RNA....I beleive

Dear Joachim! thank you for your interest! all the links is very usefull for me! But how does RNA can evolve? It's a fact that DNA replication mistake (mutation) one of the evolution factors. Accumulated differences between DNA result in biodiversity. DNA - polymeraze mistake (for example) - mutation - accumulation of mutation - new species. It's a shot and very primitive evolution events chain. well, but could RNA evolve and if YES by means of what mechanism?Because we can simulate supposed events of ancient world "in test-tube". But are they similar the truth events. Can RNA evolve or not?

Best wishes,

Xandra

Dear team, RNA molecule which prevails first , the reasons are 1. RNA can act as catalyst where DNA cannot (i.e) i mean to say in primitive stage all necessary function of the organism handle by very few molecule since RNA can act either as catalyst like protein and genetic materials, RNA is originated first ,2. Most primitive first generated organism contains RNA as a genetic materials,

you may have a question now why then DNA comes ? the reasons are 1.RNA is a single Stranded molecule have less stability where DNA is double stranded more stable structure than RNA . 2. Uracil is replaced in DNA because several research has been done Uracil is highly prone to mutation like deamination etc so the hereditary pattern may change in-order to avoid mutation and to prevent their genome to be conserved for several generation there comes a replacement of thymine there comes DNA . for these only DNA is surrounded by nuclear membrane etc to prevent it from several chemicals which may mutate (i.e) most of the organism like to save their genome and wants to be highly conserved so there comes DNA.

Now again a question may arise why still in some organism Still RNA is the genetic materials the reason is those organism having more adapdability to surrounding and it may even change their protein expression and genome have still RNA as a Genetic materials.

lots more proof is there thank you

Regards

Madhan

BioLim

Obviously RNA and it can evolve to giving DNA and then that DNA encircled into cellular membrane resulting Cell, Its the most acceptable hypothesis

Theres a great book chapter on the idea of an RNA world in The Origin and Evolution of Viruses, Second Edition by Domingo, Parrish, and Holland. As stated above some support for the idea of an RNA world comes from the catalytic function of RNA molecules in general as well as from catalytic and structural properties of small RNA molecules as seen in viroids.

Dear irfan the question is which one is evolutionary old/first RNA or DNA .RNA does not evolve into give DNA normally if so give clear explanation of it.

Dear Madhan! why not? Why RNA couldn't evolve into DNA. Any evidence, articles?

http://www.mendeley.com/research/conversion-of-a-ribozyme-to-a-deoxyribozyme-through-in-vitro-evolution/

In vitro study could support RNA to DNA

Dear Alexandra if RNA can evolve easily into DNA means there may be decrease role of RNA in our system. Once RNA evolutionarily changes into DNA ,these DNA molecule has separate properties separate function there is no part of rna to play every time for conversion/evolve into DNA.

conversion of RNA into DNA is just change in single base replacement of thymine it is happening even in DNA replication by DNA polymerase in the lagging strand. i mean to say RNA evolved into DNA that the past history we can made RNA into DNA is possible invitro not in invivo easily until our system require it like in replication etc using enzyme we can convert it.

In DNA replication, uracil base are rejected by our system during base addition it will accept thymine bases because of its conformation and two oH group in uracil. i like to say now RNA world is different and DNA world is Different.

NOW RNA WILL NOT EVOLVE INTO DNA ONLY THE ENZYME WILL PLAY A ROLE IN CHANGING THE BASES UNLESS UNTIL WE MADE TO EVOLVE .

Regards

Madhan

BioLim

Dear All

RNA can act as self catalyst and even now a good evidence is the presence of peptidyl transferase exisiting in eukaryotes (23s rRNA in eukaryotes). The need for cytosine in DNA instead of uracil is the reason that cytosine deamination is an often process and this leads to the formation of uracil (and if uracil is also present in DNA, system can't recognize the original uracil from the uracil formed from cytosine).

Moreover, presence of 2' OH in RNA (Bonds formed by 2'OH) can create a kind of unstability (highly unstable under alkaline conditions) and this may be the reason why DNA is the permanent genetic material.

Most people think RNA came before DNA, but it's important to note that there could have been entities that pass the test of being alive before there was DNA or RNA. Self-replicating entities that possess the features formally needed to evolve don't have to have a genetic system, and there's a view that nucleic acid coding was an evolved adaptation of things that were reproducing and inheriting similarity through their own physical properties previously.

Rna

Why not rudimentary peptides ?

rudimentary peptides at first? and then from peptides (according aminoacid sequence) RNA was built... hmmm... sounds like a fairy-tale

... when you have excluded the impossible, whatever remains, however improbable, must be the truth (Sherlock Holmes).

Abiogenesis - from a chemical point of view, the spontaneous arise of aminoacids is much more probable, as well as their assembly, than that of nucleic acids/nucleotides... The first organic molecules in origin, were certainly not a creation of genes, but the product of thermodynamics and chemistry alone. The hydrogenation of carbon dioxide.

see also - Parker ET, Cleaves HJ, Dworkin JP et al. (March 2011). "Primordial synthesis of amines and amino acids in a 1958 Miller H2S-rich spark discharge experiment". Proc Natl Acad Sci U S A 108 (14): 5526–31.

No papers to back this idea up but it seems to me that one problem with proteins as information storage molecules is that proteins tolerate large sequence changes before displaying a phenotypic change. So in the evolution of better functioning replicons as well as some system that would integrate nucleic acids into information storage and replication would take much longer than for nucleic acids. Just a vague thought.

Sherlock Holmes.... He was drug addicted, particularly, opium. hmmm...totally agree with Jonathon! Actually, almost all the experiments on modelling the processes of origin of life are in static condition or with Temp chaotic oscillation. But there isn't any investigation simulating the processes that are in hot water source, thermal well, deep sea well. The amplitude of oscillation, oscillation frequency in such experiments don't correspond to real nature condition.

RNA was the first due to its ability to synthesis itself at the first

Ref. molecular biology of the cell 3rd edition

@Dihya Allane

http://www.ncbi.nlm.nih.gov/books/NBK28340/

this is the first chapter check it

Dr.Ashokan KannarathValappil

I strongly believe RNA, because a system cannot work without enzyme, RNA has that property.OKay