Sorry, but I disagree with some things that have been written here...

All this evolutionary stuff....
I know, it is really popular to explain observations with evolution.

That begins with "scientific" books like men are from mars, women from venus and can even be found in scientific environments.

Sadly enough, it is very rare that evolutionary biologists, theoretical biologists, one could even say anyone with a thorough training in biological sciences contributes to that discussion.

Mostly, human behaviour is explained with evolutionary development by psychologists or physicians.

I do not want to deny them any competence for doing so, but often they seem to have misunderstood or not fully understood theories of evolution.
And please ... that this not only that nice theory developed by Darwin, but a whole, complicated field of biology!

Sorry....

One assumption being made here is that there must be an evolutionary advantage for a trait that occurs in at least 3% of the population.

Nature does not create anything to be meaningful or perfect.

E.g. nipples in men... one has not found any purpose yet, Still, they are there, as there is no selection against it.
There might even be a selection pressure for traits that might prove harmful... There are various bird species in which males are too coloured, have too heavy tails, and so on.
Somehow, females prefer them.
Why? Noone knows. It just happened, as every change in the genomes might happen, there is no meaning.

We cannot say that something is useful in a given species, at least not only because we observe it. We can only conclude that the selection pressure against it was not strong enough that all individuals with that trait were not able to reproduce.

Still, if we observe it in many of them, we can say it was no disadvantage in finding a partner and reproduction.

Everything else remains unprovable and pure speculation. Which is nice, but no science.

In humans, it becomes even more complicated. Think of how society and our environment changed in the last 5000 years!
This time was not long enough to allow major changes in our genetic heritage, but we changed definitely.

Organisms are not just developing according to their genetic background.
Depending on their environment, certain genes can be shut off, turned on, upregulated, downregulated.

And as there are many interactions, we cannot yet predict what the changes will occur when the expression changes.

--> The mere occurance of a given trait in a population says nothing about any evolutionary advantages. ADD does not have to have an evolutionary advantage.

--> As the environment of humans changes constantly and we are -luckily- very able to adapt, it is most likely that differences in the occurance of traits over time are caused by the environment.
If ADD occurs more now than 100 years ago, this development simply cannot be evolutionary, as there are so many ADDers.
Evolution takes time.

For looking up yourself (found this link at the hompage of the Institute of Evolutionary Biology at Harvard)

http://www.talkorigins.org/faqs/faq-intro-to-biology.html




I do not want to offend anyone here...
But I think, evolution has been misinterpreted and misused as explanation so much recently.
In many cases, authors just think it could fit, write it in their books, and people think it was "scientific".

Nature does not create anything to be meaningful or perfect.

E.g. nipples in men... one has not found any purpose yet, Still, they are there, as there is no selection against it.
There might even be a selection pressure for traits that might prove harmful... There are various bird species in which males are too coloured, have too heavy tails, and so on.
Somehow, females prefer them.
Why? Noone knows. It just happened, as every change in the genomes might happen, there is no meaning.




This is not necessarily true. The evolution of male humans having nipples is natural selection. It's not that nipples were created for a use, they existed on apes and did not affect our survival in any way. If nipples were a significant flaw in our anatomy that led to shorter lifetimes, then they would probably not exist.

I don't think that nipples on males is an example that nature doesn't create anything perfect - it's an example of an abnormality, not a proof. On a molecular level, nature sometimes makes extremely perfect structures - proteins are a great example. We still can't fold proteins like cells can, we're still just trying to figure out the sequencing.

That begins with "scientific" books like men are from mars, women from venus and can even be found in scientific environments.

Sadly enough, it is very rare that evolutionary biologists, theoretical biologists, one could even say anyone with a thorough training in biological sciences contributes to that discussion.

First off, many great scientists have not only researched evolution - I would say that any famous biologist firmly believes in evolution.



We cannot say that something is useful in a given species, at least not only because we observe it. We can only conclude that the selection pressure against it was not strong enough that all individuals with that trait were not able to reproduce.

Still, if we observe it in many of them, we can say it was no disadvantage in finding a partner and reproduction.

Everything else remains unprovable and pure speculation. Which is nice, but no science.
We observe that certain birds with a bright red chest get the most females to mate with. The larger the chest, the more females it gets. As it breeds, the chests get larger because there are more offspring from larger chested individuals. This isn't a sure proof - but to say that this observation isn't nearly-conclusive evidence makes no sense.


In humans, it becomes even more complicated. Think of how society and our environment changed in the last 5000 years!
This time was not long enough to allow major changes in our genetic heritage, but we changed definitely.
Are you saying that humans haven't become larger and more intelligent in that 5000 years? If that's what you're saying - try checking some data.


Organisms are not just developing according to their genetic background.
Depending on their environment, certain genes can be shut off, turned on, upregulated, downregulated.

And as there are many interactions, we cannot yet predict what the changes will occur when the expression changes.
[/b]
I can't predict the next prime number in a sequence through a formula - but I can tell you which numbers came before it in that sequence. If our afore-mentioned large breasted birds are increasing chest size by increasing their lung size - that is an interaction. At the end of the day, the chest is being enlarged through evolution. Your argument may be that we can't tie larger lung size to mating, but the chest to mating relationship still stands. This doesn't negate relationships, it questions the underlying source of them.

Unpredictability doesn't negate existence - a basic axiom of chaos theory.


--> The mere occurance of a given trait in a population says nothing about any evolutionary advantages. ADD does not have to have an evolutionary advantage.

