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Archive for August, 2010

Right or Left?

August 29, 2010 3 comments

Following on from my previous post,  is handedness observed in other animals? As the term itself is HANDedness, it is pretty intuitive that animals are mostly footed and only the other primates and bears use hand to some extent.  The polar bears are rumoured to be left handed but it is just that – a rumour. There is no scientific evidence for the polar bears being lefties. For all other primates other than humans, though they might acquire a liking for a particular hand, they do not have any preference as such. The reason being that the left and right sides of the brains are identically sized. In humans, as most of you must know, one side is bigger than the other. The lefties have their right brain slightly bigger and vice-versa. The right brain is supposed to control verbal skills and left brain is supposed to control all the quant skills and calculations. Thus, lefties are believed to be more artistic and righties more mathematical.

There is another category – ambidextrous people. By definition, they are people who can do any activity with both hands with equal ease. There are very few people who are ambidextrous in the true sense. But some do become ambidextrous – knowingly or inknowingly. For the record, three of my close friends have been non-right handed. Only one of them is lefty in the full sense. The other two eat/write with the right hand and throw/bowl etc with the left hand. Probably, at a young age, they started writing with the right hand because their teachers/parents told them that is the right way. Thus they are neither lefties nor righties not even ambidextrous – currently and are more of cross-dominant i.e. they have one hand assigned for each task. So how do you determine whether a person is a lefty or a righty in a flash? Throw something at him? No!!He would catch it with the hand nearest to him!!. Make him throw something, the action should be instantaneous and he should not be given enough time to decide which hand to use – he will definitely use his dominant hand to throw.

For a long time, the handedness was believed not to follow Mendel’s genetic rules. Mendel’s rule basically could give an idea what traits a child would have depending on his parent’s traits. For e.g. Mendel’s rules could determine what would be the color of the eyes of a child whose one parent is brown eyed and the other blue eyed. But in this case, two righty parents could have a lefty kid and two lefty parents could have a righty kid. But as late as 2007, a new gene has been discovered – LRRTM1. This gene determines the asymmetry in the brain size and in a way determines handedness.

Developing motor skills in your non-dominant hand is not very difficult and humans can learn it with enough practice. Lefties do it usually because they are forced to do it one way or the other Righties don’t usually do it but can take a shot at it. Yours truly (me, the blog writer) has learnt the same and achieved some success. What I have realized is you can do most routine actions – like throwing with left hand and with lots of practice, doing it in a rhythmic way, you can even take aim and hit the target pretty accurately. The above was an example of an action where you needed more of force/strength and less of dexterity in terms of the usage of fingers. Fingers are used the most while writing. So writing with left hand is difficult – but how difficult? I pretty much write decently with the left hand as well. My handwriting with my right hand is nothing to write home about and so the left hand is not doing very badly at that. Then which are the actions which are most difficult – the ones which need both dexterity and force – brushing teeth. It’s very difficult to reach the inner parts of your mouth from various angles that too with the right force so as to clean your teeth.

As they say- it’s all in the mind (literally too). There is nothing in this world which man can’t learn by practice. Thus, I am reiterating the well known proverb – practice makes a man perfect!!!!

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Left or right?

August 29, 2010 6 comments

Ever wondered why you use one hand more than the other or for that matter, why are you right handed? Yes, I am confident that most of you readers are right handed and hence the earlier question- why RIGHT handed. Less than 10% of people around the world are left handed. Sorry lefties!!! Most of the further discussion would be from the perspective of righties!!!! ‘Us’ would mostly mean righties!!!

The majority of tools and equipments are suited for right handers, more than left handers. The door knobs are one such example though these days I myself have seen a number of left handed knobs. The taps and screws are another example which I find interesting. For us Indians, who usually eat with our hands, tap is not a problem as more often than not we have to open the tap with our left hand. But imagine tightening a screw or capping a bottle. Right now, to tighten the screws, you follow a clockwise direction – remember – tightening requires more pressure and accuracy most of the times and you would like to have your hand in a comfortable position for the same. To loosen the screw, only the initial jerk is necessary and the rest of the action is pretty straight forward. Yes, clockwise is much more comfortable than anticlockwise while tightening and vice-versa. The primary reason is the set of muscles in our hand involved. You can refer to supination (for clockwise movement) and pronation (for anti clockwise) for the details of muscle movements.

