Wednesday, October 30, 2013

Dog, Corn and Almond : how man changed animals and plants to suit him

After you have checked your Facebook news feed, try this one – type ‘Great Dane and Chihuahua comparison’ in Google search. Some nice images will come up. Some sites will even show a side by side comparison, just like they show for mobile phones.
You are in for a surprise. Great Dane is 7 times tall and 20 times heavier than Chihuahua. Usually, they will be considered two species, but they are not. All dogs are same specie.
What do we mean when we say they are the same specie? Two animals are of the same specie when they can interbreed, which means they can mate and produce offspring. But one more condition, the offspring should also be able to produce offspring.
Horse and donkey can mate to produce mule. But mules cannot produce children. Rarely, Lions and Tigers mate to give birth to Ligers and Tigons. But these rare animals are also sterile, meaning they do not reproduce.
But all dogs, however different they might look, can mate and produce pups. So they are all one specie. But then why do they look so different? Not only they look different, they have different qualities. Retrievers can pick up a bird killed by hunter and bring it back to him. Coolies can herd sheep. Some hounds can pick up scent even across running water and after several days.
What created them? The answer is us. We created all these varieties.
Dog is basically wolf. Thousands of years ago, some wolves started lingering close to human sites. Man realized that they are useful animals. Wolves realized that man is useful company. Slowly, the wolves lost the wild characteristics. They became docile. They learned to stare into our eyes – something that very few animals do.
Now man started experimenting. He understood some basic principles of how to breed dogs for certain desired qualities. Armed with these principles, now called Selective Breeding, he created many types, called breeds of dogs.
So what is selective breeding? Suppose the breeders want to create a dog breed with long ears. They take a group of dogs, male and female, with as long ears as they can get. Now when the dogs produce their first pups, breeders select those with longest ears. When the pups grow up, they mate and create a litter. Again repeat the same process. After some generations, you will have a group of dogs with distinctly long ears. Now you have to keep them breeding inside the group. They will be called pure-breed. All you have to do is to give the breed a nice name.
Man used this technique not only with dogs, but many other animals and plants. The almonds found in the wild are bitter. The bitterness comes from a chemical that breaks into cyanide, which as we know, is poisonous. So anybody who is daring (or desperate) enough to make a snack of wild almonds will get very sick, if not die.
But selective breeding created the almonds that we eat. Due to a mistake in genes, some trees of almonds did not have bitter nuts. Some ancient children must have discovered these while they were playing and were hungry. When the elders found out about the edible almond, they used a branch from that tree to cultivate more trees.
Most of our foods are thus modified using selective breeding. The apples in the wild are only one inch in diameter, whereas our supermarket apples are three inches in diameter, nine times as large. The wild corn cob is hardly half an inch long, but we can easily buy a foot long corn cob at our nearest ‘bhuttawala’.
All this happened thousands of years ago. Most of our crops were created between 10,000 years ago and 2000 years ago. Animals were also domesticated around that time. So man moulded the genes are animals and plants without knowing anything about genetics.
The cow can produce around 20 litres of milk everyday, very little of which is needed by the calf. So why does the cow make so much milk? I think you should be able to answer that now.
(In this article, the word ‘man’ is used interchangeably with ‘human’, only for easy reading. No offence meant to women, who played a big role in shaping our foods and animals).

