Anonymous at Sun, 21 Jul 2024 00:59:22 UTC No. 16290302

Gotta be at least a hundred generations

Anonymous at Sun, 21 Jul 2024 01:14:31 UTC No. 16290307

>>16290295
I would say not many, but then I see the banking goblins and suddenly hundreds of millions of years sounds about right.

Anonymous at Sun, 21 Jul 2024 02:15:13 UTC No. 16290339

>>16290295
Pointless. Each 20min a new generation of E. coli comes to existance, for Saccharomyces cerevisiae it's closer to 2h, for human epitelial cells it's 24h and for whole humans about 20 years. So at the time life was universaly microbial we can guestimate that the density of generations per unit time was 4380 – 26280 greater than it was when our ancestors were closer to monkeys than bacteria. Hominid aDNA biologists probably have rough estimates how many generations stand between early hominids and modern humans, but I doubt anyone bothered to do this for LUCA-HUMAN, as the meaning of genereration changes substantially. Hovewer it's very likely the evolutinary genomic analysis, i.e. identification of the universal ancestral genes, identifications of the number of mutations / evolution rate was done one way or another. Obviously not for all species and all genes, although 16/18 S rDNA is probably covered. Tbh LUCA is somewhere between a conjecture and a theory, best you can do without hard concrete evidence. Similarly to suposed lack of LVCA (Last Viral Common Ancestor) as contemporary viruses appear to have begun their existance more than once, which is based on phylogenetic studies. Don't take my word for it though. I never worked on LUCA or large scale phylogenetic analysis, and I don't have time to catch up on the literature to post a well informed /sci/ reply

Anonymous at Sun, 21 Jul 2024 02:20:08 UTC No. 16290342

>>16290295
In the Ancestor’s Tale (written by Dawkins, one his good books that focuses on biology), Dawkins, who had been estimating generation numbers, gives up after he reaches the common ancestor of all monkeys or so, I think, because at that point he can’t say with any reasonable confidence that primate ancestors had similar lifespans to living primates, especially when you factor in that the ancestors of primate groups lived in the Late Cretaceous with the dinosaurs (T-rex, triceratops, dreadnoughtus and co.).
To try and go further all the way to LUCA would be madness, and if a theoretical biologist with a rather good mathematical backing like Dawkins says nah, it’s probably not his horrible political views holding him back