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Maybe I'm looking for the impossible.

Over the last 5 or 6 years, I have made a serious effort to better understand evolutionary theory. I know - that's a HUGE thing to tackle, but I feel like I have mostly been taking the science on faith.

I have taken a fair number of science courses at the undergraduate level during my lifetime (biochemistry, organic chemistry, microbiology, cellular biology, human anatomy & physiology, pathophysiology, and even a course titled "Major Ideas in Biology" which spent considerable time on the basics of evolutionary theory). However, I am still having some difficulty getting my head around how all of the various chemical, physical, and biological concepts have combined to produce something as complex and intricate as the DNA molecule.

My limited science education is pathetically insufficient to grasp how molecular coding for specifically folded proteins can give rise to an entire, complex organism such as Homo sapiens. Going beyond that, to try to understand how a few basic elements combined under just the right circumstances to create the earliest precursors for DNA, and then the eventual formation of the first rudimentary DNA molecule, is even further beyond my education.

I understand the concept of deep time, and enough fundamental chemistry, to have a basic foundation for understanding evolution, but I have realized that one really has to devote his life to the study of evolution to actually understand it at the molecular level.

Is anyone able to give a simplified explanation of how such a complex and intricate molecule was able to form from the "primordial soup" of early Earth, and the basic principles of how that single molecule, and all of its successive mutations, then led to the complex lifeforms we see today? I get the concept of cellular specialization, but the incredible coordination needed at the cellular and molecular levels almost seem like they had to have been purposefully designed. Obviously, I am missing something, as I do not believe in "Intelligent Design", but I just can't seem to work out the intricacy of complex life from my fragmented knowledge of the sciences.

Piratefish 7 June 28
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51 comments (26 - 50)

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1

i didn't go near as far as you have, but I recall coming to the same conclusion, and google tells me we are not alone there. The Hidden Messages in Water might serve you, just read it myself. Consciousness seems to have a part to play in DNA formation, will be the assertion basically

1

I got a feeling nobody knows at the moment they have various theories but none that have been backed up ...yet ,so don't sweat it

Simon1 Level 7 June 29, 2019
1

There are I think two things to keep in mind. The first being that it may be a mistake to ask for a simple understanding, biological evolution is a run away self feeding cascade, with nothing to limit its complexity, therefore even at the most basic level there may be no simple answers. And the second is that at least according to my limited reading, this is still very much work in progress, and therefore your only route to greater understanding will be to read original papers as they are published, though there is no promise that that will help.
I found that The book 'Life Asending' by Nick Lane contained a very short but lucid account of our understanding to date, especially abiogenisis and the RNA first theory.

I know that trying to understand the links between biogenesis, evolution, and consciousness is probably far more difficult than is possible even for scientists. But all have their basis in molecular biology. That is necessarily my beginning point.

@Piratefish Good luck with your quest.

1

If you consider "co-evolution" then the human race rests in a lucky cradle of all the other organisms on the planet. We all, literally, "grew up together", and we are here because all the other organisms on the planet allow it to be so. We are not some distant organism, we are right here, coated with microbes and surviving by their grace. You could not digest food without symbiotic bacteria. Our world us here because it welcomes us, and all the other species cooperates in our survival as a species,

1

The greatest mind in the world are researching DNA, how it works and how it came to be. It is an ongoing subject of study. If these folk don’thave it quite figured out yet, I would not lose any sleep over not understanding it.

One can accept an idea without understanding it completely, as I do.

1

I get the feeling that you're more interested in origin of life more than tussling with the theory of evolution. The theory does not address the issue of how life began, only how it has changed over time. Is that right?

Just want to better understand two linked concepts:

  1. How a very specific molecule single-handedly determines the entire physical process we call evolution. So, basically, the molecular and cellular basis for evolution, and

  2. How a few basic elements combined in increasingly complex ways to eventually produce a very complex, self-aware, highly intelligent organism capable of contemplating all of existence. Or, as some people have put it "hydrogen becoming aware of itself". Except I want to understand as much of that process as I can, at least beginning at the molecular and cellular levels. Afterall, these are the very basis for evolution (see number 1 above).

