Ok so as far back as we can see (Cambrian, Precambrian …) organisms stayed as simple as they where even after hundreds of millions of years in some environments.
Or rather: as complex as they were.
But things were different in the distant past, conveniently things were different exactly at a point where nobody can “see” nor verify it.
Well yeah, it's the quest of abiogenesis to figure that one out.
The expectations are basically a reverse engineering of evolution. Sort of.
It's a bit like punctuated equilibrium actually. I'm sure you're familiar with that...
In times of stable environments, evolutionary change tends to slow down. Amount of evolutionary change tends to follow environmental change. Abrupt environmental change tends to trigger extinctions. Gradual change tends to trigger increase in evolutionary change. The faster the gradual environmental change, the faster evolution follows - and the more species go extinct during said process.
This idea can also be seen in computer simulations using genetic algoritms. You'ld let a system evolve to fit certain parameters. After a while it will approach a local optimum and will remain in pretty much that form from that point on. A local optimum is when there's no easy evolutionary path left towards gradual improvement for an even better fit.
When at that point you hit the pauze button and drop the system in a different environment, that local optimum shifts. Gradual evolutionary change will quickly be introduced as the system evolves towards its new local optimum.
The same thing would occur with first life. It would suddenly find itself in a brand new environment. Which is to say: it doesn't have a genetic history yet of adaption to said environment. It doesn't find itself in the local optimum. So gradual evolutionary change will quickly be introduced as first life evolves towards its first local optimum.
As local optimums shift around all the time, life will quickly acquire a whole toolset of things and reach a fair level of complexity rather fast.
The think that first life could remain as simple as it was for 4 billion years, or even only 4 million years, is not reasonable. That would be the equivalent of taking the to-evolve model in a genetic algorithm and dropping it in a different environment and then have nothing happening. It just doesn't work that way.
Yes you pointed out a lot of things, but supported none…….. why don’t you quote the sources and the exact text?
I did exactly that in my very first response to your source.
Yes some models claim that the complexity that we see today (and not in the Precambrian) is just due to sampling bias, the average complexity has not increased……………
They are talking about the complexity of multi-cellular life as opposed to unicellular life.
For the context of this discussion, I'm not even thinking about multi-cellular life.
The very source you mentioned to support that statement, also says at the end that life, in general, grew more complex over the course of its history.
And hilariously, you quote the paragraph where this is all apparant as well:
In this hypothesis, any appearance of evolution acting with an intrinsic direction towards increasingly complex organisms is a result of people concentrating on the small number of large, complex organisms that inhabit the right-hand tail of the complexity distribution and ignoring simpler and much more common organisms. This passive model predicts that the majority of species are microscopic prokaryotes, which is supported by estimates of 106 to 109 extant prokaryotes[14] compared to diversity estimates of 106 to 3·106 for eukaryotes.[15][16] Consequently, in this view, microscopic life dominates Earth, and large organisms only appear more diverse due to sampling bias
So they are comparing multi-cellular eukaryotes to unicellular prokaryotes, where the first one is the "complex life" and the latter the "simple" life.
But compared to the "simple" life that was
first life, prokaryotes are very complex.
I'm not even talking about eukaryotes. I'm talking about complexity in general - including in prokaryotes. Including in the "simplest" of extant life forms that we know of.
They too, are the result of 4 billion years of evolution. 4 billion years worth of gradually moving from local optimum to local optimum.
But the relevant thing is than no model of evolution predicts that simple life would disappear,
"simple" life in the sense of prokaryotes, agreed.
"simple" life in the sense of "first life", no model expects such to survive. Rather the opposite.
except for those models that exist in your imagination and that you are unable to quote.
It's just how the evolutionary process works.
It's rather easy, I don't see how you can't comprehend it....
1. punctuated equilibrium (shifts of local optimum and evolutionary tendency to "move/change" towards that optimum)
2. if you are the simplest, the only way complexity can go is up. The simpler you are, the more likely it will go up.
If you can't understand the implications and inevitable consequences of these point, then I don't know what to tell you.