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Archive for the ‘Evolutionary biology’ Category

brainpower_big.jpg The “racial intelligence” bulldozer that James Watson set rolling a couple of weeks back is still whirring in our backyards as the new row over superior Jewish IQ scores is begging media attention.

This time the perpetrator is the Bell Curve fame Charles Murray and his American Enterprise Institute. I am not going into much detail about it. You can read the whole thing here.

The book ‘Bell Curve’ by Charles Murray and Richard J. Herrnstein once had the fate of being the most celebrated and at the same time, the most shunned book dealing with sociology of intelligence. The book set the scene for serious debates on the way IQ tests were used as real measurements of peoples’ intelligence.
The consensus regarding the average intelligence of various races was popularized to be as follows: Ashkenazim Jews 115; East Asians 105; Whites 100; American Indians and most Hispanics 90; African Americans 85; and sub-Saharan Africans 70. By the same order, accumulation of wealth, the level of income, achieved academic success etc., were also popularized to follow closely with the average IQs of these six racial groupings.

What do we actually know about Intelligence Quotient?

The results of large studies and their meta-analyses can be filtered down to the following concrete points:

  • IQ tests aspire to assess only 4 areas of human intelligence:

Verbal comprehension, Processing Speed, Working (arithmetic) memory and Perceptual organization (visuo-spacial).

  • People who are good at one area of intelligence (defined by the test) tend to be good at other areas too (+ve correlation).
  • IQ tests are always constrained by the cultural, linguistic, socio-economic and other contextual biases.
  • IQ tests don’t assess attributes like

Creativity, Personality, Practical sense, Social sensitivity, Leadership and Altruism.

  • IQ tests can be consistently and precisely interpreted only when the scores are very low or very high.
  • General Intelligence or ‘g’, as measured by IQ scores, is an attribute of the psyche (the software), rather than any macroscopic characteristic of the brain (the hardware).
  • IQ test scores are positively correlated to genetic make up as evident from large twin studies.
  • The effects on IQ scores thought to be caused by the environmental factors tend to disappear as the test-takers enter adulthood and further into old age.
  • Even then, there is no definitive evidence yet to link higher IQ test scores to brain size, or any particular genotype.
  • Training for IQ tests can certainly improve IQ scores.

Genetic basis for intelligence

The animal Brain plays the role of just the hardware on which the software called “mind” runs. Stretching that metaphor a little points out that there need not be a one-to-one correspondence between the hardware and the software for every behavioral trait. And studies have only shown IQ to be genetically linked; they have NOT shown that intelligence is solely a genetic quality. Having the right environment is extremely essential for the full expression of such “intelligence” genes (if there are any).
The examples of higher average IQ scores in certain human races may hence be more cultural rather than biological. Cultures that pressurize their children to achieve more in academics tend to produce better IQ scores. Just like average human height has increased over generations due to better nutrition, expression of intelligence too can hopefully improve in encouraging environs.

Is intelligence an essential survival quality?

It may be difficult to swallow without salt but it’s true: Intelligence does not confer any significant evolutionary survival advantage to any species.

Survival in the natural world, in a reductionistic sense means advantage in numbers, disease-free & adaptable gene pool and flexibility with nature. Social achievement and academic profiles, which are direct correlates of high IQ scores, have nothing to do with gene propagation and adaptability, even though various human races emphasize on these aspects more and more after every generation.

If we extrapolate the selfish gene concept to the macro evolutionary scenario, we find that the mind, consciousness, intelligence and all the emergent behavioral patterns are just a few of the myriad ways of “selfish” genes to propagate themselves.

This “rule” becomes clearer when one steps further backwards and look at the picture of evolution of life on planet earth as a whole.

iq-cartoon.jpg


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The previous article, Why Should Darwinism be Capitalistic?, invited criticism from many of my ‘evolutionist’ friends. Some were against the anti-deterministic underpinnings of the article – they were reluctant to come to terms with the ‘Nature via Nurture’ hypothesis. Others were against my suggestion that Darwinism can be supportive of Socialism rather than capitalism. What most of them complained about was my support of the job and educational reservations to weaker sections of the society.

