Voice of Fairness

My personal opinion on science, religion and politics


(This was published in the bulletin Porcupine! in Dec. 1998, when Dr. Richard Corlett was its editor. The bulletin was distributed to students and faculty in Department of Ecology and Biodiversity, University of Hong Kong. The original is at http://www.biosch.hku.hk/ecology/porcupine/por18/six.htm. I re-post it here for two reasons, 1) the original may someday disappear – Porcupine! Died of old age in 2006, 2) it might stimulate some discussion on evolution among students at University of Ottawa)

When I was contacted to write an article for the "Six papers that shook..." column of Porcupine!, I was first curious about why the number should be six instead of other numbers. The column title suggests that the number five or seven, or any other number, is less optimal than number six in most cases based on certain criteria. Have other numbers been tried before and found undesirable? Has there been a competition among numbers with this magical number six gradually emerging as a winner?

There might well be a nice story behind this number six, or there might be no story at all. However, even if there is no story behind the number six, people driven by curiosity and gifted with imagination will come up with some stories in the future and the story, if well told, will be gradually taken as truth.

The field of evolutionary biology is full of story-telling geniuses, whose stories have plagued the mind of many, especially those like me who are fond of good stories. Eventually the story will be built up to such a grandiose scale that a phenomenal effort will be needed to dismantle it. The phenomenal effort, when expressed in a publication, will then be called a classic.

One such classic is George C. Williams' 1966 book, Adaptation and natural selection: a critique of some current evolutionary thought, which I read when I was doing field work on the deer mouse populations in the Kananaskis Valley in the Canadian Rockies, in the summer of 1985. The Environmental Research Center of the University of Calgary, where I stayed during the summer of field work, has a nice library with quite a number of classics in evolutionary biology, including this classic by Williams. The book contains pointed criticisms of misinterpretations of Darwinian theory of natural selection by a number of leading evolutionary biologists. It was written in such a powerful, spirited and persuasive manner that my heart was beating extraordinarily fast when reading the book. I have since become much more critical than before, both of other people's works and of my own.

The second classic that influenced (or "shook") me greatly is John Maynard Smith's 1978 book The evolution of sex, which I read in 1989. At that time I had already finished reading G. C. Williams' 1975 book Sex and evolution, and perhaps most other publications by Williams. Because of my admiration of Williams' writings, I was almost infuriated to find someone writing on the same topic. How could anyone even dare to think that he had something to add to what Williams had just written on? I therefore read the book very critically, and consequently progressed rather slowly, trying to find flaws. Yet there is no flaw throughout the entire book, except for a very minor one close to the end of the book, which I mentioned in American Naturalist in 1992. The book contains so many ingenious ideas presented in such a lucid manner that, in my opinion, it is not rivalled by anyone, not even Williams. I have since learned that Maynard Smith had criticized group selection even before Williams, developed the concept of evolutionary stable strategies and also served, albeit for a short time, the devil's advocate in the selectionist-neutralist debate in the development of the neutral theory of molecular evolution. It is in fact through an early article by Maynard Smith that I began to learn about the debate, and it is a publication that emerged from the debate that I will now introduce as my third classic that "shook" me. But first let me give you a partial background to set the stage of the debate.

According to the neo-Darwinian theory, mutation is the ultimate source of genetic variation, which is true, but natural selection is given the dominant or "creative" role in shaping the genetic makeup of populations. Most mutations were thought to be mostly deleterious, but occasionally advantageous mutations would arise, and gene substitutions would occur as a consequence of selection of advantageous mutations. Two populations of the same species in two different environments would diverge genetically because natural selection would favor different genes that were good for their respective environments. This scenario led to two predictions. The first is that most genetic differences between populations or species are those with important phenotypic manifestations. The second is that the gene substitution rate should be low. This second prediction may not be immediately obvious to you if you have not heard of the substitution load. So we digress a bit further.

The substitution load was previously termed "the cost of natural selection" by J. B. S. Haldane. If natural selection is to improve the population, or at least maintain the population in its current status of adaptation, it has to eliminate those individuals carrying deleterious mutations. To fix a new advantageous gene, the population has to go through the selection process in which all individuals not carrying the new advantageous gene would be eliminated, which is "costly" indeed to the population. This implies that gene substitution by natural selection favoring advantageous genes is a very slow process. Hence the second prediction that gene substitution rate should be very low.

