Thread: Just How Did DNA Come About?

I'm interested of its origin.

Abiogenesis theory has shown that inorganic matter interacted to slowly form more and more complex, self-supporting whole systems... (otherwise known as organic life). The theory was that very basic RNA was formed, and then it grew more and more complex... to RNA... to mRNA/tRNA/etc... to the complex protein machineries we know of now... to DNA?

What's the missing link there?

Any theories of how simple amino acids/inorganic matter just happened to clump together can form a strand of RNA via their chemical properties? Just how did this simple RNA structure grow to be more complex...and what kind of conditions would you hypothesize were present to allow this advance?


Thanks.

Have you considered a continuous process of iterations of the possible chemical and environmental building blocks given the right hospitable environment? Since we know that life is composed of specific combinations of elements organized in specific molecular structures, and since we know that reproduction benefits from a particular structure, I consider it to be inevitable those elements and structure would be found by an iterative process. Once life is generated as a result of iteration, then hospitable environmental conditions continue to advance the life form through the same processes.

Odd speculation (since I'm the Dark Speculator, lol): Rain drops on quartz creates a small electrical current. I'm just sayin ...

If you are looking for more information, I advise you to consult this website:
http://www.evolutionofdna.com/

And for an overview:
http://www.mcb.ucdavis.edu/faculty-l...tak-SA2009.pdf

This should inform you about how the building blocks of life were likely built themselves:
The Miller/Urey Experiment

Originally Posted by mikepotter84

This should inform you about how the building blocks of life were likely built themselves:
The Miller/Urey Experiment

As a source of relevant and meaningful information I view this experiment as one of the most overrated in the history of science.

As a demonstration of concept is has value, but its specific outcomes are unimportant, except to tell us what didn't happen.

I'm uncertain why you don't accept the experiment's results. Do you feel the flask may have been contaminated? The validilty of this experiment is widely accepted within the scientific community. It has even been replicated.

And there are now other, far more plausible, hypotheses about the origin of life. They are, for example supported by multiple lines of evidence from physics, chemistry and genetics. They are potentially able to explain more than just a residue of random organic molecules; cell membranes, self-organization, self-replication, etc. We also know that even fairly complex organic molecules form naturally in all sorts of environments (including outer space).

Coincidentally, the Miller-Urey experiment was done in the same year that Rosalind Franklin (with a bit of help from Crick & Watson) uncovered the structure of DNA.

Apart from the irrelevance of the atmospheric composition used in the experiment there are other issues with this and subsequent tests. Yields are notoriously low. Small changes in the equipment geometry, or the spark duration/magnitude, or the purity of the apparatus, or the name of the experimenter's dog, all alter the end result.

The concept I refer to that this proved out is that we can investigate the chemical origins of life in the laboratory; it's just that we have learned very little of real significance thus far. Were I a creationist I could take apart any and all such experimental results with ease.

It's worth noting that Miller did not assign the same value to his results as the cheering fans on the sidelines. (See for example p62, Lifes Solution by Simon Conway Morris 2003 Cambridge University Press)

Hmm..well, this is what I learned about all through my college and high school years. I guess my teachers and professors were lying to me.

Originally Posted by mikepotter84

Hmm..well, this is what I learned about all through my college and high school years. I guess my teachers and professors were lying to me.

They do. Or not so much lying as simplifying.

I can see how the results may become contaminated or yield insufficient amounts of amino acids. This is always something to consider.