency. However, most studies to date have focused only on evolution in the prey species, and the predator traits in (co)evolving systems remain poorly understood. Here, we investigated changes in predator traits after approximately 600 generations in a predator–prey (ciliate–bacteria) evolutionary experiment. Predators independently evolved on seven different prey species, allowing generalization of the predator's evolutionary response. We used highly resolved automated image analysis to quantify changes in predator life history, morphology and behaviour. Consistent with previous studies, we found that prey evolution impaired growth of the predator, although the effect depended on the prey species. By contrast, predator evolution did not cause a clear increase in predator growth when feeding on ancestral prey. However, predator evolution affected morphology and behaviour, increasing size, speed and directionality of movement, which have all been linked to higher prey search efficiency. These results show that in (co)evolving systems, predator adaptation can occur in traits relevant to foraging efficiency without translating into an increased ability of the predator to grow on the ancestral prey type.

DENSITY AND PUPATION SITE OF APTEROUS FEMALE BAGWORMS, METISA PLANA (LEPIDOPTERA: PSYCHIDAE), INFLUENCE THE DISTRIBUTION OF EMERGENT LARVAE

1998 ◽  
Vol 130 (5) ◽  
pp. 603-613 ◽  
Author(s):  
Marc Rhainds ◽  
Gerhard Gries ◽  
Ahmad Saleh
Keyword(s):  
Life History ◽  
Oil Palm ◽  
Life History Trait ◽  
Density Dependent ◽  
Selective Pressures ◽  
Oil Palm Plantation ◽  
Interspecific Comparisons ◽  
Pupation Site ◽  
Selection Of

AbstractIn an oil palm plantation in northeast Sumatra, Indonesia, we tested the hypotheses that selection of pupation site by female bagworms, Metisa plana (Walker), influences the distribution of emergent larvae, and that intertree dispersal by larvae is density dependant. Similar intratree distributions of empty female pupal cases and early instars and significant regressions between numbers of female pupal cases and larvae per leaf for 36 out of 39 palms indicated that larvae generally remain on the same leaf where they emerged. Proportions of early instars per female pupal case decreased with increasing densities of female pupal cases per tree and were greater on trees surrounding most heavily infested palms, suggesting that intertree dispersal of early instars is density dependent. Interspecific comparisons of life history constraints between M. plana and the allopatric bagworm Oiketicus kirbyi (Guilding) reveal different selective pressures that may have converged and favoured the development of an identical life history trait.

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