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Archive for June, 2007

Darwinian and neo-Darwinian ideas of natural selection, differential extinction and adaptive evolution have traditionally been linked to capitalistic views of “survival of the fittest”. As decades passed by, people including the scientific community at large began seeing Darwinian Laws of evolution (its not just a theory any more) as a justification for the greed, consumerism, “hire-fire” notions and at times, the imperialistic overtones of right winged capitalism and market rule.

 

There are no evidences to show that Darwin himself took his theories to this extent. But the synonymity between capitalistic notions of “might is right” has been increasingly supported by many studies on genetic determinism. Now, anything from racial superiority to anti-reservation campaign is justified by these contorted interpretations of laws of evolution. Even though Galton’s eugenics failed miserably in its original form (negative eugenics), it is coming back in many new disguises from white supremacy to culture-war theories – a poetic justice to history, I should say.

 

Are the laws of evolution as anti-socialistic as is viewed to be?

 

 

It is an undisputed fact that selection process of nature is highly merit-based and extinction awaits anything that is maladapted to its environs.

 

 

 

 

What helps adaptation?
Phenotypic expressions of genes on an individual basis and in combinations.

This is where determinists hijack the theory.
First, every trait from music and arts to adoption of a religious belief becomes the responsibility of genes. And if genes are the basis of selection, then there has to be superiority and inferiority among genes, as there are superior and inferior qualities, they say. Any animal that inherits undesirable or malfunctioning genes, as a rule, becomes inferior by their standards. Some take it a little further and attribute every trait they hate, on genes.

 

Thus ‘black skin’ becomes an undesired trait; lower scores on IQ tests become an undesired trait; poor performance in economic issues becomes an undesirable trait; inability of the brain to concur with societal laws becomes undesirable…the hate-list soon grows to include anything from eating habits, ideologies, cultures to (these days) even religious beliefs!

 

It is not surprising that the Nature versus Nurture debate now revolves around this controversy.

 

What these people and scientists don’t see is the context in which “survival of the fittest” is applicable. Homosapiens as a species needs to compete with everything around, including other life forms as well as nature for survival and he is doing the job remarkably well. But within the species are we supposed to keep this rule alive? Mammals, as a group, have evolved to the present state facing stiff competition from many other groups – mostly reptiles. And it is undoubtedly, societal cooperation that has helped them the most in the fight.

Hominids are no different…

 

 

In fact, it is ‘intra-specific cooperation’ that has been key in the development of many humanly attributable qualities – like language, script, technology and science; this is true for every social animal. There is ample evidence to show that all those ‘human’ qualities that we boast about, are result of nurturing the right kind of genes. The recent expositions regarding the environmental influences on psychosocial development and human intelligence points to this direction.

 

The laws of evolution, far from being the Trojan horse for social injustice, are actually excellent tools for social-engineering in every positive sense of the word. To see this, you just have to consider the whole of humanity – rather hominids – as one large group pitched against the forces of nature. The importance of universal nurturing of advantageous traits thru global initiatives will thus become clearer in the new light.

 

This essentially will mean that leaving various sects of the society to its own fate thru unrestricted finance capital and free market economy is not only against the spirit of human evolution but also the greatest blunder that man can commit, considering the unique ability of his brain to stand up against his genes. And that is where Socialism marries Darwinism.

 

Let me conclude quoting Dawkins, the messiah of ‘selfish gene’, who wrote in a rebuttal of Lewontin, Rose & Kamin:

 

…. it is perfectly possible to hold that genes exert a statistical influence on human behaviour while at the same time believing that this influence can be modified, overridden or reversed by other influences…. human sexuality has evolved from natural selection just the same way any animal trait evolved…this means that there have been genes influencing sexual desire just as genes ever influence anything. Yet ‘genetic determinists’ have no trouble holding back their sexual desires when it is socially necessary to do so. What is dualist about that? Obviously nothing…We, that is our brains, are separate and independent enough from our genes to rebel against them…we do so in a small way when we use contraception. There is no reason why we should not rebel in a large way too…

[The Selfish Gene : 1989 OUP edition End notes to Chapter 11]

 

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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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The sudden feeling of vague familiarity about certain scenes or things of life is a common phenomenon we might all have experienced one time or the other. Many of them were dream-like experiences, while some were so vivid; we almost thought it was a replay of the past.

