LUCA (Introduction)
by George Jelliss 
, Crewe, Monday, January 20, 2025, 10:26 (1 day, 23 hours, 34 min. ago)
I came across this article on the Last Universal Common Ancestor (LUCA)
and thought you might be interested.
https://www.nature.com/articles/s41559-024-02461-1
It's a long time since I visited the Agnostic Web.
Hope you are all well.
Happy new year.
George Jelliss
--
GPJ
LUCA
GEORGE: I came across this article on the Last Universal Common Ancestor (LUCA)
and thought you might be interested.
https://www.nature.com/articles/s41559-024-02461-1
It's a long time since I visited the Agnostic Web. Hope you are all well.
Happy new year.
Delighted to see this, George, and to know that you are still with us after all these years.
David will speak for himself, but I've missed your very informative and stimulating contributions, which provided a good balance between David's and my own. But I guess we had reached a dead end in our discussions at that time.
Thank you very much for thinking of us and sending in this article. I'll need time to read and digest it, and will respond tomorrow.
Happy new year to you too.
LUCA
by David Turell , Monday, January 20, 2025, 19:28 (1 day, 14 hours, 32 min. ago) @ dhw
GEORGE: I came across this article on the Last Universal Common Ancestor (LUCA)
and thought you might be interested.https://www.nature.com/articles/s41559-024-02461-1
It's a long time since I visited the Agnostic Web. Hope you are all well.
Happy new year.
dhw: Delighted to see this, George, and to know that you are still with us after all these years.
David will speak for himself, but I've missed your very informative and stimulating contributions, which provided a good balance between David's and my own. But I guess we had reached a dead end in our discussions at that time.Thank you very much for thinking of us and sending in this article. I'll need time to read and digest it, and will respond tomorrow.
Happy new year to you too.
The article provides a different estimate of LUCA age and size. The striking point is how quickly life appeared after the Earth formed. Strongly supports the concept of a designer at work.
LUCA
GEORGE: I came across this article on the Last Universal Common Ancestor (LUCA)
and thought you might be interested.
https://www.nature.com/articles/s41559-024-02461-1
I’m afraid this huge article is mostly way beyond my range of comprehension. However, I did note a couple of passages which raised questions, but I’ll be quite happy if someone can point out what I’m missing.
QUOTE: By definition, we cannot reconstruct LUCA’s contemporaries using phylogenomics but we can propose hypotheses about their physiologies based on the reconstructed LUCA whose features immediately suggest the potential for interactions with other prokaryotic metabolisms.
If there were other “prokaryotic metabolisms” living at the same time, what is the point of singling out LUCA? If they were all interacting, could LUCA not have been one particular community of prokaryotic metabolisms?
QUOTE: A chemoautotrophic acetogenic LUCA could have occupied two major potential habitats (Fig. 3e): the first is the deep ocean […] The second habitat is the ocean surface […] Another possibility may be that LUCA inhabited a shallow hydrothermal vent or a hot spring.
Back where we started – nobody knows which it was?
QUOTE: How evolution proceeded from the origin of life to early communities at the time of LUCA remains an open question, but the inferred age of LUCA (~4.2 Ga) compared with the origin of the Earth and Moon suggests that the process required a surprisingly short interval of geologic time.
DAVID: The article provides a different estimate of LUCA age and size. The striking point is how quickly life appeared after the Earth formed. Strongly supports the concept of a designer at work.
4.2 billion years is “inferred” and approximate. How do you and the authors know the length of time it normally takes for life to appear and complexify?
I’d be interested to hear George’s own views.
LUCA
by David Turell , Tuesday, January 21, 2025, 18:03 (15 hours, 57 minutes ago) @ dhw
GEORGE: I came across this article on the Last Universal Common Ancestor (LUCA)
and thought you might be interested.
https://www.nature.com/articles/s41559-024-02461-1I’m afraid this huge article is mostly way beyond my range of comprehension. However, I did note a couple of passages which raised questions, but I’ll be quite happy if someone can point out what I’m missing.
QUOTE: By definition, we cannot reconstruct LUCA’s contemporaries using phylogenomics but we can propose hypotheses about their physiologies based on the reconstructed LUCA whose features immediately suggest the potential for interactions with other prokaryotic metabolisms.
If there were other “prokaryotic metabolisms” living at the same time, what is the point of singling out LUCA? If they were all interacting, could LUCA not have been one particular community of prokaryotic metabolisms?
QUOTE: A chemoautotrophic acetogenic LUCA could have occupied two major potential habitats (Fig. 3e): the first is the deep ocean […] The second habitat is the ocean surface […] Another possibility may be that LUCA inhabited a shallow hydrothermal vent or a hot spring.
Back where we started – nobody knows which it was?
QUOTE: How evolution proceeded from the origin of life to early communities at the time of LUCA remains an open question, but the inferred age of LUCA (~4.2 Ga) compared with the origin of the Earth and Moon suggests that the process required a surprisingly short interval of geologic time.
DAVID: The article provides a different estimate of LUCA age and size. The striking point is how quickly life appeared after the Earth formed. Strongly supports the concept of a designer at work.
dhw: 4.2 billion years is “inferred” and approximate. How do you and the authors know the length of time it normally takes for life to appear and complexify?
I’d be interested to hear George’s own views.
Using mutation rates and times of obvious change in forms allows looking backward in time. Of course, the results are estimates.