Life bit by bit

[Naraoia]

In the latest PLoS Biology, Gerald Joyce of replicating ribozyme fame muses about the nature and probability of life in terms of information.

Bit by Bit: The Darwinian Basis of Life (PLoS Biology 10:e1001323)

All known examples of life belong to the same biology, but there is increasing enthusiasm among astronomers, astrobiologists, and synthetic biologists that other forms of life may soon be discovered or synthesized. This enthusiasm should be tempered by the fact that the probability for life to originate is not known. As a guiding principle in parsing potential examples of alternative life, one should ask: How many heritable “bits” of information are involved, and where did they come from? A genetic system that contains more bits than the number that were required to initiate its operation might reasonably be considered a new form of life.
​

(And the Great Reverse Transcription might be my new favourite scientific term.)

 

[juvenissun]

In the latest PLoS Biology, Gerald Joyce of replicating ribozyme fame muses about the nature and probability of life in terms of information.

Bit by Bit: The Darwinian Basis of Life (PLoS Biology 10:e1001323)

All known examples of life belong to the same biology, but there is increasing enthusiasm among astronomers, astrobiologists, and synthetic biologists that other forms of life may soon be discovered or synthesized. This enthusiasm should be tempered by the fact that the probability for life to originate is not known. As a guiding principle in parsing potential examples of alternative life, one should ask: How many heritable “bits” of information are involved, and where did they come from? A genetic system that contains more bits than the number that were required to initiate its operation might reasonably be considered a new form of life.
​

(And the Great Reverse Transcription might be my new favourite scientific term.)

Should an inorganic system also be considered as a genetic system?

 

[DaneaFL]

I'm glad people are finally realizing that we don't always need to look for "earth-like" planets if we want to find life.

After learning more about chemistry I saw how it would be just as easy for life to evolve from a non-carbon/water-based ecosystem.

We could find some weird creatures based on silicon instead of carbon since silicon has many similar properties, but since water reacts violently with silicon compounds they would probably have to have sulfuric acid for blood instead! James Cameron you genius!

 

[Split Rock]

I'm glad people are finally realizing that we don't always need to look for "earth-like" planets if we want to find life.

After learning more about chemistry I saw how it would be just as easy for life to evolve from a non-carbon/water-based ecosystem.

We could find some weird creatures based on silicon instead of carbon since silicon has many similar properties, but since water reacts violently with silicon compounds they would probably have to have sulfuric acid for blood instead! James Cameron you genius!

HA! Gene Roddenberry's Star Trek came up with silicon-based life before Cameron came up with his "Aliens"
http://mimg.ugo.com/200903/9021/The_Devil_in_the_Dark_233.JPG

Interesting article on silicon-based life here:
silicon-based life

 

[Michael]

HA! Gene Roddenberry's Star Trek came up with silicon-based life before Cameron came up with his "Aliens"
http://mimg.ugo.com/200903/9021/The_Devil_in_the_Dark_233.JPG

Interesting article on silicon-based life here:
silicon-based life

FYI, I loved that episode.

I also very much enjoyed the link. Thanks. It was very interesting reading. I didn't know about the respiratory challenges to such life forms actually.

 

[Naraoia]

Should an inorganic system also be considered as a genetic system?

If it can replicate itself and transmit information, why not?

HA! Gene Roddenberry's Star Trek came up with silicon-based life before Cameron came up with his "Aliens"
http://mimg.ugo.com/200903/9021/The_Devil_in_the_Dark_233.JPG

Interesting article on silicon-based life here:
silicon-based life

It is indeed interesting. Thanks for posting!

I'm not sure the SiO[sub]2[/sub] problem is completely insurmountable. Ordinary cells do form solid objects that they then expel. Coccolithophores make relatively huge skeletal plates inside their cells. It could be too costly to get rid of shedloads of respiratory waste that way, though, and on a second thought, I don't know if we could trust simple proto-life forms to handle exocytosis... There is also a problem in the other direction - silicon fixation via SiO[sub]2[/sub] doesn't seem quite as easy as carbon fixation via CO[sub]2[/sub].

 

[Split Rock]

FYI, I loved that episode.

I also very much enjoyed the link. Thanks. It was very interesting reading. I didn't know about the respiratory challenges to such life forms actually.

One of favorites too! That and The Changeling; Mirror, Mirror; Trouble with Tribbles (everyone loves that one); Doomsday Machine.

 

[juvenissun]

In the latest PLoS Biology, Gerald Joyce of replicating ribozyme fame muses about the nature and probability of life in terms of information.

Bit by Bit: The Darwinian Basis of Life (PLoS Biology 10:e1001323)

All known examples of life belong to the same biology, but there is increasing enthusiasm among astronomers, astrobiologists, and synthetic biologists that other forms of life may soon be discovered or synthesized. This enthusiasm should be tempered by the fact that the probability for life to originate is not known. As a guiding principle in parsing potential examples of alternative life, one should ask: How many heritable “bits” of information are involved, and where did they come from? A genetic system that contains more bits than the number that were required to initiate its operation might reasonably be considered a new form of life.
​

(And the Great Reverse Transcription might be my new favourite scientific term.)

Would a computer program easily satisfy that requirement? For example, a 10K program can easily generate a lot more bits of information, or can expand itself to a larger program.

 

[Naraoia]

Would a computer program easily satisfy that requirement? For example, a 10K program can easily generate a lot more bits of information, or can expand itself to a larger program.

