Related Experiment Video
Updated: Sep 27, 2025
05:49
A Behavioral Assay for Investigating the Role of Spatial Memory During Instinctive Defense in Mice
Published on: July 21, 2018
9.7K
Defensive responses in invertebrates: Evolutionary and neural aspects
Giancarlo Carli1, Francesca Farabollini1
1Department of Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy.
Progress in Brain Research
|April 10, 2022
Summary
Defensive immobility, or tonic immobility (TI), evolved in higher animals, not lower invertebrates. This trait impacts survival and mating success, suggesting adaptive roles in both predator-prey and sexual selection dynamics.
Area of Science:
- Zoology
- Evolutionary Biology
- Animal Behavior
Background:
- Lower invertebrates display withdrawal behaviors like sinking and crumpling as defenses.
- Unlike higher phyla, lower invertebrates do not exhibit tonic immobility (TI).
- TI is a defensive strategy observed in animals with more complex nervous systems.
Purpose of the Study:
- To investigate the evolution and adaptive significance of tonic immobility (TI).
- To explore the relationship between TI, survival, and mating success.
- To understand the role of TI in both interspecific and intraspecific interactions.
Main Methods:
- Comparative analysis of defensive behaviors across invertebrate and higher animal phyla.
- Examination of prey-predator coevolutionary mechanisms.
- Genetic studies on insect TI heritability and its relation to boldness.
- Analysis of behavioral syndromes in beetle genetic lines with varying TI durations.
Main Results:
- Tonic immobility (TI) is present in higher animal phyla but absent in lower invertebrates.
- TI has coevolved with prey-predator interactions, leading to reciprocal phenotypic plasticity.
- In insects, TI variability is heritable and inversely correlated with boldness.
- Beetles with longer TI durations show increased survival but decreased mating success, indicating behavioral syndromes.
Conclusions:
- Tonic immobility (TI) represents an evolved defensive strategy in animals with complex nervous systems.
- TI has adaptive significance in predator-prey dynamics and may also play a role in sexual selection.
- The study highlights the interplay between defensive behaviors, survival, reproduction, and evolutionary pressures.
Keywords:
Morphological defenseNeural organizationSexual conflictSpecificity prey-predatorTI adaptationTI correlatesTI models in higher invertebratesTotal fitnessMore Related Videos
Related Concept Videos
02:26Defenses Against Pathogens and Herbivores
27.6K
Plants present a rich source of nutrients for many organisms, making it a target for herbivores and infectious agents. Plants, though lacking a proper immune system, have developed an array of constitutive and inducible defenses to fend off these attacks.
27.6K
02:39Predator-Prey Interactions
19.5K
Predators consume prey for energy. Predators that acquire prey and prey that avoid predation both increase their chances of survival and reproduction (i.e., fitness). Routine predator-prey interactions elicit mutual adaptations that improve predator offenses, such as claws, teeth, and speed, as well as prey defenses, including crypsis, aposematism, and mimicry. Thus, predator-prey interactions resemble an evolutionary arms race.
19.5K
01:20Evolutionary Psychology
478
Evolutionary psychology explores the origins of human behavior and mental processes by framing them within the context of natural selection, a theory famously propounded by Charles Darwin. This field asserts that many behaviors common across human societies — ranging from instinctive fear reactions to complex social interactions — arose as evolutionary adaptations. These adaptations enhanced the survival and reproductive success of our ancestors, thereby becoming embedded in the...
478
01:23Criticisms of the Evolutionary Perspective
167
In a study where individuals posing as strangers offered compliments and proposed casual sex to students, the responses differed significantly based on gender. Not a single woman accepted the proposal, while 70% of the men agreed. This outcome provides a useful scenario to explore through the lens of evolutionary psychology and social learning theory, highlighting the diverse perspectives on human sexual behaviors.
Evolutionary psychology provides one explanation for these findings, suggesting...
Evolutionary psychology provides one explanation for these findings, suggesting...
167
01:15Functional Brain Systems: Limbic System
4.1K
The limbic system, often called the "emotional brain," is a complex set of structures located deep within the brain. The intricate network of the limbic system supports a wide range of psychological functions, from emotional regulation to memory formation and sensory processing. This functional brain region encompasses specific parts of the diencephalon and the cerebrum, integrating the higher mental functions of the cerebral cortex with the primitive emotional responses of the deep brain...
4.1K
01:47Osmoregulation in Insects
16.7K
Malpighian tubules are specialized structures found in the digestive systems of many arthropods, including most insects, that handle excretion and osmoregulation. The tubules are typically arranged in pairs and have a convoluted structure that increases their surface area.
16.7K