These two predictions, which seem highly plausible if not obviously correct, turned out to be wrong. The gene substitution rate, when quantified at the molecular level, was found to be much higher than previously expected based on the neo-Darwinian theory. Thus the second prediction of the neo-Darwinian theory fails. The first prediction, that gene substitution was mainly through natural selection favoring advantageous genes, and that genetic differences between populations or species should mainly be reflected in those genes correlated with fitness, fails just as badly. Most substitutions are "silent" (or neutral) at the molecular level and have no bearing on fitness, and most differences among populations or species are made of such neutral differences. These observations, as well as many others, accord well with the predictions of the neutral theory, but not with the neo-Darwinian predictions.

The neutral theory is one of the few evolutionary theories that greatly influenced how molecular biologists go about their research. If molecular biologists want to find important genes, or important segments of a gene, then they should look for conserved genes or gene segments, i.e., those that are the same in mice and frogs, rather than looking for those highly variable genes or gene segments.

The neutral theory of molecular evolution by Motoo Kimura (1983) presents the conceptual framework of the theory as well as empirical evidence in support of the theory. To my understanding, the book is flawless except for a very trivial one on the evolution of codon usage in protein-coding genes, which I mentioned in Genetics in 1998. It is through reading this book that I truly appreciate Th. Dobzhansky's proclamation that "Nothing makes sense except in the light of evolution".

Now I have to challenge again the wisdom of choosing the number six. According to Dr. Corlett, the "Six papers..." article should be just about one page long. I have now covered just three publications and the article on the screen is already creeping into the third page. This is already my second attempt at limiting the article to one page, and now I have no alternative but to admit a total failure.

Rise and fall of nations

Nations rose typically because their leaders were both technically smart and morally virtuous. These leaders formulated fair laws and established wise social systems to ensure fairness. People around the world trusted these leaders and wanted to do business with them. As a consequence, such nations rose higher and their leaders gain a tremendous amount of power.

But "power corrupts and absolute power corrupts absolutely."

The original leaders, who were technically smart and morally virtuous, were gradually replaced by leaders who were technically smart but without virtue. These leaders were collectively labelled as Hegemony which wanted to have more power, more money, more privilege, and more control of the world.

But people around the world began to grow suspicious, and their trust in the Hegemony shrunk over time. They wanted shake off the shackle of control to declare independence.

The Hegemony had sensed this dangerous movement of the people around the world, and meted out punishment to those who dared to take a move to free their people. However, the Hegemony had a tendency to overestimate its controlling power, and eventually found it difficult to control the world all by itself. So the Hegemony set out to form an alliance, with a simple promise to its allies: "We go to rob the weak and poor together. I get 70% of the loot, and you get 30%.".

So military alliance was formed, and it typically would last for decades of years.

Then the Hegemony said to its allies: "Let's replace 70% and 30% by 80% and 20%, respectively. This is only fair."

The allies, although not as happy, found this acceptable. They would rob the weak more savagely to compensate for the loss they had conceded to the Hegemony.

Then the Hegemony said to its allies: "Let's replace 80% and 20% by 90% and 10%, respectively. The alternative is to place you among the robbed. You are either with me or against me."

The allies, although not as happy, found this acceptable. They would rob the weak more savagely to compensate for the loss they had conceded to the Hegemony. They did this to such an extent that some of their own people found it morally unacceptable. They felt that they had sold their souls too cheaply. There were two more reasons for these allies to worry. First, they had a rebellious young generation who were more righteous. Second, some of the people in these allied nations thought that they were just as capable as those in the Hegemony and desired to have a fair share of the loot.

So the leaders of the allies argued with the Hegemony, saying that we had been faithful allies. We had contributed to making you great again. However, we have robbed so savagely that we looked evil in the eyes of our children. This is too much a cost to balance the benefit of unfair share of the loot. Our life has become insufferable because of this.

But the Hegemony wouldn't listen. Instead, it fumed: "You ungrateful pigs. You could have been the third-class citizens, but I granted you the second-class status. How dare you ask for more?"

The allies were terrified and dashed out of the door as if being chased by mad dogs. In the wildness outside, they had struck an idea of forming their own alliance so that they would not be slaughtered individually by the Hegemony.

So these allies formed their own alliance, which would be known as Hedgemony because they had jointly hedged a bet.

