LUCA lived 4.2B years ago

[NxNW]

Every living thing on Earth evolved from one common ancestor

New research reveals LUCA, Earth’s last universal common ancestor, was a complex organism shaping early ecosystems 4.2 billion years ago.​

A global research team, led by evolutionary biologists at the University of Bristol, set out to uncover LUCA’s age. They used a mix of tools, including fossil records, isotopic data, and genetic timelines. By analyzing ancient genes that had duplicated even before LUCA existed, the team could track back further than ever before.

Their findings point to an organism that lived about 4.2 billion years ago. That’s earlier than many scientists expected—possibly before the violent asteroid storms of the Late Heavy Bombardment,
which peaked between 3.7 and 3.9 billion years ago. The results suggest life may have endured even the most hostile conditions on early Earth. (...)

 

[Ophiolite]

The results suggest life may have endured even the most hostile conditions on early Earth.

Or that some aspect of their phylogenetic analysis was flawed. I would prefer to see these results studied and confirmed by other research teams, ideally with diverse methodologies before accepting this result as probable.

The researchers state that this was already quite a complex organism (for an early lifeform). If their conclusions are true two possible implications spring to my mind:

1. Life arose in a remarkably short (geological) time frame. I would almost say, astoundingly quickly. Was this just a one in many trillions chance, or is it really just inevitble that life will appear on any terrestrial world in the Goldilock's zone. If the latter, then life must be abundant throughout the universe.
2. Alternatively, life did not arise here, but arrived by spores, as per the pan spermia hypothesis. Which would also suggest that life is abundant throughtout the universe,

The same conclusion arising from the two most obvious (to me) explanations for their observations is intersting.

(I've placed a side-bet with myself on three responses from specific members. I'll let you know if I get them right/wrong. )

 

[dlamberth]

Every living thing on Earth evolved from one common ancestor

New research reveals LUCA, Earth’s last universal common ancestor, was a complex organism shaping early ecosystems 4.2 billion years ago.​

A global research team, led by evolutionary biologists at the University of Bristol, set out to uncover LUCA’s age. They used a mix of tools, including fossil records, isotopic data, and genetic timelines. By analyzing ancient genes that had duplicated even before LUCA existed, the team could track back further than ever before.

Their findings point to an organism that lived about 4.2 billion years ago. That’s earlier than many scientists expected—possibly before the violent asteroid storms of the Late Heavy Bombardment,
which peaked between 3.7 and 3.9 billion years ago. The results suggest life may have endured even the most hostile conditions on early Earth. (...)

The linked article in the OP is an interesting read.

If the theory that a Mars size planet crashed into the Earth some 4.5 Billion years ago is true, the violent force of that collision would have turned the Earth inside out. The force would have been so great that there would have been a reset of the Earth. With that scenario in mind, LUCA would have happened within 300 million years after that collision. Could the Earth have cooled down enough and arrange itself in that time frame for life to even begin?

 

[Ophiolite]

. With that scenario in mind, LUCA would have happened within 300 million years after that collision. Could the Earth have cooled down enough and arrange itself in that time frame for life to even begin?

As you might expect there are quite a wide range of estimates for the time interval, but most seem to be in the 10 to 50 million year range. But I still find it astounding that (a) life could emerge in that time frame and (b) become comparatively complex as well. Of course, I've noticed that the universes rarely pays any heed to my classic exhibition of Dunning-Kruger behaviour.

This paper is relevant to your question: Sleep, N. H., Zahnle, K. J., Kasting, J. F., & Morowitz, H. J. (1989). “Annihilation of ecosystems by large asteroid impacts on the early Earth.” Nature, 342(6246), 139–142. It is available online (copy the citation into Google scholar)

Sleep and Kasting have a sound pedigree in planetary science and the paper was published in Nature, so though it is not recent I think the science is sound. They take heed of the probable Mars sized impact, but focous on the likely size, frequency and effect of later, large, sanitising strikes.

 

[SelfSim]

Or that some aspect of their phylogenetic analysis was flawed. I would prefer to see these results studied and confirmed by other research teams, ideally with diverse methodologies before accepting this result as probable.

The researchers state that this was already quite a complex organism (for an early lifeform). If their conclusions are true two possible implications spring to my mind:

1. Life arose in a remarkably short (geological) time frame. I would almost say, astoundingly quickly. Was this just a one in many trillions chance, or is it really just inevitble that life will appear on any terrestrial world in the Goldilock's zone. If the latter, then life must be abundant throughout the universe.
2. Alternatively, life did not arise here, but arrived by spores, as per the pan spermia hypothesis. Which would also suggest that life is abundant throughtout the universe,

The same conclusion arising from the two most obvious (to me) explanations for their observations is intersting.

A conclusion arising from speculative explanations, is a speculative conclusion.

(I've placed a side-bet with myself on three responses from specific members. I'll let you know if I get them right/wrong. )

Can I claim a cut of the winnings?

 

[Ophiolite]

Can I claim a cut of the winnings?