Another tool is the scissor. Most scissors are for right handed people – handle blade and all. A right handed scissor is one when you hold while cutting, the hand having the thumb faces outside. For lefties, this could be a problem, even if the screw is a little loose as all control is lost.

Lefties also face another problem – that of writing. Usually most of the lefties hold their pen/pencil in a peculiar fashion. They are forced to do it because otherwise, they might smear the ink of the previous letter written with their own hand. This is true for most of the written languages.

In sports, handedness plays a major role. Let’s take cricket – India’s favourite sport. Though bowling and fielding determines whether a person is righty or lefty, some people do wrongly believe that a left handed batsman is a lefty by birth. Actually, the terminology used should be top handed or bottom handed. Yes, a left handed batsman who is a righty by birth is top handed and a right handed righty is bottom handed. For top handed people, it is more like they are hitting a back hand shot (lets say in a game like tennis) with some support from the other hand. So if you are playing a game like tennis or badminton, your preference for backhanded shots might determine your preference in cricket. Now, which is better – being top handed or bottom handed? A left handed batsman has his dominant side – the right side facing the bowler which will give him more confidence. Not only that, there is this concept of right eyed and left eyed people i.e. a right eyed guy uses more of his right eye than the other. Most righties are right eyed and so on. So a top handed batsman would not only be using his dominant side, but can also see the ball more clearly with his dominant eye nearer to the ball. So he has more time than the bottom handed batsman and can execute his shots much better.

No prizes for guessing why Sourav Ganguly had such sweetly timed square cuts. Sachin Tendulkar is more of an enigma. I have read that he uses both hands and I have seen him autograph with his left hand. But I am not very sure if he has practiced that as he still bowls and throws with his right hand. In one particular match, I remember him trying to throw with his left hand and believe me it was not a pretty sight to watch. The ball somehow did reach the keeper’s gloves and the batsman of course couldn’t complete the single. But Sachin himself was all unbalanced and had thrust himself in the air.

Rafael Nadal is right handed but plays tennis with his left hand. It seems he used to play a double handed forehand. This gave his uncle and idea that Nadal could play left handed tennis. Now he  uses a double handed backhand too.

I guess this is enough for now. Read my next post to understand the science behind handedness.

Choosing Water over Land

August 27, 2010 4 comments

It’s a known fact that life originated out of water. The first living organisms – micro organisms took birth in the sea. And slowly they evolved into higher forms of life. Fishes originated and then they took reptilian form and these reptiles came to land and they evolved into mammals. But some of these mammals, strangely enough went back to water.

Modern whales owe their existence to a small wolf like carnivorous mammal PAKICETUS – the name being so because its fossils were first found in Pakistan. Pakicetus has now been included within the order ‘CETACEA’.  Pakicetus used to spend some amount of time in water – sometimes for feeding and sometimes to escape from other land-predators. The cetaceans finally fully settled in water, their lungs and bones – all developing to help them lead an aquatic life.

Let me now introduce another class of animals which you are familiar to – The ARTIODACTYLs or the EVEN TOED UNGULATES. These are all those herbivores you almost usually see – the cattle, pig, camel, giraffe etc. and most importantly hippopotamus. They are distinguished by the presence of 4 toes/hooves (as against 3 in case of odd toed ungulates like horses, donkeys, tapirs, rhinos etc), the weight of the body being borne wholly by 2 of the 4 toes. The closest living relatives of cetaceans are artiodactyls, Hippopotamus being the closest among them all. In fact the two orders – those of cetaceans and artiodactyls are together given a Clade – Cetartiodactyla. So how do early Cetaceans differ from artiodactyls? The structure of the tympanic bone in the ear is what differentiates the cetaceans from artiodactyls.

Interestingly enough, there is another close relative of whales – INDOHYUS (Meaning, Indian Pig), which was a herbivore. It was almost a contemporary of Pakicetus and most probably more recent than Pakicetus. It is a relative of the cetaceans in the sense that it has the same ear structure and belongs to the family Raoellidae.