The Hegemony got even angrier upon learning of the establishment of the Hedgemony. "It is like someone who is snoring by my bedside! Total disaster!", he shouted.

But the leaders of the Hedgemony were pretty cunning. They had clearly seen the division of the world into three castes, the Hegemony, the Hedgemony and the Rest, and they went to lobby the leaders of the Rest: "You used have a leader who recognized the world in three castes, and thought that the Rest could stand on its own feet. He failed miserably because he, although having succeeded in uniting the Rest, did not make an effort to seek leadership from the Hedgemony. The joint force of the Hegemony and the Hedgemony is far greater than the Rest. However, the joint force of the Rest and the Hedgemony might be greater than the Hegemony. If you come with us, we surely will not rob you as savagely as the Hegemony.

The Rest was all very glad to hear this proposal, and put it to action right away.

This had driven the Hegemony crazy, and it had come up with a smart strategy to break up the Rest+Hedgemony alliance. It first approached the leader of its neighboring country which Voltaire once described to be no more than a few acres of snow: "Listen, kiddo. I am going to slapping you hard, and slapping you hard in front of all people to make you cry like a baby. However, if you condemn the leaders of the Rest, I will not only refrain from hitting you, but will kindly change your diaper."

The poor "kiddo" never realized that he was a leader in a vast land that is far more than just a few acres of snow, and he immediately caved in and hurled loads of curses upon the leaders of the Rest. As a reward, he did have his diaper changed so that he now looked smart in front of young girls.

Now the Hegemony went to the leaders of the Hedgemony and said, "See the example of that kiddo? If you follow his example and curse the leaders of the Rest, I will treat you the same as I treated him", and he pulled out a few more diapers from his suitcase.

The cunning leaders of the Hedgemony saw this as a valuable leverage, and they went to whisper into the ears of the leaders of the Rest: "The Hegemony is plotting against you. However, if you give us a very good deal......"

The leaders of the Rest was immensely touched by the faithfulness of the Hedgemony, and promised to give it all. They also innocently spread out a large poster starting with the words "Our alliance with the Hedgemony for the global economy......"

The Hegemony saw the poster, went across the Atlantic and stared into the eyes of the leaders of the Hedgemony: "You! Do you intend to betray our alliance?!"

The leaders of Hedgemony were all trembling, and all said in unison, "Absolutely not! It is the Rest that has tried in vain to seek alliance with us. We have steadfastly refused. Anyone who has ever thought of an alliance with the Rest is our enemy #1!"

The Hegemony was pleased, and said, "I am going to punish the Rest for their attempt to divide us. I expect you to know where you stand." Each of the leaders of the Hedgemony said "Yes" seven times, each time louder than the previous one.

So this brought us to the present. The rise of the nation had occurred hundreds of years ago. The fall has occurred spiritually but not materially, and may not occur in the near future. This is because the fall is relative to the rise which demands technically smart and morally righteous leaders. At present, such leaders are missing.

Memory, feelings, and evolution

I wish to share an early experiment with my fellow evolutionary biologists. The key result of the experiment suggests that the length of an event staying in memory may be directly associated with the effect of the event on fitness.

The experiment was done many years ago on white-footed mouse (Peromyscus leucopus) when I was a graduate student at University of Western Ontario. It has never been published partly because I developed strong allergy to mice before the study is incomplete.

The story started when I was trapping white-footed mice with Longworth mouse traps and accidently caught a least weasel (Mustela nivalis), the most deadly enemy of wild mice. Out of curiosity I brought it back to our animal facility housing my mouse colonies on which I carried out genotyping and breeding experiment. The presence of a least weasel somewhere was almost immediately sensed by all the mice – they stopped regular eating and drinking.

For wild mice, there is no news worse than the arrival of a least weasel in their vicinity.

The news, while depressing for the mice, was found exciting by Dr. Martin Kavaliers who was at that time studying signal-transduction pathways of analgesics. Martin then did an experiment on my white-footed mice with a hot plate. The control mice, when being put on the hot plate, would lift and lick their feet constantly when the hot plate was turned on. In contrast, the mice exposed to the smell of the least weasel became so focused on the smell as to be oblivious of the burning heat under their feet – they did not lift or lick their feet as they should have when there is no weasel smell. Martin incidentally reported the least weasel as short-tailed weasel (Mustela ermine) which is bigger than the least weasel and would have a difficult time squeezing its way into a Longworth trap.

