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RE: Human Evolution? - 5/16/2008 11:57:55 AM
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Jhud
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quote:
Just 3 people in the world have this ability.
http://www.cnn.com/2008/HEALTH/conditions/05/07/miraculous.memory/index.html
Well, no, only three people in the world are known to have this ability. I am not sure what this would have to do with evolution.
I did know a fellow student in high school who had the ability to tell you what day of the week any date in history you gave him fell on; and as far as I could tell he was never wrong in a 'Rainman-esque'. In other respects Matt suffered from a form of autism that actually made other learning often difficult.
_____________________________
Jack
“I mean to live my life an obedient man, but obedient to God, subservient to the wisdom of my ancestors; never to the authority of political truths arrived at yesterday at the voting booth”
William F. Buckley Jr. 1925-2008
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RE: Human Evolution? - 5/16/2008 12:23:35 PM
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gluadys
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quote:
ORIGINAL: Jhud
quote:
Just 3 people in the world have this ability.
http://www.cnn.com/2008/HEALTH/conditions/05/07/miraculous.memory/index.html
Well, no, only three people in the world are known to have this ability. I am not sure what this would have to do with evolution.
I did know a fellow student in high school who had the ability to tell you what day of the week any date in history you gave him fell on; and as far as I could tell he was never wrong in a 'Rainman-esque'. In other respects Matt suffered from a form of autism that actually made other learning often difficult.
That would be the 'savant' condition mentioned in the article. But apparently the memory champs are not savants in this sense.
Does it have anything to do with evolution? Hard to say. Has it increased fitness? Reproduction rate and survival of offspring rate? (Of course, we wouldn't know if the subjects are practicing birth control.) At the moment it appears to be a rare but evolutionarily neutral trait.
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RE: Human Evolution? - 5/16/2008 12:47:59 PM
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Jhud
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quote:
That would be the 'savant' condition mentioned in the article. But apparently the memory champs are not savants in this sense.
Does it have anything to do with evolution? Hard to say. Has it increased fitness? Reproduction rate and survival of offspring rate? (Of course, we wouldn't know if the subjects are practicing birth control.) At the moment it appears to be a rare but evolutionarily neutral trait.
Well, yeah, and unless these three people become unusually prolific, it would seem it would be a blip, not anything to that will 'evolve'. Indeed, there is no evidence such abilities are tied to any particular set of genes, and so whether it could be propagated as evolution suggests is mere speculation.
_____________________________
Jack
“I mean to live my life an obedient man, but obedient to God, subservient to the wisdom of my ancestors; never to the authority of political truths arrived at yesterday at the voting booth”
William F. Buckley Jr. 1925-2008
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RE: Human Evolution? - 5/16/2008 3:28:20 PM
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swan42
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quote:
ORIGINAL: Jhud
quote:
That would be the 'savant' condition mentioned in the article. But apparently the memory champs are not savants in this sense.
Does it have anything to do with evolution? Hard to say. Has it increased fitness? Reproduction rate and survival of offspring rate? (Of course, we wouldn't know if the subjects are practicing birth control.) At the moment it appears to be a rare but evolutionarily neutral trait.
Well, yeah, and unless these three people become unusually prolific, it would seem it would be a blip, not anything to that will 'evolve'. Indeed, there is no evidence such abilities are tied to any particular set of genes, and so whether it could be propagated as evolution suggests is mere speculation.
All evolution starts as a blip. Correct there is no evidence these abilities are tied to any any specific genes, that's why it is being investigated to find the evidence.
< Message edited by swan42 -- 5/16/2008 3:34:25 PM >
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RE: Human Evolution? - 5/16/2008 3:37:04 PM
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Jhud
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quote:
All evolution starts as a blip. Correct there is no evidence these abilities are tied to any any specific genes, that's why it is being investigated to find the evidence.
Well, it would have to be more than a blip. It would have to provide a significant advantage for survival (which I think would be increasingly unlikely in human populations) and it would have to have some sort of direct connection between a straight forward genetic attribute and it's expression as a capability.
_____________________________
Jack
“I mean to live my life an obedient man, but obedient to God, subservient to the wisdom of my ancestors; never to the authority of political truths arrived at yesterday at the voting booth”
William F. Buckley Jr. 1925-2008
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RE: Human Evolution? - 5/16/2008 4:51:49 PM
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gluadys
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quote:
ORIGINAL: Jhud
quote:
All evolution starts as a blip. Correct there is no evidence these abilities are tied to any any specific genes, that's why it is being investigated to find the evidence.
Well, it would have to be more than a blip. It would have to provide a significant advantage for survival (which I think would be increasingly unlikely in human populations) and it would have to have some sort of direct connection between a straight forward genetic attribute and it's expression as a capability.
