Thomas Eshuis wrote:
Citations?

The one at the beginning of this thread.

Please tell me you're not trying to reinvent the eye quote-mine....

No. Just a reminder that Darwin, for some reason, regarded the origin of the photoreceptor as a problem akin to the origin of the first living cell.

So?

You should read the rest the rest of it:

but I may remark that several facts make me suspect that any sensitive nerve may be rendered sensitive to light, and likewise to those coarser vibrations of the air which produce sound.

In looking for the gradations by which an organ in any species has been perfected, we ought to look exclusively to its lineal ancestors; but this is scarcely ever possible, and we are forced in each case to look to species of the same group, that is to the collateral descendants from the same original parent-form, in order to see what gradations are possible, and for the chance of some gradations having been transmitted from the earlier stages of descent, in an unaltered or little altered condition. Amongst existing Vertebrata, we find but a small amount of gradation in the structure of the eye, and from fossil species we can learn nothing on this head. In this great class we should probably have to descend far beneath the lowest known fossiliferous stratum to discover the earlier stages, by which the eye has been perfected.

I know it was already posted, but you seem to have missed it.

And of course, there's this famous paragraph from a letter Darwin wrote in 1863 ...

On the same subject my father wrote in 1871: "It is often said that all the conditions for the first production of a living organism are now present, which could ever have been present. But if (and oh! what a big if!) we could conceive in some warm little pond, with all sorts of ammonia and phosphoric salts, light, heat, electricity, &c., present, that a proteine compound was chemically formed ready to undergo stillmore complex changes, at the present day such matter would be instantly devoured or absorbed, which would not have been the case before living creatures were formed."

Lo and behold, 100 years later, scientists started devising experiments to test this hypothesis. The Miller-Urey experiment merely being the first major one. Since then, the possibilities of prebiotic chemistry have been expanded to an extent that would almost certainly delight Darwin if he were still alive.

Calilasseia wrote:And of course, there's this famous paragraph from a letter Darwin wrote in 1863 ...

On the same subject my father wrote in 1871: "It is often said that all the conditions for the first production of a living organism are now present, which could ever have been present. But if (and oh! what a big if!) we could conceive in some warm little pond, with all sorts of ammonia and phosphoric salts, light, heat, electricity, &c., present, that a proteine compound was chemically formed ready to undergo stillmore complex changes, at the present day such matter would be instantly devoured or absorbed, which would not have been the case before living creatures were formed."

Lo and behold, 100 years later, scientists started devising experiments to test this hypothesis. The Miller-Urey experiment merely being the first major one. Since then, the possibilities of prebiotic chemistry have been expanded to an extent that would almost certainly delight Darwin if he were still alive.

But some here will think you are licking Darwin's arse and treating him like a god.
You naughty, naughty Mr Butterfly.

BooBoo wrote:

Rumraket wrote:
I think in this particular instance, Darwin is actually wrong. Of course it concerns us how a nerve comes to be sensitive to light, if we are to understand how evolution happens and how our, or similar such senses in other organisms, originated. It happens to be the case that how such cells do become sensitive to light is well within the remits of evolutionary biology, because it is well explained by understanding the mechanism of inheritance: Genetics and molecular biology.

Evidently, Darwin did not think that heritable variation and selection were sufficient to explain the origin of the photoreceptor. Or, rather, he couldn't see how slight modification to a normal cell could result in something like a specialized light-sensitive one.

Which we now understand is because Darwin didn't know about DNA.

BooBoo wrote:

Thomas Eshuis wrote:
Citations?

The one at the beginning of this thread.

Does not support your claim.

BooBoo wrote:

Please tell me you're not trying to reinvent the eye quote-mine....

No. Just a reminder that Darwin, for some reason, regarded the origin of the photoreceptor as a problem akin to the origin of the first living cell.

Except that, as others have already pointed out by giving the full quote, he did no such thing.
So you have indeed reinvented the proverbial quote-mine wheel.

Darwinsbulldog wrote:

epepke wrote:Onyx8 is correct. It's the religious who masturbate about ancient people and founders. Scientists honor the memory of pioneers, but we don't get hung up on their every word.

I hope you are not implying anything by that. If you see something wrong with admiring how well science can be done, and who those people were, then I feel sorry for you. It has fuck all to do with licking the arses of priests and gods, for fucks sake!

Read a bit more carefully next time DB:

Scientists honor the memory of pioneers

Rumraket wrote:
Which we now understand is because Darwin didn't know about DNA.

