Genes, phenotypes and populations

[plus]

It's refreshing to see something new, isn't it?

It is interesting, although it may appear to be certain individuals with the majority belief propogated by the media trying to clutch at straws. And I think that if there is discrimination to any side of the argument, it is certainly to the argument which is not this one.

 

[selfAdjoint]

Unfortunately some of the "popular" earlier studies had questionable financial backing and the results may have been biased.

So now scientific publications are to be rejected because of their funding? How about sticking to the science and refuting it if you can?

 

[Evo]

Unfortunately some of the "popular" earlier studies had questionable financial backing and the results may have been biased.

So now scientific publications are to be rejected because of their funding? How about sticking to the science and refuting it if you can?

If a study comes into question because of who paid for it and the people conducting it, yes, I would question it's validity. Wouldn't you? Would it be prudent not to?

 

[marcus]

Unfortunately some of the "popular" earlier studies had questionable financial backing and the results may have been biased.

So now scientific publications are to be rejected because of their funding? How about sticking to the science and refuting it if you can?

I only want to highlight a general topic which has been obliquely, maybe not intentionally, raised.

I could imagine that if you adjust for socioeconomic status, nutrition, every environment thing that you can, and take two populations, say of Finns and Japanese

it might turn out that what you are testing for (IQ in this case, I think you were discussing) is more heritable in one than in the other

Someone here, bobf I think, happened to post some abstracts and one was of a Japanese IQ heretability study using homozyg and heterozyg twins and it gave the result heretability = 0.58

Now you could have another population with comparable environment as those Japanese, I suppose, and it might have, say, heretability 0.52.

this does not say which has the higher or lower average IQ. It is interesting in itself. In what kind of population do you get more reliable transmission of a factor, whether it is high or low on average we don't care, instead we measure reliable transmission. I have a guess about this.

does anyone know of a study about it? heretability in different pops?
of IQ or something else----with S.E.S. leveled out, I mean

BTW correct me if I am wrong but low heretability of some index can indicate plain randomness I would suppose, noise in the channel, it is not a dichotomy between gene and environment but also some roulette, or?

 

[Nereid]

This may be thoroughly OT, so apologies in advance if it is ...

IIRC, there has been some questioning of the results of drug trials presented in peer-reviewed medical journals, on the basis that the researchers have not presented the full set of trial data. Apparently (and I admit that I would need to check to be sure my memory isn't tricking me) the researchers (or their institution) did the research using funds from a big pharma company, and the research contract prevented them from disclosing certain data.

Another example (different source?): papers written by a drug company employee (or contractor?), but submitted to the journal by a 'big name' in the field (in return for a fee); the extent to which the listed author took the time and care to assure himself of the veracity of the paper being entirely up to that individual.

IMHO, the full disclosure of all funding sources for all research papers is important to keep science clean.

 

[Monique]

Do you finally admit that some families might have some combination of genes causing them to commit more crime, or to have lower IQ?

Did I ever refute that? No.

You still have not answered my question. And this question also goes to Evo.

It is a balance between environment and genetics, only when you carefully control for the environment will you be able to say anything about the genetics.

Commiting crime and having low IQ are not clear defined phenotypes, it can mean anything! When you show me brainscans of a family that shows an underdeveloped frontal lobe and you tell me that all the people with that characteristic are very violent: yes I'm going to tell you that there must be a relation and that it is likely that genetics is the underlying cause.

The problem with the dicussions have been that the phenotypes are poorly defined and that the populations that are being compared are too different to allow for a comparison.

 

[Neo]

When you show me brainscans of a family that shows an underdeveloped frontal lobe and you tell me that all the people with that characteristic are very violent: yes I'm going to tell you that there must be a relation and that it is likely that genetics is the underlying cause.

Actually, this has already been done, although not for an entire family, as it doesn't need to be. Phineas Gage had a tamping iron an inch and a fourth in diameter thrust into his frontal lobe and survived it. His behavioral patterns were altered dramatically by this... He became fitful, irreverent, vacillating, capricious, indiscriminately promiscuous, grossly profane, violent, etc. He exhibited none of these characteristics prior to incurring this mental injury. Therefore, this type of mental disability, specifically of the frontal lobe, leads to these personality problems beyond a reasonable doubt.

As neuroanatomical structure and function is primarily determined by genetics, its high likelihood of the being the underlying cause is already well established.