Why a "significant" advantage? Even a very small advantage can be selectable.
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RE: Human Evolution? - 5/16/2008 6:30:24 PM
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drmark
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quote:
Just 3 people in the world have this ability. Of course this is human evolution. Three humans are producing change in the proportional distribution of alleles in a population over generations. Voila - human evolution!
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Jeremiah 31:31-34. The time is NOW, fellow saints!
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RE: Human Evolution? - 5/16/2008 6:39:46 PM
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Method
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quote:
ORIGINAL: Jhud
Well, yeah, and unless these three people become unusually prolific, it would seem it would be a blip, not anything to that will 'evolve'. Indeed, there is no evidence such abilities are tied to any particular set of genes, and so whether it could be propagated as evolution suggests is mere speculation.
I agree with Jhud here. The link between the brain and genetics is not well understood. You have to go way out on a branch to claim that this ability is due to a specific mutation.
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RE: Human Evolution? - 5/16/2008 9:00:37 PM
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gluadys
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quote:
ORIGINAL: drmark
quote:
Just 3 people in the world have this ability. Of course this is human evolution. Three humans are producing change in the proportional distribution of alleles in a population over generations. Voila - human evolution!
We don't know that yet, because we don't know what, if any, genetic connection exists between the capability and the underlying genetic structure. And we don't know if it is leading to differential reproductive success either.
But if we are able in the future to establish a genetic connection and show that those with this capacity leave more offspring than normal in the population, yes, that would be human evolution.
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RE: Human Evolution? - 5/16/2008 9:24:58 PM
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drmark
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quote:
And we don't know if it is leading to differential reproductive success either. quote:
those with this capacity leave more offspring than normal in the population Oh, silly me! I somehow missed this part of your previous definition of evolution. What is the importance of "reproductive success" and "leave more offspring" to the concept of evolution?
_____________________________
Jeremiah 31:31-34. The time is NOW, fellow saints!
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RE: Human Evolution? - 5/16/2008 10:02:59 PM
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Veritas
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quote:
ORIGINAL: drmark
quote:
And we don't know if it is leading to differential reproductive success either. quote:
those with this capacity leave more offspring than normal in the population Oh, silly me! I somehow missed this part of your previous definition of evolution. What is the importance of "reproductive success" and "leave more offspring" to the concept of evolution?
Reproductive success and having more offspring cause the change in the proportional distribution of alleles in a population over generations. The definition does not contain everything there is to know about evolution.
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RE: Human Evolution? - 5/16/2008 11:41:13 PM
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gluadys
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quote:
ORIGINAL: drmark
quote:
And we don't know if it is leading to differential reproductive success either. quote:
those with this capacity leave more offspring than normal in the population Oh, silly me! I somehow missed this part of your previous definition of evolution. What is the importance of "reproductive success" and "leave more offspring" to the concept of evolution?
Fundamental. That is how the distribution of alleles changes in a population. Without differential reproductive success, the proportion of alleles in a population remains constant as shown by Mendel's experiments.
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RE: Human Evolution? - 5/17/2008 1:34:47 AM
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Bettawrekonize
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I personally think that most people (the large majority), if they practiced (put the mental effort involved), if they took care of themselves (ate right, got enough sleep and exercise, stayed away from alcohol and drugs (besides drugs for legitimate medical reasons)), have amazing mental capabilities and could remember just about everything they read or came across (and do amazing mathematical calculations with their brains). Of course, such a thing requires huge amounts of mental energy and, for the most part, is inefficient, so I'm not going to waste my effort doing this and I think that most people won't either. I think that our brains are already capable of going far above and beyond what is necessary for our current survival (and have always been able to) but most of us either don't take care of themselves or they simply don't need to expend the necessary mental energy involved because it's inefficient. I mean, seriously, the brain is meant to be efficient. It's inefficient for us to remember everything we come across, we only need to remember that which is relevant. If someone told you a wrong phone number and then they corrected themselves, do you need to remember both the wrong number and the right one? A waste of mental energy and space, you only need to remember the correct one. It's too inefficient for us to remember every unnecessary detail we come across and the brain wasn't designed to be inefficient. We look for and remember that which is relevant, it's much more efficient than just arbitrarily remembering everything we encounter. To some degree, it makes sense that our memories fade with time because more recent information is usually more relevant. I still think we retain much of the older memories too, but it just takes us longer to reference because, since the most recent memory is usually more relevant, our recent memories would be stored in a place for faster seek time which pushes back the older memory to locations that would have a slower seek time. It's kinda like a trade - off so that much energy is not required to search your entire memory every time you need a piece of information (since necessary information is more likely to be recent, it can be searched first. Otherwise, you'll have to poll your entire knowledge base every time you want to remember an event that occurred yesterday and that's inefficient. It's like searching an entire hard drive every time you want to find a document. It's better to group information according to how likely you are to need it and then search the information that is more likely to contain what you need first and recent information is exactly what is more likely to contain what you need so it gets searched first. Think of your start menu and desktop. On your hard drive, we try to sort information roughly in some sort of nested hierarchy because that makes sense. On your desktop, you have shortcuts/references to information that you are most likely to use. On your start menu, you have shortcuts to information that you are likely to use, but not as likely as the information on your desktop. Your brain probably works in a similar manner. As the information becomes older, it is less likely to be used in the recent future so it gets moved from your desktop to your start menu in a sense. Then, it eventually gets taken off of your start menu because it's cluttering your start menu and other links become more useful for the near future since they become more recent. But you still keep the majority of the information on your hard drive somewhere, even if the references are not on your start menu or your desktop. Of course, this is oversimplified but you kinda get the point).
