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Archive for October, 2007

 

 

The past week saw the greatest controversy in a year ignited by the seemingly racist comments of the 79 year old Nobel Laureate James Watson.

Watson who shared his Nobel with Francis Crick, and Maurice Wilkins for the discovery of the Double-helical structure of DNA, had always been at the helm of controversies mostly b’coz of his fascination for Eugenics.

The latest of his comments on intelligence and race came in an interview in Sunday Times on Oct 14.

He says that he is “inherently gloomy about the prospect of Africa” because “all our social policies are based on the fact that their intelligence is the same as ours – whereas all the testing says not really” and I know that this “hot potato” is going to be difficult to address. His hope is that everyone is equal, but he counters that “people who have to deal with black employees find this not true”.

He adds that you should not discriminate on the basis of colour, because “there are many people of colour who are very talented, but don’t promote them when they haven’t succeeded at the lower level”. He writes that “there is no firm reason to anticipate that the intellectual capacities of peoples geographically separated in their evolution should prove to have evolved identically. Our wanting to reserve equal powers of reason as some universal heritage of humanity will not be enough to make it so”.

Watson was quick to apologize for his biased and baseless comments once the interview became controversial and his credibility challenged not just by the general public, but the scientific community as well.

He said …”to all those who have drawn the inference from my words that Africa, as a continent, is somehow genetically inferior, I can only apologize unreservedly. That is not what I meant. More importantly from my point of view, there is no scientific basis for such a belief.”

But whatever he said now, the damage has been done. Watson’s claims on “evidence” regarding intellectual levels of races have given the right wing neo-conservatives a chance to reiterate their anti-reservationist, anti-pluralistic demands toppling political balance everywhere.

Watson knows very well that there aren’t any statistically significant evidence to suggest that there are genetic differences in intelligence among human races identified in studies yet. In fact the last part of what is quoted as his statement (about the possible differences in the evolution of intellectual capacities of peoples geographically separated) may be quite plausible, but reading Watson in the context that he himself has set up through his eugenic rantings in his “post Nobel” years reveals a “prejudiced” man.

The funniest part is in two simple but powerful facts of neurobiology and cognitive science:

  1. there are as yet no IQ tests that are perfectly culture-free and context-independent which can be administered universally to all sects of Homosapiens
  2. no genes identified yet have been directly linked to any kind of animal intelligence.

Without satisfying these two ideal conditions, it is scientifically impossible to extract objective evidence regarding intellectual inferiority and superiority at the genetic level.

Page 3 Tag: Watson’s own reputation had been under question for long when new revelations about the role of Ms. Rosalind Franklin in the ‘DNA helix discovery’ and how her data was used in the discovery without giving her any credits came out. Story goes that Ms. Franklin was ungratefully excluded from the Nobel winning work after Watson and team “stole” the data from Ms. Franklin. Ever since the allegations came up, Watson had been attacking Ms. Franklin (even after her death) passing comments on her being intellectual but autistic and so on.

The Sunday Times interview is here.

See also :

Intelligence – Myths and reality

Evolutionary Socialism – a cause for affirmative action.

 

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Sex differences in cognition and behavior–such as increased aggression in males–are usually thought to involve hormones, which can “masculinize” or “feminize” a brain temporarily or permanently. But now, a mouse study shows that some sex-linked genes don’t need hormones to shape male and female behavior.

 

The Y chromosome in males have been identified to contain the gene SRY (Sex determining Region Y ) that determines the formation of testicles long back, and by early ’90s scientists had learned how to breed mice whose genes and hormones function independently. Since human SRY is similar to SRY of mice, a model of SRY function has been developed in mice.

By knocking out the testes-determining SRY gene, on the Y chromosome, researchers made XY mice that churn out estrogen; and by adding SRY to females, they produce XX mice that manufacture male hormones.

With the help of such mice, it was shown that genes unrelated to hormone production also played an independent role in aggression and nurturing behaviors. This was a new revelation because, until then it was believed that only the hormones determined such behaviours.

A team led by neuroscientist Jane Taylor of Yale University was interested in habit-forming behaviors in which gender differences also have been documented. She and her colleagues trained these mice, as well as normal male and female mice, to poke their noses through one of three holes in order to obtain a food pellet. Then, some of the mice were subjected to “conditioned taste aversion”. After eating the food, they were injected with a chemical that made them sick (something like what we use in alcoholic patients to help them quit drinking.) Ordinarily, mice will quickly learn to avoid the food, but they will still eat it if they have developed an automatic habit. That happened more often for the XX mice regardless of whether they produced male or female hormones.Thus, they say, the sex difference must have something to do with genes that are not involved in the production of sex hormones.