So here are some clarifications on the issue. These are excerpts from email replies, orkut messages and internet chats. They represent my attempts to detail the:

  • the influence of environment on gene expression (nature via nurture).
  • the use of neo-darwinian evolutionary principles to fight nature’s selection forces.
  • the concept of all-round social upliftment for maximum expression of best genes.
  • the necessity of social reservation and proactive steps to uplift the backward sects of each population.

An analogy to ponder over

Imagine, two pots, with randomly allocated seeds from the same batch. The two plots have equivalent genetic potential. One plot received fertilizer (an environmental condition), the other pot receives no fertilizer. The average height (i.e. intelligence) differences between each pot will be due to environmental differences (fertilizer), however the height differences amongst individual plants within a pot are due to genetic differences (assuming similar conditions throughout the pot).
Which set of plants have a better chance of disseminating their progeny..?
Which set of plants can ensure that most of their “good” genes are transferred to the next generation ?
Progeny of which set of plants are more likely to survive with the better genes ?

Analysis

The gene for higher intellect (henceforth called “smart-gene”) definitely appears in a family/clan/race as a result of mutation and random chance, as evolutionary laws say.

Let me elaborate this:

A child named ‘Z’ in a family of traditional cobblers in India in 800 AD gets a few smart-genes. He has this constant urge to learn, enjoy philosophy or engage in intellectual pursuits. But the strict caste system and social practices of untouchability forbids him from following his heart. Even his family which doesn’t care about education is against his wishes and the boy is compelled to follow his father’s profession, marry somebody from his own caste and spend his life in the way, the strict society wanted him.

His wife, who is from a plain ordinary cobbler family, has no smart-genes. Now our “index” case of smart-gene-mutant is Mr.Z, who has very very small chance of passing his mutant smart-genes to his son or daughter. But still, let us simply suppose the genes were fortunately inherited by Mr.Z’s son. But even then, the son too has very little chance of passing that to the third generation because of the same socioeconomic set up that prevented his father from achieving his own dreams. If he defies the society, the family will soon be destroyed even before a third or fourth generation of children is born.

What if Z’s daughter is the one who inherits the smart-genes? The prospects are worse for a woman in such a rigidly hierarchical and casteist society!!

As long as the same socioeconomic conditions prevail around the family, the smart-genes find less and less chance of inheritance.

Note that there is no inheritance of acquired characters here.
The smart-genes simply rose as a result of “random aimless mutation” as Dawkins often puts it.
The only factor that environment strongly influences, is its chance of being inherited into the subsequent generation.
This situation is a kind of ‘man-made’ negative selection.
The same way we weed out poor yielding poultry or sheep from a farm.
The same way dogs, which are epitomes of servitude and fidelity, were selectively evolved from wolves

Now consider the same situation in a modern liberal Western society like the USA.

The modern Mr. Z, who inherits the smart-genes, takes a scholarship exam, pursues a college education, research in Duke, become a top rated cardiologist in North Carolina and marries the daughter of his research guide. Now his children have because his wife is likely to have the same in her gene pool too. Now, since his wife’s family has a history of intellectual members, the odds of her transmitting the smart-genes to the next generation are also higher. In whichever way you look, Mr. Z’s progeny will have greater chance of inheriting their parents’ smart-genes.

The atmosphere, in which their children grow up, will be stimulation to their genetic potentials. Better nutrition, visuo-spacial challenges of the city and top class education bring the best out of those old smart-genes.

These children, who seek out their own kind (Dawkin’s “green beard effect”) in the society, marry from families of similar or higher intellectual status. The odds of their successive generations becoming smarter improve with every generation.

Note that our Mr. Z of the21st century American city not only faces zero resistance from society but enjoys the fruits of liberty, equality and government’s financial aid in the form of grants, job reservations, scholarships, insurance etc.

This situation is beautifully condensed in the very famous FLYNN EFFECT.

Dr. James Flynn, after doing a meta-analysis of many Western IQ studies done over generations, plotted it against time, and found that average IQ scores increase with generations in the Western societies.