The mechanism of inheritance is not he issue. Rather, it is how a nerve cell becomes sensitive to light and why Darwin regarded this transformation as something he would not try and explain through variation and selection.

Thomas Eshuis wrote:
Does not support your claim.

And what claim would that be?

Except that, as others have already pointed out by giving the full quote, he did no such thing.
So you have indeed reinvented the proverbial quote-mine wheel.

No. You have completely misunderstood and misread what this thread is about. We are not discussing the broader issue of the evolution of the eye, only the origination of the photoreceptor cell and why Darwin was so insouciant about explaining it.

Thomas Eshuis wrote:

Darwinsbulldog wrote:

epepke wrote:Onyx8 is correct. It's the religious who masturbate about ancient people and founders. Scientists honor the memory of pioneers, but we don't get hung up on their every word.

I hope you are not implying anything by that. If you see something wrong with admiring how well science can be done, and who those people were, then I feel sorry for you. It has fuck all to do with licking the arses of priests and gods, for fucks sake!

Read a bit more carefully next time DB:

Scientists honor the memory of pioneers

Yes. but Onyx8 said:-

Why should we care what a long dead scientist thought about the matter?

We care about what Darwin said, because Darwin [right or wrong] was a great scientist. He speculated about the origins of life and many other matters, including vision, sexual selection, geology etc. indeed, science builds on what has gone before [the triumphs and the mistakes]. So a scientist that does not read about previous work done in the field is a blithering idiot. That is why in every higher degree: Honours, masters, or doctorate one does a fuckin' serious lit review.
As Darwin virtually invented at least two new disciplines in science: evolutionary biology and soil science, then he is worth a read.
The point of reading Darwin is not for the facts, [for he made some mistakes], but for his ethos, his methodology, his prudence, his clear delineation between theory and mere speculations. The care he took in his work. His examination of assumptions. If you have read enough scientific papers [in any subject] you would know that many scientist would profit by examining how he came to his findings, rather than what he actually found it. In comparison, when one reads Newton, one sees of course, brilliance but also clear arrogance, a lack of prudence born of confidence from his obvious and well deserved successes. In alchemy, Newton abandons prudence. His other big mistake, the "clockwork universe", clearly came from his religious beliefs. Darwin transcended that worldview. The older Darwin saw through Paley.
And while Newton was obsessed with mechanism, Darwin was the empiricist. Mechanisms, while useful and even important in science, are not essential. Darwin really needed two mechanisms: He found one [Natural selection], but not the other [mechanism of inheritance]. Irrespective of the actual mechanism for inheritance, NS worked. This I think, was part of his genius. Being able to work out what was vital and what was not in his models. [And today we know that there are two modes of inheritance: genetics and epigenetics].
Newton I suppose, was the last scientist to put god in a model and get away with it [well, for 300 years]. He thought god made the clockwork universe, which he didn't actually test for, and made no difference to his results. But to be fair, the instrumentation of the day would not have allowed him to see the anomalies that his clockwork model generated, and which led eventually to the Einsteinian universe.

No. You have completely misunderstood and misread what this thread is about. We are not discussing the broader issue of the evolution of the eye, only the origination of the photoreceptor cell and why Darwin was so insouciant about explaining it.

You seem to be purposefully ignoring the rest of the sentence, and indeed the rest of the page on the evolution of the eye.

Frankly, though, I don't care.
Even if Darwin had come to the conclusion that fairies were responsible for the development of eyesight, what does it matter?
Modern evolutionary theory has moved past Darwins initial work, so what is your point?

KeenIdiot wrote:

No. You have completely misunderstood and misread what this thread is about. We are not discussing the broader issue of the evolution of the eye, only the origination of the photoreceptor cell and why Darwin was so insouciant about explaining it.

You seem to be purposefully ignoring the rest of the sentence, and indeed the rest of the page on the evolution of the eye.

Frankly, though, I don't care.
Even if Darwin had come to the conclusion that fairies were responsible for the development of eyesight, what does it matter?
Modern evolutionary theory has moved past Darwins initial work, so what is your point?

The thread's title, I believe is:- "Abiogenesis and evolution: totally different?" The eye is just an example used, and within that, the photoreceptor. As I have been trying to explain, Darwin wasn't particularly worried about something he had little or no information or [eg genetics], and didn't needlessly speculate. And when he did speculate, he made it clear that was what he was doing. If there is fault, it is with the thread's title, not me.
The discussion about the minutea of photo-receptors is not addressing the topic of the thread. Neither photoreceptors or eyes can possibly be relevant to the discussion about evo and abogen similarities and differences. HTH.

