There is nothing lurking actually. I’ve thought about it and wanted to hear other opinions (I am wise you see;). But unfortunately the rebuttal to your explanation has to be seen as a pro-choice: what if the mother doesn’t see the unborn kid as her purpose to live. What’s running through my mind is that certain mammals ( i think the zebra is one) have the option to temporarily stop the pregnancy waiting for a more opportune moment to continue gestation or to stop it altogether. In such a case I would side with your argument of invitro fertilisation as being a longer term strategy. But the issue with a human embryo is that the mother does not have that inbuilt choice.
Take the analogy which can be reminiscent of the “The Eternal Jew” propaganda documentaries so once again I have to apologise if i offend anybody - it is not my intention - but please do rebutt this argument.
A tapeworm lives off the host; it injures the host as far as depriving the host of some nutrients. an unborn kid lives off the host; it injures the host as far as depriving the host of some nutrients. If we assume the mother wants the kid, then your argument as a long term strategy holds - the foetus/embryo is not a parasite. But what if the mother/host does not want the kid - doesn’t that make the foetus/embryo a parasite?
I am pro-choice in fact only because this is the way i look at the situation and am more than willing to accept a rebuttal to the above argument.
In vitro fertilization is the mixing of eggs with sperm in a laboratory dish in order to achieve conception. The fertilization strategy used by humans is “in vivo fertilization” and refers only to the actual fertilization. Humans are placental mammals if we are talking about the growth and development of the embryo/foetus.
A human mother not perceiving her child as her sole reason for existing doesn’t AFAICS somehow make a foetus into a parasite. If that were the case, then a wanted foetus is not a parasite but an unwanted one is a parasite. In other words, there is no factual answer, only subjective ones and this whole thread is in the wrong forum.
Again I don’t think the desire of the parent to be a parent has anything to do with it. It is a function of our species, it’s how we reproduce, it’s how she passes her genetic information to future generations, her body does actively react to ensure the survival of the baby.
Morning sickness (may) happen to ensure the baby does not get nutrients that could harm the baby at critical growth stages (though I’m not sure what causes this, in other words does the baby release something that causes the mother to get sick, or does the mother).
Absolutely not. From the biological point of view, it is the one and only point of being alive in the first place. Life’s only “purpose,” if it can be said to have one, is to perpetuate itself. From a biological point of view, there is no way that your own offspring could be considered a parasite.
Whether or not a human female “wants” her offspring is entirely irrelevant with respect to whether it can be considered a parasite or not. The offspring is beneficial from the point of view of continuing her genome, and therefore is not a parasite.
Perhaps it is just the cynic in me, but I would gather this clause is inserted specifically so that a developing offspring is not included as a parasite. Which, to me, is a little cheap, but that’s what you get for looking into definitions.
There’s a simple enough resolution. Go find a biology textbook or dictionary written prior to Roe v. Wade, so we can make sure the pro-life movement didn’t slip their own definition into the book.
I recall my physical anthropology professor telling us that during times of famine, a fetus will leach nutrients from the mother to the mothers detriment, even the calcium from her bones. Maybe not technically parasitic, but at least reminiscent.
from the 13th anniversary of his/her birth until he/she leaves home
Now seriously, as many pointed out above pregnancy is part of the propagation of the species. However, in a set of multiple gestation, one fetus can parasite the other(s) by getting more blood supply than the rest, thus provoking problems that could range from low birth weight to death on the “parasited” fetus(es).
Normally, symbiotic, commensal and parasitic relationships have to be between members of different species. If the relationship is between members of the same species, it’s really a different category. Besides, since providing nutrients to one’s offspring (whether before or after birth) is absolutely essential to survival for mammals. Since having a large number of offspring who survive is the single most important measure of fitness for a species, the mother/embryo or mother/fetus relationship is unquestionably a beneficial one.
It’s true that the embryo/fetus depends on the mother for nutrition during gestation, but this isn’t parasitic, since the embryo/fetus is not harming the mother; the relationship would be commensal or even symbiotic, if those labels were appropriate. The mother will generally increase her intake of food in order to provide for the baby. Her own nutritional needs will still be fulfilled (which may not be the case for a person hosting a parasite), and some of the extra food she eats will nourish the embryo/fetus. This is no different than breastfeeding or providing food to children.
In a broader sense, remember that in modern societies most people are not food producers in their own right, and don’t obtain food from nature. Does that mean that non-farmers are parasites?
I don’t think the ‘different species’ requirement is ‘cheap’. Nearly every species has some sort of relationship between members of that species that might be classified as symbiotic, commensal or parasitic. For example, males of virtually all species (at least, those which reproduce sexually) depend on females to produce zygotes using their sperm; females of virtually all species depend on males to fertilize their ova. Young mammals depend on their parents. In some cases, organisms from different species have evolved symbiotic, commensal or parasitic relationships that increase the fitness of one or both species. Biologists who study these relationships are interested in the ways that one species depends on another; the ways that members of a species depend on other members of the same species is a different matter altogether.
Roches I appreciate the lucid explanation, especially the elaboration that the term parasitic/commensal and symbiotic should be applied to different species. If possible could you explain the category it would fit when you state “If the relationship is between members of the same species, it’s really a different category”, especially because it is the crux of your explanation.