Monday, October 28, 2013


Would you like to be immortal, live forever? On a more sensible note, would you like to live 1000 years?
Of course it’s not possible today. But see what one scientist has to say on the subject:
“The first human who will live up to 1,000 years is probably already alive now, and might even be today between 50 and 60 years old”.
(Aubrey de Grey – forerunner of anti-aging research, on Television, in 2008. I can't help if his name sounds a little fishy when you pronounce it!)
That would include a lot of us. Are we that close of achieving such a lifespan? We once considered it to be mythological.
The largest lived human being was Jeanne Calment from France. She died in 1997, at an age of 122 years. She met the painter Van Gogh when she was 13 years old, saw the Eiffel Tower being built and did a small role as herself in a movie when she was 114 years old.
Let’s see what we can learn about Lifespan Extension, the word everybody uses.
First we have to understand why we die. Some of us die because of natural causes, like diseases or aging. Some die due to unnatural causes like accidents, violence or suicide. We will consider here only the natural causes, of course.
The biggest natural killer is old age. Age will certainly get you, if nothing else does. But what does aging actually mean?
Aging is not any one thing. It’s a collection of lot of things that are going wrong. Damage to cells, tissues, organs is the most important part of aging.
During most of our life, the cells that make up our various body parts divide to form new cells. This is our body’s way of repairing any damage that occurs. Now, every cell can divide only a certain number of times. After that count, the cell division stops. No further repair takes place.
Damage to important tissues and organs results into death. It is clear then, that to extend our lifespan, we have to overcome aging.
For one, we can postpone aging. We already know a lot about how this can be done. Diet, exercise, healthy lifestyle delay aging. Certain nutrients and supplements are known to restrict the damages. Herbal remedies in ancient sciences like Chinese Medicine and Indian Ayurveda serve the same purpose.
But the postponement of age is limited, and not guaranteed. In order to really overcome aging, we must be able to repair the damage that small and big parts of the body have suffered. Let’s see what knowledge we have in the repair department.
Science has been studying the animals who are good at defying death. One kind of Jellyfish is theoretically immortal. The trick that it plays is simple – it has two phases in its life. When it suffers aging in the second phase, its cells change themselves to go the first phase. It can repeat this cycle indefinitely, but is usually eaten by some fish who is not aware of its scientific significance.
Lobsters are also ageless creatures. They do not slow down, weaken, or lose fertility with age. In fact, older lobsters may be more fertile than younger lobsters. Also, they never stop growing. Lobsters are known to live up to 60 years. Nobody knows what will happen if they are not killed by humans or predators.
A salamander can not only regenerate a limb, but can regenerate the lens or retina of an eye and also the intestine.
These animals are able to repair damages to their body. What if we can emulate them?
Now, to repair the damage, we have to do multiple things. Let’s make a small list, as examples-
- Repair DNA : The genetic code is inside every cell and every time the cell divides, it is copied. As with all copying, this copy also makes errors. The errors are called mutations and some of them are harmful. These mutations need to be found and corrected.
- Clear the junk: Our cells are like factories. They create junk like real factories. This junk has to carried away.
- Fill up cell loss: Some cells die and do not get regenerated. We have to compensate for this loss.
- Kill stubborn cells: Some cells are supposed to stop dividing and die. They do neither. What they achieve is that they stop other cells from dividing too. These cells have to be killed.
- Replace organs: Even after solving cell problems, if organs suffer damage, replace them with organs created from other cells of the same body.
We already have many of the technologies needed. Nanotechnology, Gene Therapy, Organ Cloning are some techniques that are being tried, though none of these is mature yet.
A lot of not-for-profit foundations and for-profit companies are working in this field. The Methuselah Foundation encourages research in anti-aging. It gives a prize to anyone who can stretch the lifespan of a mouse beyond current record. Currently, the prize is 4 million dollars and longest mouse age is 5 years. Recently in the news, Google has announced a new venture California Life Company (or Calico) to solve the challenge of aging.
Many people have serious issues with Lifespan Extension. There are ethical and social debates. What would happen if human beings suddenly start achieving such stupendous lifespan? You can find all this interesting debate on the internet. You better get informed and make up your mind. Who knows, in a few years, we might wake up one day to see a Life+ link on Google home page!

Saturday, October 26, 2013

Introduction to Nobel Prizes 2013 – III : Chemistry

Are you of the firm opinion that the best use of a computer is to share your vacation pictures on Facebook? Think again. How about helping to create new medicines?
But, before we get to computers and medicine, we have one stop to make - proteins. Proteins are present in every cell of our body. Many parts of body are made of proteins. The proteins like hormones and enzymes control the chemistry of the body.
We also remind ourselves that molecules are the smallest parts of a material. Suppose you have got a bit of common salt in your hand. You split it into two. Take one part and again split it into two. You do this again and again and the salt will become really small. After a while you won’t see it. But it will still be salt. Don’t stop splitting. The last particle that can respectfully call itself salt is a molecule of salt. You split it more and it is no longer salt.
Now, thus prepared, let’s go to medicine.
Many medicines work by attaching themselves with proteins. A molecule of the medicine meets a molecule of a protein. What they do after meeting decides whether you are going to feel better or going to stay in bed longer.
The minutes of meeting of drug and protein molecules is thus the key to finding new medicines. These details are too complicated to be written on the back of a bus ticket, however. They are too much even for a notebook page, or the whole notebook, for that matter.
The scientists who were honoured by the Nobel Prize for Chemistry this year discovered how these molecular meetings can be imagined using computer. Their work is being used not only for making new medicines, but also to understand how green plants make food in their leaves, and how we can process sewage, to give a few examples.
Three scientists shared the prize. All three work in the U.S., but hail from different countries.
Martin Karplus is 83 years old and comes from Austria. He teaches in Harvard University and a university in France.
66 years old Michael Levitt is British and associated with Stanford. He is a Israeli citizen.
Arieh Warshel, 72, is also an Israeli citizen. He does his research in University of Southern California.
The most astounding thing is, they did this work forty years ago, when computers were rare. There were no personal computers, only large computers owned by institutions. Their work was not treated with enthusiasm initially. Their colleagues in chemistry thought it was a waste of time.
But as computers became more powerful and more familiar, the work of Karplus, Warchel and Levitt became important to scientific community and the industry. Today, many pharmaceutical companies use this technology to discover new drugs.

