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So, I've never seen an episode of Dr Who. My question is... >> | |
| | | Subject: on the state of learning in the U.S.
Posted Mar 7, 2010 by Not the monkey - Skreeeeeeeeeeeee
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23544
  | | Hee hee. What a controversy I've stirred up.  .
My own attitude to AAH is that it's interesting. But I'd like to know a bit more - especially about what the African climate was like around the (putative) changes. I understand the suggestion is the changes might have occurred at a time when humans were active along the southern Asian coast with an ice age to the north. And I'd like to know more about the spread of H Habilis.
Still - interesting, no? My own interest was rekindled when I discovered that the author of a book I read - ooh - mumblemumble years ago is the Grandma of a hootooer I spent a pleasant afternoon with last year.
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| | | Subject: on the state of learning in the U.S.
Posted Mar 7, 2010 by  Effers;England.
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23546
| | My highlight of the last few pages here was that Stoppard quote that anhaga gave. That has now gone into the folder on my desktop, of my all time favourite quotations.
So no Piltdown Man discussion here yet then..how it wasn't really a hoax afterall. Mind you my favourite hoax thing is to do with the Loch Ness Monster.
'.. underwater photographs. Two were rather vague images, perhaps of a rhomboid flipper (though others have dismissed the image as air bubbles or a fish fin). The alleged flipper was photographed in different positions, indicating movement. On the basis of these photographs, British naturalist Peter Scott announced in 1975 that the scientific name of the monster would henceforth be Nessiteras rhombopteryx (Greek for "The Ness monster with diamond-shaped fin").[50] Scott intended that this would enable Nessie to be added to a British register of officially protected wildlife. Scottish politician Nicholas Fairbairn pointed out that the name was an anagram for "Monster hoax by Sir Peter S".[51][52]..'
from,
http://en.wikipedia.org/wiki/Loch_Ness_Monster
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| | | Subject: The Dawkins' thread
Posted Mar 7, 2010 by ~ jwf ~
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23548
| | >> I finally 'finished' the Greatest Show On Earth. <<
There is a section in the final chapter I'd love to quote but it goes
on for a page or two. Basically, he is talking about memory. First he ascribes the property of memory to DNA - suggesting that each species passes on a database of information needed by that species.
"Information on how to handle the present so as to survive into the future is necessarily gleaned from the past. Non-random survival of DNA in ancestral bodies is the obvious way in which information from the past is recorded for future use..."
Apparently he is still open to the idea that DNA is capable of preserving memories - and suggests that these 'generic' memories are essential to survival. He does not deny that these could be specific, in fact he suggests they may include important specific knowledge of predator and prey behaviors. He suggests that seemingly 'instinctive' and 'reflexive' behavior helpful to survival is built right into our DNA.
He adds that there are three other memories. 
The immune system, the nervous system and culture. He calls these 'the four memories' and explains how the immune system for example 'learns' from experience and remembers how to make specific antibodies. And the nervous system (including conscious and unconscious memories) also learns to avoid unpleasant experience and seeks pleasant ones. As for 'culture'...
"The world in which we live is richer by far because of those who went before us and inscribed their impacts on the database of human culture..."
"All four memories are part of, or manifestations of, the vast superstructure of apparatus for survival which was originally, and primarily, built up by the Darwinian process of non-random DNA survival."
He does seem to be trending toward the possibility that some part of our existence does live on. But more tellingly, he seems to be on the verge of an epiphany concerning the true nature of ancestor worship.
~jwf~
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| | | Subject: The Dawkins' thread
Posted Mar 7, 2010 by anhaga
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23549
| | Funny. I don't get the same impression, ~jwf~. Now, I admit I've not read the book, but from what you're saying, I don't get the impression that Dawkins is talking about DNA having a memory in the sense of an individual's DNA acquires a life-experience which is passed on to the individual's offspring. Isn't he actually saying that each strand of DNA codes information, the DNA which is able to reproduce itself in a new generation codes information which has been useful in the ancestors life, and the DNA which does not reproduce itself in a new generation codes information which was not as useful and that information is 'forgotten'.