--> As the environment of humans changes constantly and we are -luckily- very able to adapt, it is most likely that differences in the occurance of traits over time are caused by the environment.
If ADD occurs more now than 100 years ago, this development simply cannot be evolutionary, as there are so many ADDers.
Evolution takes time.
A trait is not necessarily an evolutionary advantage - that is NOT part of the theory of evolution. A trait is a genetic quality - be it hereditary or a mistake. People are born with genetalia every day and that is a trait. It is definitely NOT an evolutionay advantage - it is simply a trait.

Saying that changes over 100 years aren't evolutionary isn't quite accurate. There are fluctuations, but with such a large population it is easy to create large changes in non-relative numbers.

It is true that we cannot predict protein folding by knowing the sequence.

But -as far as I know- the "Anfinsen-experiment" has shown that one does not need any additional information than the sequence for protein folding.
The protein will always fold in a way that it reaches the state with the "lowest energy", depending on the solution it is in.
There are already bioinformatic tools to predict protein structures, they do not work well, but this is because we do not have the calculation capacity yet to go through all the possible states.

Proteins seem to be amazingly perfect, but they are not necessarily so.

There might always be other structures that would do its job as well, the question is whether the necessary mutations to obtain that protein have already occured.

And a mutation that is of advantage is improbable, and mutations in higher eucaryotes as we are are already not probable.

It's not that nipples were created for a use, they existed on apes and did not affect our survival in any way. If nipples were a significant flaw in our anatomy that led to shorter lifetimes, then they would probably not exist.

That was what I said, things disappear when they are a flaw. Anything else does not have to be an advantage, it is simply not interfering with reproduction.
It does not necessarily have to shorten the lifetime to disappear, it only has to lower the probability of fertile offsprings.

For example, if there was a "nun-gene", and all women with that allele became nuns, it would disappear over time. The carriers might be very longliving, still, the probability to come to the next generation would be lowered.

An other example is our long childhood and the incredible helplessness of our babies. It would be "better" to carry children longer.
Females of our species have wide hips. This interferes with our ability to run, it is, biomechanically speaking, nonsense.
But we women have these wide hips to be able to give birth to our children, who have enormous heads, compared to other species.
So we are now living in a sort of equilibrium: helpless babies vs fitness of females.
Maybe it would be better if our hips were constructed completely different, so we could carry children longer and run faster.
But the mutations leading there have not happened yet.

I answer now not everything in the order you wrote it, sorry:rolleyes:

Are you saying that humans haven't become larger and more intelligent in that 5000 years? If that's what you're saying - try checking some data.
No, I did not. Maybe the last 200 years are better as an example, as we have more data about the last generations.
In most industrial countries, people are now taller than they were before.
As far as I read the literature, most researchers think this is due to a more protein- and energy- rich diet.

At least in europe, there is a correlation between protein intake in youths and the development of height. OK, this does not say anything yet...
Furthermore, there was a decline in height during certain periods of our history when there was not enough food.
Now, this development seems to have stopped. Since 60 years, there has been peace now and noone was starving.
People who were born during the last 40 years were carried by mothers who did not starve. They themselves never starved.
Athletes who have to restrain food intake are shorter than you'd expect them to be, given the height of their siblings, parents... of cause, statistically, not everyone.

Intelligence has even increased during the last 50 years, at least the one measured by IQ tests.
50 years is definitely not enough for evolutionary changes, it corresponds to less than 2 generations. Except, of cause, people who could not reproduce before are able to do so now, e.g. people who became impotent and now... there is viagra ;)

Unpredictability doesn't negate existence - a basic axiom of chaos theory.

Sorry, I made my point not clear enough. I wanted to say that there are major changes in the expression of our genes, determined by our environment.

I know: absence of evidence is no evidence of absence. I like that one:D

This isn't a sure proof - but to say that this observation isn't nearly-conclusive evidence makes no sense.

Yes, you are right, in most cases it is like that. Still, there are some species, in which sexual selection led to harmful changes. As for example some exotic birds. I am sorry, but I do cite now, as it is complicated for me to be sure I express myself correctly in English

"Evolution can get stuck in a positive feedback loop. Another model to explain secondary sexual characteristics is called the runaway sexual selection model. R. A. Fisher proposed that females may have an innate preference for some male trait before it appears in a population. Females would then mate with male carriers when the trait appears. The offspring of these matings have the genes for both the trait and the preference for the trait. As a result, the process snowballs until natural selection brings it into check. Suppose that female birds prefer males with longer than average tail feathers. Mutant males with longer than average feathers will produce more offspring than the short feathered males. In the next generation, average tail length will increase. As the generations progress, feather length will increase because females do not prefer a specific length tail, but a longer than average tail. Eventually tail length will increase to the point were the liability to survival is matched by the sexual attractiveness of the trait and an equilibrium will be established. Note that in many exotic birds male plumage is often very showy and many species do in fact have males with greatly elongated feathers. In some cases these feathers are shed after the breeding season."
Chris Colby
A trait is not necessarily an evolutionary advantage - that is NOT part of the theory of evolution. A trait is a genetic quality - be it hereditary or a mistake. People are born with genetalia every day and that is a trait. It is definitely NOT an evolutionay advantage - it is simply a trait.

Exactly this I wanted to say. We cannot say anything about the contribution to evolutionary fitness of a given trait. We can only conclude that it was not that harmful yet that is disappeared.

Saying that changes over 100 years aren't evolutionary isn't quite accurate. There are fluctuations, but with such a large population it is easy to create large changes in non-relative numbers.

I used evolutionary change in the sense of a real, statistically significant change, not in the sense of a fluctuation.

I'm curious about your next answer:)

The great big theory of ADD that we see mentioned or alluded to, in thread after thread is something along the lines of ... ADDer as the genetically honed anachronistic hunter in our new world of predominantly gatherers.