 

[marcus]

...Commiting crime and having low IQ are not clear defined phenotypes, it can mean anything! When you show me brainscans of a family that shows an underdeveloped frontal lobe and you tell me that all the people with that characteristic are very violent: yes I'm going to tell you that there must be a relation and that it is likely that genetics is the underlying cause.
...

I have to say that although I recognize human subspecies or whatever you want to call them (lots of synonyms for the idea of races) are an albeit- fuzzy-yet-useful concept with phenotypical and genetic meanings (and social also!)---although I recognize these things I nevertheless find M's position here fully tenable and scientifically respectable

It seems to me that, as stated here, M's position arises from purely scientific considerations and involves no political or social agenda
(whereby it differs from some other people's position on either side of this)

and the sign is, as often the case with real science positions, that it can change
as the observations change

(which dogmatic kneejerk people who make a taboo of this or that topic are not so flexible and also dogmatic jerks who merely want to bash liberals)

this is an important point in the discussion for me
and it may have occurred earlier but I just joined the discussion or reached the sidelines where I could see, so I didnt notice this position before here

So I say screw those people who want to push the science faster than it should go because of some imagined moral imperative. And also good for M. for having stated a flexible conditional non-ideological position. There is no single correct position and maybe some reputable human geneticists also take a different position, but this seems solid to me, one possible stance.

It is very clear: you may very well find, in Nature journal, in say 2006
a family with frequent violence whose brainlobes scan a certain way

THEN you have a sign, because it is a family of genetically related persons, that there is a genetic factor to that particular violence. A professional human geneticist will look at this without blinking---no matter what political party he or she likes to vote for.

OK maybe this seems very simple and trivial. But I don't think so.

In the meantime until a violence-related phenotype is identified, we geneticists can ignore violence. Well? Well sure, maybe violence is socially important, or morally, but genetically it is not on the radar until there is something like this observed. All the rest is just speculation and wishful thinking. (I am talking like I imagine a geneticist might, to illustrate.)
Sure we wish we had a violence-related phenotype which we could study and maybe find a genetic means of reducing violence! But in science one must above all avoid wishful thinking---and acting as if you had some information that you don't merely because it would be nice to have.
(I say "we geneticists" to see how it feels to say this, I'm obviously an outsider myself.)


Sorry if I am sounding pedantic (or condescending which is not at all how I feel), I simply want to lay out a kindergarten grade-school basis that underlies the discussion so there cannot be any confusion

 

[Monique]

As neuroanatomical structure and function is primarily determined by genetics, its high likelihood of the being the underlying cause is already well established.

Right, that is why I never refuted the possibility. But you can't say that all the people who commit crime have such a physical defect.

 

[marcus]

Actually, this has already been done, although not for an entire family, as it doesn't need to be. Phineas Gage had a tamping iron an inch and a fourth in diameter thrust into his frontal lobe and survived it. His behavioral patterns were altered dramatically by this... He became fitful, irreverent, vacillating, capricious, indiscriminately promiscuous, grossly profane, violent, etc. He exhibited none of these characteristics prior to incurring this mental injury. Therefore, this type of mental disability, specifically of the frontal lobe, leads to these personality problems beyond a reasonable doubt.

As neuroanatomical structure and function is primarily determined by genetics, its high likelihood of the being the underlying cause is already well established.

Neo I am not taking one or another side of this debate, whatever it is about. Anatomy is not genetics.
Brain anatomy and, in this case, anatomical damage, can affect behavior.
We are talking bout genetics. You may be very intelligent but what you say about Mr. Gage and the hot iron does not seem relevant at all. I'm outa here.

 

[Monique]

Anatomy is not genetics.

sure it can be..

 

[marcus]

Anatomy is not genetics.

sure it can be..

Sorry about the ambiguity.

I didnt mean to say anatomy is not genetic. AFAIK human and other animals anatomy is mostly genetically determined---it seems sort of obvious that is true even if not a precise statement.
One can work out and get bigger muscles or eat better and lose weight but this is having comparatively little control over anatomy.

What I meant is that Anatomy and Genetics are not identical.
Mr Phineas Gage underwent a trauma that changed the anatomy of his brain without changing his genes.

