Yes, science should rethink the definition of life
| January 12, 2012 | Posted by News under Origin Of Life |
credit Laszlo Bencze
At Science Slashdot, there’s a discussion around “Should science rethink the definition of life?” Trouble is, some folk don’t seem to grasp the extent to which the definition of life is a this-planet problem:
When NASA says it wants to find out if Mars was ever suitable for life, they use a very circumscribed version of the word. They are looking for signs of liquid water, which all living things on Earth need. They are looking for organic carbon, which life on Earth produces and, in some cases, can feed on to survive. In other words, they’re looking on Mars for the sorts of conditions that support life on Earth. But there’s no good reason to assume that all life has to be like the life we’re familiar with. In 2007, a board of scientists appointed by the National Academies of Science decided they couldn’t rule out the possibility that life might be able to exist without water or carbon. If such weird life on Mars exists, Curiosity will probably miss it.”
Yes, but surely we just can let that be NASA’s problem for now. If NASA doesn’t find it, we won’t either.
This-planet problems that are right in our ballpark include:
1. Megaviruses and mimiviruses that behave like degraded cells. Where should we draw the line? Same with parasites that have grossly simplified their genome by outsourcing vital life functions. What considerations should rule?
2. Some life forms that are way off the standard have probably lived and died on this planet without ever coming to attention. Consider, for example,
“Researchers haven’t been able to decide whether the remains come from animals, bacteria or close relatives of animals that thrived at the dawn of animal evolution.” Some wonder if they are a fungus. “What isn’t widely appreciated is that the Doushantuo rock formation contains billions of microfossils, many of which have no traits that are diagnostic of any living group and contain features that are not of biological origin.” says one researcher.
Matt Kaplan, “Enigmatic fossils are neither animals nor bacteria,” Nature, 22 December 2011
Which raises an obvious question: If we can’t classify it, what makes us sure that it is life? Following that up might get us somewhere.
3. Too many sources fall back on the outmoded “It’s life if it is capable of undergoing Darwinian evolution.” Outmoded because many simple life forms are well known to make only limited use of Darwinian evolution when undergoing great changes – horizontal gene transfer rules among them.
One can always argue that natural selection plays a vital role in trimming those life forms that are unable to compete. But, quite honestly, that isn’t an important enough role to justify forming a definition of life. For all we know, the same thing happens among agglomerations of chemicals in outer space that we do not consider life or even on their way to becoming life.
Probably, a useful definition of life will be found in information theory, not Darwinism. Could it be pegged to a level of information, as measured? Thoughts welcome. Many of us are just beginning to think about it.
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15 Responses to Yes, science should rethink the definition of life
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I’ve said it before but it bears worth repeating. True ‘Life’, at least for me, is, at minimum, a conscious being, not some arbitrary threshold of molecules, erroneously presumed to be ‘randomly’ assembled into molecular machines, that ‘finally’ has achieved the capability to self-reproduce (i.e. supposedly some molecular threshold between viruses and bacteria), no matter how impressive that assembly of self-reproducing molecular machines happens to be! The plain fact is that any definition that neglects to take consciousness into its definition of true ‘Life’ will not even be looking in the right place to start as to ‘scientifically’ establishing when true ‘Life’ begins, nor to discerning whence ‘true Life’ came from in the first place!
notes to prove the point:
The argument for God from consciousness can be framed like this:
references:
Here is the key experiment that led Wigner to his Nobel Prize winning work on quantum symmetries:
i.e. In the experiment the ‘world’ (i.e. the universe) does not have a ‘privileged center’. Yet strangely, the conscious observer does exhibit a ‘privileged center’. This is since the ‘matrix’, which determines which vector will be used to describe the particle in the experiment, is ‘observer-centric’ in its origination! Thus explaining Wigner’s dramatic statement, “It was not possible to formulate the laws (of quantum theory) in a fully consistent way without reference to consciousness.”
Verse and music:
corrected link:
Evanescence – Bring Me To Life
http://www.youtube.com/watch?v.....38;ob=av2e
When NASA is looking for carbon and water is admitting that life is information. No other element than carbon can build all the chemistry to store the information for life.