Don't agree at all ... but why is this theory so popular?

--It's real easy to grasp.
...but that doesn't mean it's right

and

--It kinda' gives us that 'it kinda' makes sense' kinda' feeling
...but that doesn't mean it's kinda' :-) correct

Evolution is fascinating ... particularly of genes, or characters with a 1:1 relationship with genes.

As the character under question involves more and more genes ... and the genetic contribution takes a back seat to environmental influences ... and my favourite ... in conditions of the mind (where we're considering the alteration in functionality of an entity which is not understood in its normal state) ... so does classical Darwinian evolution of genetic mutation/selection/de-selection, become more difficult to apply - or at least to prove that we should be looking to it, to provide clues to that entity's existence.

Which is all a long winded way of saying that I agree.

SB.

I include this from my first google hit ...
the reference isn't important.

I'm hoping that the analogy may be seen by some ... of this paragraph's thrust, and ADD.

The 'Missing Link' is the term for the separation of man from ape.
Copied From Google 1:
The "Missing Link" has evaded science to date. The ultimate enigma in seeking the answer to mankind's most puzzling question: Who are we, and where did we come from? The orthodox explanation, largely derived from Charles Darwin is that humans evolved from apes by way of some intermediate species. But evolution cannot account for the appearance of *Homo sapiens*, which happened virtually overnight instead of the millions of years evolution requires and with no evidence of earlier stages that would indicate a gradual change from *Homo erectus*. The hominid of the genus *Homo* is a product of evolution. But *Homo sapiens* is the product of some sudden evolutionary event. He appeared inexplicably some 300,000 years ago, millions of years too soon.

A very real biological event which irrefutably occurred.

SB.

That was what I said, things disappear when they are a flaw. Anything else does not have to be an advantage, it is simply not interfering with reproduction.

My own little pet theory is that until the industrial revolution, it wasn't much of a disadvantage. It has only been recently, when we need to be on time for things, do standardized quantities of work, attend mass education, etc., that it becomes a liability.

My own little pet theory is that until the industrial revolution, it wasn't much of a disadvantage. It has only been recently, when we need to be on time for things, do standardized quantities of work, attend mass education, etc., that it becomes a liability.

I think that as well.
I just read recently about the "attention deficit trait"-theory of Hallowell (I think it was him).
It says more or less that because of all those distractions of modern life and all the informations that we are bombarded with, even perfectly normal people can show an "ADD-like" behaviour. Apparently this disappears in vacations or less demanding times.

In Germany, we have a "Neuroscience-Guru", a professor who is very famous here, and he says, that children playing lots of computer games develope "ADD-like" traits. According to him, the games train you to get a very wide focus to be able to react to all those things happening at once.
I do not know actually how well these theories are established ....

Unluckily, I do not know enough about psychology to be able to say anything more about that.

But this theory might be true for myself. I always asked myself why I am that happy in vast, empty regions like northern scandinavia.
Maybe I just enjoy having nearly no stimuli, just white snow, no people, nothing. :rolleyes:

or 'Intelligent design', but a very real biological event which irrefutably occurred.

Actually, it happens quite often that larger structures are all at once remodeled.
Genes can regulate things in a hierarchical order.
I do not know, whether you've seen once those pictures of flies that have a leg at the very place where normal flies have eyes. This is just one mutation.
There are genes that turn on whole programs, as for example "leg" or "eye".


BTW: I do not want to say it is impossible that ADD has an advantage.

Neither am I sure it is all due to changes in the socialization, it could be also toxins, tobacco smoke being everywhere, don't know.

An other theory I find interesting is that in very structured societies it is easier to stick to rules, the daily life followes a certain pattern and you do not have to make up your own structures.
Maybe we are overwhelmed by the choices and the responsibilities we have.
I would not want to give that up, either...


I only wanted to say that in my opinion, evolution is often not fully understood and "flattened".
I am very aware of that I do not know where ADD comes from, I know there are many people who know much more.

Maybe that is typically ADD: I got angry as people took those speculations as granted.
And I think people who write books should take more responsibility for what they write. Of cause one has to simplify as not every reader can be an expert on your field.
But I'd wish authors and journalists would make more clear what is a hypothesis and what not.
Media shape our reality, and we have the right to be as well-informed as possible.
In my opinion, media abuse their power by only writing what is selling best.

Not to be taken seriously, this is entirely made up by myself with no supporting data ;)
Some ADDers report having a high sex drive. In males, reproductive success depends on the number of females they are able to mate with. Now imagine a promiscuous male who spreads many copies of the responsible genes, (if they exist). Note that ADHD is particularly easy to spot in males. The question is: Can he spread enough to offset any potential drawbacks? Or it might just be a case of plain old case of hitchhiking, i.e. tight linkage with an advantageous allele with little recombination between the two loci.

Re: Flashy, conspicuous males:
"No one knows" isn't quite what's going on, as there are certainly theories surrounding sexual selection and female choice.
In certain swallows, a long tail is correlated with a low parasite load, i.e. "good genes". Therefore, some characters are "honest signals" or indicators of good health. The handicap theory predicts that a male who escapes predation in spite of being very easy to spot, or who manages to forage even with a massive tail that gets in the way etc. must be good at flying away quickly, etc. A female that chooses to mate with a "sexy" male (which may be influenced by genes) that appeals to the majority of females instead of a drab one is more likely to have "sexy" sons with high reproductive success that are more likely to pass on her genes. If there was no meaning, we would be looking at neutral or nearly neutral evolution, hitchhiking, etc.

Men have nipples because in the womb we all start out as females, and it's more efficient to just keep the nipples instead of carrying extra genes around to make them disappear.