< Message edited by Bettawrekonize -- 5/17/2008 2:18:44 AM >
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RE: Human Evolution? - 5/17/2008 9:17:41 AM
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drmark
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quote:
Fundamental. That is how the distribution of alleles changes in a population. Without differential reproductive success, the proportion of alleles in a population remains constant as shown by Mendel's experiments. So now you've defined "evolution" as differential reproductive success. Am I getting this right?
_____________________________
Jeremiah 31:31-34. The time is NOW, fellow saints!
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RE: Human Evolution? - 5/17/2008 10:27:07 AM
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gluadys
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quote:
ORIGINAL: drmark
quote:
Fundamental. That is how the distribution of alleles changes in a population. Without differential reproductive success, the proportion of alleles in a population remains constant as shown by Mendel's experiments. So now you've defined "evolution" as differential reproductive success. Am I getting this right?
More specifically, differential reproductive success is the mechanism of natural selection. Differential reproductive success is the means by which allele distribution in the gene pool is changed. i.e. some of the current generation contribute more to the next generation's gene pool than others. When this leads to the progressive dominance* of one allele over another, that is evolution.
*By "dominance" in this case, I mean only that one allele is found in the gene pool much more frequently than the other. This is not to be confused with "dominance" in the Mendelian sense which refers to gene expression, not to gene quantity.
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RE: Human Evolution? - 5/17/2008 10:44:55 AM
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drmark
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Okay, so if A=B and B=C, then A=C. Thus, evolution is natural selection. So, what does this have to do with the "origin of species"?
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Jeremiah 31:31-34. The time is NOW, fellow saints!
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RE: Human Evolution? - 5/17/2008 1:10:43 PM
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gluadys
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quote:
ORIGINAL: drmark
Okay, so if A=B and B=C, then A=C. Thus, evolution is natural selection. So, what does this have to do with the "origin of species"?
Not quite. Selection is the engine of evolution if you will, but an engine needs fuel. Selection needs something to select, so you need various alleles.
The primary thing evolution does is change the characteristics of a species over time. So we have what Darwin called "descent with modification". Now one can quibble over whether a population B which is a modification of population A is objectively a new species. It is a judgment call. We can describe Homo erectus and Homo sapiens, and note the degree of morphological change. But if we could reconstruct a Homo erectus, would there be a reproductive barrier? Hard to say.
When following the phyletic differences in a single lineage, it is probably best to think of "species" as convenient labels for "what this population looked like in this time frame". It is rather like an analogy to the development of an individual. At various points in its continuity from conception to death, it wears labels such as embryo, fetus, infant, toddler, child, adolescent, adult and senior citizen. Yet it is the same person.
Just so a phyletic lineage could be seen as a temporal equivalent to "ring species" in which those close to each other are the same species, but as the distance between two populations increases there is less interaction, less gene flow, and finally, no gene flow. "Species" is a convenient conceptual label for different stages in the history of a population marked by significant genetic and/or morphological differences.
Now cladistic speciation provides a different picture. That adds a new wrinkle, because we are no longer dealing with a single lineage, (population A modified to produce population B) but with a division of the original lineage into several branches: population A into populations B, C, D, .... And then sub-divisions of each of those.
Most speciation is cladistic. That is the source of the nested hierarchy. Evolution that was only phyletic would not increase the number of species or the degree of biodiversity. However, it is probably important to understand the nature of the phyletic process before embarking on an exploration of the cladistic process, as the latter incorporates the first and depends on it.