The reason for this is not because the earlier generations had no smart-genes. It’s just that modern western societies are more liberal & conducive for the better expression of these genes to their fullest potentials.

They permit mix up of all kinds, resulting in a global improvement of intellect rather than focal areas of brain development.

That is the most important thing about supporting reservation and other social initiatives to uplift all the sections of population rather than letting natural selection take its toll.

A short verbal ability test administered to about 12,500 adult American Blacks and whites between 1974 and 1994 support this effect of social influence. It clearly shows a narrowing of the IQ differences over recent years – a telltale sign of positive influence on gene expression.

Defying Natural Selection

It may seem strange that in highly competitive meritocratic modern societies, natural selection actually has very little toll on the individual.

If you look deeper, you will see the reason.

With the general improvement in intelligence, human societies progressively have (and will) become altruistic. It’s the selfish gene’s covert strategy to promote the survival of its own kind.

Our hospitals, medical equipments, diagnostic gadgetry, ever expanding array of drugs, humanitarian organizations, peace organizations, trade partnerships etc are towering examples of this altruism and a blatant defiance of Natural Selection.

I am not forgetting the resurgences in imperialist notions especially in recent war histories, but those can be dispensed as the old animal instinct still refusing to go off the skin.

Once the concept of “Nation” and “Nationality” wither away in the future, such notions will have no meaning at all. And by that time hominids, as a species will have something else to fight against…!

Reservation Issue

The whole meaning of reservation, scholarships and grants is to promote the maximal expression of the good genes in these oppressed castes and sects. For that, first of all, there should be some potentially smart genes that can be worked upon to be fully expressible. This means, we can’t expect the whole of those backward castes to ascend to an equal stance with the rest of the society within a very short period of time, simply from affirmative actions. Affirmative actions should essentially be followed by two things if it’s to yield rapid results: # 1) Positive change in social psyche, in accepting them and acknowledging their contributions. # 2) General increase in equality and opportunities for all.

That’s when we can claim that the society has become truly meritocratic.

 

The reservation of seats at the IITs and institutions of excellence is a complex issue. But one thing can be said. Setting apart 20 or 30% seats to the backward classes will not take away any opportunity from the general merit-class. Because, they already are evolutionarily advanced to seek and earn their share. They are already advanced intellectually. What i mean to say is that, economic independence and wealth do not solve the issue at all. The root problem is in the genes, and the remedy requires more than just a few perks to a few individuals. Mixing their genome with the general population will be the ultimate cure, but that would be too fantastic for an expectation in our society.

Spin-offs on Eugenics

I believe, we all have to learn to tolerate the current diversity of our species. We might have to accept the reality of religion-genes, criminality-genes, racism-genes, communism-genes, capitalism-genes, atheism- genes, agnosticism-genes, and what not for that matter. Within our species, each of these has a time and place – to dominate, to stagnate and even to whither away or may be even replaced by totally new genes for totally new things. But the million dollar question is whether our race is ready for that.
Most societies, be it capitalistic or communist, are growing more authoritarian by the day.
That’s a problem with all kinds of eugenics. One might argue for positive eugenics, on the basis that it promotes good qualities of human genome. But as far as our science knows it, most smart-genes are associated with some or the other kind of psychologic / organic defects in the brain – autism and schizophrenia being the ends of a spectrum. Finding a balance in the gene bridge is the biggest problem.

When smartness becomes unlimited, the person becomes a total rebel defying all laws imposed by the society.. When artistic areas of the brain are genetically pushed to its limits, the person experiences regression of the other areas which may even tend towards autism..!! (the autistic idiot savant syndrome is the best example of this kind).

If we promote negative eugenics, by not permitting” diseased” genes from reproducing, that will be an encroachment into the very nature of our life on this planet. But its a re surging concept now. Most genetic screenings are in one or the other way, negative eugenics. Its only a matter of time before the “criminals” in jails will be banned from reproducing…!!

 

Are you saying that we have to go against evolution?

Yes..!
I was exactly trying to say we have to go against evolution in this matter….!
Or else, this race won’t last another millennium…that’s for sure.