There, I answered that one, any other questions? ;)

Actually, it happens quite often that larger structures are all at once remodeled.
With respect to this last sentence -- would you have any thoughts on how you see this process as occurring? ... whether it fits under the banner of classical evolution? ... or some other less understood aspect of evolution? ... whether it can be used to understand the development of language? ... or ADD? ... whether this process we discuss is always associated with a higher level structure forming? -- and *what* that structure might be -- if we're discussing the *-mind-*?

PS :-) any thoughts welcome -- no matter how unsupported or freaky ... ! - really I am just after a gut feeling.

As a clue to where I see all of this going --- what would be the easiest way, a way, a conceivable change within us -- that would allow us to flourish in the information age. -- What do we need to be able to do?
-- How might this be possible? --What would be the experiential perspective in individuals orienting to this change?

BTW - do you have the name of the neuroscience chappy that you mention?

SB.

Piaszw,

Thank you for the intriguing post. It has (and should continue to) generate a variety of responses.

If you get a chance, please check out some of the work by Russ Barkley.

He originally studied to become a molecular biologist.

That (scientific) background is still evident in his works, as he considers himself more of a scientist than a clinical/nueropsychologist.

Happy Holidays

mctavish23
(Robert)

Piaszw,

Totally agree that evolution and natural selection have been misunderstood and misrepresented for many of the reasons you discussed about the actual processes. I've posted a few times about selecting-against verses selecting-for.

But, I have to disagree with your statement: "Sadly enough, it is very rare that evolutionary biologists, theoretical biologists, one could even say anyone with a thorough training in biological sciences contributes to that discussion. Mostly, human behaviour is explained with evolutionary development by psychologists or physicians."

First, most research psychologists (and physicians even moreso) DO receive a great deal of training in biological principles. This is also the direction the field is going, with brain imaging technologies becoming more feasible. In addition, there are MANY programs now that offer a degree in "Evolutionary Psychology" or "Evolutionary Psychopathology" or "Developmental Evolutionary Psychology".

In my department, most of the professors are interdisciplinary. While the majority have PhDs in neuropsychology, cognitive psychology, biopsychology, or social psychology, MANY (especially the neuropsych professors) have bachelors and/or masters degrees in biology or a related field. (My advisor has a degree in physics!)

Many collaborate with people in other departments like anthropology, biology, geography, and engineering.

At UCLA, there's a "Center for Behavior, Evolution, and Culture" includes people from a number of different disciplines, including Anthropology, Applied Linguistics, Economics, Neuroscience, and Psychology.

Sorry for the rant, but I really do think that the majority of people discussing evolutionary theories are qualified to do so. Certainly, there are exceptions.

Just an FYI:

The existence of nipples in men is an artifact of the period of fetal development in which gender is undifferentiated.

In the same way that a "genital bud" develops into a male organ or female organ depending on the types of hormones present, the "pectoral buds" either become functional or non-functional, and the male nipple is much like a belly button--it's just a scar.

First, most research psychologists (and physicians even moreso) DO receive a great deal of training in biological principles. This is also the direction the field is going, with brain imaging technologies becoming more feasible. In addition, there are MANY programs now that offer a degree in "Evolutionary Psychology" or "Evolutionary Psychopathology" or "Developmental Evolutionary Psychology".

I partly agree. My University doesn't even offer a "straight" Psychology degree. People are forced to take it with another subject from another department. The neuroscience stream requires taking five semesters of cell & molecular biology modules followed by a developmental and a systems module. Personally, I've never noticed any Psychologists in those courses. I do know a few who do the "biology" stream, which is essentially ecology & evolution related modules as well as philosophy of science. They appear a bit lost at times when things get jargon-heavy, though. There's also a Psychology unit Biologists can take unless they're on the Master's course (I'm assuming there must be a reason...)

Toad: The majority of our genome consists of non-coding regions, so efficiency isn't the explanation you're looking for ;)

The mental health field is moving towards "evidenced based" practices.

Simply put that means: Prove what you just did actually works for whatever it is you used it for.

It's been 30 yrs since I was in grad school, so I have no idea what's being taught, other than what our interns tell me.

From a strictly, clinical/child/applied psych standpoint, there's more emphasis on really knowing what the research currently says about the various disorders.

tc

Happy Holidays
mctavish23
(Robert)

Squirrel said:
Toad: The majority of our genome consists of non-coding regions, so efficiency isn't the explanation you're looking for ;)
Yeah but...Uh, it would be a waste of resources and un-neccesary to kick in idle genes to make the nipples go away.

Best to just keep them, don't cut them off either like in the Pink Floyd The Wall movie, that's effective, but not necessary either.

So men, suck in that gut, stick out that chest and be proud of your nipples and the efficiency of Mamma nature.

I'm proud of my man-buds.
:)

he 'Missing Link' is the term for the separation of man from ape.
Copied From Google 1:
The "Missing Link" has evaded science to date. The ultimate enigma in seeking the answer to mankind's most puzzling question: Who are we, and where did we come from? The orthodox explanation, largely derived from Charles Darwin is that humans evolved from apes by way of some intermediate species. But evolution cannot account for the appearance of *Homo sapiens*, which happened virtually overnight instead of the millions of years evolution requires and with no evidence of earlier stages that would indicate a gradual change from *Homo erectus*. The hominid of the genus *Homo* is a product of evolution. But *Homo sapiens* is the product of some sudden evolutionary event. He appeared inexplicably some 300,000 years ago, millions of years too soon.