The term “déjà vu” is believed to have been used first in 1876 by French physician Émile Boirac. Each episode last a few seconds only and is much common for Younger people to have these dream-states more often than older adults, yet people of all ages experience déjà vu, especially when they are stressed. There is a reverse of déjà vu, called jamais vu. Here, a familiar person or place is rejected as having never seen before.Many mysteries cloud this curious play of brain chemistry and many of them give rise to beliefs in rebirth, telepathy and clairvoyance. But is this strange feeling of familiarity really a message traveling thru time and space, from the light cone of our past? Or is it just some unconsciously managed memory trace that is peeking up at a second stimulus thru the same neural pathway?

Science has been tracking this question for many years but the stumbling block in investigating the phenomenon is the problem of recreating it in labs.

The Freudian psychoanalysts call déjà vu a replay of suppressed memories. They call it paramnesia. The original event was somehow linked to distress and was being suppressed from conscious recognition, no longer accessible to memory, they say. Temporal lobe epilepsy patients have been thought as good candidates, but their memories lack the true quality of déjà vu – the subject’s disbelief in the memory!

Dr. Vernon M. Neppe[/b] , the Director of the Pacific Neuropsychiatry Institute in Seattle, empirically defined the term déjà vu as: [u]

“any subjectively inappropriate impression of familiarity of a present experience with an undefined past.”[/u]

(His book titled [i]The psychology of Déjà vu: Have I been here before?[/i] has detailed out a long list of déjà vu presentations long back in the 1980s.)

In déjà vu, the subjective feeling of “replay of past” is imminently followed by a feeling of disbelief and rejection of the memory trace, as is widely documented. The act of seeing or hearing also does evoke a feeling of familiarity. It doesn’t pertain just to the memory alone. These qualities are absent in epileptic patients’ recollections and in drug-induced hallucinations. In such cases, the patient or the subject strongly “believes” in these traces of replayed “memory”. A similar phenomenon is seen in schizophrenics too (‘false recognition’). Hence many scientists believe that there should be a “non-epileptic” theory for deja vu that will encompass al the attributes of the phenomenon.

 

New light on an old problem

Robert Efron, in 1963 suggested the delayed vision theory. He stated that it is possible that sometimes the blending of information into the temporal lobe might not synchronize well and this may result in the deja vu episodes. Words flashed too rapidly to subjects without giving time for the conscious brain to register them were later identified as familiar by the same subjects in the pioneering experiments of Dr. Larry Jacoby in 1989. Recent simulated studies on attention and priming for attention have brought out certain correlations between gaps in attention and feelings of familiarity as in déjà vu. There are also reliable correlations between déjà vu and stress/fatigue as well as mood swings. It seems that whereas déjà vu may be triggered during times of peak tension when one is overly alert, it may be even more likely when one becomes tired and attention starts to wane. Alan Brown of the Southern Methodist Univ and Elizabeth Marsh at Duke University, ran a few tests on a group of students; based on the idea that deja vu’s originate in subliminal suggestion. They support the the diverted attention theory.

According to the theory, people sometimes see things twice in quick succession: the first time superficially or peripherally; the second time with full awareness. You might glance at a building while talking on a cell phone, for instance, and not really register it, then give it a second look a little while later after you get off the phone. You might not remember the first glance, but your brain has registered it subliminally, so the second glance may seem oddly familiar (see Dr.Brown’s new book [i]The Déjà Vu Experience[/i])

Temporal lobe – seat of Deja vu

Open brain surgery stimulations of déjà vu in temporal lobe has been done from the time of Dr. Penfield the latest being that of Dr.Bancaud.These expositions are being investigated with greater fervor, ever since the Alison R. Preston and John D.E. Gabrieli paper on the role of hippocampus as a scrap book of the brain, has come out.

