Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Predator-Prey Interactions

Predator-Prey Interactions

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.

Limits to Natural Selection

Limits to Natural Selection

Organisms that are well-adapted to their environment are more likely to survive and reproduce. However, natural selection does not lead to perfectly adapted organisms. Several factors constrain natural selection.

Lethal Alleles

Lethal Alleles

Agouti: A Lethal Allele
Lucien Cuénot discovered lethal alleles in 1905 while studying the inheritance of coat color in mice. The agouti gene is responsible for the color of the coat in mice. This gene codes for an agouti-signaling protein, which is responsible for melanin distribution in mammals. The wild-type allele gives rise to gray-brown coat color in mice, while the mutant allele gives rise to yellow coat color. In addition to coat color, the agouti gene is associated with the yellow...

Microbial Interactions: Predation

Microbial Interactions: Predation

Microbial predation refers to the process by which one microorganism kills and consumes another to obtain nutrients and energy. It encompasses both bacterial and protozoan predators. This interaction plays a crucial role in shaping microbial communities and regulating nutrient cycling.Bacterial Predators: Epibiotic vs. EndobioticBacterial predators are classified based on their mode of attack as either epibiotic or endobiotic. Epibiotic predators, such as Vampirococcus, attach to the surface of...

Frequency-dependent Selection

Frequency-dependent Selection

When the fitness of a trait is influenced by how common it is (i.e., its frequency) relative to different traits within a population, this is referred to as frequency-dependent selection. Frequency-dependent selection may occur between species or within a single species. This type of selection can either be positive—with more common phenotypes having higher fitness—or negative, with rarer phenotypes conferring increased fitness.

Conservation of Small Populations

Conservation of Small Populations

Small population sizes put a species at extreme risk of extinction due to a lack of variation, and a consequent decrease in adaptability. This weakens the chances of survival under pressures such as climate change, competition from other species, or new diseases. Large populations are more likely to survive pressures such as these, as such populations are more likely to harbor individuals that have genetic variants that are adaptive under new stresses. Small populations are much less likely to...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Predictions From Evolutionary Theory for Urban Environments.

Evolutionary applications·2026

Same author

Evolving nature-based solutions for urban resilience.

Science (New York, N.Y.)·2026

Same author

Spatially-nested topologies stabilize meta-ecosystems via cross-scale source-sink dynamics.

Ecology·2026

Same author

Best practices for moving from correlation to causation in ecological research.

Nature communications·2026

Same author

Urban freshwater salinization reshapes Erythemis simplicicollis (Odonata: Libellulidae) life history timing and predator-prey interactions.

Environmental entomology·2026

Same author

Managing Ecosystem Transitions Using a RAD Framework Incorporating Ecological, Social, and Economic Contexts.

Environmental management·2026

Search research articles

Related Experiment Video

Updated: May 26, 2026

A Real-Time Interactive System for Studying Confrontational Pursuit Behavior in Rodents

A Real-Time Interactive System for Studying Confrontational Pursuit Behavior in Rodents

Published on: May 16, 2025

The deadly effects of "nonlethal" predators.

Shannon J McCauley¹, Locke Rowe, Marie-Josée Fortin

¹Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario M5S 3B2, Canada. smccauley@calpoly.edu

|December 15, 2011

Summary

Predator presence alone, even without attack, increases dragonfly larvae mortality and metamorphic failure. These nonconsumptive effects highlight stress responses impacting survival during critical life stages.

More Related Videos

Linking Predation Risk, Herbivore Physiological Stress and Microbial Decomposition of Plant Litter

Linking Predation Risk, Herbivore Physiological Stress and Microbial Decomposition of Plant Litter

Published on: March 12, 2013

Lethality Bioassay Using Artemia salina L.

Lethality Bioassay Using Artemia salina L.

Published on: October 11, 2022

Related Experiment Videos

Last Updated: May 26, 2026

A Real-Time Interactive System for Studying Confrontational Pursuit Behavior in Rodents

A Real-Time Interactive System for Studying Confrontational Pursuit Behavior in Rodents

Published on: May 16, 2025

Linking Predation Risk, Herbivore Physiological Stress and Microbial Decomposition of Plant Litter

Linking Predation Risk, Herbivore Physiological Stress and Microbial Decomposition of Plant Litter

Published on: March 12, 2013

Lethality Bioassay Using Artemia salina L.

Lethality Bioassay Using Artemia salina L.

Published on: October 11, 2022

Area of Science:

Ecology
Evolutionary Biology
Animal Behavior

Background:

Nonconsumptive predator effects, including stress responses, are common in nature.
Studies often use caged predators to assess these effects, primarily on larval stages.
Less is known about whether these effects are exclusively sublethal or extend beyond larval development.

Purpose of the Study:

To investigate if predator presence alone impacts dragonfly larval survivorship, metamorphosis, and adult size.
To determine if nonconsumptive predator effects extend to metamorphosis success.
To assess the role of stress responses in prey vulnerability.

Main Methods:

Experiments were conducted using larvae of the dragonfly Leucorrhinia intacta.
Larvae were exposed to caged predators (non-lethal exposure).
Survivorship, metamorphic success, and adult body size were measured.

Main Results:

Larvae exposed to caged predators exhibited higher mortality rates.
Larvae reared with caged predators showed increased rates of metamorphic failure.
No significant effect of predator presence was observed on adult body size.

Conclusions:

Mere exposure to predator cues can induce stress responses in prey.
These stress responses increase prey vulnerability to other mortality factors.
Nonconsumptive predator effects can significantly impact survival and development beyond direct predation.