Ok, first off, can you make sense the claims of
this article, which I posted above (it's not long)?
Because if so, then I think it will help to clear up exactly where the lines of disagreement lie.
Each individual has a unique combination of the previous generation's DNA insofar as they have two parents. In this sense, each individual is simply a smaller sample of the greater whole, which is the entire genome, one datapoint in a spectrum of information. Whenever reproduction occurs, the two datapoints are combined to yield a new datapoint. Maybe it's novel, maybe it's a repeat of previous expressions; that's not what matters. What matters is how stressful that datapoint's life has been. That serves as telemetry for the genome's selection process.
No, not even identical twins have exactly the same genetic make-up. This is why DNA methylation is such an important field of study. Identical twins often have phenotypical differences between them, and those differences are thought to be as a result of epigenetic differences.
But your observation is apt in that a genome is only as diverse as the number of individuals that the genome is represented by. A species of only a few individuals has only a very narrow message bandwidth to figure out how to get out of the evolutionary extinction pit and thrive again. Every genome is driven to perpetuate itself,
as a genome. It tries to select the best version of itself in order to do so.
That's not the complete picture. The complete picture is that the genome itself is evaluating the success of these mutations. Good mutations are actively preserved, bad mutations are silenced or bred out. In many cases, the genome doesn't lose old functionality when it mutates new functionality, there's evidence to indicate that epigenetic processes first use gene duplication and then tinker with the copy instead of the original.
And as per above, the majority of the differences between humans, chimps, gorillas etc. are as a result epigenetic changes, not genetic mutation. Epigenetic tweaking is thus an incredibly powerful (and reversable) system which can control whether or not any particular traits are expressed or silenced.
I prefer to speak the
whole truth.
https://www.damninteresting.com/on-the-origin-of-circuits/
When reading this article,
imagine if the selection process that was mimicing natural selection was in fact inside our DNA instead of simply in the environment. Think of the implications; how fast would life in general be able to adapt (i.e. evolve) to novel situations?
What I'm basically saying is that if the principles by which evolution operate are like a super computer, then you can't really see what's happening if you try to pull a couple of chips out and describe their architecture and how they might relate to one another. To understand how evolution truly works, you have to look at all of the chips as being part of
one message. Each genome is a different message. When species speciate, it means the genomes have drifted so far apart that they can no longer meaningfully communicate.
Darwinian evolution is to this idea as Newtownian gravity is to general relativity. Yes, in certain respects, there are elements of truth to the principles that Darwin enunciated. But the actual real life process of evolution is orders of magnitude more reactive, complex, intelligent and just downright
elegant.