This event is nothing to do with a God, as such - or 'Intelligent design', but a very real biological event which irrefutably occurred.
SB.
Actually, this is not true. Many fossils have been found that are excellent intermediates between Homo erectus and Homo sapiens. You can read about them and view photos of the fossils here. (http://www.talkorigins.org/faqs/homs/species.html)

For example, on this page (and in other places) you can read about "archaic homo sapiens", many specimens of which are as good an intermediate between erectus and modern humans as you could ask for. Just to quote from that page:

"Archaic forms of Homo sapiens first appear about 500,000 years ago. The term covers a diverse group of skulls which have features of both Homo erectus and modern humans. The brain size is larger than erectus and smaller than most modern humans, averaging about 1200 cc, and the skull is more rounded than in erectus. The skeleton and teeth are usually less robust than erectus, but more robust than modern humans. Many still have large brow ridges and receding foreheads and chins. There is no clear dividing line between late erectus and archaic sapiens, and many fossils between 500,000 and 200,000 years ago are difficult to classify as one or the other."

In my opinion, that's about as good a description of an intermediate fossil as you're likely to find anywhere.

Although the graphs does fill in a few more blanks it doesn't seem to get them all filled in. None of them do.

These are probably times when there were "parts of both" the pre-modern man and modern man as I am assuming they inter-breed???

Okay and now that I have looked at pictures drawn by cave people and read some interesting things about breast of a man. What does any of this have to do with weather nor not ADD can be linked to an evolutionary process. Why or why not????!!!


One assumption being made here is that there must be an evolutionary advantage for a trait that occurs in at least 3% of the population.

Three percent as quoted above hmmm. ADD diagnosis is apx 7% of the population almost twice the figure and only including those who are identified doesn't include borderlines and those who have learned to adapt to their traits by altering their environment. In other words your figures are in no way totally conclusive they can't be as not every ADDer on the face of the planet has been identified. Many never will be so reality check there are no real numbers to gauge how many people are actually effected by these cluster of traits. Shall we begin there????



I do not want to offend anyone here...
But I think, evolution has been misinterpreted and misused as explanation so much recently.

No offence taken.. it takes so much more to offend me. :D



ADD does not have to have an evolutionary advantage.

to what do you base this assumption?? Please do NOT use the tired school organizational job, traffic tickets stuff. Despite my lack of some fancy degree I do know school rooms, cubicles and motor vehicles happen to be too recent to be a determining factor in evolution. Read the site from Harvard. Excite me with some originality. :eek: This is the fourth or fifth thread about same subject I have read and now participated in the last two months.


As the environment of humans changes constantly and we are -luckily- very able to adapt, it is most likely that differences in the occurrence of traits over time are caused by the environment.

Could our apparent adaptability be due to the fact we happen to be the ones doing the changes?? We are changing our environments to suit us having zip to do with our natural ability to adapt. Seems like our manipulating our own environment would over time decrease our natural ability to adjust to environmental changes.


If ADD occurs more now than 100 years ago, this development simply cannot be evolutionary, as there are so many ADDers.
Evolution takes time

Now these are the statistics I have been waiting for through out all these evolution debates on ADD. Now exactly how many people had ADD 100 years ago?????? How many people had ADD 1000 years ago???? If there are not statistics on the number of ADDers 1000 years ago vs number 100 years ago compared to ADDers today then there is absolutely no way to know weather or not ADD has any advantages true!!!!! More importantly no one knows if ADD had any disadvantages either !!!!! But the below may be the closest clue to how ADD could possibly been an advantage in the reproductive possibilities in those who had ADD, especially in the male population!!!!

Harvard Source quote:
The females then mate with the males that most interest them, usually the ones with the most outlandish displays. There are many competing theories as to why females are attracted to these displays.

Few things can be more outlandish than an ADHD male!!!

Maybe the above explains why I found the following an enjoyable response that truly needed no elaboration besides I knew what he meant. I also like the way he interrupted all the highly educated lines of thought with a simple answer which was more accurate then many of the previous explanations.


To interrupt highly formalized debates to interject some simple logic has always attracted my attention ….may an evolutionary process as described above. More than likely as mirror of one of my frequent tactics to which I can relate.


originally posted by Toad
Men have nipples because in the womb we all start out as females, and it's more efficient to just keep the nipples instead of carrying extra genes around to make them disappear.

There, I answered that one, any other questions


You are correct in that the nipples of a man may have no disadvantages however sense we all are most attracted to that which is familiar maybe the nipples had another not mentioned advantages. Not mentioned due to the family friendly theme of the open forum!!!!!

I shall allow ADD imaginations and experimentation do the rest!!!!! :o

Quote:
ADD does not have to have an evolutionary advantage.

meadd823:
(Prepare to be bored to death :D)

Note that the question isn't whether ADD had a disadvantage at a given point in time. If there was no advantage, the responsible allele or alleles (if they exist) can't have been positively selected for, even if they may not have been selected against.

Slightly detrimental alleles that are tightly linked to alleles (i.e. found nearby on the same chromosome) under positive selection can "hitchhike" through the population. Due to the tight linkage, recombination between the two loci during meiosis is very unlikely, so they are inherited together in most cases. If the net effect on reproductive success is beneficial, both will increase in frequency.

Another scenario that doesn't involve positive selection: Under certain circumstances, some mutations don't affect the fitness of the invidual. The degree of polymorphism, i.e. sequence variation, found in our genome can't be explained entirely by natural selection. Say a mutation arises and doesn't happen to enhance or decrease reproductive success. Whether it disappears or stays in the population depends largely on chance.
Now consider purifying selection (this is merely an example):
Say there is a change in the environment and all of a sudden, the trait that didn't affect you previously is now under selection. You now have a normal distribution along a continuum, i.e. the majority of values will be in the middle of the range with less values tending towards either extreme. Over time, due to changing environmental factors, the bell curve you started off with may begin to narrow as the more extreme values are removed from the population. You will still find values that are "more extreme" than others, albeit less extreme than the ones that were present in the population before. Those extreme values will not be present in your average member of society, but certainly in a few people.

