robbertypob said:
It's pretty incredible really isn't it, to think that something as unimaginably complex as a human being can arise according to preset laws.
It makes me think about emotions and awareness. What are these things?
Importantly here we don't know whether or not laws are "preset"* but that this context fades against the fact that evolution is contingent. If you started Earth all over again, you wouldn't get the same result, including us. [Lenski's long term experiment demonstrates that, for example.]
* E.g. symmetries and symmetry breakings like causality (relativity) may be forced in order to have any physics at all, at least it is difficult to envision physics without them. But the set of symmetries and symmetry breakings that makes the standard model or particles may not be so constrained but was set by coincidence, at least one can envision particle models with differing masses.
Emotions and awareness are demonstrated biological traits, evolved because they increased the fitness of the population at the time and potentially kept because they still do so, or don't do sufficient harm, or else are 'locked in' by contingency. I wouldn't worry too much about how they work, but enjoy them while I have them.
mfb said:
If you refer to abiogenesis: there are still many open questions, but the gaps get smaller and smaller over time.
A huge number of atoms, arranged in such a way that something happens that we call "cell division".
The same can be said for evolution as for the area of abiogenesis, remaining questions will always be at hand. But lately we can say so much more on abiogenesis, because while there were proposed or seen problems, akin to the original chicken-and-egg problem of DNA and protein synthesis, they have all (which I know of) fallen in the last year. While we do not yet know all the details of the darwinian pathway of small, survivable steps life emerged along, something that is shared by all phylogenies, we do know that there are no stumbling blocks.
For a similar example, bats are known to have complex echolocation when they use it to catch prey. They can modify the strength to resolve the prey as they come closer without drowning the return signal in a high volume return "scream". How did they evolve that, while not starving to death meanwhile? It now turns out that when you live at the equator, the insect prey is large enough (I think was the resolution) that you don't need the volume control that other bats have evolved in temperate zones. Darwinian chicken-and-egg problem resolved by more data.
Coincidentally, the Astrobiology-15 conference has a session on testing pathways. It seems to attract science on the most likely pathway, the "fuel cell" theory. It emerged as a theory after studies of the cell, more precisely chemiosmosis, and what type of geosystem could realize it. A recent result claims further that there is a physical constraint so that chemiosmosis can only evolve in those geosystems. That is, even if cells emerged elsewhere, they have to evolve metabolic efficiency (need chemiosmosis) in those settings, a fact (besides others) that makes the settings the most likely emergence environment.
But the upshot is, even if there is still no consensus on the theory of emergence, there is now predictive, well tested theories and observations, and astrobiology (the science of abiogenesis) is now, unless I am mistaken, so called "normal science".
Re cell division, it is a basic property of membranes, you can see it when you blow bubbles. There is a recent paper that likely demonstrates, by some abiotic enzyme cycle building membrane components, that cell growth and division are purely physical processes at heart, so that early cells (which encapsulation in fuel cell theory starts out as passive and mineral like, as pores in chemical garden effluent encrustations) likely coopted what was at hand. [But I haven't read it yet.]