@Piratefish It's not about single molecules...it's about billions, maybe trillions of organisms, some of which develop a favorable trait, that end up passing those traits along more often than those with unfavorable traits.....life on earth has been around for a looooooooooong time, most of which is generational in terms of hours or days, not decades like us....there are very, very many unbeneficial traits which have gotten passed along, and immediately been eliminated from the pool

@JordanG76 Except that a single molecule, DNA, governs all of it. Take away DNA, and there is no complex life, or evolution.

@Piratefish -- mRNA

[dnaftb.org]

1

evolutionary theory is way beyond me. although i've read about it & tried to understand it.
my simple mind always takes me back to a precision time piece. could it assemble itself?

The difference is that there is purpose behind the watch. It was intentionally created. Whereas evolution has no intent or purpose, and creates nothing.

Random changes to certain molecules are literally the very thing that makes evolution even possible. But to get from atoms to molecules, then from molecules to cells, then from cells to us, requires an unfathomably long time (about 13.5 billion years, give or take a few million). And I'm trying to understand as much as I can about the evolutionary process at the molecular and cellular levels.

1

Maybe this will bring you along a bit. [scientificamerican.com]
[ncbi.nlm.nih.gov]

1

I'm proud to be a great ape!

0

I think there are some significant misunderstandings going on here. Stop thinking of evolution as a process that always leads to more complex lifeforms. Evolution has no end goal, no purpose to it. Organisms produce successive generations, with individuals in each generation possessing certain combinations of traits. Those traits or combinations thereof either aid or hinder each individual's survival. Those traits that aid survival will tend to be passed on to offspring, those that hinder survival won't (as the individuals possessing them tend to die before breeding). Which traits aid or hinder depends entirely on the environment. We happen to be descended from omnivorous scavengers that survived better with greater reasoning abilities and more dextrous manipulating limbs, as this allowed us to adapt to our environment without having to wait generations to evolve more survivable traits, like thick fur to endure colder winters, or claws to grapple fast-moving prey. If intelligence had not been a survival trait, it would not have become so widespread in our species. Intelligence is a bit of a trap, though, just like any other trait taken to extremes (see: sabertoothed tigers). It can hinder survival, if it does not adapt to new dangers. Most species don't have this problem, but we can now alter the world faster than we can adapt to it, due to holdovers of previous survival traits. I could go so much longer, but I've already left a wall of text, so look into the evolution of human threat detection. It's fascinating stuff.

Liam Level 3 June 30, 2019

Not at all what I am trying to understand. I want to know how molecular and cellular biology for the basis not only for life, but how they are the very basis for the process we call evolution. I know exactly what the theory of evolution deals with. I want to know how a simple molecule single-handedly determines the process for literally every species on the planet. Genes are everything, and they are a huge mystery from the standpoint that all they are is the result of a single molecule.

@Piratefish That's what I just explained. Evolution occurs due to environmental stresses over the course of generations. What you're looking for has nothing to do with evolution.

0

You might do best to keep abiogenesis and evolution separate. I find that Aron Ra delightfully explains evolution to my satisfaction. Keeping in mind that I’m not after complete knowledge, just answers.

I have always kept them separate. However, one cannot disregard molecular and cellular biology when contemplating evolution. After all, without the DNA molecule, there would be no evolution.

0

There were simpler forms of life, that still had intent of a sort. More like virus and prions... their growth in complexity was part of evolution too... It didn't just start after stable nucleic acids just "happened" to form.