Neurobiologist Lawrence Cahill of the University of California, Irvine, says that the study “relates very well to established sex differences in the acquisition of addictive habits.” For example, women progress from casual drug-taking to a drug habit faster than men do–a phenomenon some have attributed to hormones. Taylor says that the work also implies that women can be good multitaskers–by quickly forming habits that leave their higher brain functions free for other chores.

Blogger’s Post Script: The last piece about the study implying that women can be good multitaskers seems to be a hasty extrapolation to me, as the quoted study doesn’t provide results of any of that sort, although estrogen has been linked to many skilled activities and greater attention span. It is also important to keep in mind that the precise mechanisms of sex differentiation are still unknown and that gender differentiation is accomplished through a cascade of gene activations. Further factors are involved, then, before as well as after the SRY expression – for example the WT-1, SF-1, DAX-1, SOX-9 genes. (I’m not being chauvinistic here – just bringing to notice a bad practice in science reporting, that’s all.)

Report in Nature Neuroscience. (21 October).

News modified from Sciencenow.

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nobel-banner.jpg

And it goes to :
Mario R. Capecchi, Martin J. Evans and Oliver Smithies for their discoveries of “principles for introducing specific gene modifications in mice by the use of embryonic stem cells”

Mario R. Capecchi, born 1937 in Italy, US citizen, PhD in Biophysics 1967, Harvard University, Cambridge, MA, USA. Howard Hughes Medical Institute Investigator and Distinguished Professor of Human Genetics and Biology at the University of Utah, Salt Lake City, UT, USA.

Sir Martin J. Evans, born 1941 in Great Britain, British citizen, PhD in Anatomy and Embryology 1969, University College, London, UK. Director of the School of Biosciences and Professor of Mammalian Genetics, Cardiff University, UK.

Oliver Smithies, born 1925 in Great Britain, US citizen, PhD in Biochemistry 1951, Oxford University, UK. Excellence Professor of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, NC, USA.

Their discoveries led to the creation of an immensely powerful technology referred to as gene targeting in mice . It is now being applied to virtually all areas of biomedicine – from basic research to the development of new therapies.

Our DNA is packaged in chromosomes, which occur in pairs – one inherited from the father and one from the mother. Exchange of DNA sequences within such chromosome pairs increases genetic variation in the population and occurs by a process called homologous recombination.
Mario R. Capecchi demonstrated that homologous recombination could take place between introduced DNA and the chromosomes in mammalian cells. He showed that defective genes could be repaired by homologous recombination with the incoming DNA.

Oliver Smithies who worked on Blood diseases, initially tried to repair mutated genes in human cells by correcting the disease-causing mutations in bone marrow stem cells. (Bone marrow stem cells give rise to all blood cells.) In these attempts Smithies discovered that endogenous genes could be targeted and modified by homologous recombination .

The cell types initially studied by Capecchi and Smithies could not be used to create gene-targeted animals. This required another type of cell, one which could give rise to germ cells. Only then could the DNA modifications be passed on from the parent cell to the daughter cells.

Martin Evans worked with the technology of modifying Embryonic Stem cells from mouse cells genetically and for this purpose chose retroviruses. Retroviruses have the machinery to integrate their genes into the chromosome of cells they infect.
He demonstrated transfer of such retro viral DNA from Embryonic Stem cells, into the mouse germ line. Evans also applied gene targeting to develop mouse models for human diseases. He developed several models for the inherited human disease cystic fibrosis and has used these models to study disease mechanisms and to test the effects of gene therapy.

Capecchi and Smithies had demonstrated that genes could be targeted by homologous recombination in cultured cells, and Evans had contributed the necessary vehicle to the mouse germ line – the ES-cells. The next step was to combine the two.

A “KNOCK-OUT ” mouse is one in which a certain gene has been selectively inactivated. The inactivation is achieved byhomologous recombination of the mice embryonic cells with a small segment of genetic material we artificially insert into it using retroviruses.

How do we benefit?

The technology opens the opportunities to selectively shut-up mutated genes that are known to cause diseases in mammals. This helps us to study what exactly is the function of the “disease gene”. Gene targeting has helped us understand the roles of many hundreds of genes in mammalian fetal development by creating mouse models for human diseases in labs.