Another set of mammals which took the aquatic route are the SIRENIA – the sea cows, manatees and dugongs.  SIRENIA are completely herbivorous and feed on plants growing under the sea. Now guess who are the closest relatives of these creatures? Elephants. Yes, Elephants and the Sirenia both evolved from common ancestors PRORASTOMIDAE which were mostly terrestrial animals known to be amphibious too. While they finally went and settled to lead a fully aquatic life to have evolved into Sirenia, somewhere down the line some of them have even come out of water and evolved into Elephants. No marks for guessing why elephants are such good swimmers and why they like to wallow in water so much. The skin of pachyderms is also fit to lead a dual – aquatic plus terrestrial lifestyle. Thus, in a way elephants represent a set of animals who went back to water and then again came back to land.

Here, I would like to touch upon another set of mammals that have gone back to water, though not fully. They are the PINNIPEDs or the super family of mammals having seals, walrus, sea lions etc who feed in water but stay on land. Thus they are semi- aquatic. But it is true that they have evolved from bear-like animals which were fully terrestrial.

Thus, we can see that though evolution forces most animals into being aquatic or terrestrial or amphibious, some of them still like to go back to what suits them the most by evolving themselves.

Unearthing Human Intelligence

August 2, 2010 4 comments

Let me ask you a question. How intelligent were the dinosaurs?  You all might say – ‘definitely not as intelligent as man’. And with walnut sized brains, i must agree they were really dumb. But studies have shown that troodon, the most intelligent dinosaur could have evolved into as intelligent and complex species as man himself.

Encephalization quotient is a measure of ratio of brain to body mass and in a way that reflects the intelligence of the species. Lets look at the Encephalization quotient of various animals.

Man – 7.44

Bottlenose Dolphin – 5.31

Orca (killer whale though actually a dolphin not a whale) – 2.57

Chimpanzee – 2.48

Elephant – 1.87

Whale –  1.76

Dog – 1.17

Cat – 1.00

It is pretty clear that the cetaceans (dolphin, whale etc) are almost as smart as humans and in some cases smarter than our ancestors. But indeed they ran out of luck when it comes to dexterity as they ended up in water and clearly you can’t read and write with your fins. Here i am specially highlighting dexterity as dexterity is something which would enable your brain to evolve as you start handling tools and eventually when the language was developed dexterity alone could help humans form a written format of the language. Even this dexterity was something which we got from our primate ancestors and which we didn’t earn it for ourselves. The monkeys made immense use of their fingers to grab branches of trees and thus even this is an evolved trait.

So by bragging about how intelligent humans are, aren’t we undermining the efforts of so many of our ancestors – reptilian mammals 65 million years ago, then the earliest primates 36 million years back ? Well maybe not. But surely, it was a matter of luck  and timing. What we have got now is not something we have earned but something which was GIFTED to us.

And how are we making use of this SPECIAL GIFT? Of course, full credit to humans for the various developments that have happened since the middle ages and in the past 200 years, man has changed a lot literally. Here, it would not be wrong to say that man has started evolving mentally and very less physically. But has that been of any help?

In the middle ages, man invested in technology only for war and weaponry.  Somewhere in between the Middle Ages and the modern era, man made a lot of important inventions and discoveries. As a result, we have all the comforts of modern technology in our day to day life. But how many of us have access to such a life?  The so called intelligent ones among us have very conveniently developed ways to earn wealth at the cost of others. Speaking about current usage of technology, nuclear fusion has not yet been used for generating electricity but it has already been used for constructing weapons of mass destruction.

Every year a large number of species are wiped out from the face of the earth because of human activities. The global climate change is very much evident now and threatens the very existence of human race. In many newly discovered geographies like Australia, man himself introduced a number of species for his own convenience. Then when he has found out that they are becoming a trouble for him, he has started culling a number of these animals and other animals. Man himself has been multiplying at an enormous rate depleting all the natural resources provided by Mother Nature.

It is not even a matter of superior intelligence but a matter of sheer common sense that we should not be hunting animals just for fun. In spite of man reaching a superior intelligence level man resorts to vulgar methods of entertainment like the infamous Seal hunting in Canada, where young seals are hammered to death.  In a way we are at the top of the food chain because of our intelligence levels. We are the APEX predators now. But is it not our responsibility to use our intelligence with discretion and not use our power for wasteful activities.

The evolution is an ongoing process. Man might go from strength to strength in terms of evolution but at the cost of other living species on the planet. And if sheer brain to body mass ratio is what is intelligence is, then my Question is ‘ Are we really that intelligent?’. It is for you to decide!!!!!

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