Why, because, its the unique ability of the hominids to manipulate nature to meet his needs rather than letting nature manipulate him.

Thats simply what we have been doing ever since we branched out from the primate ancestors…Just look around and we will see only those things that man has built, invented or designed, to suit his needs, to help alleviate his toil, to ease his life, to bring out the maximum of his potential…!

Our hospitals defy the very basics of natural selection by differential extinction,
Our prenatal checkups do the same
Our geriatric centers do the same
Our schools do the same
Our railway, airlines, banks, bridges and roads, our space stations, satellites, rockets, hydel power stations, nuclear reactors….you name it…Everything helps man in one way or the other in defying Nature’s forces, and saving him from being deselected..!

So why don’t we extend this privilege to all classes of people in every population..?

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Ever since its discovery, Tyrannosaurusrex, paleontologists and laypeople have been mesmerized by the sheer enormity of this giant carnivore. Every time a new discovery or debate concerning T-rex pops up, it attracts fans from every field; very few historical things have enjoyed such phenomenal popularity – the Titanic, the Pyramids etc are a few on the list.

T-rex has been bestowed with the titles of the most ferocious animal that ever walked the earth and the largest predator on land. But is the story of T-rex, a bit over-hyped? Is it worth these titles any longer?

 

New evidences on the predatory behaviour of dinosaurs are coming up, thanks to the bionic technology that uses computer simulations merging paleontological findings with physics of animal body.

Why is this tyrant-lizard so popular?

 

The first Tyrannosaurus rex fossil was discovered by Barnum Brown in 1902. By the time T- rex was named by Henry Osborn in 1905, news about this strange and seemingly formidable “predator” was out and names that captured the popular fantasy of a “dragon” like ferocious lizard became a necessity. (Dynamosaurus imperiosus, was a synonymous name Osborn later suggested for Tyrannosaurus !). T-rex soon was seen as the materialization of the mythological dragon; the ultimate killing machine. And Hollywood was quick enough to take this fantasy to its extremes, Jurassic Park being the ultimate reference.
After all that popular appeal and fan-following, its now become difficult for both scientists and the masses to see T-rex as a huge, awkward, lumbering beast that waddled out of the bushes to pick off the remains of a carcass.

 

Not the largest predator.

T-rex now has only the fourth position with regard to size among predatory land animals, Spinosaurus being the first, Giganotosaurus being the second and Carcharodontosaurus being the third. Discussions and comparisons on the predatory capabilities of these four dinos had heated up the paleobiology circles recently; the debate is still on. Spinosaur, as depicted almost correctly in Jurassic park III, is currently the largest carnivore. But compared to T-rex, the other three dinos had weaker build and teeth designed for slicing up flesh. T-rex brain case is larger, has solid teeth to crush bones, and supposedly has a better build.

 

These points gave T-rex an edge over the others and T-rex fans finally had some reason for consolation.

 

Stiff spine, sharp senses : hyena or lion ?

 

Then came the expositions about the spine. A US team has used detailed computer models to work out the weight of a typical “king of the dinosaurs”, and determine how it ran and turned. The results indicate a 6 to 8-tonne T. rex was unlikely to have topped 40km/h (25mph) and would take a couple of seconds to swivel 45 degrees. The study indicates the animal would have changed direction incredibly slowly because of its massive inertia, taking more than two seconds to make a quarter-turn. The species certainly could not have pirouetted rapidly on one leg, as popular illustrations have sometimes pictured it, and other large dinosaurs, doing. The more agile prey would have given the slip to a marauding T. rex quite easily, it seems.
A massive blow to the “predatory” nature!

 

But that wasn’t the end of controversial findings. Dr. Lawrence Witmer, from Ohio University, used the medical scanning technique of computed tomography (CT scanning) to reconstruct the shape of the animal’s brain, including its inner ear, which is involved not only in hearing but also body-balance.

 

T. rex has the inner ear comparable to that of a much smaller, very agile animal. It had a heightened sense of equilibrium and balance and employed rapid turning movements of its eyes and head to track its prey.

