If evolution ensures survival of the most adaptable species, how did it not vanquish mental depression in humans? This question has been on my mind for several years, and it is time to examine it in the context of a new hypothesis proposed by two scientists.
Background
Between 30 to 50% people suffer from a major depressive episode in their lifetime. It is generally considered to be a disease of the brain, an illness that needs treatment. In the millions of years of human evolution, natural selection was at work, ensuring that the ones among us who were best at surviving, adapting, and reproducing, carried the human species forward. Mental depression reduces ones ability to survive, adapt, and reproduce. It would then be reasonable to expect that those humans afflicted with this disease would have become extinct by now. The genes responsible for, or conducive to depression, should have eroded out of the thriving gene pool. But that, as we know, is far from the truth.
While animals are also known to experience depression, it is still an emerging field of research, and I am skeptic whether their sadness is just a rational response to external circumstances or is full-blown causeless depression like in humans.
Meredith Small, an anthropologist at Cornell wrote last year:
The capacity to feel presumably helps us solve problems and survive, and is essential for group living, and perhaps inconsolable depression is simply emotional baggage that tags along with the good stuff. Or maybe unhappiness and a tendency towards suicide is the product of the uncontrolled nature of our quicksilver minds. We think a lot, and our wondering minds are just as likely to think sad as happy.
LiveScience quotes Meredith in Why Did Evolution Produce Depression, along with Paul Andrews and J. Anderson Thomson, Jr., who have argued in Scientific American that “depression is in fact an adaptation, a state of mind which brings real costs, but also brings real benefits.”
The Hypotheses
The two scientists have published their views in a Scientific American article “Depression’s Evolutionary Roots”. The key points:
- Depression should not be thought of as a disorder at all. They argue that depression is in fact an adaptation, a state of mind which brings real costs, but also brings real benefits.
- One reason to suspect that depression is an adaptation, not a malfunction, comes from research into a molecule in the brain known as the 5HT1A receptor….The ability to “turn on” depression would seem to be important, not an accident.
- Depressed people often think intensely about their problems. These thoughts are analytical and persistent. Depressed people have difficulty thinking about anything else. This analytical style of thought, of course, can be very productive and can help you solve the problem causing the depression.
- Analysis requires a lot of uninterrupted thought, and depression coordinates many changes in the body to help people analyze their problems without getting distracted.
- Symptoms of depression make sense in light of the idea that analysis must be uninterrupted. The desire for social isolation helps the depressed person avoid situations that would require thinking about other things. Inability to derive pleasure from sex or other activities prevents the depressed person from engaging in activities that could distract him or her from the problem. Even the loss of appetite could be viewed as promoting analysis because chewing and other oral activity interferes with the brain’s ability to process information.
- If depressive rumination were harmful, then bouts of depression should be slower to resolve when people are given interventions that encourage rumination, such as having them write about their strongest thoughts and feelings. However, the opposite appears to be true. Several studies have found that expressive writing promotes quicker resolution of depression, and they suggest that this is because depressed people gain insight into their problems.
- There is another suggestive line of evidence. Various studies have found that people in depressed mood states are better at solving social dilemmas.
- Depression is nature’s way of telling you that you’ve got complex social problems that the mind is intent on solving. Therapies should try to encourage depressive rumination rather than try to stop it, and they should focus on trying to help people solve the problems that trigger their bouts of depression.
Critique of An Unquiet Mind
- The semantic difference between “disorder” and “adaptation” has huge ramifications and consequences in how society treats depressed people. These gentlemen have perhaps not thought through these ramifications. By their own account, they describe the unhealthy, self-destructive, treatment-worthy behavior of people in this state of mind, so what goals do we achieve by terming them an adaptation rather than an illness, disease, or disorder?
- I am not sure if this is “missing the wood for the trees”. Humanity would benefit greatly if scientists studying the brain and depression focus on their excellence at dealing with trees and not try to paint the woods.
- Analytical and persistent thinking in depression is usually in the form of obsession and brooding – two words, often associated with depression, conspicuously missing in the article. The obsessive nature of thinking in depression is rarely productive, and often self-destructive.
- Dealing with lack of distraction in the next point, here I would like to point out the conspicuous absence of the discussion of anxiety in the article. Most forms of depression are closely associated with anxiety, and there is no discussion of whether anxiety also contributes to “productive analytical thinking”.
