Renewable Revolution

50,910 views•Feb 4, 2020



👨‍🔬 Vincent Racaniello
50K subscribers

Virus particles are constructed in three ways: with helical, icosahedral, or complex symmetry. We discuss the principles of helical and icosahedral symmetry and how larger and larger viruses are assembled. Some particles are wrapped with a lipid envelope, derived from the host cell, which is embedded with viral glycoproteins.

Category Science & Technology


Agelbert COMMENT: There is a logical paradox involved in Vincent Racaniello's view that viruses, which are obligate parasites, as correctly defined by Vincent Racaniello, are "more ancient in the evolutionary ladder" than ribosome containing living cells. According to Modern Evolutionary Theory, which I am sure Vincent Racaniello does not question, prokaryotes were the only form of life on Earth for millions of years until more complicated eukaryotic cells came into being through the process of evolution.

Considering the prevailing view in the scientific community of the Darwinian evolutionary sequence stated above, viruses initially were parasitical exclusively of bacteria (i.e. prokaryotes). Vincent Racaniello's belief that viruses, always obligate parasites, "PRECEDED" bacteria, which have the complex machinery that the obligate parasite must access to reproduce, is a logical fallacy. It is putting the virus parasite "cart" before the bacterial host "horse". 

The more likely evolutionary scenario, one that most, if not all, virologists have unfortunately rejected, is that viruses devolved from prokaryotes that were subjected to several essentially simultaneous mutations that were both faulty and advantageous.

👉 The faulty mutation produced the obligate parasite, lacking the ribosome and other cell machinery that is sine qua non for perpetuation of the species through replication.

👉 The evolutionary advantage of the bacterial mutation to a virus (which had to have happened simultaneously with the loss of cell machinery for replication, or else there would be no viruses today), was an amazing toolbox of specific proteins beneficially mutated  to facilitate attacking and hijacking a bacterium in order to reproduce. There is no other logical way to view this. Any other way to view this is unscientific straw grasping.

Viruses are an example of Devolution, not Evolution. No OBLIGATE parasite, be it a virus or any example of the highly complex species of parasites from the subphylum Chelicerata, has ever existed PRIOR to the existence of the host that said parasite requires, do not pass go, do not avoid extinction, for the survival of that species. There is no random "evolutionary pressure" that can be pseudo-scientifically speculated about, even with lots of hand waving and charts, that would constitute "evidence" of the PRIOR existence of a parasite to some, not yet evolved, life form said parasite exists to target. No host, no host parasite that lives from targeting the host, PERIOD.

Furthermore, Vincent Racaniello's claim that viroids, that have a limited ability to self assemble, are the RNA spark that got the (added to his speculation that all those transposones in our genome are "evolutionary evidence" that we were "something else" before) evolution of life ball (i.e capsid ) rolling is more unscientific straw grasping.

WHY? While it is true that the T1 icosahedral capsid could certainly have come about randomly from this self assembling property of protein fragments, that does not even remotely begin to scientifically explain, steps by thousands of SIMULTANEOUSLY REQUIRED random steps (SEE: Factorial math mind boggling numbers), the amazingly specific viral machinery existing for the purpose of protecting some RNA (be it +RNA or whatever) inside that capsid and, within a limited amount of time from the moment the virus was formed and ejected into the intercellular environment, seeking to gain entry into a specifically targeted host through a specifically targeted receptor site, at which point even more specifc, finely tuned tools to hijack the host machinery are used for replication.

The point is that a capsid made of self assembling proteins is not the relevant evolutionary issue. The relevant evolutionary issue is that a virus, being an obligate parasite, that lacks even one of the tools I just listed above (in an overly simplistic fashion), goes extinct, period.

NOTE: I recognize that 👨‍🔬 Vincent Racaniello 👍 is, without a doubt, an expert in viruses, and explains their structure and function elegantly, clearly and beautifully. If he stayed away from the logically flawed speculation about the "evolutionary importance of viruses", he would be better off.

Finally, there is the issue of proper protein folding, an indispensable part of successful protein synthesis. Every one of the those self assembling T units Vincent Racaniello beautifully described, that make up the non-covalent icosahedral structure that forms a virus capsid, MUST be folded a very specific way. Even with exactly the same proportion of atoms from different elements, bonded in exactly the same way in these capsid assembly molecules, they will not function properly if they are not folded properly.

Viruses do not have Ribosomes and Chaperonins. They never did have Ribosomes and Chaperonins.

What that means to people who don't see a problem with the claim that the "self assembly" ability of capsid proteins in viruses is "proof" that viruses "started the evolution of life" is that without Ribosomes, which are key to the complex process of synthesizing proteins to be later folded by Chaperonins (Chaperonins are any of a family of large chaperone proteins that function chiefly to assist in the folding of newly synthesized proteins), NONE of those viral capsid forming T units will be folded properly.

That's right, they DO NOT "self fold" properly. That's right. They self assemble to form a capsid ONLY when their T units are PREVIOUSLY folded properly. That's right. Randomly, the exact same capsid protein molecules will have thousands, if not millions, of possible three dimensional arrangements, of which ONLY ONE ARRANGEMENT, specific to each and every member of any given family of T units, WILL WORK. Even the tiniest 60 facet capsid requires that all of its T units be folded in exactly the same way in order to self assemble.

Viruses are an example of Devolution, not Evolution.