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The ability to control someone’s mind, change their behavior, and force them to perform self-destructive, unnatural acts seems like a scene from a bad alien-zombie movie. However, some parasites, such as worms of the phylum Acanthocephala, manage to do just that – they infect another organism, drain their resources, and then alter their host’s behavior and physiology to become more susceptible to a predator, who is the parasite’s next host. They manipulate the host, so that it does not hide when it senses visual and olfactory signals that indicate a predator’s presence; it does not reproduce, and it escapes non-host predators with greater efficiency. The variability, specificity, and flexibility of the behaviors induced in the intermediate host demonstrate the complexity of the parasite-host relationship. Moreover, the extent to which the parasite controls the host shows the dependency of even the most basic behaviors and instincts, such as hiding from a predator or finding a mate, on physiological, chemical, and genetic factors.

Author: Dina Yangirova


Parasitism is a long-term, durable interaction between two species, in which one uses the other as a source of nutrients, a transport vehicle, or a habitat without providing anything in return (Combes 2001). The parasite’s activities lack the glory and drama of a predator eating its hard-won prey. Instead, the parasite works quietly and diligently behind the scenes, often hidden, but nevertheless profoundly influential in the life of its host. For instance, the parasite might literally, physically change the host, because some of its genes become expressed by the host. Moreover, the parasite influences the host by consuming the resources that it would otherwise use for its own growth, repair, or reproduction. It may also influence the dynamics of the host population by killing individuals susceptible to infection, and thus indirectly increasing the number of infection-resistant individuals. By doing so, the parasite is creating strong selective pressures for the host to develop defenses against exploitation, which in turn causes selection for parasites that can bypass these defenses. In this way, the host and the parasite find themselves in an evolutionary arms race, which has wide-ranging effects on both organisms (Combes 2001).

Effective transmission to another host or transmission of the eggs to another host is an important task for parasites, because otherwise when the host dies due to the parasite’s activities or otherwise – the parasite, its offspring, and most importantly its genes will perish as well. Transmission can occur through contact, consumption, or an active free-living stage (Combes 2001). This task becomes especially important if the parasite requires more than one host to complete its development and reproduce. In such cases, one of the most extreme cases of host manipulation by a parasite can be observed, in which the parasite turns its host into a veritable zombie by radically changing its behavior and appearance to increase the chance of transmission to the next host. An organism that vividly demonstrates this phenomenon is a thorn-headed worm of the phylum Acanthocephala, which causes radical changes in the life and behavior of its invertebrate intermediate host in order to improve the chances that it will be consumed by its next, vertebrate definitive host . A relationship between parasitic worms of the phylum Acanthocephala and their hosts provide great insights into the dynamics and complexity of parasite-induced behavioral modifications, and provide a great demonstration of the extended phenotype .

Questions & Answers

what is variations in raman spectra for nanomaterials
Jyoti Reply
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
yes that's correct
I think
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
scanning tunneling microscope
how nano science is used for hydrophobicity
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
what is differents between GO and RGO?
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Mockingbird tales: readings in animal behavior. OpenStax CNX. Jan 12, 2011 Download for free at http://cnx.org/content/col11211/1.5
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