Burner Level 6 June 29, 2019
0

From simple single cell life to a blue whale - how did this happen? Time, chance mutations, survival of the fittest - -
how did humanity develop? by the same process, or maybe a spaceship full of beings from an advanced ivilisation turned up and screwed around with things - it is impossible to know exactly what happened, but a timeline can be established
There are two examples of evolution that stand out for me - firstly the eye, as it has developed in different species, from a simple receptor of light to a complex lens system .. and a butterfly (moth), that needs camoflague against a tree trunk to survive and changed colour, rapidly in evolutionary terms, to adapt to pollution darkening tree bark
sorry don't have details - long time ago when I looked into this

0

You do not have a problem with the "theory" of evolution. You have a problem with how life itself exists.
When it comes right down to it, it is impossible to explain existence. How did carbon, hydrogen, oxygen, and nitrogen come into existence?
Sure, it's hard enough to figure out how the DNA molecule formed out of raw materials. But where did the raw materials come from? Where did everything come from?
This is a gigantic mystery and until some future date, if ever, it will remain a mystery.

0

The best way I understand it, is that nature throws massive numbers at these issues. Nature does not have a reason or purpose. There is just an abundance of certain elements, massive numbers, and on the time scales being discussed, given enough time, like in the millions of years, any number of outcome, not only become possible, but probable.

SCal Level 7 June 29, 2019
0

We may be 100 years away from understanding how DNA 1st started - but the Theory of Evolution is sound.

gater Level 7 June 29, 2019

Not what I am talking about at all. The DNA molecule is imperative to evolution. You cannot have evolution without it. Period. Understanding the molecule, and how it formed is a necessary first step in setting the stage for understanding evolution at the molecular and cellular level. These are the very basis on which evolution is built. Maybe you are comfortable with compartmentalizing these inextricably linked concepts, but the way my mind works does not allow me to do the same.

@Piratefish Right, but just because we don't understand how DNA 1st formed, that doesn't mean that we won't understand how, in the future.

0

I can't answer. I haven't studied nearly as much as you but I've always had an issue with some of your points regarding how it all began, which makes me feel it's more likely molecular life on Earth was seeded, as opposed to originating. But then one has to ask where the seeds come from.

0

Scientist has shown how the most important ingredient came about life's origins. So extremely complex macromolecule known as DNA. There is another type of genetic molecule called RNA, and activate rna actually builds DNA. Some viruses don't have DNA but they do have rna and this has led many scientists hypothesize life beginning in the RNA world. RNA and DNA are both made of many times repeated components called nucleotides. It took a while but researchers have shown how RNA nucleotides could have formed naturally in conditions now expect it of the prebiotic Earth.

I understand all of this (well, mostly at the general level). But I am trying to wrap my head around how a very specific molecule completely governs the evolution of every species on the planet, simply by instructing organelles to fold proteins in very specific ways. Attached to this (at least for me), is also trying to understand the molecular and cellular basis for consciousness.

However, it appears most people stopped reading my post as soon as they saw the word "evolution", and have simply regurgitated high school level science for me. If it were that easy, I wouldn't even bring it up. I am trying to get my head around far more than just evolutionary theory - that is only one part of the equation.

0

The most cogent theory I've seen on the subject is Lynn Margolis' theory on cell evolution. She was Carl Sagan's wife.

0

Hey pirate fish.

First, let me start with saying, I think you are more educated in this subject than I am. My formal education only included chem 101, 102, the wonderful world of molecules and one semester of biology.

I am a steadfast non theist. Like you I have wondered often about the first steps of life.

I have sort of a wishy washy perspective of an idea of how life came to be. Still working on it in the back of my mind, but here goes a shot at trying to explain it.

Okay. Imagine something is out of balance. In this case it is an acid naturally forming towards alkalinity.

There are two substances. They are not even. The acid group is broken down into individual low pH molecules. The acids begin to combine with substance two. In doing so their pH rises. Their is a shortage of substance two. There is a physical compelling force making each of the molecules drive to combine with the second substance.

Any difference, no matter how miniscule, in the structure of a molecule from group one, will segrigate and form a different grouping of different molecules.

From this, over time organisms develope. The molecules become more advanced in taking their share of available resources. They become single cells and continue to evolve into larger beings. This being, single cells working together as a group entity.

From this intelligence evolves.