Humans happen to have quite slow reproductive cycles, making the lag between a change in the environment (even if they caused it themselves) and the point in time where evolution is able to catch up quite long. But then, not all means of adapting to the environment need necessarily involve heritable traits. The question is: Who is changing our environment? What if "average" people were the ones changing it to suit their needs? How does that affect someone who isn't "average"?

Just to interject, I saw a book the other day at a bookstore that might be relavent to this discussion:

Why Do Men Have Nipples? Hundreds of Questions Youd Only Ask a Doctor After Your Third Martini (ISBN: 1400082315)

Okay, I've never read it, so I'm not sure if it answers the question seriously, but I though I'd bring it up here. :)

The question is: Who is changing our environment? What if "average" people were the ones changing it to suit their needs? How does that affect someone who isn't "average"?

Depends on how they aren't average. It isn't like ADDers have an arm growing out of our foreheads okay.

The fact is ADD is only a trait where a certain cluster of traits appear more extreme and/or more frequently than the average population. Although many focus on ADD attention differences isn't ADD a bit more than that????

If non-ADDers are making environmental changes to suite them selves then why is the world becoming more ADD??? If one focuses on one thing too long five others will be missed.


Multi media, 501 channels, immediate info 24/7 via internet on any thing in any language, satellite radio without advertising, instant every thing from food to pictures, things smaller than the palm of the average human hand that can remember a zillion and one songs, don't go to the store order on line. I won't even touch e-bay directed specifically for impulsive buyers. If the “normals” are changing our environment then they have more ADD than I could ever hope for.

Don’t look now but just might be the ADDers who are making the changes so the environment is more reflective of “us”

ADD being a disadvantage in the past possibly. ADD being a disadvantage now maybe but not for long. Especially us ADDers who thrive in multi-tasking soon we will be the only ones capable of keeping up!!!!

As my mom used to say time does and will tell all!!!!!


Just to interject, I saw a book the other day at a bookstore that might be relavent to this discussion:

Why Do Men Have Nipples? Hundreds of Questions Youd Only Ask a Doctor After Your Third Martini (ISBN: 1400082315)

Okay, I've never read it, so I'm not sure if it answers the question seriously, but I though I'd bring it up here.

Nope no ADDers around here:p

Wish I could type what I am thinking without getting into trouble!!!!! Too funny HF!!!

Ok maybe it's the lack of sleep or the silly mood I'm in but the only word I'm able to focus on in this thread is Nipples. So either you all really love talking about nipples or I totally missed the point. I'm betting it's the second option. Ohhh well nipples, nipples, evolution of nipples. :D

So either you all really love talking about nipples or I totally missed the point.

A little of both perhaps it is the "ADD factor" at work you are seeing.

Original post is about the writer of the post disagreeing with ADD being touted as an evolutionary advantage.

One of the statements that was used was that a trait does not have to enhance the chances of survival of a species to exist as long as the trait doesn't decrease the chances of the bearers survival it may merely be passed down with no real reason.

Mentioned as a trait that neither increases nor decreases a species chances of survival namely humans was the fact that all males have nipples even though they seem to serve no porpoise.

Being ADDers instead of focusing on the main topic of ADD and evolution the discussion focused on the apparently useless trait of male nipples.

This should help clear it up for all who have ADD, those who do not may continue feeling lost despite my ADDed clarification!!!

I havent read all this thread but i know one thing. You can't explain Evolution in humans with Darwin. Humans have been on top of the food chain for far too long for natural selection to effect our evolution. "No Tigers eating the slow people anymore". For that very reason its going to be impossible to predict were our species is heading or how we will get there.

I have trouble agreeing with the notion that I have an advantage over an "average" person when it comes to new technologies. Knowing how to do thousands of things on my laptop doesn't help when I'm trying to use it to read lecture notes and all of a sudden feel compelled to look for information on the internet when I should be trying to get my degree ;) *must stop procrastinating*
Evolution also requires an immediate advantage. "This might come in handy in a few generations time" doesn't tend to fly very well.

I havent read all this thread but i know one thing. You can't explain Evolution in humans with Darwin. Humans have been on top of the food chain for far too long for natural selection to effect our evolution. "No Tigers eating the slow people anymore". For that very reason its going to be impossible to predict were our species is heading or how we will get there.
That's quite frankly not true. According to the Red Queen hypothesis, we have to run and run as fast as we can and still remain in the same place with regard to competitors and predators.
If you think you're not under selection, consider pathogens for a moment: One our genes under selective pressure is involved in producing lysozyme, which is secreted in our tears and destroys bacterial cell walls. Likewise, some of the greatest differences between chimps and humans are found in the immune system. Microorganisms' genomes change very rapidly due to very short generation times and high mutation rates, especially in RNA viruses that lack proofreading mechanisms. As a consequence, pathogens are always coming up with new tricks and our genes have to "come up with" ways of defending us if they want to survive.
Furthermore, if you only look at the fitness of an individual, you're likely to miss part of the picture. If someone else passes on more copies of their genes to the next generation, those alleles will increase in frequency. Escaping getting eaten by a tiger doesn't necessarily mean you'll automatically find a mate before someone else.

While it may be true that evolution in humans may not be occuring at the same rate as in mice, for instance, you can't say it isn't occuring at all. Humans tend to think they're the ultimate chef d'oeuvre of evolution and let their preconceptions mislead them...

ADHD is NOT an advantage.

