The Origins of Life on Earth

[Brian G Turner]

A couple of interesting videos on YouTube about the origins of life on Earth I thought I'd share:

 

[RJM Corbet]

No final truth, no highest light, just always more questions, imo ...

 

[Brian G Turner]

Questions are good.

If there's one thing I learned in school is that science is full of mystery, and to me that's what makes it compelling.

After all, if science had all the answers, there'd be no point studying it because there'd be nothing new to learn.

 

[Venusian Broon]

No final truth, no highest light, just always more questions, imo ...

Does any question have a 'final' truth, other than trivial ones and tautologies?

A great deal of the questions asked by Greek philosophers over two and half thousand years ago remain unanswerable. So we know that some questions are really hard to answer

 

[RJM Corbet]

After all, if science had all the answers, there'd be no point studying it because there'd be nothing new to learn.

Of course that's not what I'm saying. I'm saying a couple of these bright young men sound supremely confident that there IS an answer. One of them pastes up a four-point definition of life that includes abiogenesis origin as part of the definition. Absolutely certain. Already decided. But the origin of life may keep receding the closer 'we' get. There may not be a LUKA. No definite certainty. Not ever.

Sure 'we' need to keep looking. These guys assume LUKA is definite and certain, just around the corner, but it may not be. It may be an 'uncertainty principle' sort of thing. Solutions to what life is are never going to be simple. Imo. I find them rather superficial actually, except for the PBS guy. He is much more nuanced in his talks.

 

[Dave]

I admit that I didn't watch all of both those films, I had just skimmed them to see if there was anything that I didn't already know about. Certainly, the idea of the the pre-cellular bodies sharing information rather than replicating themselves is, to me, an additional step back, and is closing the gap between primordial soup and life as we know it. I hadn't heard of LUKA but DNA analyses has advanced so far in recent years that I should have expected that research was going on.

These guys assume LUKA is definite and certain, just around the corner, but it may not be.

LUKA is just a name, much the same as "Lucy" the AL 288-1 Australopithecus afarensis. Genetically, as shown in the film, a single progenitor like LUKA must have existed, and would have lived around hydrothermal vents. I thought that was well explained. However, it will no longer exist today, so I'm not sure what you mean by "just around the corner," because there will be no fossil or physical evidence to be found. That genetic evidence (which is compelling) may be the best that we can ever get as far as proof.

 

[RJM Corbet]

LUKA is just a name, much the same as "Lucy" the AL 288-1 Australopithecus afarensis.

Of course LUKA is just a name.

... a single progenitor like LUKA must have existed, and would have lived around hydrothermal vents. I thought that was well explained. However, it will no longer exist today, so ...

It means there must have been a point at which life became life, at the end of a process? I'm saying it may turn out to be more like the 'uncertainty principle' -- something can never by its nature be pinned down?

I'm saying that there's a bit of confirmation bias around hydrothermal vents, etc. It's speculative. Highly speculative, actually. But it's presented as really pretty much certain? Perhaps it's just the 'breezy' You Tube manner of presentation, but I find the speakers' certainty quite irritatingly over confident.

EDIT: Said my bit. I'm outta this one ...

 

[Dave]

I'm sure you understood it, but their confidence is the chemical evidence - that that combination of elements is found nowhere else on Earth.

I'm more astonished by what it is possible to know from the genetic studies but I shouldn't be as this field has advanced more quickly than anything else in the last few decades. Did you know they could take a sample of seawater or river water, and tell you every species that lives there from a DNA analysis? You don't need to wait around or to use any nets.

It means there must have been a point at which life became life, at the end of a process?

There doesn't need to be a process with a beginning and an end. It is just random circumstances resulting in one that eventually works. There were thousands of millions of years of trials.

I don't know if there is an equivalent in science, but in history it is called a "Whig Model" - that everything is perceived as a straight line from the past to the present - there is really no such thing, it doesn't exist. History is much more complicated and full of random events. Evolution used to be viewed in this same way, generally because people believed that divine intervention was necessary for "life" to exist. That the addition of some kind of "spark" was a necessary prerequisite before life became "life." So, that point was pushed further and further back in time. Now, scientists are becoming much more open about what "life" actually is. Wouldn't self replicating A I 'Terminator' machines fit all of the criteria of "life?" Stephen Hawking even suggested that a complex computer virus could be viewed as "life." As discussion of religion is not allowed I cannot provide further detail in that regard but I don't believe there is any point where life became life, and so looking for such a point is futile.

 

[RJM Corbet]

There doesn't need to be a process with a beginning and an end. It is just random circumstances resulting in one that eventually works.

I understand this too. I did not say a linear process.

As discussion of religion is not allowed I cannot provide further detail in that regard but I don't believe there is any point where life became life, and so looking for such a point is futile.

Where does religion come into it?

Leaving aside Stephen Hawking's well known 'life' application to computer viruses and his prediction that AI will push human intelligence aside and take over, there may not be a hairline crossing where non-life became life, but the 'quest for LUKA' implies some defined ... area then ... at which life became life? Isn't that exactly what the guy is saying?

Like you, I disagree. It'll will-o-the-wisp away forever, imo.

@Dave I came back in to correct the idea that I am talking simplistically about a clear linear process (of abiogenesis). However my knowledge is not enough to continue here, although it would be good to hear what other people think because these Chrons science discussions are quite educational, at least for me they are.