I was trying to say the obvious (which might be common mistake of mine). One can conjecture that genetically determined brain structure has a huge lot to do with determining behavior. In future, more may be learned about this. One can reasonably conjecture that a disposition towards or against violent aggression is genetically determined to a high degree. But however plausible, these are only conjectures. apparently one has not yet seen a brainscan characteristic correlating to violence that is shared by members of a family. therefore one can not yet act like one knows for sure that the conjecture is true.

BTW, I believe one has observed anatomical structures in male songbird brains that correspond to their singing habits. It seems to me plausible that one might find structures that correspond to enjoying fights in bars but I gather one has not observed this at least till now. I wonder have realtime brainscans been done on football fans while they are watching a particularly good game on TV to learn if blood flows to some particular location.

 

[ryokan]

I have just read the discussions sucited in this interesting thread.
I don't see any need to use the term "race". I believe that the Monique's concepts are enough illustrative.
The advances in the knowledge of a gene aren't studied in basis to significative differences in phenotype between two goups. On the contrary, they are centered on "isolated" populations where a particular phenotype is most expressed, because of the early studies are based in linkage analysis in pedigrees.
I think that "race" is obviously a non-scientific concept which is currently associated to minor anatomic phenotypic differences (mainly skin colour) or to cultural characteristics. I think that the genetic value of the term "race" is null. On the contrary, as it was said, it is useful to center the genetic studies in well known, "isolated" populations.

I don't like concepts as IQ. I think that such concept could be interesting from a statistic viewpoint, but not at individual level. IQ isn't comprehensive enough to qualify the man's intellectual capabilities and it can be stigmatizing. I suggest at this respect the lecture of one famous Stephen Gould's book. I remember the excitement that was created in other similar cases to IQ: for example, the old associations between XYY and criminality (with the consequent film) or the most recent findings of genes "associated" to bipolar disease or even homosexuality.
In passing, of course, Alzheimer is not related to IQ. It is simply a disease, although obviously IQ don't up with Alzheimer.

It is very difficult to stablish clear relationships between genes and phenotypes when they are both polygenic and very modifiable by environment. At somatic level, obesity is a simple example. Remember you here the excitement with ob mouses and leptin?

I think that Phineas Gage is more illustrative to neurosciences than to Genetics. Genetically, it can be interpreted as the effect of an environmental change (great, dramatic) on a behavioural phenotype influenced by genetics. In simplistic terms, here the expression of some genes in some cells would be changed by the expression of others following an environmental influence.

Finally, I believe also that extra-scientific interest (commercial or merely curricular) to make a research can unfortunately influence its results in some cases.

 

[Monique]

I don't see any need to use the term "race". I believe that the Monique's concepts are enough illustrative.
The advances in the knowledge of a gene aren't studied in basis to significative differences in phenotype between two goups. On the contrary, they are centered on "isolated" populations where a particular phenotype is most expressed, because of the early studies are based in linkage analysis in pedigrees.
I think that "race" is obviously a non-scientific concept which is currently associated to minor anatomic phenotypic differences (mainly skin colour) or to cultural characteristics. I think that the genetic value of the term "race" is null. On the contrary, as it was said, it is useful to center the genetic studies in well known, "isolated" populations.

I agree completely.

 

[nuenke]

Socioeconomic status modifies heritability of iq in young children
Eric Turkheimer, Andreana Haley, Mary Waldron, Brian D'Onofrio, and Irving I. Gottesman.

The different ways that intelligence expresses itself developmentally is important for understanding learning, or how to best prepare children for adulthood - that is to maximize any ability they have or not to hinder it.

But with regards to individual differences, what really counts is the IQ one has in adulthood, because that is where it matters the most. Up until adulthood, hopefully one will be protected, cared for, etc. After growing up you are on your own. It is well recognized that the brain keeps changing, and that intelligence when a child is young is much more malleable than when a child approaches adulthood. As adults, the heritability of IQ approaches 80% as the shared environmental impact on intelligence and a host of behaviors diminishes (except for autonomy and sociability I think are the exceptions). As we mature our genes and the non-shared environment seems to take over. In psychometrics, this point is often missed or ignored - genes matter more when we grow up. Until then, the developmental process is rather open in order to understand the ecological niche each organism has been dumped in to. Humans need a long time to mature, prune neurons, deposit fatty tissue around axons, etc. Most of this occurs when we are in our teens.

 

[Neo]

I think that Phineas Gage is more illustrative to neurosciences than to Genetics. Genetically, it can be interpreted as the effect of an environmental change (great, dramatic) on a behavioural phenotype influenced by genetics. In simplistic terms, here the expression of some genes in some cells would be changed by the expression of others following an environmental influence.