Friday, October 25, 2013

Selfless Ants: how elderly termites defend their colony by sacrificing their lives

The elderly people are very important to our society. They posses a lot of knowledge which they pass to the younger generation. The younger people protect our seniors carefully.
But ants have a different way of life. Here, the elderly ants protect the younger ones. It is the old that take the more risky tasks, such as gathering food from faraway places.
Now, scientists have found a remarkable behavior in some types of ants and termites. The elderly actually explode themselves like a bomb in battle with predators.
These type of termites grow a sack of toxin on the back throughout their life. By the time they are old, the sacks become sizable. When enemy attacks, these senior termites are at the forefront. Their sacks burst while fighting, spilling the toxin and killing a lot of enemies.
This is an extreme example of sacrifice. But the study of social insects- like ants, bees, termites- can tell us about many such examples of selflessness. The key to this behavior is hidden in the peculiar genetics of these insects. But more on that some other time.

Thursday, October 24, 2013

Looking back in time

We all want to go back in time. Well, nobody knows if that is possible. But looking at the past is quite easy.
Every time you look at something that is far away, you are actually looking at the past. Because even though light travels very fast, it takes some time to leave that thing and reach your eyes.
Horizon is about 5 km away. So when you look at a ship on the horizon you are seeing the past, though only fraction of a second ago.
But when you are looking at stars, it’s another matter. They are far away, and light takes a long time to reach us. When you look at the sun, you are looking 8 minutes in the past. Alpha Centauri, the star nearest to us is the third brightest star in the sky. When you look at Alpha Centauri, you are seeing things that happened four years ago.
Now scientists have found a galaxy (which is nothing but a large group of stars) that is really far far away. It is farther than anything we have known before. When you look at this galaxy, you will be taken 1300 crore years in the past. At that time, our universe was very young, a crying baby merely 80 crore years old!
Alas, even through the most powerful telescope in the world, this newly found galaxy appears as a faint dot of light. That is definitely not an arresting sight for non-astronomers like you and me.
Scientists say that they can find galaxies even farther away, taking us very close to the beginning of the universe. To look so far back, they are building telescopes nine times bigger than the biggest we have today.

Wednesday, October 23, 2013

The Venus and the scientist

I want to tell you the story of ordeals of a scientist, who wanted to measure distance to the Sun. What I admire is his strength. Despite of the many misfortunes, he stood firm and continued his work.
This story is narrated in the book ‘A Brief History of Almost Everything’ by Bill Bryson.
Before I tell you the story, you should know what the Transit of Venus is. Sometimes, when you see from earth, the planet Venus appears to be passing over Sun. This is called transit of Venus.
The transits are very rare. They come twice in eight years, then do not happen for more than 100 years. The last two happened in 2004 and 2012. Next one will be in 2117, but few of us can hope to see it.
Now, two hundred and fifty years ago, in 1761 there was a transit of Venus, and many scientists were eager to observe it. They wanted to take some measurements, and use them in calculating the distance from earth to Sun.
(In 1761, Marathas were still big rulers, British had just begun to spread in India and there was no Telephone; it would be invented only after 100 years).
One of these scientist was Le Gentil from France. He wanted to observe the transit from India. He started his journey one year in advance. But on the day of the transit he was still on his ship. The ship was horribly unsteady and it was impossible to measure anything.
Gentil was not discouraged. He reached India and started preparing for the next transit that would come eight years later. After a long preparation, he was perfectly ready. On the day of the transit, as he began his measurements, a cloud slid in front of the Sun and remained there for almost the entire time of the transit.
Bryson writes:
“Stoically, Le Gentil packed up his instruments and set off for the nearest port, but en route he contracted dysentery and was laid up for nearly a year. Still weakened, he finally made it onto a ship. It was nearly wrecked in a hurricane of the African coast. When at last he reached home, eleven and a half years after setting off, and having achieved nothing, he discovered that his relatives have declared him dead and enthusiastically plundered his estate.”
(The most useful measurement was taken by Captain James Cook, who later discovered Australia. Using his measurement, the distance to the Sun was estimated as 15 crore kilometres.)