Well, your response fell comfortably within the predicted parameters (including being the first, and perhaps only, to reply.)

 

[eleos1954]

Every living thing on Earth evolved from one common ancestor

New research reveals LUCA, Earth’s last universal common ancestor, was a complex organism shaping early ecosystems 4.2 billion years ago.​

A global research team, led by evolutionary biologists at the University of Bristol, set out to uncover LUCA’s age. They used a mix of tools, including fossil records, isotopic data, and genetic timelines. By analyzing ancient genes that had duplicated even before LUCA existed, the team could track back further than ever before.

Their findings point to an organism that lived about 4.2 billion years ago. That’s earlier than many scientists expected—possibly before the violent asteroid storms of the Late Heavy Bombardment,
which peaked between 3.7 and 3.9 billion years ago. The results suggest life may have endured even the most hostile conditions on early Earth. (...)

"possibly" and "suggests" means they don't know

 

[Laodicean60]

"possibly" and "suggests" means they don't know

And there a a lot of those kinds of words when it comes to origins in science.

 

[Larniavc]

And there a a lot of those kinds of words when it comes to origins in science.

And in fact, ALL science. As I know that you know that science is a tentative venture.

 

[SelfSim]

Well, your response fell comfortably within the predicted parameters (including being the first, and perhaps only, to reply.)

I feel honoured to be so predictable.

Coming back to your post #2, and in the spirit of rising to the challenge of elevating ourselves beyond our own opinions, I remain truly intrigued by the approach which leads to the inference that 'life must be abundant throughout the universe' and the weaker suggestion that 'life is abundant throughout the universe'.

I agree that both are logically sound .. but so too, is the argument that 'life does not exist' in the first place .. (yet paradoxically, here we are). If life is not a property of matter, and 'material' things are what exist, then life does not exist. The logic leading to 'life is abundant throughout the universe' is thus flawed .. because it rests solely on an insufficiently objective definition and theory, for 'what life is'. (Or: 'Why Life?')

This missing definition is all important when it comes to support for logical generalisations attempting to include the Universally distributed case. (Ie: Unless you can provide illumination?)

 

[Ophiolite]

I feel honoured to be so predictable.

Coming back to your post #2, and in the spirit of rising to the challenge of elevating ourselves beyond our own opinions, I remain truly intrigued by the approach which leads to the inference that 'life must be abundant throughout the universe' and the weaker suggestion that 'life is abundant throughout the universe'.

I agree that both are logically sound .. but so too, is the argument that 'life does not exist' in the first place .. (yet paradoxically, here we are). If life is not a property of matter, and 'material' things are what exist, then life does not exist. The logic leading to 'life is abundant throughout the universe' is thus flawed .. because it rests solely on an insufficiently objective definition and theory, for 'what life is'. (Or: 'Why Life?')

This missing definition is all important when it comes to support for logical generalisations attempting to include the Universally distributed case. (Ie: Unless you can provide illumination?)

Interesting. I must leave it to future Ophiolite to respond as the terminator, with a small 't' passed her a few hours ago.

 

[AV1611VET]

A global research team, led by evolutionary biologists at the University of Bristol, set out to uncover LUCA’s age. They used a mix of tools, including fossil records, isotopic data, and genetic timelines. By analyzing ancient genes that had duplicated even before LUCA existed, the team could track back further than ever before.

And to think:

Ancestry.com can only go back approximately 6 to 8 generations.

Either ancestry needs better tools, or science is pulling our legs.

 

[jacks]

I'd never heard of LUCA before, so had to look it up. It seems to be one of several competing theories on similar DNA, etc. There is of course no fossil records. (from my AI, I don't know enough to figure it out myself. ) include:

Convergent Evolution: This occurs when different species independently evolve similar traits or genetic sequences due to similar environmental pressures or challenges. For example, the wings of bats and birds are structurally different but serve the same function, illustrating how similar traits can arise independently.
Horizontal Gene Transfer: This is the transfer of genetic material between organisms in a manner other than traditional reproduction. It is particularly common in bacteria, where genes can be exchanged through processes like transformation, transduction, or conjugation. This can lead to similarities in DNA among unrelated species.
Genetic Drift: This is a mechanism of evolution that involves random changes in allele frequencies within a population. Over time, genetic drift can lead to similarities in DNA among populations, especially in small populations where chance events can have a larger impact.
Gene Duplication and Divergence: Genes can be duplicated in an organism's genome, and over time, these duplicates can evolve new functions or become non-functional. This can lead to similarities in DNA sequences as well as the emergence of new traits.
Functional Constraints: Certain genes and genetic sequences may be under strong functional constraints, meaning that they must maintain specific functions to be viable. This can lead to conservation of certain DNA sequences across different species, even if they do not share a recent common ancestor.

So it's a very interesting article, but it isn't claiming to be the end all explanation. It's a is a theory within a theory.

 

[Ophiolite]

And to think:

Ancestry.com can only go back approximately 6 to 8 generations.

Either ancestry needs better tools, or science is pulling our legs.

