Faizal_Ali
July 19, 2021, 12:27pm
246
Ahmed has another video up in his ongoing “course” on evolution:
Does anyone want to offer some constructive criticism? Because there is a lot to critcize. Just for starts:
Most of Ahmed’s supposed “paradoxes” arise from his strange belief that LUCA was RNA based. That is, of course, not the scientific consensus:
Its genetic code was likely based on DNA,[26] so that it lived after the RNA world .[b] If DNA was present, it was composed exclusively of the four modern-day nucleotides : deoxyadenosine , deoxycytidine , deoxythymidine , and deoxyguanosine . The DNA was kept double-stranded by a template-dependent enzyme , DNA polymerase , which was recently proposed to belong to the family D.[29] The integrity of the DNA benefited from a group of maintenance and repair enzymes including DNA topoisomerase .[30] If the genetic code was DNA-based, it was expressed via single-stranded RNA intermediates. The RNA was produced by a DNA-dependent RNA polymerase using nucleotides similar to those of DNA, with the exception that the DNA nucleotide thymidine was replaced by uridine in RNA.[21] [22] [23] [24] It had multiple DNA-binding proteins , such as histone-fold proteins.[31]
The last universal common ancestor (LUCA) is hypothesized to have been a common ancestral cell from which the three domains of life, the Bacteria, the Archaea, and the Eukarya originated. It is suggested to have been a "cellular organism that had a lipid bilayer and used DNA, RNA, and protein". The LUCA has also been defined as "a hypothetical organism ancestral to all three domains". The LUCA is the point or stage at which the three domains of life diverged from precursing forms of life (a A...
I have to ask, Ahmed: What kind of research did you do in preparing this course? Did you have it reviewed by any qualified biologists? It seems you did not even do the minimum level of research that would involve reading Wikipedia.
EDIT: Never mind, I see there is already a discussion on this:
@Ahmed_AbdelSattar recently made a video called “LUCA’s Paradox” where he outlined issues he has with the idea that life evolved from a universal common ancestor. Specifically a common ancestor that was an RNA-based organism.
[LUCA's Paradox | #EvolutionCourse Session 3]
Now, you might think that, since all organisms (unless you count viruses) have DNA, the common ancestor also had DNA. However, there are some clues that suggests that DNA-based genomes evolved independently Bacteria and Archaea after they diverged from LUCA. For one, some of the proteins involved in DNA-replication are unrelated. This paper discusses this in more detail:
Ahmed also used an image of this paper in his video, but he cited this paper as
“Speculation about LUCA evolving viable RNA error-correction:”
But that is NOT the title of the paper. This isn’t how you properly cite your references @Ahmed_AbdelSattar
Now, moving onto the “paradoxes”. After viewing them, most of them aren’t really pa…
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