Knowing how to do thousands of things on my laptop doesn't help when I'm trying to use it to read lecture notes and all of a sudden feel compelled to look for information on the internet when I should be trying to get my degree ;) *must stop procrastinating*
I prefer to think of it as a double-edged sword. I do think there are aspects of being on this end of the spectrum that are advantageous, but they call it impairment for a reason.

I like your example, Squirrel.


Evolution also requires an immediate advantage. "This might come in handy in a few generations time" doesn't tend to fly very well.
Actually, evolution doesn't require advantage. It requires disadvantage. Traits are selected out, not in. One giraffe might survive because one has a longer neck to reach the leaves while another dies because the leaves at the bottom were eaten by hippos, but it is the disadvantage that limits the species, not the advantage. If hippos didn't eat the leaves, both the long-necks and the short-necks would survive.

If ADHD isn't a great enough disadvantage, it won't be selected out. This explains how an impairment can survive without being an advantage.



While it may be true that evolution in humans may not be occuring at the same rate as in mice, for instance, you can't say it isn't occuring at all. Humans tend to think they're the ultimate chef d'oeuvre of evolution and let their preconceptions mislead them...
I think it is difficult for people to comprehend how evolution can be responsible for such a "perfect world" where complicated symbiotic relationships and what look like too many coincidences are present. What they miss is that the model of evolution actually predicts exactly that.

I think humans are a terrific example of Darwinian Evolutionary Theory.

Actually, evolution doesn't require advantage. It requires disadvantage. Traits are selected out, not in. One giraffe might survive because one has a longer neck to reach the leaves while another dies because the leaves at the bottom were eaten by hippos, but it is the disadvantage that limits the species, not the advantage. If hippos didn't eat the leaves, both the long-necks and the short-necks would survive.

If ADHD isn't a great enough disadvantage, it won't be selected out. This explains how an impairment can survive without being an advantage.





Exactly this is what I wanted to say: The existence of a given trait does not allow the conclusion it is advantageous.

It might be, we can't prove the opposite either :D

I think I have to apologize about what I said about psychologists.
I was angry and I guess I wanted to provoke. Sorry.

Of cause, there are many scientists who are able to contribute very much to other fields.

And maybe I thought of something different than you did by "thorough education" ....
I thought of someone who has really done research on that topic, who might have a PhD in that area....

I would like to ask an expert in population genetics, theoretical or evolutionary biology what he thinks about those theories.
As far as I know, there are not too much of them who participate in this discussion.

HMMM. Did not want to cause so much trouble. I simply wanted to remember people that in popular books about science, theories are often presented as truth.
And that many authors do not really have the qualification they should have.
Sometimes I have the impression they "guess" something, write a book which becomes popular and distort peoples view of the world.

Maybe I should add that I'd probably be the first one to be hunted.
I'd simply stumble over the next tiger:D

OK, I have DAMP, dyspraxia plus inattentive ADD.
(Still, I can be impulsive and have hyperactive thoughts, as I've proven by wanting to provoke with this thread);)
Guess hartmann did not think of people like me.

Exactly this is what I wanted to say: The existence of a given trait does not allow the conclusion it is advantageous.
Yeah, most people either misunderstand evolution or forget that this is the case.


It might be, we can't prove the opposite either :D

Quite true. Can't prove anything, but we can't even gain much support for cause in this case. It would take a lot more evidence than we have now to even hypothesize a causal connection.


I think I have to apologize about what I said about psychologists.
I was angry and I guess I wanted to provoke. Sorry.
No problem. You provoked, alright! But the insult was slight compared some of the other insults to psychology I've read on these boards! ;)


And maybe I thought of something different than you did by "thorough education" ....
I thought of someone who has really done research on that topic, who might have a PhD in that area....
Well, having a specific PhD obviously indicates they've studied that area extensively, but it doesn't exclude others from a pretty thorough knowledge.

In my experience, there are PhDs out there with very narrow knowledge and those with very wide knowledge. In addition, someone might have a wide knowledge base that encompasses a number of disciplines and someone else the same amount of other disciplines. The important thing for anyone doing research or using research (like clinicians) in my opinion, is that they consider implications of what is known from various perspectives. Interdisciplinary approaches are always more likely to end with conclusions that are closer to truth. Just my opinion.


I would like to ask an expert in population genetics, theoretical or evolutionary biology what he thinks about those theories.
As far as I know, there are not too much of them who participate in this discussion.
You might check out The Center for Evolutionary Psychology at UCSB.

http://www.psych.ucsb.edu/research/cep/

It's co-directed by a Leda Cosmides from the Department of Psychology, Developmental Evolutionary Area and John Tooby from the Anthropology Department.

Leda Cosmides has a BS in biology along with an MA in psychology and a PhD in cognitive psychology with minors (I didn't know anyone did minors for PhDs!) in both cognitive development and evolutionary biology.
I'm not sure what John Tooby's degrees are in, but he specializes in biological anthropology.

Together and apart they've published quite a bit on genetics and adaptation as well as attempting to explain behavior through evolution.

Now, I'm aquainted with them both and, while I like their ideas at times, I'm somewhat critical of their research methods, narrow focus (everything is from an evolutionary perspective with little regard to opposing viewpoints), and conclusions (a lot of post-hoc thinking, IMO).

However, they are very well-respected in the field and their work is cited more than any other evolutionary psychologists I know of.

My point here is that there is a great deal of genetic expertise that houses itself in other disciplines and my have some interesting points of view.

Of course, you probably won't agree with Cosmides & Tooby (I rarely do), but I guarantee they'll make you think about your own viewpoint.


HMMM. Did not want to cause so much trouble. I simply wanted to remember people that in popular books about science, theories are often presented as truth.
TOTAL AGREEMENT HERE.