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RE: Human Evolution? - 5/18/2008 1:12:05 AM
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swan42
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quote:
ORIGINAL: iluvatar
quote:
ORIGINAL: Jhud
quote:
Just 3 people in the world have this ability.
http://www.cnn.com/2008/HEALTH/conditions/05/07/miraculous.memory/index.html
Well, no, only three people in the world are known to have this ability. I am not sure what this would have to do with evolution.
I did know a fellow student in high school who had the ability to tell you what day of the week any date in history you gave him fell on; and as far as I could tell he was never wrong in a 'Rainman-esque'. In other respects Matt suffered from a form of autism that actually made other learning often difficult.
My sister-in-law has several disabilities including some in the autism spectrum. For a long time, we got a kick out of her telling everybody what day of the week any particular date fell on... until we started looking them up and realized she was wrong most of the time. 
-Dan.
There is an equation with a simple algorithm for perform this trick, I'm sure you could learn it with a little practice.
In any case, this trick for mapping the day of the week to a specific date in the past (or future) is not what the memory article is about at all.
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RE: Human Evolution? - 5/18/2008 11:01:05 PM
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Jhud
Posts: 6709
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quote:
Why a "significant" advantage? Even a very small advantage can be selectable.
Well, first off there is no evidence that this offers even a small advantage.
And of course, a whole range of abilites can and do exist in any given population , none of which have the effect of leading a population down a particular novel evolutionary path.
_____________________________
Jack
“I mean to live my life an obedient man, but obedient to God, subservient to the wisdom of my ancestors; never to the authority of political truths arrived at yesterday at the voting booth”
William F. Buckley Jr. 1925-2008
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RE: Human Evolution? - 5/19/2008 12:12:09 AM
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gluadys
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quote:
ORIGINAL: Jhud
quote:
Why a "significant" advantage? Even a very small advantage can be selectable.
Well, first off there is no evidence that this offers even a small advantage.
No dispute there. As I said, I was speaking in general, not of this specific example.
quote:
And of course, a whole range of abilites can and do exist in any given population , none of which have the effect of leading a population down a particular novel evolutionary path.
Right. That is the natural range of neutral variation that exists in any population. But when a variation offers any advantage, however slight, it is selectable. It doesn't have to be something significant or obvious.
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RE: Human Evolution? - 5/19/2008 10:51:20 AM
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Jhud
Posts: 6709
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Right. That is the natural range of neutral variation that exists in any population. But when a variation offers any advantage, however slight, it is selectable. It doesn't have to be something significant or obvious.
Well, of course any genetically expressed characteristic of an organism is 'selectable', I think the larger question, "under what circumstances is a particular genetically expressed characteristic selected and come to typify and organism". I would say generally the answer in this case is, "that characteristic which becomes critical to the survival of the organism in the particular environment it finds itself."
And I would further suggest that those circumstances wherein one particular characteristic is critical are rare indeed.
_____________________________
Jack
“I mean to live my life an obedient man, but obedient to God, subservient to the wisdom of my ancestors; never to the authority of political truths arrived at yesterday at the voting booth”
William F. Buckley Jr. 1925-2008
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RE: Human Evolution? - 5/19/2008 3:42:16 PM
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swan42
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quote:
Well, of course any genetically expressed characteristic of an organism is 'selectable', I think the larger question, "under what circumstances is a particular genetically expressed characteristic selected and come to typify and organism". I would say generally the answer in this case is, "that characteristic which becomes critical to the survival of the organism in the particular environment it finds itself."
"Critical to the survival of the organism" is not required for selection. Selection only requires the characteristic to be passed on to more offspring. Survival of the organism often desirable to accomplish the task of passing on the characteristic to more offspring and the environment the organism finds itself does not need to be different or change. Though a changing environment is often a pivotal moment that selects against organisms that lack the characteristic of interest.
quote:
And I would further suggest that those circumstances wherein one particular characteristic is critical are rare indeed.
Indeed. These are rare events.
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RE: Human Evolution? - 5/19/2008 3:48:02 PM
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Jhud
Posts: 6709
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From: Lake Wobegon
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quote:
"Critical to the survival of the organism" is not required for selection. Selection only requires the characteristic to be passed on to more offspring. Survival of the organism often desirable to accomplish the task of passing on the characteristic to more offspring and the environment the organism finds itself does not need to be different or change. Though a changing environment is often a pivotal moment that selects against organisms that lack the characteristic of interest.
Funny, you seem to be saying here that in order for a characteristic to be selected, it need not actually be … selected. Ah, the mysteries of the amazingly vague notion of evolution.
Of course, something that says nothing is very difficult to disprove.
_____________________________
Jack
“I mean to live my life an obedient man, but obedient to God, subservient to the wisdom of my ancestors; never to the authority of political truths arrived at yesterday at the voting booth”
William F. Buckley Jr. 1925-2008
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