While Martin’s experimental mice were field-caught, the same phenomenon was also observed in lab-born white-footed mice that never had any real encounter with the least weasel, so that “memory” of the bad thing (i.e., the least weasel) may have been somehow encoded in DNA and re-enacted through proteins (which would be truly intriguing). In this way, the memory of the weasel becomes permanent and will not be eroded by the passing of time. (Of course there is also the possibility of new-born mice learning from others.)

I then did an experiment in my semi-natural enclosure which has been described in some of my early publications. The experiment also involved a hot plate, enclosed within a card box, and placed inside the semi-natural enclosure. In one part of the experiment (Memory-Of-Good-Thing-Expt), sunflower seeds and Purina rat chow were scattered on the hot plate, but the hot plate was never turned on. 

White-footed mice are crepuscular and active mostly during twilight hours. Similar to any other field mice, they are always cautious to new things added to their environment, and would investigate the box carefully before entering. After some initial exposure, however, the mice would recognize the box as a good source of food and would enter the box quickly to eat, and females would bring the rat chow back to their nest-boxes. If you take the box away for one day and put it back at the same location, the mice would still recognize the box and enter it readily without further investigation – their memory told them that it was a godsend.

By the way, the white-footed mice have reasonably good memories and memorize the routes along which they dart from one hiding place to another. If you put a card box on such a route, they will typically dart head-on against the box, producing a loud sound breaking the silence of night, a consequence that the card box is not in their memory of the routes. Sometimes I wonder if they would run right into a predator if the predator knew their routes and just sit there with a wide-open mouth (they don’t, thanks to their smelling capabilities). Of course, there is also benefit of darting from one hiding place to another by using the map in the memory instead of by vision. These mice don’t see very well during twilight hours (Mice are not cats or owls). Relying on their vision might delay their escape from predators.

Leaving aside the many interesting biological aspects of the mice, let’s come to the other part of the experiment (Memory-Of-Bad-Thing-Expt), in which the setup is the same as Memory-Of-Good-Thing-Expt except that the hot plate did get turned on when mice were inside (Make sure that you do not have a thick layer of food on the plate preventing the heat reaching the mice). These mice, experiencing the bad feeling of burning, avoided entering the box in spite of the inviting food inside.

The boxes were then taken away for three weeks, after which the mice were again exposed to their respective boxes. Those mice in the Memory-Of-Good-Thing-Expt seemed to have forgotten altogether the good food associated with the box. They resumed the cautious approach and restarted the investigation. In contrast, those mice in the Memory-Of-Bad-Thing-Expt appeared to instantly recognize the box as evil and avoided entering the box.

In short, memory of bad things lasts longer than memory of good things, at least in this particular case. From an evolutionary point of view, this is not difficult to understand. While the good thing may not enhance their fitness very much, the bad thing (the burning and the weasel) could do serious damage. I very much wish the conclusion generalized because it is important.

Mistakes are typically associated with bad feelings, but we learn from mistakes, with the consequence of a lot of bad feelings staying in our memory and lasting for a long time.

One corollary from the conclusion is that, when one gets old, if there is no constant reinforcement of good things and good feelings, then one could potentially be left with memory of bad things and bad feelings. This corollary was made particularly pertinent when a former colleague, a well-established Peromyscus researcher, Dr. Jerry O. Wolff, committed suicide, exactly seven years ago, on May 10, 2008. I met Jerry several times, mainly through conferences and through his visit to my former supervisor’s (Jack Millar) lab. We regarded Jerry as an excellent colleague and did not, and still do not understand why he would have chosen suicide to end his life. Had he lost good things and good feelings in his memory? Did bad things and bad feelings took an upper hand? While our knowledge of science and technology has progressed so much, our knowledge of hope and love has lagged so far behind.

We often see old people indulged in the so-called “good old days”, the kind of nostalgia that historians, psychologists and politicians all unanimously dismiss as mass delusion, i.e., a Garden of Eden that has never existed. Indeed, if we measure wealth, health, life span, degree of democracy and rationality in human behaviour, etc., we will find the present day beating all “good old days” by a wide margin. But do we have more human interactions to reinforce good things and good feelings in our memory if we get old today? Will our brain be gradually poisoned by the bad things and bad feelings?

