Actually on a more serious note, one of the interesing reflections to come out of all these threads on 'origins of life' is the question of whether life is self-generating, and, if so, what that could possibly mean. To take your metaphor a little further, if the 'autopoesis' model is correct, it is like we are a chemical reaction that has given rise to civlization. Seems spookier to me than 'God did it'. And where else in existence is the idea that something 'occurs without cause' regarded as an explanation?
It has even occurred to me that at the very point, most of the edifice of Western philosophy actually collapses. If you really drill down to this level and then say, well, somehow, life self-originated, or began without cause, then I do wonder whether there is anything left of what the Western tradition actually understood as 'reason'. Because it removes the first link in the chain of causality that used to underpin the Great Chain of Being, and it seems an awfully short step from this point to the other thread-du-jour, namely, nihilism.
well I think the really interesting philosophical question is - the billion dollar question - is how biology emerged from chemistry.
But, I ask, how could, and when, did chemistry start to adapt?
Surely the 'ability to adapt' is the touchstone of life itself. So at the point where chemicals are adapting, and furthermore, able to propgate this adaptive ability, then we can confidently say 'this is life'. The theory of evolution by natural selection can't go there, because at some point, there was nothing to be selected.
Well - you haven't defined what you mean by complex.
Even so - we'd not expect to see complex life on earth without some notion of eyes because eyes have been present in important transitions - the early tetrapods had them - so everything that came later had eyes as part of their genetic legacy.
But if the story had been different - who knows?
Highly speculative. Just because that gentleman speaks with a highly polished BBC voice does not make it less so.
I quote: 'These well-adapted molecules were able to pass on their traits while weaker and less well-adapted molecules would have broken apart'. According to what theory? The theory of evolution by natural selection has never been applied to non-living matter.
This is what he is doing. It is a just-so story, as far as I am concerned.
Incidentally, I am not fundamentalist, although the more I read, the more sympathetic I am to various versions of the ontological argument and the argument from design. And I still don't reckon anyone has overturned the Hubert P. Yockey argument which applies information theory to DNA.
"The origin of life made easy". What a splendid combination of condescension and presumption. As if the many researchers who believe that the origin of life has never, and may never, be understood, are all signed-up members of the Ken Ham Young Earth Creationist Museum. It is interesting how clearly this debate exposes prejudices on both sides of the argument.
Let's say the most complex and dominant forms here on earth, and in particular the vertebrates.
The tetrapods and the fish have never really left this concept for hundred of million years. (The very few exceptions and curiosities are insignificant in the big picture and the fact they are so rare is even a proof for that).
I don't think so.
They exist sensibly eyeless in their given niche.
It is the relative rarity of that niche that imforms the rarity of the animals who live there.
Where the niche more abundant so would the eyeless creatures be.
When you say complex what do you mean?
Was I right in assuming you meant things like, say, the great apes?
Thanks for this interesting film.
The Eurycea rathbuni is really interesting but still it has eyes and it developed out of animals that were not blind.
I dont think you would get life surviving. I think it needs conditions similar to ours for life to survive at all.
Of course - no tetrapod (amphibians, reptiles, mammals and birds) lacked eyes as a legacy because the transition between fish and tetrapod had them.
What it does demonstrate is a possible alternative to the idea of relative complexity without eyes. It's not necessary to have them to be an interesting vertebrate animal with compensatory senses.
If the transitionary form had been a similar eyeless (for all practical purposes) animal then the resulting forms may not have developed them - depending on their ecological niche.
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How would it survive on comets then?
The physical and chemical environments on this planet alone are very varied - you can't really talk about Earth as one type of environment, but our understanding is pretty much limited to it for purposes of example.
It would be easy enough to imagine a planet with similar chemical compositions that had far more extensive cave systems and a relatively inhospitable surface - and that wouldn't rule out 'complexity'.
Dave Allen wrote:
So that sounds like the tetrapod just got their pair of eyes by chance and from then on kept this method for 400 million years just because it was given by coincidence. And maybe the fishes the tetra pod developed from have chosen the eyes just by coincidence?
Furthermore in the world of the tetra pods, technical spoken, is there any tool possible which is more advantageous (in general) than two eyes?
Now, is it really likely that there are a wide range of huge cave-structures or hot vents-systems on other planets that last for billion of years?
And under this circumstances, is it not very likely that the concept of this huge number of "balls", orbiting bigger hot fireballs in this universe is meant/designed to be nothing else then to let there be some kind of surface to let such things happen as here on earth?
I would like to get some selective answers to the question on the end of the following text.
I am not a creationist or something like that and I know my issue is tangenting some other threads. Anyway I am not looking for a wide range of general points, but only "technical" opinions about this particular question/opinion, and for this reason I concentrate on eyes.
Looking at the forms that life has developed on this planet, it seems as if there is something involved that is not based on coincidence, but on unavoidable logic. For example: A pair of organs for visual perception.
All vertebrates, fish, mammals,birds, reptiles, amphibians, are using this tool (with few exceptions of later atrophy), as well as most of the more complex invertebrates. And they all are using a pair of such organs. It doesn't matter if you look in the face of a bird, a lizard, a snail or an ant, you will always see this pair of visual organs.
Thinking of that like an engineer, it seems that this construction (a pair of optical /visual- sense eyes) is something that has to be used inevitable when constructing a complex animal that is meant to successfully live on land or in the water. The optical /visual perception has too many advantages; to abandon this option would not be a clever thing for the engineer. Furthermore it would not be clever to use only one eye or more then two of these organs. The best way is to take two / a pair of eyes. This way the stereoscopic vision is provided while a third or fourth eye would not bring a real advantage relative to the effort.
It looks like in general this pair of eyes had to develop this way out of logic, the same as a car would always be equipped with round wheels and not with quadratic or triangular "wheels".
Btw, the same as with the eyes, the engineer would construct legs for the land animal and fin-like tools for those in the water, as this are the best tools for locomotion in /on the particular element (with very few exceptions existing like tail motion).
So, now the question:
Is there any logical argument possible, why / how on some other planet in this universe living things would not develop a pair of eyes when reaching a similar complexity as here on earth?
Life on another planet could have any number of eyes.
It turns out that genes can embody high level abstractions such as "do what it takes to form an eye." Pluck out the Eyes absent gene from a mouse and insert it into the genome of a fruitfly whose eyeless gene is missing, and you get a fruitfly with eyes. (1) Not mouse eyes, mind you, but fruitfly eyes, which are built along totally different lines. A mouse eye, like yours or mine, has a single lens which focuses light on the retina. A fruitfly has a compound eye, made up of thousands of lenses in tubes, like a group of tightly packed telescopes. About the only thing the eyes have in common are that they are for seeing.
What does this tell us? Information, organized into concepts, is demonstrably out there in the world, and without violating the laws of physics it can guide processes as they unfold. As in the genes, so in the mind.