Tuesday, October 22, 2013

The Sleepy Brainwash

Why do we sleep? Sounds like a stupid question. We sleep because we feel sleepy, buddy.
- Yes, yes. But why do we feel sleepy?
- Now you are wasting my time, mister.
We spend a third of our life sleeping. So sleep must be doing something very important to us.
Scientists are trying to find out what benefits sleep has. One such very important benefit has been found recently. Sleep washes our brain of harmful chemicals.
Brain needs a lot of fuel to do its job. You know that our body uses glucose as the fuel. As much as 20% of all glucose consumed by the body is used by brain alone! Naturally, all this fuel burning leads to waste products. These are toxins and have to be removed.
Researchers studied mice and found that these toxins are removed during sleep. When the body is awake, brain has to see and think and do a lot more work. Busy with all this work, it cannot do the cleaning. Brain really is just like us working householders, postponing the cleaning to weekend, isn't it?
This is an important function of sleep, and scientists say that there will be many more. Some scientists think that when the toxins build up, we feel sleepy. So it's not a stupid question, after all.

Introduction to Nobel Prizes 2013 – II : Physics

The picture of the atom in your mind might have a cute little nucleus at the centre, with obedient electrons revolving around it, like a miniature solar system. Well, science no longer shares this endearing picture. If you can look inside the atom, it would be like a big sweet shop, with hundreds of different types of particles appearing and disappearing, just as the sweets do during these pre-Deepawali days.
But till fifty years ago, scientists were scratching their heads about a puzzle. None of these exotic particles appeared to have any property that can explain why atoms weigh anything at all. Peter Higgs was one of the scientists in 1964 to propose the existence of a particle, which was later named Higgs Boson in his honour, that lends mass to atom.
It rarely happens in science that a theory or scientist becomes a household name. Even if we think hard, Einstein with his flowing hair and his special theory of relativity is the only example that comes to mind. So many important breakthroughs are made every year, but people at large remain unaware of them.
So would have been the case with Peter Higgs and his invention too. Higgs Boson would have remained buried in science papers and journals, but a popular science book in 1993 decided to call it the ‘God Particle’. The name became immensely popular. Newspapers and magazines used the word with little discretion. It was one of the best marketing campaigns for science in recent times.
The scientific community was in earnest quest to find the particle, however. In 2008, the European organization CERN built a multi-billion dollar machine called Large Hadron Collider. One of the jobs of the giant machine was to confirm the existence of Higgs Boson. A big team of scientists from many nations worked on the LHC. They succeeded in finding the illusive particle last year.
Prompted by this, the Nobel prize committee awarded this year’s Nobel for Physics to two of the scientists who originally proposed the particle. The prize was given for ‘contribution to understanding the origin of mass of sub-atomic particles’.
Peter Higgs, now 84, is a professor in the University of Edinburg in Scotland, and is planning to retire next year. He was out hiking in the hills when the announcement came. He learned the big news from his neighbors.
Francois Englert from Belgium shared the prize. He independently proposed the particle in 1964, when he was only 30. He is a professor at the Université libre de Bruxelles, or the Free University of Brussels.
We Indians should feel proud about the name Boson. It celebrates the Indian scientist Satyendra Nath Bose, who lived and did his research in Calcutta ninety years ago. Einstein himself read and translated his research paper in German. His joint research with Einstein led to a better understanding of the atom. All the particles in the atom fall in two major kinds. One of them – the boson- is named in his honor (The other one is called Fermion).
As many as six scientists submitted papers with proposals similar to Higgs in 1964. The team of scientists at CERN contributed to the actual discovery of the particle. But the Nobel went to Higgs and Englert. Life, and especially Nobel Prizes are not always fair, are they?

Introduction to Nobel Prizes 2013 – I : Medicine and Physiology

This year, Nobel Prize for Medicine was given to three eminent scientists for their work on traffic.
No, not the traffic that makes our life difficult, but the kind of traffic that we owe our life to. The traffic inside our cells.
Our cells are like complicated factories. They are forever producing and discarding stuff.
Needless to say, they need a very good transport system to carry the goods around. The vehicles that do this job are called Vesicles. So the Nobel Prize announcement says ‘for discovery of machinery regulating vesicle traffic’.
The prize was shared by three scientists.
Randy Schekman is a 64 year old scientist from California. He conducts his research at the University of California at Berkeley, in the lab that bears his name.
62 year old James Rothman conducts his work on the other side of America, in Yale University. He has worked in various institutions including GE Healthcare as Chief Science Advisor.
Thomas Sudhof is the youngest of the three at 57 years. He was born in Germany and studied his medicine in Germany as well as the US. He is a professor and researcher at Stanford.
All the three scientists have a Stanford connection. Schekman did his PhD at Stanford, Rothman started his career there and Sudhof is of course currently doing his work at the university.
Rothman discovered how this transport mechanism works, while Schekman described how it goes wrong. Sudhof found how the same process happen inside neurons, the cells inside our brains.
Of course, these scientists have made these discoveries long ago (in case of Schekman, in 1970’s) and they are now part of all standard cell biology textbooks. But Nobel Prizes do take time to come. For example, the German scientist Ernst Ruska, who invented Electron Microscope in 1932 was given the Nobel in 1986, more than half a century later!