 

But Dr. Jack Horner, the leading scientist who supports the “Scavenger T-rex” theory, carried out microscopic analysis of the dinosaur’s vertebrae. His team found tissue remnants related to the animal’s nuchal ligament, which provides passive support for the head and neck. The study also points at how rigid it was from the neck all the way back to the tail.

 

The teeth that crush bones are typical of a scavenger… the puny fore-legs are very unlikely evolutionary weapons for a hunter…the extraordinarily latge olfactory lobes of the T-rex brain is typical of a scavenger that sniffed for its food…the massive hind legs are those of a walker, not a sprinter….thus goes the evidence against the “hunter T-rex” theory.

 

We like our T. rex to be the monster from hell, threatening to rip the heads off poor, screaming kids when their jeep gets stuck in Jurassic Park. But evidences are throwing light on a scavenger-lizard now, claims Dr Jack Horner.

 

The simplest way to come to terms with this new reality is to compare an ideal predator like the Velociraptor or the Cheetah with T-rex and see the voids for yourself.

 

“We want people to do what scientists do, which is to take all that in, think about it, and then come to a conclusion….my own view is that the truth lies somewhere in the middle. We know it wasn’t a fast-running creature like a cheetah, but I certainly think it would have been capable of killing a small, old or weak animal.” says Horner.

 

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A new bird from the family of Oviraptors (the egg-stealers among dinos) has been discovered by paleontologist Xing Xu and team of the Beijing’s Institute of Vertebrate Paleontology and Paleoanthropology in the Gobi Desert in north-central China.

 

Initially thought have belonged to the T-rex family (see artists scale- drawing), this giant “bird of prey” is now grouped under the family of smaller raptors – an unusual reunion.!

 

The finding complicates the evolutionary descent of birds from dinosaurs. Progressively from within advanced theropods as you come to birds, their size gets smaller and smaller. But after some species originate and spring off the bird line, you get secondary gigantism.

“Big size has some advantages such as having fewer predators and having more food resources that are unavailable for small animals,” Xu notes. He is joined by Thomas R. Holtz Jr., a vertebrate paleontologist at the University of Maryland at College Park who adds “ Gigantoraptors grew muc h faster and reached adulthood more quickly than did tyrannosaurs. There was an incentive [for such a creature] to get big really soon” Size is certainly a defense. And there is ample evidence to believe that these giant-birds lived at a time when T-rex ruled the earth.

The length and proportions of Gigantoraptor’s leg bones hint at another of the dinosaur’s survival skills – its speed. The bird-like femur suggests it would have been among the fastest dinosaurs of its body size.

It also is not clear whether the creature was feathered, though Xu speculates it was like most other animals in its lineage. If so, it would be by far the largest known feathered animal of all time.

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VATICAN CITY (AP) — The Vatican’s chief astronomer has declared that “intelligent design” isn’t science and doesn’t belong in science classrooms, the latest high-ranking Roman Catholic official to enter the evolution debate raging in the United States.

The Rev. George Coyne, the Jesuit director of the Vatican Observatory, said placing intelligent design ideas alongside the theory of evolution in school programs was “wrong” and was akin to mixing apples with oranges.

 

Intelligent design isn’t science even though it pretends to be,” the ANSA news agency quoted Coyne as saying on the sidelines of a conference in Florence.
“If you want to teach it in schools, intelligent design should be taught when religion or cultural history is taught, not science.”

 

His comments were in line with his previous statements on “intelligent design” — whose supporters hold that the universe is so complex that it must have been created by a higher power.

Critics say intelligent design is merely creationism — a literal reading of the Bible’s story of creation — camouflaged in scientific language and say it does not belong in science curriculum.

In a June article in the British Catholic magazine The Tablet, Coyne reaffirmed God’s role in creation, but said science explains the history of the universe.

 

If they respect the results of modern science, and indeed the best of modern biblical research, religious believers must move away from the notion of a dictator God or a designer God, a Newtonian God who made the universe as a watch that ticks along regularly,” he wrote.

 

Rather, he argued, God should be seen more as an encouraging parent.