The mouse experiment described above might also be relevant to parenting as well. Parents perhaps should be particularly cautious when dispensing punishment to their children, especially when parents sometimes do wish their children to remember the bad feeling of punishment for a long time. A child is likely to become troublesome and lost without constant reinforcement of good things and good feelings in his/her memory. A home should not be a transient Biblical Garden of Eden with a cruel one-strike law.

May we keep alive our fond memories of love and friendship until the end of our days!

(Written on May 10, 2015)

Science and Religion: II

Religious people often feel offended when they are told that God has no place in science. They should not if they know the fundamental difference between science and religion.

Suppose we have a financially stressed government official who suddenly became a billionaire. People with a certain degree of curiosity would want to know how he suddenly became so wealthy. One may suggest that the official might have a recent raise in salary, but such a salary raise typically can explain very little of the dramatic change in his wealth. 

Now suppose that the official, through one of his representatives, issued a statement that God had made him rich by dumping a billion dollar in his bank account. Of course, an almighty God has infinite explanatory power of everything. Making someone wealthy surely would not raise any difficulty to His almighty hands. However, a right-minded person probably would not believe in such a statement and would most likely demand a thorough investigation of the financial dealings of the official.

The simple truth is that, when we are dealing with earthly matters, we are satisfied only with earthly explanations. A holy explanation has no place in such earthly matters and will simply be rejected outright.

Now suppose we have another scenario in which a fully grown and sexually active young man came to us with the information that he was only one day old. Any modern scientist would reject the age information as false because the information is incompatible with our observation of the young man being fully grown and sexually active. Given the cell replication rate in human development, one day is simply not enough for a zygote to transform itself into a fully grown and sexually active young man. Modern science will simply deny the existence of any man who is only one day old yet is fully grown and sexually active, and will conclude that the man is much more than just one day old. Even deeply religious people would probably deny the existence of such a man if the Genesis story of Adam and Eve was not recalled in time.

Just as modern science would conclude that a fully grown and sexually active man is more than one day old, it would also conclude that the earth, which has recorded many time-consuming changes, must be much older than a few thousand years. An earth that is only a few thousand years old raises the same difficulty as a fully grown and sexually active young man who is only one day old. Just as most of us will reject the idea of the one-day-old young man, most scientists will also reject the idea of a young earth. A holy explanation has no place in the physical world and will consequently be rejected.

Yes, an almighty God can make a billionaire out of a pauper, or a fully grown and sexually active young man who is only one day old, or an earth (or even a universe) jumping out of nowhere a few thousand years ago, but scientists deal with only earthly matters where invocation of a holy explanation is simply forbidden. Based on earthly laws (which are often better known as natural laws) governing the earthly matters, we reject the possibility that a pauper can suddenly become a billionaire through God, that a fully grown and sexually active man can be only one day old, or that an earth (or a universe) that has experienced numerous time-consuming changes was formed only a few thousand years ago.

The most fundamental difference between religion and science is that God is allowed as an explanation in the former but absolutely not in the latter.

When scientists state that God has no place in science, they do not mean that scientists do not need love and are not caring. In fact, many of them are very loving and caring. By “God has no place in science” they only mean that God should never be invoked as an explanation for observed variation in things of nature. 

Scientists need public understanding and support in their practice of excluding God as an explanation for their observed changes in physical entities around us. Such a practice is sometimes quite challenging and difficult. For example, cancer remission has been observed in many cases, and many scientists have been wracking their brains day and night for an understanding of the remission so that they can better help those less lucky one. If we do allow God as an explanation, then the life of these scientists would be much simpler. Whenever they see a case of cancer remission, they will just give each other a knowing smile and say “He did it again”. But I doubt if any church or any religious group or any government would be willing to grant our scientists such an easy life. The world will indeed become quite a bit more hazardous if they do.

So don’t be offended if you are told that God has no place in science. If God does desire to be part of an explanation of the dynamic universe, He most likely will give us a clear sign. At the moment, I believe that His priority is with helping the victims of natural disasters and human atrocities, not with offering holy explanations of natural phenomena.

(Prompted by an article on the debate about including "creation science" in the science curriculum of public schools)

(Re-posted from my Google+)

Science and Religion: I

One thing particularly strange in this world is that one can achieve much and do a great deal of good even if his or her religious belief is entirely wrong.

An engineer can design great cars or trains or ships or airplanes, and his belief that the universe was created 6000 years ago or took shape 4 billion years ago has little to do with his accomplishment.

