I started my exploration tonight on something I had heard a few weeks back about the origin of life and how prior to DNA / RNA world of today, that life was likely all RNA based. Additionally, there are theories into a more simplistic age in which life was based on something that was neither RNA nor DNA; but, that is for another post…
When I think about DNA (Deoxyribonucleic Acid); what comes to mind is programming. That DNA is like the playwright of life. The intricacies of ourselves that these DNA programs control, not only outline what we are, but also explain how we are. We start out in life, depending on how you look at it, as two pieces; one peace being the Ovum (ironically the largest cell in the human body)the other being the Sperm. Each providing data, pre-programming and the materials necessary to begin the production; together they complement and initiate the replicable genetic programming that is necessary to make a new human.
The way that this happens is the Ovum and Sperm are dense with life granting materials, balanced except for mDNA of which only the Ovum contains , which then go through the rapid process of organizing and building the blocks in a process called genetic recombination and Meiosis that will eventually become a little, smelly, needy, cute human baby.
So, how do components of RNA and DNA combine? Well, in nature, atoms combine into molecules of all sorts (H2O, Protein, Amino Acids etc.), which in turn gravitate towards other molecules in order to make combinations. These combinations of molecules, depending on how they work out, can create life. Each molecule has a job, based on the Atom's abilities that make up each molecule. If all the right components of are brought together you get a strand of RNA or DNA ~ enough instructions as well as materials to make life.
The 'gravitation' is the main question that needs answering. It is found that in large collections of organically rich water, for example, that many combinations are made. However, no matter the concentration, it appears that molecules will combine into simplistic structures; and those more complex combinations, like RNA and DNA, do not seem to happen due to proximity alone. The issue here lies in the fact that scientists can find no examples of these natural complex combinations and research does not imply random connection of complex molecular structures like nucleotides (nitrogen, carbon and oxygen atoms as well as carbon sugar and one phosphate group) Nucleotides are a precise combination of particular various types of atoms, that exist in RNA.
So, for further thought. How do atoms host attributes that will control a life's immune system, nerves or neurons? What trigger meiosis (the convergence of genetic material?) And, what triggers genetic material to replicate? Most of all - how do these complex, life granting combinations - come to be?
Now to digress a minute as I learned that there are multiple comets that have crashed into earth, that contain molecules! I found this very exciting. Not only were many molecule's matching those on Earth- present, there were also a number of new ones not found on Earth. Here is one of the organically rich comets; Murchison Meteorite
KAS
Hi KAS, I've yet to read the "RNA" article you refer to, but a couple of logical questions ?
ReplyDeleteWhy is the RNA-life precursor interesting if neither RNA nor DNA can be shown to actually arise in these solutions ?
Why are the organic meteorites interesting ? Does that not simply shift the problem of the evolution of organic material to another place, rather than solve the problem ?
Ian,
ReplyDeleteSorry- the article is linked to the title.
The RNA life precursor, as in the naturally happening molecular combinations, is not witnessed yet to combine to such complex levels; however, it is understood that independant combinations exist and that particular combinations create RNA and DNA - life.
So, I find it interesting because it proves that molecules combine - without any guidance - to create combinations in order to become something greater than each part.
If we know that they do this naturally and that a particular combination can create RNA - then, all we need to know is what makes the molecules combine in complex manners (environment, etc.)
Yes, the same problem exists with the meteorites. I found the idea that molecules of a varying kind existing on a meteorite interesting- because it shows life granting properties from another planet.
If you meant the precursor to RNA that I briefly touched on; that is only a non fact based theory right now; which theorizes that before DNA and RNA there was another complex molecular structure that also was life granting.
KAS