Interesting question. These ideas certainly make you rethink your definition of life

 

[juvenissun]

Interesting question. These ideas certainly make you rethink your definition of life

Actually, the definition of life is not a science question, but a philosophical or theological question.

 

[Naraoia]

Actually, the definition of life is not a science question, but a philosophical or theological question.

While you could make interesting philosophy out of it if you were so inclined, it certainly is a scientific question. Scientists want to talk about the properties of life, the probability of life on other worlds, and so on. A definition certainly helps one do that. IMO, neither philosophers nor theologians are likely to be much help in finding the best definition for scientific purposes.

Myself, I'm not sure we actually need an agreed-upon definition of "life". There are properties of life that various people have considered part of a definition, and they're probably better defined than life itself. I'm thinking of properties such as reproduction, metabolism and evolution. I think you can have a fruitful discussion about these phenomena and their combinations without referring to to such a vague and slippery concept as life.

(Maybe you could say the same about that other notoriously fuzzy word in the dictionary of biology, "species". Species definitions multiply like E. coli, but they could be expressed in terms of less nebulous concepts: reproductive isolation, ecological role, genetic or phenotypic cluster, whatever the most applicable species concept involves. You don't have to talk about "species" at all to discuss things like that. Like "life", "species" is a shorthand, and it's a shorthand for something different for different people.

Gods, am I in a philosophical mood tonight :o)

 

[Radagast]

While you could make interesting philosophy out of it if you were so inclined, it certainly is a scientific question. Scientists want to talk about the properties of life, the probability of life on other worlds, and so on. A definition certainly helps one do that.

It's a philosophical question, in the sense that it's decided by philosophical rather than experimental methods. However, the debate relies on scientific knowledge.

This book is of course one of the early steps towards answering it.

 

[juvenissun]

While you could make interesting philosophy out of it if you were so inclined, it certainly is a scientific question. Scientists want to talk about the properties of life, the probability of life on other worlds, and so on. A definition certainly helps one do that. IMO, neither philosophers nor theologians are likely to be much help in finding the best definition for scientific purposes.

Myself, I'm not sure we actually need an agreed-upon definition of "life". There are properties of life that various people have considered part of a definition, and they're probably better defined than life itself. I'm thinking of properties such as reproduction, metabolism and evolution. I think you can have a fruitful discussion about these phenomena and their combinations without referring to to such a vague and slippery concept as life.

(Maybe you could say the same about that other notoriously fuzzy word in the dictionary of biology, "species". Species definitions multiply like E. coli, but they could be expressed in terms of less nebulous concepts: reproductive isolation, ecological role, genetic or phenotypic cluster, whatever the most applicable species concept involves. You don't have to talk about "species" at all to discuss things like that. Like "life", "species" is a shorthand, and it's a shorthand for something different for different people.

Gods, am I in a philosophical mood tonight :o)

Academically, we don't need to have a unique definition of life. But practically, we need ONE, and not more than one.

For example, we need to define what is a life when we consider abortion. Once we have that definition, we SHOULD use the same definition for other practical considerations. Otherwise, it could not be applied to the abortion issue either.

So, we do need an acceptable definition of life. May be we should put this issue on the election ballot.

 

[juvenissun]

It's a philosophical question, in the sense that it's decided by philosophical rather than experimental methods. However, the debate relies on scientific knowledge.

This book is of course one of the early steps towards answering it.

The development of AI confused everything. Cloning is another bombshell.

 

[Radagast]

The development of AI confused everything. Cloning is another bombshell.

Great successes in AI might confuse things, but that hasn't happened yet. And cloning doesn't affect the definition of life, surely?

 

[juvenissun]

Great successes in AI might confuse things, but that hasn't happened yet. And cloning doesn't affect the definition of life, surely?

Would the killing of a human clone the same as the killing of the original human? If I have 5 clones, could I treat them as biological robots?

 

[juvenissun]

Great successes in AI might confuse things, but that hasn't happened yet. And cloning doesn't affect the definition of life, surely?

How do you count a human with X% nano-robots in his body? What is the number of the X, so the individual is not a human, or a life, any more? I guess it is possible to make the X a real number in a few decades.

How much of a human is still alive if all legs and arms are artificial?

 

[Elendur]

Would the killing of a human clone the same as the killing of the original human? If I have 5 clones, could I treat them as biological robots?

Of course the clones are equal. Do you treat children bad just because they're small copies of the parents?

 

[Radagast]

Of course the clones are equal. Do you treat children bad just because they're small copies of the parents?

Indeed. Clones are just identical twins of the original who have a different birthday.

 

[Naraoia]

It's a philosophical question, in the sense that it's decided by philosophical rather than experimental methods. However, the debate relies on scientific knowledge.

Good point. I guess I just don't tend to see such practical issues as "philosophical". Says a lot about my feelings towards philosophy

Academically, we don't need to have a unique definition of life. But practically, we need ONE, and not more than one.

For example, we need to define what is a life when we consider abortion. Once we have that definition, we SHOULD use the same definition for other practical considerations. Otherwise, it could not be applied to the abortion issue either.

It already can't. Even by stricter definitions of life used in biology, a being consisting of a single cell that contains genetic information, metabolises, regulates its internal environment, and divides, is alive. If the abortion debate had anything to do with the scientific definition of life, it simply wouldn't exist.

So, we do need an acceptable definition of life. May be we should put this issue on the election ballot.

Oh, gods no. That would be a terrible idea.

Indeed. Clones are just identical twins of the original who have a different birthday.

Well put!