….the relational/familiarity distinction predicts that patients with focal hippocampal damage would be selectively or disproportionately impaired on associative recognition, but exhibit intact or less impaired performance on single-item recognition. However, patients with selective hippocampal damage were equally impaired on the single-item and associative recognition tasks….. results suggest that the hippocampal formation contributes similarly to declarative memory tasks that require relational or familiarity processing…. the para-hippocampal gyrus differentiates between familiar and unfamiliar stimuli – and does so without having to retrieve a concrete episode from our memories.

The excitement is inexplicable, as the research has opened new ways to understand how we create a world of our own around us rather than fit ourselves into the world around. And that’s were evolutionary psychology starts taking up the issue.

 

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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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Consciousness: How sure are you on that?

One of the fundamental problems of studying the phenomenon of Consciousness is in defining it objectively. To define it, one has to make a replicable model of consciousness, using some universal aspect of animal behavior that can be measured independent of the internal state of the individual’s brain in a lab setting.

Neuroscientists have, long ago, concurred on the usefulness of measuring CONFIDENCE as a function of consciousness.

What is this?

Let me explain a bit:

A subject has to see the direction of movement of a blinking dot on a screen first. After seeing, he has to decide for sure which direction the movement occurred. Since the perception of movement and the decision on its direction can be “unconscious” as far as the brain is concerned. So, to make this unconscious perception a conscious and purposeful one, the subject is asked to make a finite choice – a sort of betting – on the direction of the motion of the blotch on the screen by means of selecting a number. For example, 1 to indicate pure guessing, 2 for some uncertainty and 3 for complete certainty. This procedure assumes that when the subject has little awareness of the dots’ direction of motion his confidence is low, whereas if he clearly “saw” the motion, his confidence is high.

 

Navindra Persaud of the University of Toronto and Peter McLeod and Alan Cowey of Oxford University took this to the next step, by adding a bit of “real” gambling (Nature Neuroscience January 2007). In their version, subjects first make a decision regarding whether they’ve perceived something and then must gamble either a small or a large amount of money on their confidence in this decision.

 

Their first experiment involved a patient code-named GY. This man has a rare acquired pathology called “blindsight”. His brain areas involved in the sense of vision were damaged in an accident. Now, his eyes “see” the blotch on the screen but since the visual areas of the brain never receive signals from the eyes, he doesn’t have the “conscious” feeling of having seen the blotch. But physiologically speaking, he does “see” the blotches. The phenomenon of “blindsight” gives scientists an opportunity to test the subjective “unconscious” feelings and make the patient convert them into “conscious” feelings. When asked to indicate the presence or absence of a faint, small grating on a computer screen, he does so correctly in 70 % of all trials, which is far above chance (50 %). Yet he fails to convert this superior performance into money when betting; he places a high bet on only about half (48 %) of his correct choices. When GY is consciously aware of the stimulus, he wagers high, much as we all would. His gambling thus seems to reflect his conscious awareness of his belief that he saw the blotch rather than his actual (unconscious) detection of the stimulus, suggesting that Gambling may provide a means to measure awareness.

 

The second experiment involves an artificial grammar task. In this task participants learn a small number of short letter sequences. They are then told that the sequences obeyed a simple rule (like for example, that every “x” is always followed by an “a”). But they are not told what the rule is. When shown a new sequence, subjects mostly determine correctly whether the new sequence follows the unknown rule. Yet very rarely can the subjects decipher why they believe a sequence does or does not obey the rule. The overall rate of correct classification is 81%.Yet subjects do not convert performance into money. High bets follow a correct choice 45 % of the time and follow a false choice 32 % of the time. In short, the subjects are usually right about whether the sequence follows the rule, but they lack enough confidence to bet on it.In the final experiment, the Iowa gambling task subjects pick the top card from one of four decks. Each card wins or loses the subject a certain amount of money. Two of the four decks have a net positive yield and two a negative yield, which the subjects don’t know. Subjects place a low or a high bet on the chosen card before it is revealed and lose or win accordingly. The outcome of the experiment is that they usually turn over at least 30 cards on those decks before they gain the confidence to bet aggressively on the results. That is, they wait for a certain time before they can believe in their own knowledge of the nature of the decks.

