The Chronicles of Narcissist

[Dannyalcatraz]

I'm sorry, but discovering that an unwanted creature was growing inside me against my will would only be marginally lessened if it were a potential human being. Either way my response is "get it out of me right freaking now!"

Your personal squick factor doesn't make a fetus into a parasite.

 

[MechaPilot]

Your personal squick factor doesn't make a fetus into a parasite.

No, my personal squick factor is a personal consideration.

However, a parasite is defined as "an organism that lives in or on another organism (its host) and benefits by deriving nutrients at the host's expense."

Note that no mention is made of having to be of a different species.

Now, Supreme Court Justice Learned Hand was certainly correct when he cautioned against "making a fortress of a dictionary." However, taking it simply as one single piece of evidence in making the case that a fetus is a type of parasite, it is certainly on point in that a fetus

1) is an organism that

2) lives in a host, and

3) derives nutrients at the host's expense.

 

[Dannyalcatraz]

This article:
http://www.cephalopodiatrist.com/2012/10/why-babies-arent-actually-parasites.html

Referencing this work:
http://onlinelibrary.wiley.com/doi/10.1111/j.1600-0897.2010.00836.x/full

Points out that a parasite thrives at the cost of its host, but that offspring- at least those carried by a mother internally (as opposed to externally deposited eggs)- have a positive effect on the immune system of the mother, at least for certain pathogens.

IOW, there is a symbiotic, not parasitic, relationship between fetus and mother.

 

[Umbran]

However, a parasite is defined as "an organism that lives in or on another organism (its host) and benefits by deriving nutrients at the host's expense."

Note that no mention is made of having to be of a different species.

That's because you are (perhaps unintentionally) cherry-picking. If you speak with a parasitologist, or even check another dictionary, you'll find a slightly different definition:

http://www.thefreedictionary.com/parasite or
http://dictionary.reference.com/browse/parasite

"1. an organism that lives on or in an organism of another species, known as the host, from the body of which it obtains nutriment."

We shouldn't go to general dictionaries to discuss the minutiae of scientific (or legal) accuracy.

 

[MechaPilot]

This article:
http://www.cephalopodiatrist.com/2012/10/why-babies-arent-actually-parasites.html

Referencing this work:
http://onlinelibrary.wiley.com/doi/10.1111/j.1600-0897.2010.00836.x/full

Points out that a parasite thrives at the cost of its host, but that offspring- at least those carried by a mother internally (as opposed to externally deposited eggs)- have a positive effect on the immune system of the mother, at least for certain pathogens.

IOW, there is a symbiotic, not parasitic, relationship between fetus and mother.

Those are interesting articles. However, I would argue that the net effect is what matters, and not each individual aspect of the transaction between the two organisms. After all, if a parasite depends on the survival of the host for its own survival, it would not be inherently evolutionarily disadvantageous to the parasite to contribute marginally to the survival of the host.

Now, we can certainly ask the question of whether an organism is a parasite if it provides a benefit that doesn't outweigh or fully compensate for what it takes from the host.

 

[MechaPilot]

That's because you are (perhaps unintentionally) cherry-picking.

If I am cherry-picking, I assure you it is unintentional. I do not believe in taking a position based on intellectual dishonesty.

If you speak with a parasitologist, or even check another dictionary, you'll find a slightly different definition:

http://www.thefreedictionary.com/parasite or
http://dictionary.reference.com/browse/parasite

"1. an organism that lives on or in an organism of another species, known as the host, from the body of which it obtains nutriment."

We shouldn't go to general dictionaries to discuss the minutiae of scientific (or legal) accuracy.

That's very true, that's why I posted what I did about not making a fortress of a dictionary. However, the first step in approaching anything is the general step. As a tax accountant, when interpreting the U.S. tax code (which is statutory law) one should evaluate the language according to its common meaning and usage unless directed by the code to use other (perhaps more technical) definitions.

It's also true that science often has different definitions for things that common language does. A prime example of this is Pluto. Is it a planet? Scientists have said no, it is not. However, it is still mentioned (along with the question of what its status should be) when discussing the solar system. This is true even in academic settings. My college astronomy professor paused his discussion of the planets to inform us that in his classroom "Pluto is a planet."

 

[Dannyalcatraz]

After all, if a parasite depends on the survival of the host for its own survival, it would not be inherently evolutionarily disadvantageous to the parasite to contribute marginally to the survival of the host.

By definition, a parasite does not.

There are other hosting paradigms in which the hosting creature does receive a benefit from the hosted
creature, but parasites don't.

Mutalism: both partners benefit. An example of mutualism is the relationship between the Egyptian plover and the crocodile. In the tropical regions of Africa, the crocodile lies with its mouth open. The plover flies into its mouth and feeds on bits of decaying meat stuck in the crocodile’s teeth. The crocodile does not eat the plover. Instead, he appreciates the dental work. The plover eats a meal and the crocodile gets his teeth cleaned. Coincidentally, the Egyptian plover is also known as the crocodile bird.
Commensalism: only one species benefits while the other is neither helped nor harmed. For example, remora fish are very bony and have a dorsal fin (the fin on the back of fish) that acts like a suction cup. Remora fish use this fin to attach themselves to whales, sharks, or rays and eat the scraps their hosts leave behind. The remora fish gets a meal, while its host gets nothing. Selfish, sure, but neither gets hurt.
Parasitism: One organism (the parasite) gains, while the other (the host) suffers. The deer tick is a parasite. It attaches to a warmblooded animal and feeds on its blood. Ticks need blood at every stage of their life cycle. They also carry Lyme disease, an illness that can cause joint damage, heart complications, and kidney problems. The tick benefits from eating the animal's blood. Unfortunately, the animal suffers from the loss of blood and nutrients and may get sick.

 

[MechaPilot]

By definition, a parasite does not.

There are other hosting paradigms in which the hosting creature does receive a benefit from the hosted
creature, but parasites don't.

If the net result of the benefit and the harm is more harm than benefit, which model does it fit into?

 

[Dannyalcatraz]

That doesn't happen, AFAIK.

In the case of offspring, you may choose to value it differently, but from a biologists perspective, the chance to pass along one's genes to another generation is a HUGE benefit.

 

[MechaPilot]

That doesn't happen, AFAIK.

In the case of offspring, you may choose to value it differently, but from a biologists perspective, the chance to pass along one's genes to another generation is a HUGE benefit.

If you mean that a fetus doesn't do more harm than good to the mother, I would say that the physical toll is significant. I would also say that the only benefit to the mother thus far illustrated is in the increase in immune response to certain specific illnesses mentioned in your article. How much does this increase actually affect the mother's chance of contracting one of those illnesses? That's just one of the questions that bear answering when determining if there is a net harm or net gain, and the article itself mentioned that our understanding is incomplete.

And, when talking about an unwanted fetus, you also have to contend with the psychological harm of being forced to carry an unwanted fetus. Psychological harm very well can result in physical harm as stress hormones lower your immune system. Plus, psychological harm can be very significant even where it doesn't create physical harm. And that's without getting into any kind of discussion of the social and economic harm done.