Is Sperm a lifeform?

[GREATBLOKE]

Are all viruses lifeforms? [computer viruses aside].

[SixSixSix]

Why are computer viruses not eligible?

Sounds a bit organicist to me.

[MRC_Hans]

Sperm is not a life form. It is part of a life form.

Vira are life forms. True, they cannot exist independently, but the same is true about much higher life forms that have adapted to a parasitic (or symbiotic) lifestyle.

Computer vira lack metabolism, so per definition, they are not life forms. That is, per our definition; computer vira might use a different definition.

Hans

[Soapy Sam]

Depends how broad minded you are.

I find the life / non life distinction pretty useless in some contexts .
The closer you look at a boundary, the more it turns out to be a boundary ZONE.

And we need to keep in mind that many boundaries exist only in the human mind.

[SixSixSix]

Originally posted by MRC_Hans
Computer vira lack metabolism, so per definition, they are not life forms. That is, per our definition; computer vira might use a different definition.


From dictionary.com:

me·tab·o·lism

1. The chemical processes occurring within a living cell or organism that are necessary for the maintenance of life. In metabolism some substances are broken down to yield energy for vital processes while other substances, necessary for life, are synthesized.

So fair enough, computer viruses don't really have any chemical processes, but it could be argued that some viruses don't either (they nick them from the host). On the other hand computer viruses have non-chemical processes that are necessary for the maintenance of its run-time - a metabolism of sorts, if one expands the definition a bit.

Granted I don't think computer viruses are alive. But there are many lines you could draw, and there are many biologists would not place organic viruses in the "living" category either. If we ever create self aware computers - which while not by any means "on the horizon" are certainly not theoretically impossible - then we will need to at least consider the possibility that they would count as alive despite not having a metabolism. Best to get in early. :)

[MRC_Hans]

Originally posted by Soapy Sam
Depends how broad minded you are.

I find the life / non life distinction pretty useless in some contexts .
The closer you look at a boundary, the more it turns out to be a boundary ZONE.

And we need to keep in mind that many boundaries exist only in the human mind. Agreed on all points. But the only definitions we ever have to go by are our own current ones.

Hans

[c4ts]

Zygotes don't have organelless, neither do viruses.

[Alkatran]

I almost feel like arguing that humans are simply the method sperm use to survive and reproduce... :D

[BillHoyt]

Originally posted by Alkatran
I almost feel like arguing that humans are simply the method sperm use to survive and reproduce... :D

Been there. Done that.

[Dr. Imago]

For something to be called a true "life form" it must possess the ability, on it's own, to replicate. A sperm does not, as a distinct entity, have this ability (i.e., a sperm does not possess the ability reproduce by itself and make more sperm). A virus is in the grey zone because it possesses the instructions to replicate, but requires a host organism's machinery in order to do so. Viruses are definitely interesting little things. But, even more so are plasmids and prions.

-Dr. Imago

[jmercer]

Welcome to the forum, Dr. Imago. Beat me to it! :)

[GREATBLOKE]

Nice concise answer Dr. Imago. One problem... according to that definition, mules (donkey and Horse hybrid) and Tygons (lion / tiger hybrid) are not alive?

[Alkatran]

Originally posted by Dr. Imago
For something to be called a true "life form" it must possess the ability, on it's own, to replicate. A sperm does not, as a distinct entity, have this ability (i.e., a sperm does not possess the ability reproduce by itself and make more sperm). A virus is in the grey zone because it possesses the instructions to replicate, but requires a host organism's machinery in order to do so. Viruses are definitely interesting little things. But, even more so are plasmids and prions.

-Dr. Imago

Humans require sperm to replicate, and are therefore not alive? Humans do not possess to reproduce themselves without sperm.

[c4ts]

Originally posted by Alkatran
Humans require sperm to replicate, and are therefore not alive? Humans do not possess to reproduce themselves without sperm.

Humans replicate themselves, and sperm are part of how they do it. Think of it this way: A gun is a weapon because it shoots bullets, but the bullets themselves are not weapons. The zygotes are a method of delivery, they don't share any qualities with the organism that develops except for a few protein strands. Sperm don't make more of themselves, they don't have systems which can perpetuate themselves, and so they don't intake or excrete anything,whereas human beings do all of that.

[tofu]

Originally posted by SixSixSix
Why are computer viruses not eligible?

Sounds a bit organicist to me.

Yeah, right.

I'd like to see a definition of life that applies to computer viruses without also classifying things like fire or for that matter Walmart inc. as being alive.

[Earthborn]

Originally posted by Dr. Imago
For something to be called a true "life form" it must possess the ability, on it's own, to replicate.I know very few people who are able to replicate on their own. Most of them need someone else to do it together. Are they not lifeforms?
I also know a few people who could not replicate at all, even if they got help from someone else. How about them?

Methinks your definition needs some work.

[Dr. Imago]

Well, for simplicity's sake, "on their own" refers to the species level, where sexual differentiation plays a role in reproduction in some species. One also shouldn't confuse being alive with being a species, and we're of course barring the pedantic exceptions (e.g., the mule, a child born without sexual organs, etc.). As a reduced to the absurd example, one could theoretically consider HeLa cells to be both alive and a species. I would not. Echinoderms are also an interesting exception, as are certain bacteria. Each possesses the capability to replicate by both sexual and non-sexual means. But, they can replicate. That's the key. Sperm cannot.

-Dr. Imago

[GREATBLOKE]

I don't think that labeling exceptions as "Pedantic" is a fair way to support a set of criteria.... as good as it is ... this might become more obvious WHEN we find life on another world.

I sometimes get the feeling that there's a wrong assumption that we are making about life. Otherwise, it might be easier to define. Maybe one day someone will point out something obvious that we've all over looked.