Seriously, does he anywhere state, suggest or imply that an individual's reproductive DNA is actually reprogrammed by the individual's experience so as to code for some new information in any sense other than the sort of random mutations that have been acknowledged for years? If he is suggesting that such a directed-by-experience reprogramming is possible, then he's no longer a Darwinian but rather, a Lamarckian. I'd be surprised by such a development.
Again, is he not simply saying that the DNA which survives into the next generation codes for the 'tricks' which have proved successful in the life of the ancestor, rather than that the 'tricks' the ancestor has used have changed the coding of the DNA?
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| | | Subject: The Dawkins' thread
Posted Mar 8, 2010 by ~ jwf ~
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23550
| | >>...simply saying that the DNA which survives into the next generation codes for the 'tricks' which have proved successful in the life of the ancestor, rather than that the 'tricks' the ancestor has used have changed the coding of the DNA? <<
It's kinda chicken and egg innit. He does seem to imply that 'learning' (ie:experience) is the basis for memory systems and implies that it must alter coding - at some point, to some degree.
Perhaps he is opening his mind to new possibilities or maybe he just takes it for granted that he doesn't have to argue against specific memory being passed on.
It's a bit hard to tell, his writing is a bit sloppy and repetitive in this book. Large sections seem to have been just dashed off. All of it needs a good editor, if only to reduce the constant forward, sideways and backflash references such as "As I said in Chptr Three", "Let's leave that for a future chapter"... etc. I swear he dictated the whole thing into a recorder as if he simply lecturing to a class of sophomores, the speech is casual, almost extemporaneous and peppered with asides and paranthetical cross references in a most un-academic way.
The DNA 'memory' section follows a series of almost rhapsodic episodes describing various outcomes between predators and prey. He seems at a loss to explain why a baby gazelle can sometimes flick and turn and outwit a predatory cat even having no prior experience of what works. Then he takes the other side and wonders how some big cats 'just seem to know' which way the gazelle is gonna jump.
I guess all I'm saying is that he now seems to be envisaging a new way to see just how detailed and complex and specific some DNA 'memories' must be. And he extends the DNA memory mechanism as the model for three other memory systems, the immune system, the nervous system and cultural systems.
His whirled view seems to be widening!
Thank the gods!
BTW: I do recommend the book to anyone still wondering about 'evolution'. But they should be warned that he is still quite ungracious in his condemnation of anyone who doesn't agree with him.
~jwf~
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| | | Subject: The Dawkins' thread
Posted Mar 8, 2010 by anhaga
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23551
| | Well, I guess this will demonstrate that I, for one, am not an unquestioning disciple of Dawkins:
I don't think that DNA has the sort of memory that you are suggesting he is hinting at. The germ DNA is not modified by experience in such a way as to pass the advantage of that experience on to the offspring. Certainly germ DNA is modified by such experiences as working at Chernobyl or rubbing DDT on one's genitals, but the resulting modifications will not likely be advantageous to one's offspring. And, certainly DNA which codes for advantageous traits will preferentially survive into the next generation, and so, constitute something that might loosely be termed 'memory', but it is survival of an unchanged code, not the production of a new code. And there is no 'memory' of unsuccessful traits.
I am not a Lamarckian.
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| | | Subject: The Dawkins' thread
Posted Mar 8, 2010 by ~ jwf ~
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23552
| | And Dawkins would deny being an ancestor worshipper.
But all genetic-evolutionists, archeologists, paleontologists, geologists, history buffs and students of literature and the Classics are all ancestor worshippers. It comes with the territory and works its insidious way into the heart and mind even as one consciously and vehemently denies such notions with atheistic contempt.
I am not a Lamarkian either, but I suspect that where there's smoke there's probably somebody rubbing two sticks together in a cave somewhere.
The best argument for an open mind in these things is to consider the vast expanses of time involved in evolution. I must admit this latest book has given me a whole new appreciation for the immense temporal distance between us and our blessed ancestors. And he has certainly made an impression on me concerning the relatively short history of all mammals. It leaves me with renewed conviction that anything is possible.
In fact the notion of multiple universes now seems to be just a metaphor for understanding the gazillions of variations that have occurred right here on Mother Earth. In that light, anything really is possible.
