Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Tibor Gánti's ideas about the origins of life

nationalgeographic.com

Post reply on HN
Print view View original

31–40 of 143 posts

Re: Tibor Gánti's ideas about the origins of life

#31

Post by dekhn »

adrian_b wrote: post #23
angst_ridden wrote: post #10

Earlier quoted context omitted.

I think you've got a minority opinion calling crystals "alive," although it does jibe with one definition of life that I heard: "any self-sustaining system that reduces internal entropy."

While obviously crystals are not alive, they satisfy more careless definitions of life that were sometimes encountered, i.e., when put in a "nutritive" solution, they are able to grow and reproduce themselves.

This is just wrong (as you say, careless). The criteria is "metabolism", not growth and reproduction. Similarly, viruses are not alive although they can reproduce. Interestingly, there are some highly parasitic organisms with limited ability to metabolize, that is, they have lost their genes and instead depend on their host organism (but I think all those examples still have some level of metabolic capability).

Re: Tibor Gánti's ideas about the origins of life

#32

Post by Ericson2314 »

adrian_b wrote: post #27
Ericson2314 wrote: post #5

Considering that the first proto-computers were not programmable, I can't help but be skeptical that the first life needed genetic material. Certainly there were lipid membranes. Maybe there were spontaneous proteins, maybe there was purely-catalytic RNA. I guess it's also a matter of line drawing. I'm OK with calling crystals life, for example. One should feel bad about breaking up big ones the same as one should fe…

It is pretty certain that the first life did not use any kind of genetic material, because that is impossible. When RNA or any other kind of genetic material first appeared, the first thing that must have been possible to do with it was to copy it, a.k.a. to replicate it. If the genetic material was used first to do anything useful, e.g. to control protein synthesis or to catalyze directly any useful reaction, that g…

Have you seen the research of Ribosomes being quine-like? (the structural nucleic acids and genes for the protein parts are related).

Re: Tibor Gánti's ideas about the origins of life

#33

Post by Ericson2314 »

dekhn wrote: post #31
adrian_b wrote: post #23

Earlier quoted context omitted.

While obviously crystals are not alive, they satisfy more careless definitions of life that were sometimes encountered, i.e., when put in a "nutritive" solution, they are able to grow and reproduce themselves.

This is just wrong (as you say, careless). The criteria is "metabolism", not growth and reproduction. Similarly, viruses are not alive although they can reproduce. Interestingly, there are some highly parasitic organisms with limited ability to metabolize, that is, they have lost their genes and instead depend on their host organism (but I think all those examples still have some level of metabolic capability).

I don't really know what "metabolism" means, abstractly. I am deader than a virus without chloroplasts existing elsewhere. Viruses need a host for the productive bit, I had food for the non-reproductive bit. Viruses don't break down fast enough compared to their abundance to cause extinction, so why fault them for optimizing?

People commonly theorize that virus came from rump parasitic cells. I wouldn't be surprised if at some point a huge virus with a membrane accidentally picked up enough stuff to become a cell again. To go back to chloroplasts again, it would be like how brown algae is an ex-heterotroph.

Re: Tibor Gánti's ideas about the origins of life

#34

Post by sterlind »

dekhn wrote: post #31
adrian_b wrote: post #23

Earlier quoted context omitted.

While obviously crystals are not alive, they satisfy more careless definitions of life that were sometimes encountered, i.e., when put in a "nutritive" solution, they are able to grow and reproduce themselves.

This is just wrong (as you say, careless). The criteria is "metabolism", not growth and reproduction. Similarly, viruses are not alive although they can reproduce. Interestingly, there are some highly parasitic organisms with limited ability to metabolize, that is, they have lost their genes and instead depend on their host organism (but I think all those examples still have some level of metabolic capability).

Viruses need a host environment to replicate. Fish need water and plant life or other fish to replicate. Algae needs nutrients to replicate. Every lifeform can only exist in some host environment. Viruses simply happen to have biological host environments, right?

Re: Tibor Gánti's ideas about the origins of life

#35

Post by pnut »

matz1 wrote: post #21
Ericson2314 wrote: post #7

Earlier quoted context omitted.

I don't think so. Primitive proto-life has little moral value, just as vegans eat plants, hypothetical super-vegans only eat blue-green bacteria, and hypothetical hyper-vegans have a 500 year deadline to be electrically powered. I don't believe in a hard barrier between life and non life, so any discrete moral function would be non-computable, and therefore I reject it outright.

I don't believe in hard barrier between life and non life but interestingly the barrier between human and non human animal are seemingly very discrete.

Considering the radical diversity in the spectrum of human cognitive capabilities, I'm not so sure it's a discrete transition from non-human to human.

What is a human?

Re: Tibor Gánti's ideas about the origins of life

#36

Post by sthnblllII »

> many biological molecules can be constructed from just six simple molecules, including water, methane...

There is no news here. This is just the same speculation that has been made thousands of times before for decades. Of course we can make big molecules from small ones in a lab. Of course life has to reproduce, metabolize and have a boundary from the environment. Pointing this out is not "the key to the origins of life". It is still an interesting topic, but why cant national geographic discuss these things honestly?

Re: Tibor Gánti's ideas about the origins of life

#37

Post by offtop5 »

kvetching wrote: post #18

Related to this; Check out the book The Revolutionary Phenotype. "The Revolutionary Phenotype is a science book that brings us four billion years into the past, when the first living molecules showed up on Planet Earth. Unlike what was previously thought, we learn that DNA-based life did not emerge from random events in a primordial soup. Indeed, the first molecules of DNA were fabricated by a previous life form. By…

Thanks , purchased

Re: Tibor Gánti's ideas about the origins of life

#38

Post by posterboy »

sthnblllII wrote: post #36

> many biological molecules can be constructed from just six simple molecules, including water, methane... There is no news here. This is just the same speculation that has been made thousands of times before for decades. Of course we can make big molecules from small ones in a lab. Of course life has to reproduce, metabolize and have a boundary from the environment. Pointing this out is not "the key to the origins o…

> and have a boundary from the environment

This is not self evident. Maybe this is the news?

I am not sure, what are you saying?

Re: Tibor Gánti's ideas about the origins of life

#39

Post by breck »

Has anyone seen a visual tree of life that starts before life on earth?

Or in other words, say at some point we discover aliens in a distance galaxy. Would we be cousins? Are there visualizations that show what that kind of family tree would look like?

I am a neophyte in this area but I'm sure there's a lot of good research out there.

Re: Tibor Gánti's ideas about the origins of life

#40

Post by Jweb_Guru »

matz1 wrote: post #21
Ericson2314 wrote: post #7

Earlier quoted context omitted.

I don't think so. Primitive proto-life has little moral value, just as vegans eat plants, hypothetical super-vegans only eat blue-green bacteria, and hypothetical hyper-vegans have a 500 year deadline to be electrically powered. I don't believe in a hard barrier between life and non life, so any discrete moral function would be non-computable, and therefore I reject it outright.

I don't believe in hard barrier between life and non life but interestingly the barrier between human and non human animal are seemingly very discrete.

Are they? Some primates have better working memory than we do, for example. Of course we would never confuse another species for a human, but I also think we would not confuse a domestic house cat for anything else despite them coming in many shapes, sizes and colors, so I assume you mean something more profound than just that we look visually different.
Post reply on HN