But more likely, Soapy Sam has it right ... "life" is a poor fuzzy word, particularly at the boundries.

~~~~~~

Here's what Wikpedia has to say about The Definition of LIFE (http://en.wikipedia.org/wiki/Life)

[Brahe]

Originally posted by c4ts
Zygotes don't have organelless, neither do viruses.
A zygote is a fertilized egg cell and most definitely has organelles. Viruses do not have organelles.

Just in case you're interested, prokaryotes do not have organelles (though they may possess interior membranes) and are alive. For more information, here 's a tutorial (http://www.biology.arizona.edu/cell_bio/tutorials/pev/main.html).

[Brahe]

Originally posted by Dr. Imago
Well, for simplicity's sake, "on their own" refers to the species level, where sexual differentiation plays a role in reproduction in some species. One also shouldn't confuse being alive with being a species, and we're of course barring the pedantic exceptions...But, they can replicate. That's the key. Sperm cannot.
I may be misreading your statements, but I think this is incorrect. Human sperm cells are just as human as you or I (though obviously most people wouldn't consider them human beings). Unless you want to contend that humans (or any other sexually reproducing animal) aren't alive, then you must consider sperm themselves to be alive.

Of course, while one of my liver cells is alive, I don't think we would consider it a life form on its own. So the question is, are sperm individual organisms on their own (as opposed to parts of a collective)? And I think the answer is yes. That we humans spend so little of our life cycle in haploid form does not detract from this.

[BillHoyt]

Originally posted by Brahe
I may be misreading your statements, but I think this is incorrect. Human sperm cells are just as human as you or I (though obviously most people wouldn't consider them human beings). Unless you want to contend that humans (or any other sexually reproducing animal) aren't alive, then you must consider sperm themselves to be alive.

Of course, while one of my liver cells is alive, I don't think we would consider it a life form on its own. So the question is, are sperm individual organisms on their own (as opposed to parts of a collective)? And I think the answer is yes. That we humans spend so little of our life cycle in haploid form does not detract from this.

I agree with you; sperm are alive. I also agree with your earlier post; zygotes have organelles. One point I disagree on is "the collective" portion of your post. The organelles already represent a collective that became fused long ago. If you'd like to google this, I suggest you start with "Margulis endosymbionts"

[BillyJoe]

Sperm is a half-life. :D

But seriously, if a sperm is not alive, it must be dead. And, therefore, an ovum must also be dead. A zygote, on the other hand is living. So, when a dead sperm enters a dead ovum, a living zygote is produced. A sperm is, therefore, the "spark of life".

Okay, I was not being serious.

BJ

[stamenflicker]

Sperm don't make more of themselves, they don't have systems which can perpetuate themselves, and so they don't intake or excrete anything,whereas human beings do all of that.

It's a good thing something is looking after my sperm reproduction, cause I'd be out like.... tomorrow.

Flick

[Soapy Sam]

Once, there was a last Dodo.

It may have been perfectly healthy right up till it squawked it's last, but it was unable to reproduce ( due to the shortage of other Dodos).

Yet it was, indisputably, alive.

I see no clear reason why something must be able to reproduce, even in theory, in order to be considered alive.
This seems to be pure sexism. Or asexism. Whichever.

Treebeard the Ent was alive*

*(For a certain meaning of "alive")

[BillyJoe]

It's a fact of life that some things are definitely alive and some things are definitely dead, but that there are also things in between that are not clearly either alive or dead. This is as you would expect if life evolved.

BJ

[NeilC]

The definition of what is required to be considered a lifeform has been made up by looking at things that are lifeforms and seeing what is common to them.

The ability to reproduce is key to this. Something can be alive without being a lifeform. A tree is a lifeform but a leaf is not. The only difference between them in terms of the definition of a lifeform is that the leaf cannot reproduce. It excretes, reacts to it's environment etc etc. It is part of a lifeform.

Sperm are like this. They are specialised cells, part of a human lifeform. They are alive but they are not a separate lifeform.

[BillyJoe]

Splossy,

It doesn't help.
It just shifts the focus.

Is a virus a lifeform?
A prion?

BJ

[NeilC]

Sorry - doesn't help what?

I thought the question was about sperm?

That might be answered by seperating the definitions "alive" and "lifeform".

Prions and viruses are a different matter.

Anyone know if you get "good" viruses? Ones that are not pathogenic?

[Soapy Sam]

Bacteriophages?

But now you're into moral definitions.

Good?

What does Santa bring "good" little virii?

[Piscivore]

Originally posted by Soapy Sam
What does Santa bring "good" little virii?

Pink ribbons for their protein coats.


So a sperm is "alive" but not a separate "lifeform", is that what I'm hearing?

[rppa]

I'm surprised at you people.

How could anybody see this thread title and not think immediately of Every Sperm is Sacred (http://www.taboo-breaker.org/religion/sperm.htm) ?

[BillyJoe]

Splossy,

Originally posted by Splossy
Sorry - doesn't help what?

I thought the question was about sperm?

That might be answered by seperating the definitions "alive" and "lifeform".

Prions and viruses are a different matter. Right, I lost track of title of this thread. Anyway, the point is that, regardless of whether you focus on "life" or "lifeform", there will always be a grey area where it is difficult to be certain one way or the other. The only winner, in a sense, is evolution.

Originally posted by Splossy
Anyone know if you get "good" viruses? Ones that are not pathogenic? I suppose you mean from the human perspective. There are certainly viruses that are not pathogenic to man. I don't think there are viruses that are "good" for humans, except indirectly (for example the myxoma virus used to help keep down rabbit numbers in outback Australia)

BJ