~jwf~
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| | | Subject: The Dawkins' thread
Posted Mar 8, 2010 by Not the monkey - Skreeeeeeeeeeeee
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23553
| | >>I don't get the impression that Dawkins is talking about DNA having a memory in the sense of an individual's DNA acquires a life-experience which is passed on to the individual's offspring.
Strange if it did. It would only pass on the experience acquired up until the moment of conception. Assuming that the experience transmitted has survival value, we could test this epidemiologically: do younger siblings survive longer than elder siblings?
>>In fact the notion of multiple universes now seems to be just a metaphor for understanding the gazillions of variations that have occurred right here on Mother Earth. In that light, anything really is possible.
The Squiggles Multiverse Theory:
'Well in *my* universe...' 
(I always knew you where on another planet, but now you're (ahem) exceeding expectations. )
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| | | Subject: The Dawkins' thread
Posted Mar 8, 2010 by anancygirl
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23555
| | DNA and memory;
One of the questions it reminds me of is, How does a Monarch butterfly that is born in late August early September know to migrate to a forest in Mexico? The life cycle of this butterfly is quite unique as those who migrate back to my neck of the woods, in the spring, mate and die as do the next generations of the summer months, only those with no immediate connection to their ancestors make the flight in the fall to Mexico. BTW this is not a short migration but thousand of miles.
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| | | Subject: The Dawkins' thread
Posted Mar 8, 2010 by Effers;England.
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23556
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~jwf~ I am slightly confused by what you're meaning in terms of DNA passing on 'memories'. DNA codes for 'behaviour', is that what you're meaning? But such 'behaviour' will have been acquired like any other trait the DNA codes for in the phenotype via natural selection. I also got the impression you were suggesting something Lamarkian.
But if you're not, maybe you could explain more..because like anhaga I have also not read this book.
But yes for Darwin's rottweiller to be going over to the 'darkside' of Lamark in any way would be an earthquake of unimaginable proportions, which would make his little local difficulty on his website forum at present, seem like a mere pebble rolling down a hill. I've always had the impression that Dawkins being a scientist, has an open mind about ideas, you have to, because if the evidence, as acquired through experimentation, points in a direction that had hitherto been thought unlikely, you have to go with that. My understanding is that no such evidence has yet been gathered for anything in vaguely Lamarkian, such as memories acquired in a lifetime being passed on through the genes. But maybe I'm misunderstanding your meaning?
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| | | Subject: The Dawkins' thread
Posted Mar 8, 2010 by Not the monkey - Skreeeeeeeeeeeee
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23557
| | Monarchs - apparently they navigate by a combination of in-built compasses and sensing the sun's position. While not denying that their ability to return to the same sites generation on generation is Very Clever Indeed...surely it doesn't take that much in terms genetic inheritance? A Great Lakes butterfly doesn't have to 'remember' where a particular Mexican valley is. All it has to do is, on the onset of winter, start to follow a course blindly.
This is only inherited memory in the same sense that remember to dilate our pupils when a bright light is shone in to them - albeit on a wonderfully more sophisticated level.
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| | | Subject: The Dawkins thread
Posted Mar 8, 2010 by Not the monkey - Skreeeeeeeeeeeee
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23560
| | Incomplete answer to anancy...
We'd be talking about a sort of multiple selection for different parts of the journey, depending on time of year and the butterfly's stage in the reproductive cycle. It all seems very complicated, yes - albeit possible to break down into some quite simple mechanisms. I think we have to go with this unless and until we find a memory mechanism.
Incidentally...it's probably noteworthy that butterflies from a wide range across the US/Canada converge on the narrow Isthmus of Panama (in the Mariposa Reserve, Mexico). Possibly within this area there aren't so many viable Monarch habitats, hence their flocking. (That's Monarchs east of the Rockies. Other populations have different overwintering sites. Seemingly, Monarchs west of the Rockies flock in more diverse areas.)
What I'd like to see (and somebody might well have done this) is a long-term genetic study. Yes, East-of-Rockies Monarchs migrate to Mariposa...but do the descendants of (eg) Manitoban Monarchs always return to Manitoba?
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