Darwin never actually had a theory of where we come from in terms of the origin of life.
His "origin of species" theory was about what people like to refer to as "evolution", even though he never used that word in his famous book.
And "evolution" is not about the formation of life. Evolution is about how life diversified and adapted (i.e. changed physiologically) over time after it was initially formed.
Life must first be formed (or created), then life changes to adapt; i.e life then evolves.
The religious view of creation, as odd as it seems to some, in no way refutes evolution. It only argues a different starting point from a scientific view of the formation of life.
The religious view of creation is about as improbable as any it is possible for the human mind to conceive. Darwin had his views about creation but kept those to himself because he knew that what he actually did publish was revolutionary enough for society at that time to be dealing with. He was very careful not to anger the religious establishment any further by actually, verbally denying the biblical creation.
What he did do was publish something he was very careful to call a 'theory' and let the scientific community loose on it, putting his trust in objective, enquiring minds to pick up the baton and run with it.
And they have done.
Now, some argue that the term "creation" is a bit of a misnomer in biological terms. They argue that the term "creation" suggests something was started from nothing but this can't be true. Life had to start from something. At least two separate things had to come together to begin the process and those two things had to already exist. So, the act of creation was, in reality, an act of evolution itself. Two non-living objects evolving into one living object, albeit at a microorganism level.
Today we have the theory of "Abiogenesis", the process by which life arose from non-living chemical matter. This suggests that a single ancient gene may have used each of its opposite DNA strands to code for different chemical catalysts. Those separate catalysts would both have activated amino acids, which then formed proteins – essential to the production of living cells.
Around 100 years ago the “primordial soup” model of abiogenesis started to gain traction. It suggests that in the Earth’s prebiotic history, simple organic matter was exposed to energy in the form of heat from volcanoes and electrical storms. These created energy that would have catalysed chemical reactions that over a few hundred million years, could have produced self-replicating molecules.
After WWII an experiment was conducted where scientists combined water, methane, ammonia, and hydrogen in sealed vials in an attempt to replicate Earth’s original atmosphere. They bombarded the vials with heat and continuous electrode sparks to simulate volcanic activity and lightening. Eventually, the reaction produced a number of amino acids – which are the building blocks of proteins and, by extension, life itself.
This, of course, was a very simplistic explanation and doesn't really work because what would have happened very slowly in the primordial ocean had to be speeded up in the lab. Not really replicating actual conditions. So, back to the drawing board.
Scientists began to work with the most basic building blocks. In living cells, reactions are catalysed by enzymes called aminoacyl-tRNA synthetases. These complex molecules belong to two separate families, or classes. Class I synthetases activate 10 of the 20 amino acids that form proteins. Class II synthetases activate the other 10.
In the experiments, synthetases had all but their essential and universal components stripped away. It was found that the remaining structure, which was called “Urzymes,” were functional. These Urzymes probably resemble the ancestral molecules which eventually gave way to life.
It was discovered that Urzymes within the elaborate modern aminoacyl-tRNA synthetases ignored all the bells and whistles created by evolution. What they did show, however, was that they were fully capable of translating the genetic code.
The genetic code itself is strangely organised. One coding strand forms the outer surface of the protein, while the other forms the core. In other words, the two strands rely on “inside-out” interpretations of the same genetic information.
A way was devised to show experimentally that the two families are related to each other. The experiment showed that the ancestral Class II protozyme was built from exactly the same blueprint as the ancestral Class I protozyme, only the blueprint behaved as if it were written on glass and interpreted from the opposite side. The stunning thing is that both interpretations work equally well in the test tube.
In other words, nature solved the protein production problem by developing a single gene to do two separate jobs. And while the study leaves many questions unanswered, it does provide a “new set of tools” with which to move forward.
No theory is fully accepted until it is proven and abiogenesis still has a long way to go. It aint perfect by a long shot.
But it makes a lot more sense than the Biblical creation.
Want to read more..? Check out Miller-Urey (1952).