“God in his infinite freedom continuously creates a world that reflects that freedom at all levels of the evolutionary process to greater and greater complexity,” he wrote. “He is not continually intervening, but rather allows, participates, loves.”

The Vatican Observatory, which Coyne heads, is one of the oldest astronomical research institutions in the world. It is based in the papal summer residence at Castel Gandolfo south of Rome.

Last week, Pope Benedict XVI referred indirectly to the evolution debate by saying the universe was made by an “intelligent project” and criticizing those who in the name of science say its creation was without direction or order.

Questions about the Vatican’s position on evolution were raised in July by Austrian Cardinal Christoph Schoenborn.

In a New York Times op-ed piece, Schoenborn seemed to back intelligent design and dismissed a 1996 statement by Pope John Paul II that evolution was “more than just a hypothesis.” Schoenborn said the late pope’s statement was “rather vague and unimportant.”

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We have discussed what intelligence means and how it is inherited, I would like the readers to follow me thru a small digression where we will have a “zoom-in” on the exact ways by which genes work in the brain.
The technical details might be indigestible to the general reader hence an oversimplified version of the story is presented in the posts below. I should make clear at the outset that this is indeed a digression and skipping these few posts wont break the continuity of the whole thread…heh he Scientists…especially geneticists, have strange ways of naming genes and proteins that discover. Most genes are named based on the “effect” they produce in the body if they start malfunctioning. For example the now famous gene that helps in memory functions is named Amnesiac, (!??)because its mutation or absence can result severe “forgetfulness” in the carrier ! Genes like comatose and mini brain are of this kind. Another popular way of naming genes and proteins is giving the names-names of comic or epic characters or names of individuals, breeds, and even objects resembling the proteins for that matter; examples of this kind being leonardo, homer, Miranda, dachshund, slipper, sickle etc. Some scientists are fond of names from classical languages other than the “done-to death” Latin. A protein (an amide to be exact) called anandamide called so because anandam– pronounced “aanaanthom”- is the Sanskrit word for bliss or euphoria. So my readers can now speculate on the effects of this protein in brain..

Biological systems are built in order to respond to environmental stimulus. Learning takes this ability to extremes. Memory involves increasing the efficiency of how brain cells “communicate” with one another, otherwise called synaptic function.
Memories are thought to be due to lasting synaptic modifications in the brain. Repeatedly used information is processed in the brain by what is called Long term Potentiation. This mainly includes tuning the nerve cells to make them ready for repeated firing of the synapse. (a Synapse is the fancy term for the point of contact of two connected nervecells).

What is the role of genes and their protein products in these synaptic changes?

Coincidence of information from two or more modalities (for example: a baby inadvertently touching a hot iron rod) results in increased neural activity, that is, an influx of Calcium ions. Elevated amounts of Calcium ions in nerve cells cause Ca2+ to bind to a protein called Calmodulin. The Calcium-Calmodulin complex joins hands with another molecule called Adenylate Cyclase. The final combination of all three increases the cellular manufacture of a molecule known as Cyclic AMP or c-AMP for short. This molecule is called a second messenger. The job of a second messenger is to wake up genes in a cell; cAMP does just that. Thru a series of reactions subsequently, it stimulates a number of genes like CREB, Dunce, Rutagaba, Amnesiac and so on. These “activated” genes start making a lot of proteins that enhance the nerve-to-nerve connection, making the route clear for easy passage of ionic signals. The connexions thus made form the secret behind learning & memory.

Here’s a short list of some weird (!) genes and their functions in brain, to amaze your friends at the next party…

Homer : required for brain cells to control movement of limbs and body parts, and also behavioural plasticity.

Rutagaba : required for changing synaptic connexions for modifying learned things.

Dunce : destroys cAMP. And regulates amount of info stored.

Amnesiac : Needed for associating various stimuli to learned concepts.

Leonardo : Strongly associated with learning and smell, especially in fruit flies.

BALB : Makes you introverted but good at tracking back old ways.

NCS-I : Determines flexibility of learning.

BDNF : Encourages growth of nerve cells.

…you can extend this list to any number of pages…so complex is the simple task of learning..!

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