Mind Control Everywhere!
Being able to
have mind control seem like a sophisticated power that many would like to have.
In Vampire Diaries, the evil vampire, Damon, is known to use this type of
techniques on others such as Jeremy. You can also find this type of behavior in
cartoons such as SpongeBob Squarepants when Plankton takes over SpongeBob’s
mind to try to get the secret formula for the crabby patty. Unfortunately,
being able to control something or someone’s mind is very unrealistic – but not
for certain parasites. This unique characteristic has given the parasites the
upper hand when it comes to the evolution of parasites vs. host. Getting a host
to do whatever, or go wherever is a necessity in order to get to their next
life cycle. (1)
How and Why Does This Happen?
When the
parasite has finally encounter the intermediate host and is able to survive the
host immune system, the next step for the parasite is to somehow manage its way
to get to its definitive host. It has been report by Poulin that usually the
intermediate host is not the average meal that the definitive host would eat
which is why this could become tricky for the parasite (2). Thanks to the
product of natural selection, genetic manipulations, which is manipulation of
an organism’s genome that has influenced another organism’s phenotype, is the
reason of how parasites has the advantage over their host. Being capable of
changing its phenotype is also one of the main reasons why parasites modify the
host behavior. There are actually more other reasons to answer why specifically
the parasite changes the host behavior. Another reason, probably the most
obviously, is because it helps the parasite fulfill its life cycle. The last
reason for why the parasite changes the host’s behavior is because it inherited
this specific trait from an ancestor and it is now just embedded in the way it
functions. (3)
Zombie Snails
Snails are one
of the many organisms that are the victim of a parasite that is able to have
mind control over them once infected. This specific parasite that is
responsible is the Leucochloridium worm. This worm is able to get inside the
snails eye stocks and also a result makes the eyes look more like yummy
caterpillars to worms. Most importantly, the Leucochloridium worm takes over
the snail’s brain. The way they are sufficient in doing so is by having the
snail work its way up in plane view site so that predators, in this case birds,
are quickly able to spot the infected snail. This process in the end makes for
a happy parasite family that is now it able to achieve its finally life cycle
in the birds stomach. The way that the cycle is able to start over again is
that the snails eat the infected birds feces. Already you can quickly observe
and apply the reasons to why this particular parasite wanted to have the snail
behave differently. It was capable of changing the snails phenotype which in
return helped it successfully complete its life cycle by being able to enter
into the birds digestive tract and lastly the mind – control is inherited so it
can again go through the same life cycle each time using this trait so that it
can strongly complete the life cycle with little to no problem. (4)
References
References
(1) The Art
of Being A Parasite by Claude Combes
(2) http://www.otago.ac.nz/parasitegroup/PDF%20papers/Poulin2010-ASB.pdf
(3)http://books.google.com/books?hl=en&lr=&id=dKSyEsRTk5kC&oi=fnd&pg=PA243&dq=parasite+manipulation+of+host+behavior&ots=-wyxiQvfeL&sig=oofSlPgZODIaykggdlY9k4KEY5U#v=onepage&q=parasite%20manipulation%20of%20host%20behavior&f=false
(4) http://animaldiversity.ummz.umich.edu/accounts/Leucochloridium_paradoxum/