Wasn't aimed at you, DarwinsBulldog.

BooBoo seems to be ingoring the rest of what Darwin wrote, in order to make their point.
Such as here:

Or, rather, he couldn't see how slight modification to a normal cell could result in something like a specialized light-sensitive one.

When he or she has already been provide the rest of the sentence where Darwin stated:

but I may remark that several facts make me suspect that any sensitive nerve may be rendered sensitive to light, and likewise to those coarser vibrations of the air which produce sound.

Which contradicts the statement.

I recognize they aren't a Creationist, but it seems that they pulled this part of the sentence out of context in order to mke a point that isn't held up when the rest of the sentence is provided.

Whether Darwin, over a century ago, thought one thing or another about the evolution of eyes or the relation of evolution and abiogenesis doesn't much matter. Science has moved on.

KeenIdiot wrote:Wasn't aimed at you, DarwinsBulldog.

BooBoo seems to be ingoring the rest of what Darwin wrote, in order to make their point.
Such as here:

Or, rather, he couldn't see how slight modification to a normal cell could result in something like a specialized light-sensitive one.

When he or she has already been provide the rest of the sentence where Darwin stated:

but I may remark that several facts make me suspect that any sensitive nerve may be rendered sensitive to light, and likewise to those coarser vibrations of the air which produce sound.

Which contradicts the statement.

I recognize they aren't a Creationist, but it seems that they pulled this part of the sentence out of context in order to mke a point that isn't held up when the rest of the sentence is provided.

Whether Darwin, over a century ago, thought one thing or another about the evolution of eyes or the relation of evolution and abiogenesis doesn't much matter. Science has moved on.

Yes, I know all that. Booboo got it wrong. But the OP was not wrong to include Darwin in a discussion about abiogenesis and biological evolution, because natural selection is the presumed mechanism for both. That surely, was Darwin's idea when he talked about the warm little pond. He did not know about genes, or even their presumed precursor [ribozymes]. Modern work on chemical evolution is based on some sort of replication > error > selection process where the more efficient patterns [for example, a more efficient ribozyme/ autocatalysist emerges for each "warm little pond"]. This includes work on black smokers under the sea etc. As Cali correctly pointed out, the Urey-Miller experiment was a test of Darwin's basic concept. Can at least some of the building blocks of life arise from abiotic chemistry? And of course, the answer is yes.

Ok, then I take what I said back. Darwin is relevant.

BooBoo wrote:

Rumraket wrote:
Which we now understand is because Darwin didn't know about DNA.

The mechanism of inheritance is not he issue. Rather, it is how a nerve cell becomes sensitive to light and why Darwin regarded this transformation as something he would not try and explain through variation and selection.

The mechanism of inheritance IS the issue, because it is the basis of mutation, of heritable change.

That IS how a nerve cell becomes senstitive to light. Cells are made of fats, proteins and carbohydrates. These can be changed by mutating the proteins and enzymes that make them. If a cell has proteins that aren't sensitive to light, then mutation is the mechanism by which you make those proteins sensitive to light.

BooBoo wrote:

Thomas Eshuis wrote:
Does not support your claim.

And what claim would that be?

That Darwin saw the evolution of the eye as a problem.

BooBoo wrote:

Except that, as others have already pointed out by giving the full quote, he did no such thing.
So you have indeed reinvented the proverbial quote-mine wheel.

No. You have completely misunderstood and misread what this thread is about. We are not discussing the broader issue of the evolution of the eye, only the origination of the photoreceptor cell and why Darwin was so insouciant about explaining it.

He did not consider it a problem for evolution BooBoo.

Bare in mind they is no one decent definition for what 'life' is, on the Earth all life has DNA/RNA but there is nothing to indicate that is required for life. Presumably earlier forms of life won't have had that.

The eye is one evolution easier stories, so many intermediate types of eyes/light sensitive cells its a joke. Got to revise for this and I can't keep all the examples in my head

Thomas Eshuis wrote:
That Darwin saw the evolution of the eye as a problem.

I am making no such claim. I am merely saying that Darwin compared the problem of the origin of the photoreceptor cell to the origin of life itself.

He did not consider it a problem for evolution BooBoo.

He did not consider it related to evolution but rather to origination.