Not really.

Genetically, on a more deeper level, it can be inferred that one of the functions of the frontal lobe is to rationally govern behavior through higher-order reasoning, abstract conceptualization, and long-term planning, functions which have already been established by the scientific community.

The structure of the brain is determined almost entirely by genetics, mainly I would say because neuroplasticity is not significantly maintained after puberty and it has been shown that it decreases rapidly after six years of age. Even before this time, environmentally-induced change via neuroplasticity has limits, as neuroanatomical structure is essentially genetic in nature.

 

[ryokan]

The structure of the brain is determined almost entirely by genetics, mainly I would say because neuroplasticity is not significantly maintained after puberty and it has been shown that it decreases rapidly after six years of age. Even before this time, environmentally-induced change via neuroplasticity has limits, as neuroanatomical structure is essentially genetic in nature.

I think that it remains yet the old dilemma nature-nurture. The environment plays an essential role in brain development. I don't believe that experimental evidence have discarded an important role to neuroplasticity in adult brains.
Simplifying, the sources of our knowledge on human brain function are the following:
Experimental:
- mainly extrapolated from experiments in other species
- studies in human subjects treated with electricity or chemicals.
Observational:
- Clinical and pathological observations of brain diseases, including mutations and trauma / stroke...)
- Epidemiological studies, as conducted in siblings
- Correlations between behaviour and functional imaging (MRI, TEP..)

So, our knowledge on human brain is, in great measure, indirect and very, very limited.

I think that there is yet need of a lot of new experimental and observational findings to obtain solid conclusions on the role of Genetics in brain structure and function. Furthermore, the importance of this determination could differ among specialized areas/functions.
At other level, as dramatic case of environment on gene expression, I would remember the so called "reaction norms" in Drosophila, where the observed phenotype (number of omatidia) is strongly dependent of both genotype and temperature

 

[BlackVision]

Another strange thing about Black Vision is his name. As if he was, like Korean, and didnt want anyone to know. So he puts Black on his name to suggest that he's black.

This is so ludicrous. "Black Vision" is the name of my band. Is Ozzy Osbourne trying to suggest he's black with his band name "Black Sabbath"?

 

[BlackVision]

Also english not first language, so could be Asian, e.g. korean.

English is my 1st language. I was born was raised in Los Angeles my entire life. Your assumptions and prejudice are quite offending I must say.

 

[marcus]

..."Black Vision" is the name of my band...English is my 1st language. I was born was raised in Los Angeles my entire life...

I retract, with apology, any guesses about you and where you were coming from.

Also, thanks for providing a little bit of background, like the band. Best wishes, whether it is with the music or with the studies at UC.

 

[hitssquad]

Alzheimer's as a disease vs Alzheimer's as a normal feature of aging

Alzheimer is not related to IQ... although obviously IQ don't up with Alzheimer.

• Clinical features at the initial examination of 42 patients with probable Alzheimer's disease were tested for prognostic value at subsequent follow-up of 54 +/- 25 months. These potential prognostic features were of three types: degree of severity features (eg, IQ scores); variable clinical features (eg, extrapyramidal signs); and individual distinguishing features (eg, gender, education, and age).

It is simply a disease

Alzheimer's status as a disease is contradicted by evidence that all humans of all ages exist in some stage of development of Alzheimer's. It has been pointed out by some life extensionists that if it may be true that if we are all gradually developing Alheimer's, we might want to take some preventive actions such as the administratiion of neuroprotective chemicals.

 

[ryokan]

Clinical features at the initial examination of 42 patients with probable Alzheimer's disease were tested for prognostic value

Alzheimer's status as a disease is contradicted by evidence that all humans of all ages exist in some stage of development of Alzheimer's.

This Abstract talks on Alzheimer's disease.

And... What is a disease?
Is prostatic cancer a disease ? All men, if old enough would develop a prostatic cancer.

Overdoing a little, If you understand by disease "some stage of development" of such disease, all we are patients along all our lifetime.

 

[0TheSwerve0]

I've got a quick question about sex chromosomes. What will happen if the one x chromosome is not inactivated in the female? I keep reading about the double doses females will get and that the fetus will be spontaneously aborted if inactivation does not take place. What actually happens when neither is inactivated?