But, even some of the best resources have big mistakes. That's why I think it's so important for people to understand the nature of science itself and how it works. Understanding this provides some insight into how brilliant theories can be crap and things we think are obvious turn out to be untrue. It also allows us to examine what is printed & decide for ourselves how much to take as "fact".


And that many authors do not really have the qualification they should have.
:D Dr. Phil (a psychologist) sells diet books and Dr. Laura (a physiologist) does counseling!

Yep. There's a LOT of CRAP out there.


Sometimes I have the impression they "guess" something, write a book which becomes popular and distort peoples view of the world.
They probably just see an opportunity to scam people and go for it. A few, I'm sure, actually believe their own crap.

Exactly this is what I wanted to say: The existence of a given trait does not allow the conclusion it is advantageous.
Yeah, most people either misunderstand evolution or forget that this is the case.


It might be, we can't prove the opposite either :D

Quite true. Can't prove anything, but we can't even gain much support for cause in this case. It would take a lot more evidence than we have now to even hypothesize a causal connection.


I think I have to apologize about what I said about psychologists.
I was angry and I guess I wanted to provoke. Sorry.
No problem. You provoked, alright! But the insult was slight compared some of the other insults to psychology I've read on these boards! ;)


And maybe I thought of something different than you did by "thorough education" ....
I thought of someone who has really done research on that topic, who might have a PhD in that area....
Well, having a specific PhD obviously indicates they've studied that area extensively, but it doesn't exclude others from a pretty thorough knowledge.

In my experience, there are PhDs out there with very narrow knowledge and those with very wide knowledge. In addition, someone might have a wide knowledge base that encompasses a number of disciplines and someone else the same amount of other disciplines. The important thing for anyone doing research or using research (like clinicians) in my opinion, is that they consider implications of what is known from various perspectives. Interdisciplinary approaches are always more likely to end with conclusions that are closer to truth. Just my opinion.


I would like to ask an expert in population genetics, theoretical or evolutionary biology what he thinks about those theories.
As far as I know, there are not too much of them who participate in this discussion.
You might check out The Center for Evolutionary Psychology at UCSB.

http://www.psych.ucsb.edu/research/cep/

It's co-directed by a Leda Cosmides from the Department of Psychology, Developmental Evolutionary Area and John Tooby from the Anthropology Department.

Leda Cosmides has a BS in biology along with an MA in psychology and a PhD in cognitive psychology with minors (I didn't know anyone did minors for PhDs!) in both cognitive development and evolutionary biology.
I'm not sure what John Tooby's degrees are in, but he specializes in biological anthropology.

Together and apart they've published quite a bit on genetics and adaptation as well as attempting to explain behavior through evolution.

Now, I'm aquainted with them both and, while I like their ideas at times, I'm somewhat critical of their research methods, narrow focus (everything is from an evolutionary perspective with little regard to opposing viewpoints), and conclusions (a lot of post-hoc thinking, IMO).

However, they are very well-respected in the field and their work is cited more than any other evolutionary psychologists I know of.

My point here is that there is a great deal of genetic expertise that houses itself in other disciplines and my have some interesting points of view.

Of course, you probably won't agree with Cosmides & Tooby (I rarely do), but I guarantee they'll make you think about your own viewpoint.


HMMM. Did not want to cause so much trouble. I simply wanted to remember people that in popular books about science, theories are often presented as truth.
TOTAL AGREEMENT HERE.

But, even some of the best resources have big mistakes. That's why I think it's so important for people to understand the nature of science itself and how it works. Understanding this provides some insight into how brilliant theories can be crap and things we think are obvious turn out to be untrue. It also allows us to examine what is printed & decide for ourselves how much to take as "fact".


And that many authors do not really have the qualification they should have.
:D Dr. Phil (a psychologist) sells diet books and Dr. Laura (a physiologist) does counseling!

Yep. There's a LOT of CRAP out there.


Sometimes I have the impression they "guess" something, write a book which becomes popular and distort peoples view of the world.
They probably just see an opportunity to scam people and go for it. A few, I'm sure, actually believe their own crap.

Quote:
Evolution also requires an immediate advantage. "This might come in handy in a few generations time" doesn't tend to fly very well.


Actually, evolution doesn't require advantage. It requires disadvantage. Traits are selected out, not in. Sorry, I didn't word that very clearly. I wasn't implying that there is such a thing as traits being selected in, since you either develop a mutation or you don't.
I wasn't referring to evolution as in selection and survival, but strictly to changes in allele frequency over time, which depend on an individual's reproductive success. For a "new" advantageous allele to invade, it has to confer greater fitness to heterozygous individuals (fitness = 1+hs where hs > 0) than the versions of the gene already present (fitness = 1). If hs = 0 we're looking at a neutral mutation, and the frequency may increase by chance, i.e. genetic drift. (NB: "advantageous allele" is consistent with my Evolution Prof's terminology)
What I meant to say in my original post: Whether s is negative of positive is subject to change, but what matters is s *at the time I'm ready to reproduce*, i.e. ADD can't be "selected for" because it "might be useful in the future", although it may be dragged along through the population by other means than direct selection on a certain locus.

Of course, an increase in the proportion of one allele is going to lead to a decrease in the frequency of another allele that might drop out of the population, as you stated in your hippo example, since the proportions add up to 1 by definition.
(Careful with statements concerning the "disadvantage that limits the species" though. Studies on sex ratios show evidence against selection on the species level)

(Careful with statements concerning the "disadvantage that limits the species" though. Studies on sex ratios show evidence against selection on the species level)
My turn to say "I should have been more clear." But you covered it. :)