I thought I'd touch on something that is relevant both to recent scientific news and some of the stuff I've studied in some of my science classes. In looking at the beginning and origins of life, there are tons of huge questions. The (not-so-shocking) biggie: how did it begin? Let me preface and conjecturing with this: there are no definitive answers (well, obviously there are, but we don't have them since we don't have time machines (yet)), and I am only exploring presently more scientific ones.
In looking at how life began then, we have to somehow explain how proteins ( 1, what we're all made of, 2 things responsible for catalyzing chemical reactions or, in other words, making the
teeny tiny molecular processes in the body possible) and genetic material/DNA (what codes for these proteins that make us up) came about. But the problem therein is, what came first, DNA or protein? Proteins, as we know them, cannot form without some DNA to provide the directions essentially for how to make that protein. Meanwhile, DNA is assembled by proteins. So, it's been a pretty difficult chicken or the egg conundrum for scientists, but a discovery in the 1980s potentially offered to solve this problem and pave the way for a more thorough understanding of life's beginning: ribozymes!
Ribozymes are molecules that can replicate
themselves and store genetic material (DNA is made up of lots of genes that code for specific proteins, hence DNA is said to contain/be composed of genetic material)—that is, ribozymes solve the chicken or egg conundrum by providing a molecule that is both! These ribozymes are actually RNA molecules rather than DNA molecules. The main difference between DNA and RNA is that RNA is single-stranded while DNA is double-stranded. Anyhow, scientists didn't think it was likely that DNA molecules spontaneously formed during early Earth, so RNA coming first is realistic.
In any event, these ribozymes are now believed to have accounted for an RNA-dominated early world. These ribozymes, too, are theorized to have evolved into modern day DNA and protein molecules. It all seemed so perfect! Annoyingly perfect for science, y'know? But fret not, 'twas not so perfect or simple! For, you see, scientists could not resolve how RNA molecule (or the ribozymes that RNA molecules can be) would have actually formed on the Earth so early on.
But, after decades, scientists have finally determined (okay, not entirely, but they've make great, great progress in understanding) how RNA got started! In the primordial soup that is early Earth (to clarify, we're talking about...let's say, four billion years ago or so), it is very difficult to imagine the components of RNA (a base, a phosphate group, and a ribose sugar) coming together to become one, the reason therein being that they all exist rather stably independent of each other. However, by altering the order in which these components come into contact with one another, scientists have come up with a viable way for ribozymes to come about that agrees with the models of geochemistry of dear old early Earth.
As stated, the research isn't complete and there are still some things to be figured out, but this is still a great advancement in the understanding of early life. These sorts of advancements are crucial in further understanding the origins of life, providing us with a great appreciation for the complexity and diversity of life, lending us some insight to the direction life is going, and directing us in our searches for life elsewhere in the universe. Like I said, this news was very relevant to some of the material I've covered in my classes, so I was actually pretty enthused to see that an adequate explanation has finally been provided for how these RNA molecules and ribozymes spontaneously formed in the delicious primordial soup. Hope it sparks your interest too, and if nothing else, one must admire what Earth has come from...from soup and goop (ostensibly) to me and you!
The original (and full-sized image that makes the text legible) should be checked out for a chuckle (I got one, anyhow) here: http://www.mbio.ncsu.edu/JWB/PrimordialSoup.jpeg
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