I think bornagain77 is right regarding true life requiring consciousness.
The more interesting question is: how do we classify non-conscious life? Would it be a classification that ruled out man-made entities? For example, a computer virus might have a high information content, it could be capable of reproducing and possibly even evolving. And I don’t think the possibility that such properties could one day be found in a machine can be ruled out. If a machine can ever contain it’s own 3d printer perhaps it could also create a copy of itself? How would we classify that?
Even assuming we were to find something on Mars, would be able to tell if it was life-from-God or “life”-from-life?
So are you saying that plants are conscious?
Or that plants are not life?
Elizabeth:
The problem of the relationship between life and consciousness is a very difficult one.
I would like to say that I do believe that life cannot be defined only in mechanical terms. IOWs, I do believe that something more than a working machine, however complex, is necessary for life to exist.
It is possible that consciousness is part of the scenario. But I must say that the consciousness of a plant, or of bacteria, would probably be very different from the consciousness we experience in ourselves. Unfortunately, we don’t even have direct access to subjective experiences in higher animals, least of all in bacteria, and so our empirical approach is very limited here.
That life is more than it seems can be hypothesized from many observations, the most outstanding of all being the fact that up to today life only comes from life, and that we are not able to create new life from non living components, not even if we have all the components already available, and informationally structured.
So, the existence of life could well go beyond the “simple” problem of biological information (which is the point of ID). I suppose this can make of me one of the few neo-vitalists (but I am always looking for company).
The relationship between “life” (whatever it is) and “consciousness” remains IMO an open problem, not easily approached empirically at the present state.
Oddly, you have sort-of company in a few materialists
Hofstadter, for instance, and me, in the sense that I think consciousness is best considered on a continuum, not simply “present or absent”, and quantified by evaluating the question: “what is X conscious of“? The larger (and more reentrant) the answer to that question, the more conscious I would say X was. In other words, I do think there is “something it is like to be a bat”, which is rather more than it is “like to be a mosquito ” and even more than “it is like to be a plant”. But I do think the continuum hits zero well before total non-reactivity.
And I also think there is nothing non-mechanical about it
Plants are conscious- they respond to stimuli…
At the basic level, I see biotic life as:
A system with encoded information capable of taking in materials and energy and forming reproducible cells.
A smartphone responds to touch. Do you think it’s conscious?
Elizabeth:
While I appreciate your company, I can survive without Hofstadter’s
I agree about the continuum, absolutely not about ““what is X conscious of“? And absolutely not about the “nothing non-mechanical”.
And with all respect, I find the “loop” or “reentrant” concept really stupid (excuse me, Douglas…)
If it met all the other criteria, yup.
1- Must contain a genome (Yockey)
2- Must be able to reproduce or have come from reproduction
3- Response to stimuli (yes plants respond to stimuli)
4- metabolism
5- Growth
6- composed of one or more cells
7- adaptation
8- homeostasis
Bornagain:
Again you quote Richard Conn Henry:
So I ask you again, does this mean that you now accept what you thoroughly ridiculed when I proposed it, namely that Bishop Berkeley, Bruce Gordon, Jonathan Edwards, I, and many other thinkers are correct when we contend that there is no material world, that it is an illusion, a kind of virtual reality orchestrated by God?
I keep asking and you keep ignoring my question.
Not that I’m entirely sure how this would work, but what about trying to define life based on “normativity” like what that Best Schools blog was on about the other day (in three parts, 1, 2, 3)?
In my opinion consciousness can be tested for with a kind of Turing test. A test candidate who displays the ability to comprehend new information and the ability to create new information in response must be conscious. I don’t mean the test would take the form of a puzzle to be solved, but rather a detailed conversation (something like this thread). Here I’m also thinking of the Chinese room thought experiment. I’m convinced any computer taking such a test would fail.
So by my definition plants can not be conscious, and it seems unlikely that any animals could be either. Yet plants and animals are clearly still life.