But whenever the subjects were questioned about their knowledge of the “rule” of the card game, the subjects increasingly started aggressive betting. The questioning gave them a way to ponder on their own knowledge and how it could be turned advantageous. This demonstrates that if subjects learn to trust their gut they can do better.

The wagering techniques used by Persaud, McLeod and Cowey rely on people’s instinct for reaping a profit. This method is a far better one in reliably measuring consciousness b’coz it doesn’t alter the instinct. Rather, it simply assesses how one converts the unconscious perception into a purposeful, conscious, action.

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Searching for free Pubmed Articles

This article which came in a popular science blog i usually search for new links, is one of my fav. Its been my fav method of searching the web for free science publications other than the usual “google-search” method.

I’d lke to share this here:

 

How to find free scientific publications

1. Go to the NCBI.

 

2. Choose the link to PubMed. (It’s in the top blue bar, under the DNA icon)

 

3. Click the Limits tab (circled below).

 

limits.gif

 

 

4. Click the box next to “Links to free full text.”

 

5. Select any other Limits that might apply.

I often pick English for the language since I can’t read any other language. I wouldn’t try to impose too many limits at first, though, since you don’t always know how articles were categorized when they entered the database. You can always narrow the search later.

6. Enter your search terms and click “Go.”

 

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You Have to be an ATHEIST to believe in Evolution!

Theories of Origin of Life on Earth include the following:
Creationism:    life on earth was designed and CREATED in all its splendor and diversity by an divine intelligent being, which, since then has been regulating its fate.
intelligent alien design:     life on earth was designed by non-divine intelligent aliens. After this creation-act,life on the planet was left to evolve and to its fate…! Some theosophists believe that this Alien is equivalent to GOD and the “prophets” of our times like Jesus, Mohamed or Krishna were either one of those aliens or their messengers..!
Life is Cosmopolitan: Supporters of this hypothesis suggest that life originated in some distant planets and was carried along with asteroids and meteor/cosmic dust to Earth. The search for life on nearby planets that resemble earth (at least theoretically) is a way to test the credibility of this hypothesis.
Abiogenesis or spontaneous origin of life:     This is the current neo Darwinian view held by science as most credible of all.

In the phenomenal Sci-Fi CONTACT, Carl Sagan tells about a fantastic contact made by a human representative and an extra-brilliant alien civilization. This ancient civilization is imagined as to have survived several catastrophes and as successful in harnessing the power from the Stars to the fullest. This novel tells us about the protagonist and her accomplice an international space crew) shaking hands with their long lost friends and relatives..! Sagan being a strong supporter of Neo-Darwinism says nothing about life on earth being created by those aliens. Yet, the novel partly favored the concept of Intelligent Design.
But such theories, are rooted in human mind’s wishful thinking. And theories of UFOs and crop circles stay on far more shakier grounds than Theory of Evolution and Spontaneous genesis of Life.
The complexity of the designs of organisms is what has bewildered scientists all these centuries. It has spawned a bunch of ideas ranging from Pure Creationism to Pan Genesis and Alien-Designed life forms as mentioned above. All this arise because we under estimate the power of Natural Selection (NS). We also often forget that the chief mechanism of nature’s filtration is differential extinction of bad and incompatible designs. Its just like admiring an artist for his best works when all his bad works have been destroyed. Similarly, we look at the best and most complex designs of nature with awe while all the poorer designs have been cleansed by extinction.

It has to be remembered that more than four-fifths of all the species that ever lived on this planet are extinct due to incompatibility or poor design, which is a very bad record for even an average architect, not to mention a super-intelligent Alien (or GOD) creator.

More over, a theory like “Intelligent Design” can make little testable predictions. That’s why we accept Abiogenesis as the best theory around.

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