0

My friend, it sounds like you know more than enough science to understand biological evolution. It's really quite simple. Natural selection allows what works better to persist while eliminating less fortunate forms. DNA mutations provide a steady stream of new forms to try out. Forms that work survive to be further improved upon in later generations. Let this process play out over billions of years and it produces some wonderful and amazing critters. The key is that, instead if always starting from scratch, nature works by taking what exists and modifying it.

Here are the five basic points of the Theory of Evolution:

In every generation, DNA mutations give rise to organisms with different adaptations within a population. Darwin called this diversity of abilities "natural variation."

In every population there is always over-reproduction, so individual organisms have to compete for resources. (Thomas Malthus famously wrote about this "struggle for existence," and Darwin was well acquainted with Malthus's work.)

The environment constantly eliminates those individuals that are less fit. Those that are better suited to the environment tend to survive and pass on their good genes. Darwin called this sorting process "natural selection."

Over generations the process of natural selection acting upon the population's natural variation leads to changes. The beneficial mutations accumulate in the gene pool. With time descendants look less and less like their ancestors. Darwin called this process of change through the generations "descent with modification."

(If a small group of individuals leaves the main population to set up a colony in a different environment, that group may evolve separately from the mother population, thus forming another branch on the tree if life.)

The Earth is very, very old, and descent with modification has been going on since the first cells self-assembled from organic molecules present on early Earth. (In considering the Earth's great antiquity, Darwin had the advantage of familiarity with the work of two early geologists: James Hutton, and his student, Charles Lyell.) The ancestry of all present species can be traced back to a single, ancient, common ancestor.
That's it. Five points.

0

You said it, you are obviously missing something. Perhaps reading "Evolution for Dummies" can resolve your "doubts."

No "doubts".

Just want to better understand two linked concepts:

  1. How a very specific molecule single-handedly determines the entire physical process we call evolution. So, basically, the molecular and cellular basis for evolution, and

  2. How a few basic elements combined in increasingly complex ways to eventually produce a very complex, self-aware, highly intelligent organism capable of contemplating all of existence. Or, as some people have put it "hydrogen becoming aware of itself". Except I want to understand as much of that process as I can, at least beginning at the molecular and cellular levels. Afterall, these are the very basis for evolution (see number 1 above).

@Piratefish same advice as given.

0

White fish and black fish inhabit the water. Water level goes down, white fish get eaten first. Water level goes up, black fish reproduce and flourish.
Next generation, a mutation may be acceptable if water level is unchanged. Mutations come from modification of dna by gamma rays from the sun mostly.
How was that? I think I'll have that order of fish and chips now. I just wanna know where tartar sauce came from.

0

Death is the key to evolution. And time: evolution requires time to make an observable effect.

All creatures die. All creatures experience genetic variation. In addition to genetic variation, creatures are faced with changes in climate and geology.

After thousands of generations some offspring are a little different from their progenitors. Some get an advantage from a little change, and some get a disadvantage. The ones that get an advantage are more likely to live to reproduce.

After millions of years and millions of random modifications, those tiny advantages add up.

Just want to better understand two linked concepts:

  1. How a very specific molecule single-handedly determines the entire physical process we call evolution. So, basically, the molecular and cellular basis for evolution, and

  2. How a few basic elements combined in increasingly complex ways to eventually produce a very complex, self-aware, highly intelligent organism capable of contemplating all of existence. Or, as some people have put it "hydrogen becoming aware of itself". Except I want to understand as much of that process as I can, at least beginning at the molecular and cellular levels. Afterall, these are the very basis for evolution (see number 1 above).

@Piratefish the molecules of DNA are themselves the product of evolution. Single-celled organisms have fewer and shorter DNA molecules (genes). It's more than just genes - there's a whole complex system of chemistry that generates proteins & other molecules by following the recipes stored in DNA.

#2 consider that humans don't materialize whole. We grow from clusters of cells.

It might seem intentional, like "intelligent design", but it's just the outcome of billions of random interactions. Interactions which favor the experiment that survives long enough to repeat itself.

0

I'm no expert on biology, but as far as I am aware we have no idea. There are many competing theories including rna self replication, inorganic evolution via molecular repetative production ( vice self replication ) and random organization of organic compounds.

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