Or, Ancestry.com has the simplified, largely automatic, context restricted tools, which permit the rapid processing of large volumes of samples to generate formulaic results that satisfy an enquiring clientele for a reasonable price and an acceptable profit. In contrast a large team of researchers are using several sophisticated, time-consuming, expensive, cutting-edge tehcniques, to develop methodologies, gather data, establish baselines, validate and cross results, in order to arrive at a subtle, insightful provisional insight into an intriguing problem.

But I understand that such contrasts are of no interest to you and indeed are unwelcome, since they contradict and refute your narrow-minded, fact-free perception of the research.

 

[AV1611VET]

But I understand that such contrasts are of no interest to you and indeed are unwelcome, since they contradict and refute your narrow-minded, fact-free perception of the research.

So you agree with me that Ancestry needs better tools?

 

[Ophiolite]

So you agree with me that Ancestry needs better tools?

No! Read what I wrote! No. Not in the slightest. I disagree with you completely! Are you trying for a slot in Trump's cabinet? Ancestry has a fine set of tools for the simple job it sets out to do. How could anyone interpret what I wrote as meaning I agree with you, or was that a fifth rate, 1st grade, effort at what, in your befuddled mind, passes as sarcasm?

 

[AV1611VET]

No! Read what I wrote! No. Not in the slightest.

Then what's keeping them from going beyond 8 generations?

You mentioned "context restricted tools."

That sounds like fancy talk for needing better equipment.

 

[Ophiolite]

Then what's keeping them from going beyond 8 generations?

You mentioned "context restricted tools."

That sounds like fancy talk for needing better equipment.

Market forces. Weak customer desire. Disproportionate cost. Larger error bars on the data clients are interested in. Inertia to change coincident with the stage of organisational development Ancestry is at. There a plethora of possibilities, none of which are of any interest to me, since they have zero relationship to the research introduced in the OP.

A luxury automobile is comparatively useless for driving across waterlogged, muddy ground because that is not in its design objectives. That's why they don't figure out a way of fitting it with tank treads.

And if you still don't get it, context restricted tools are where you don't provide something that is either not needed, or is to expensive for the application. (And by the way, you've done nothing to establish that there is any good reason to "go beyond eight generations". )

 

[J_B_]

As you might expect there are quite a wide range of estimates ...

'Estimate' may be the operative word, or maybe more so 'assumptions', i.e. what any particular study on the matter is assuming about what I would expect to be a very noisy, very data-thin past.

 

[SelfSim]

So I asked our friendly AI Gemini the following question:

'Are there any post publication critiques of the paper: 'The nature of the last universal common ancestor and its impact on the early Earth system'?'

The response follows (my emboldenments):

'Yes, the paper "The nature of the last universal common ancestor and its impact on the early Earth system" has been subject to various critiques and discussions following its publication. These critiques often focus on specific aspects of the study, such as the proposed age of LUCA, the nature of its metabolism, and the implications for early Earth ecosystems.

Here's a more detailed breakdown of the post-publication critiques:

1. Age of LUCA:

• The paper proposes an age of approximately 4.2 billion years ago for LUCA, based on divergence time analysis of pre-LUCA gene duplicates, calibrated using microbial fossils and isotope records.
  
  
• While this age is within the range of other estimates, it's still a subject of ongoing debate, as different methods and datasets can lead to varying age estimates.
  
  
• Some critiques have questioned the assumptions and limitations of the specific methods used to estimate the age, particularly regarding the calibration of divergence times.
  

2. Nature of LUCA's Metabolism:

• The paper proposes that LUCA was a prokaryote-grade anaerobic acetogen, meaning it likely utilized anaerobic respiration and produced acetate as a byproduct.
  
  
• This proposal has been met with mixed reactions, as some argue that LUCA's metabolism could have been more complex or even dependent on geochemistry.
  
• Critics have pointed to the potential role of other metabolisms in early life, such as methanogenesis, and the limitations of current evidence for a solely acetogenic LUCA.
  

3. Impact on Early Earth Systems:

• The paper suggests that LUCA played a significant role in the development of early Earth ecosystems, likely as a part of an established ecological system.
  
  
• Some critiques have questioned the extent to which LUCA's metabolism and ecological niche impacted the early Earth, particularly regarding the role of acetate in the development of other metabolisms.
  
• Others have emphasized the importance of geochemical factors and other potential players in the early Earth environment, suggesting that LUCA's impact may have been less profound than suggested in the paper.
  

4. Methodology and Interpretation:

• Several critiques have focused on the methodologies used in the study, particularly the use of phylogenetic reconciliation and divergence time analysis.
• Some have raised concerns about the potential for artifacts and biases in these methods, which could lead to inaccurate inferences about LUCA's nature and its impact.
• Others have questioned the interpretation of the results, suggesting that the findings may be open to alternative explanations or interpretations.
  

In essence, the paper's findings have been met with a mix of acceptance and further questioning, highlighting the ongoing debate and complexity of understanding the nature of LUCA and its role in the early evolution of life on Earth'.