The debate "Think hard on your own. What is your definition of life" was started by
February 9, 2019, 10:18 pm.
33 people are on the agree side of this discussion, while 16 people are on the disagree side.
That might be enough to see the common perception.
It looks like most of the people in this community are on the agreeing side of this statement.
Brynn posted 8 arguments, InfinityMachine posted 1 argument to the agreers part.
Brynn, SMNR, finthechat, InfinityMachine and 29 visitors agree.
Saam, Genius66342001 and 14 visitors disagree.
There are multiple definitions for "life" because there are different ways of being alive. What is conventionally defined as life is defined by autonomy and complex change and growth over a cycle from birth to death.
more specific definitions fail.
molecules that carry information and change through natural selection seems pretty straight forward.
Could you expand on your checklist? They are a little vague
1. must work to avoid decay and disorder
2. create closed system
3. molecule that can carry information
4. information must evolve by natural selection.
this checklist sounds better. having hereditary information is a far more accurate term than reproduction.
I guess I'm referencing something from a previous debate. I wont bring that debate in here, but if we ever return to the abortion debate I may reference this discussion.
however I do believe viruses prove the flaws in the criteria. how do you feel about viruses? are they closer to life, or closer to rock?
hybrids are not something caused by humans.... over the course of evolution it is unthinkable that recently speciated animals didnt occasionally breed making sterile hybrids. this has nothing to do with humans.
Unquestionable fact? No. It's because it's the most strict yet best definition to include most all life forms while still excluding other things. Honestly the reproduction part of the definition only doesn't work because humans have created the problem and it would have to be adjusted for us creating an exception. I'm open to adjusting this definition with new information which is exactly why I question and would change the reproduction section to fit in mules and ligers.
yes you contest the definition of reproduction, but you strictly enforce other criteria as unquestionable fact. you cant have it both ways.
right.... which is why I said I contest the definition for reproduction. Not the other criteria
and yet you questioned one of the criteria earlier because of evidence...
either way, the criteria of life are not fact, they are hypothesis. its certainly a great starting point for theorizing, but it's not enough to outright dismiss something.
viruses clearly do not fit almost all the criteria for life, yet the debate over their classification is a huge amongst the highest levels within the field.... because the criteria of life are not fact, they are educated guesses, like string theory or multiverse.
ok but engines and cars don't follow the other 6 characteristics they fall short of. Which is why they aren't living
you have to follow all the criteria.
reproducing mules isnt the only falt in the criteria. engines have a metabolism, and cars respond to stimuli.
I think it's a matter of multiple criteria. not all, but kinda like a point system where reproducing is 5 points while having a metabolism is 3. get to 10 and you qualify as life. cause life will always come up with an exception to everything.
ps. the numbers are totally random, dont do math with them :)
So I use the definition of life that's the scientific one but question the section about reproduction since it excludes things such as ligers and mules.
This is like how evolution doesn't occur to an individual and is a population wide phenomenon
Sterility isn't what excludes mules and ligers from the definition of life. The part of the definition regarding reproduction is on a species ability to self replicate without "aid" from other species. So as long as an individual falls within that species it is living. Mules and ligers are a "new" species and none of them can reproduce on a species level which is what excludes them.
Might I ask what your definition of life is, Brynn, so we can see where ours is mistaken?
My main issue with that definition is that it doesn't include ligers and mules and such because they are born sterile. But, I do not currently have a better definition, so I continue to use that one.
Yeah, it never says anywhere that it has to reproduce without help
and virus RNA definitely qualifies as a complex molecule.
also viruses are not cells or made of cells, thus my complex molecule requirement.
in nature we at most have single digit molecules like h2o, nh4, co2, or crystals that can have infinite atoms, but it's only 2 atoms repeating, like nacl (salt)
the simplest or organic molecules like simple sugar are c6h12o6. 24 atoms.
fats are 3 of those place an extra base of about 10 more atoms. ~82 atoms
and proteins are hundreds to thousands.
the only way you will find these in nature is if life dropped it there.
so then you believe viruses are not alive as they have no metabolism, do not grow, and do not react to stimuli outside a host?
I feel that if we discover life that doesnt fit our definition, then we must adjust our definition. not the other way around.
I dont see the "reproduction without help" being in any definition. wouldnt that rule out plants that require pollination?
No history buff I was talking about jdawgs definition because that's the scientific definition which does require that.
I'm not certain that excludes viruses. I don't want to speak for nemiroff, but he said it self replicates. He didn't say it self replicates on it's own. Even our own species requires both genders to reproduce. As long as it can reproduce organisms that are like itself, that would seem to be life, regardless of what steps it requires.
My only problem with that is the reproduction section of that definition requires that the species can reproduce without "help" from other species. Which excludes viruses.
I agree with the biological definition of life, which is that to be considered living one must be about to respond to stimuli, reproduce, grow and develop, and maintenan homeostasis.
I believe anything that self replicates and is made of complex molecules is enough to be considered life.
I would say having a metabolism, but that would rule out viruses, which are clearly different then rocks and other nonliving matter