Gene targeting has already produced more than five hundred different mouse models of human disorders, including cardiovascular and neuro-degenerative diseases, diabetes and cancer.
Mario R. CapecchiMartin J EvansOliver Smithies

Source: nobelprize.org

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Overzealous Science Journalism.

Scientists always keep complaining that the public doesn’t understand science. Yet university and lab newsroom reports of latest research claiming of “break-through” are becoming glaring examples of how sober facts of science can finally be contorted into flashy news totally detached from reality. Quite often it is seen that the researches themselves indulge in this unbecoming activity as they prepare reports about their research for the layperson. May be it’s their craving for the limelight or may be it’s the pressure from the funding groups or university themselves.

Overzealous science reporting often exhibits two kind of basic flaws: first, where the interpretation of the research findings and their extrapolation are themselves far fetched; second, where the journalist’s understanding of the research data is imperfect.

The chief problem cropping up when researchers report their own study is that they hardly bother to contain their explanations within the limits of their research data. Instead, there is a more-than-needed emphasis on the broader implications of the new study and why the study is “so important”. This leads to unrealistic extrapolation of research data – a menacing issue especially in the field of social psychology and behavioral sciences.

Take for example the story from the Beckman institute, University of Illinois regarding the re-running of the famous Duncker’s Fortress/Tumor Problem : “Researchers Find Eye Movement Can Affect Problem-solving, Cognition.”

 

They report in the current (Aug., 2007) issue of Psychonomic Bulletin and Review that by occasionally guiding the eye movements of participants with a tracking task unrelated to the problem, they were able to “substantially affect their chances of problem-solving success” to the point where those groups outperformed every control group at solving the problem. These results, they conclude, demonstrate that “it is now clear that not only do eye movements reflect what we are thinking, they can also influence how we think”.

A quick run through the original paper will tell us that such generalizations were too hasty, while even the answer to the basic question of whether the problem-solvers really used the visual clues offered by eye-tracking, remains elusive yet. Remember that even with very explicit visual and analogical cognitive clues, Gick and Holyoak had not produced satisfactory results in the 1983 ‘modified re-run’ of Duncker’s original Fortress/Tumor Problem experiment.

The trends in sociobiology are much more deplorable than this. Darwinian principles in evolutionary psychology and sociobiology have almost (or at least in popular appeal) become synonymous with genetic determinism. The world is trained to ask “Did my genes make me do that?” and the media promptly replies quoting a new research: “Blame it on your genes, baby!” And then there is the new idea of “neuro-marketing”, where the detection of a flurry of regional brain activity in an fMRI on seeing a brand is “branded” as “BRAND PREFERENCE”.

Newsroom boys found it less exciting to term it “learned preference” which had been the more appropriate explanation for the behavior any way.

There are more instances of such absurd reporting in other realms of science. The recent “Soliton theory of Nerve impulse conduction” of the Copenhagen University researchers and the “Faster than Light Signal transmission Experiment” of the NEC research institute group in Princeton are reasonably good experimental designs whose results were totally contorted to look outlandish.

The Soliton Theory of Nerve Conduction was revolutionary on one account: it suggested a broader perspective into which the established ionic conduction theories could be viewed in. All it sought was to answer the perplexing age-old question – ‘why isn’t there much resistance heat generated in the nerves as a result of electrical conduction?’ Whatever the scientific plausibility of the findings, it wasn’t even close to anything the news headline shouted: nerves use sound, not electricity!”

Similar is the story of the recent claims of Sending electromagnetic impulses at supraluminal velocities. The article as usual came in popular media with roaring headlines such as “Speed of light barrier broken” and “Time travel becoming a reality”. Astonishingly unscientific claims like” Relativity being questioned” kind of interpretations were also not uncommon.
What the NEC Research Institute group did really was that they created an anomalous dispersive medium and achieved propagation of a pulse at velocities above that of light in vacuum thru early re-phasing of the component waves. Only the group velocity got faster than light, while the phase velocity remained unaffected. There is nothing NEW about this as far as relativity or time travel is concerned, notwithstanding the brilliance of the experimental setup.

Science reporting, like any other reporting, is fast yielding to sensationalism. Flashy headlines, digressions peppered with quotes from veterans, unrealistic extrapolation of lab data, unnecessary links to science fiction and fantasies, hasty generalizations, overemphasis on genetic determinism are tricks being regularly used at the newsrooms to ensnare the uninformed reader. And what finally happens is the spread of half truths that can finally boomerang on the scientific community itself.

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