 

[RJM Corbet]

It's not directly on topic to the thread. But this is the PBS latest talk, 18/07/2019. I like the way this guy goes about his business. He isn't making definitive/authoritative statements and he retains the open attitude that properly defines 'the scientific method'. I look forward to the next installment:

 

[RJM Corbet]

 

[Venusian Broon]

Yeah, isn't mathematics wonderful

 

[Robert Zwilling]

Make Lucas plural, last universal common ancestor, put the s at the end so it reads speculations, but at the same time means more than one. The lucas line that precedes the genetic structure we are aware of is more like a shadow or a silhouette of a large group of entities just like the rest of the tree that comes after it. The tree before the current tree. It probably doesn't make any sense to attach our DNA observations to the tree that came before our tree, and maybe a different tree came before that one. Maybe if the single line used by the charts is seen as a strand of lines that would look better. All too often we look for the single cause when there are multiple causes driving events. If the tree before ours worked like training wheels on a child's bicycle or like booster rockets on a space capsule launch then the training wheels or booster rocket would never show up at the final destination and just looking at the wheels or the booster rocket might never yield any clues as to what the capsule or bicycle looked like even though there is much similarity.

The hydrothermal vents provide a good explanation for where life starts on any planet with a hot core. It is an automated process that is pretty robust and can self start under a wide variety of circumstances. The water is already there, the required elements are in the minerals coming out of the planet's core, a mechanical process that in no way guarantees what kind of results will development but it keeps on pumping. Might not even need a sun close by and is completely independent of things like photosynthesis. The life that eventually forms is dependent on the characteristics of the physically evolving planet. Much the same way history is randomly shaped by peoples discovery of the environment and their interactions with the environment and other people on a personal and impersonal manner. History goes forward the way the tides wash stuff up on the beach, things are going to wash up and you have a rough idea, but the content is never completely predictable.

I favor the idea that the Earth's water came out of the interior as it cooled down. Supposedly there is at least as much or maybe 2 or 3 times as much water locked inside minerals as there is on the surface. If the water was packed inside the interior as the molten Earth first solidified it would make it very easy for the water to make it's way to the surface by simply being burped out as the Earth matures, No need for comets or other strange things happening in the chaotic dust cloud of formation. Another automatic early life formation process that answers a lot of questions but still leaves the development of the life that comes afterwards completely random.

Bacteria use horizontal gene transfer to fortify the overall structure of the bacterial world. That process resembles data packet transfer protocol that handles old, new, delayed, and random requests to transfer data. If insects and bacteria are inserting genes into our genome on a random basis that could impede or enhance our genetic evolution, probably does both. Maybe it is supposed to be that way.

 

[Dave]

Where does religion come into it?

It has the need for a "creator" of "Life" and therefore implies that such a point at which "non-Life" becomes "Life" must exist, because Life was only created by the "creator." Many people still believe this and I don't wish to begin a long drawn out argument on something that cannot be proven either way.

...there may not be a hairline crossing where non-life became life, but the 'quest for LUKA' implies some defined ... area... at which life became life? Isn't that exactly what the guy is saying?

I think we are actually on the same page. As I said, I didn't watch the whole video, so if "the guy" implied this then I don't agree with him either. I agree with what @Robert Zwilling just outlined. I think we will increasingly break down any barrier we have artificially created to define "Life" and "non-life" as being different things. I see that sharing on information between 'whatever it is we want to call it' as an important stage prior to self-replication, that fills in one of the gaps between them.

I think that we will come to question "what is Life?" again and again as we delve deeper.

 

[RJM Corbet]

I think we will increasingly break down any barrier we have artificially created to define "Life" and "non-life" as being different things.

Sorry. You've lost me?

I see that sharing on information between 'whatever it is we want to call it' as an important stage prior to self-replication, that fills in one of the gaps between them. I think that we will come to question "what is Life?" again and again as we delve deeper.

Late edit. Ok, I understand.

 

[Dave]

Without labouring the point, the reason I think this is important is only because we blithely talk about "The origin of Life" and try to discover if there is "Life on other planets," and on these missions to other planets, false positives have been found that were dismissed as merely "chemical reactions." However, we might discover at some future point that the problem of finding Life lies with the setting of our actual question itself, particularly in regard to these underwater hydrothermal vents.

 

[BAYLOR]

Without labouring the point, the reason I think this is important is only because we blithely talk about "The origin of Life" and try to discover if there is "Life on other planets," and on these missions to other planets, false positives have been found that were dismissed as merely "chemical reactions." However, we might discover at some future point that the problem of finding Life lies with the setting of our actual question itself, particularly in regard to these underwater hydrothermal vents.

If life evolved here then, given the size of the universe and how many possible earth-like planets , there's a more than reasonable chance that it exists elsewhere.

 

[Brian G Turner]

there's a more than reasonable chance that it exists elsewhere.

If life exists here, then either:

1. Life is an ordinary expression of the physical laws of the universe, and will therefore arise wherever conditions favor it across the universe,
2. It was a miraculous event that goes against the physical laws of the universe, and therefore can only exist on Earth.

I definitely favour #1.

 

[RJM Corbet]

There's a third:

Life originated here, against incredible odds, is not at all ordinary, and therefore is quite possibly unique to our world? Or at least to our galactic cluster, or whatever?

 

[Brian G Turner]

There's a third:

Life originated here, against incredible odds, is not at all ordinary, and therefore is quite possibly unique to our world? Or at least to our galactic cluster, or whatever?

That's certainly a very empirical point of view. After all, a lot of scientists refused to accept the possibility of other planets around other stars until we saw them, for probably the same reason.

However, IMO it contains the same bias - that we are somehow special and miraculous, and an exception to the laws of the natural sciences that otherwise govern our universe.

Some will disagree.