A physics professor can create photonic sensors to monitor minute changes in temperature in a minute particle, and her belief that the universe was created 6000 years ago or took shape 4 billion years ago has little to do with her accomplishment.

A surgeon can send his lancet to a tumour with amazing precision, and his belief that the universe was created 6000 years ago or took shape 4 billion years ago has little to do with his accomplishment.

A farmer can plan all his crops and execute his plans beautifully, and his belief that the universe was created 6000 years ago or took shape 4 billion years ago has little to do with his accomplishment.

A real estate agent can sell 50 houses per year, and her belief that the universe was created 6000 years ago or took shape 4 billion years ago has little to do with her accomplishment.

If these people believe that the universe was created 6000 years ago, let them keep their beliefs, because their beliefs about the universe do not really matter in their career.

But there are people who will almost do everything wrong in their career if they believe that the universe was created 6000 years ago, and these include astrophysicists and evolutionary biologists. For these people, their beliefs about the universe matter a great deal. Indeed, nothing they observe in nature makes sense without believing that the universe is very old.

So what can we say about science and religion? The world is quite complex and we cannot be expert in everything, especially not in both the physical and the spiritual worlds. If you know something that works for you, or some theory that makes sense to you, then stick to it and you will be fine. However, it is important to keep an open mind when that something stops working for you or that theory no longer makes sense.

The world changes, so do religious views and scientific theories, but one thing probably will stay for a long time with little change, and that is the scientific method of validating our beliefs and establishing new theories about the physical world through observation, experimentation, and conceptualization.

(Re-posted from my Google+)

Mental Depression

What is mental depression? There are many different definitions. I will start with one which, while not quite right, serves as an excellent starting point.

Let A be what you already have, B be what you deserve to have by time t, D = B – A. Let p(D, t) be probability that you will have D by time t. You are suffering from mental depression if you perceive p(D,t) = 0, and the degree of your mental depression increases with D.

There are various counselling approaches to treat mental depression, but three of them are frequently practiced. The first approach, given the definition, is to persuade the patient to desire less. If B = A, then D = 0. So the disease is cured and the patient is happy. If B < A (which means that one feels that he/she has more than he/she deserves, i.e., D <0), then the patient is no longer a patient, but will become a Christian singing praises to God. Unfortunately, most patients found such an approach offensive and will not continue.

The second approach, somewhat related to the first and the third, is to help the patient to change his/her perception from p(D,t) = 0 to p(D,t) > 0. This includes two sub-approaches. The first sub-approach is to break down D into various components, e.g., D1, D2, ..., Dn, and so that p(Di, t) > 0 at least for some i. This has the same effect of shrink B so that it will be closer to A. Although p(D,t) = 0 when t is now, p(D,t) may be greater than 0 when t is several years from now. As long as the patient can perceive p(D,t) > 0, he/she would have hope and will suffer mental depression less. Councilors of this approach often will change p(D,t) to a more complicated form, i.e., p(D,t,Spouse+). This is because p(D,t) may be 0 with a nay-saying spouse, but would become greater than 0 with a yes-saying spouse. Such a change in perspective would imply that the spouse or other key relatives would need to participate in the counselling as well. Unfortunately, spouses or other key relatives, perceiving a cost in changing their position from nay-saying to yes-saying, are often not enthusiastic in participating in this type of counselling.

The third approach is based on the observation that patient is often depressed because of a conflict between the patient and those related to the patient, especially spouses. The conflict occurs when the patient believe that he/she deserves B but the spouse thinks otherwise. The patient suffers because he/she feels that nobody is paying attention to what he/she deserves. Given this, the councilor of the patient will simply affirm to the patient that he/she does deserve B, and that it is the fault of the society (and of his/her spouse) not to have recognize this. Most patients generally are very fond of this type of counselling. Some of them could even be described as being addicted to it. For this reason, this type of counselling is widely practiced, not only because patients love it, but also because it requires little professional knowledge. Unfortunately, this type of counselling often aggravate the conflict between the patient and his/her relatives.

There are other approaches, associated with alternative definition of mental depression. Some scientists would argue that the term “mental depression” is entirely misleading because many “mental depression” patients have a physical basis for the depression, often associated with anemia, fatigue or anything factors contributing to low oxygen supply to the brain. In fact, any serious discussion of mental depression would require substantial profession biomedical knowledge. For the time being, I will stop and leave readers think for a while.

(Re-posted from my Google+)