- Uninterrupted “analysis” often leads to suicide. Not eating leads to serious physical harm. Substance abuse is also a serious problem with those afflicted with the illness of depression. The idea that suicide, starvation, and substance abuse “can be viewed as promoting analysis” is not just ridiculous, but very insensitive. The brains ability to process information is not enhanced by any of these activities.
- The studies confirm that emotional expression is an important healing factor in depression. It is not just the writing, but the family, friends, consultation and therapy that follows it, which is often crucial for resolving issues.
- The first study is of whether mood influences level of cooperation in people and had just two experiments. The second examines how family relationships are relevant to adolescent depression. The notion that people with depression are better at solving social dilemmas is again, preposterous and highly insensitive.
- Many forms of human depression have no cause in the external world. It is not a rational response to an external social problem. It is often causeless and intrinsic or inborn. The scientists view of depression seems to be very narrow minded.
Conclusion
It is clear that we do not have any definite answer yet. Though Depression has been studied in all cultures, we do not know if it existed in early stages of evolution. If it didn’t, and we find that it has developed in recent history (in evolutionary terms), I’m sure natural selection will eventually eliminate it.
Meanwhile, it does not behoove Scientific American to publish such articles. If you want to learn about mental depression, here is the best place to start.
When I was in school, I was asked to participate in a debate: “Science: A Cure Or A Disease?”. Yes, my school sucked.
Since then, I’ve been observing how the discipline of science remains largely misunderstood or not understood at all.
New Scientist has just published “13 more things that don’t make sense”, a sequel to their highly popular “13 things that don’t make sense” article in 2005. Both the articles give you a brief glimpse of phenomena that science has yet to understand and are an interesting read for knowing more about cutting-edge experiments and yet-to-be-formulated theories.
If you observe the domain of the “13 things”, they deal with
- Issues of time, space, mind and body
- The world beyond human sensory perception either on a micro or macro scale
- Time spans vastly beyond that of human life
Is this surprising in the least? If you contrast how long science has been in existence compared to the universe, life on earth, and the beginning of homo sapiens, to say that nature has an unfair advantage would be a huge understatement.
On the one hand, I am happy that articles like these catch popular attention. They serve to generate interest in science among the general populace. Carl Sagan is best known for his misquoted phrase “billions and billions”, though he never uttered it in the entire Cosmos series. Catchphrases work and are sometimes justified.
On the other hand, I dislike the lame attempt at sensationalization. How many times have you heard or read “unexplained”, “mysteries”, “unanswered” in the context of science? There are no mysteries in science, only in nature.
New Scientist’s 2005 article remains the most forwarded article in the site’s history. The article’s popularity led to a popular book of the same name. If this were a non-profit organization popularizing science, I wouldn’t have written this post. In Jan 2009, it ran a cover with the title “Darwin was wrong”.
The magazine has been criticized by sci-fi writer Greg Evan:
The combination of a sensationalist bent and a lack of basic knowledge by its writers…is rendering it unreliable often enough to constitute a real threat to the public understanding of science.
And did you notice the use of the number 13?
In the discussion surrounding my popular post Religion vs. Gender Equality & Feminism, there was a reference to religion and environmentalism. As if on cue, the Pope has now said:
“Is it not true that inconsiderate use of creation begins where God is marginalized or also where his existence is denied? If the human creature’s relationship with the Creator weakens, matter is reduced to egoistic possession, man becomes the ‘final authority,’ and the objective of existence is reduced to a feverish race to possess the most possible.”
Atheists everywhere are up in arms with the headline “Pope blames atheists for global warming” all over the web. Read this post for a particularly incisive response. When the President of the National Secular Society labeled the Pope’s comments as inflated and self-serving, moderate voices asked whether this is a surprise and should be news in the first place.
If you wish, you can explore www.environmentalism.com and be surprised. I consider the final word on this topic to be of Michael Crichton, who argues that we need to take environmentalism out of the clutches of religion and bring it back to the scientific discipline:
“We know from history that religions tend to kill people, and environmentalism has already killed somewhere between 10-30 million people since the 1970s.”
You read it right. There is no typo in the above quote.
Every time we read about nature and wildlife in India, it is almost always depressing news about how elephants are being tortured and how the tiger population is dwindling to extinction. However, there has been a lot of good news too, which is mostly ignored. It is extremely unusual for new biological species to be discovered, and the number of new discoveries from India in recent years is simply astounding. Here is a sampling of some of these treasures.
Peacock Blue Tarantula
Outlook reports: The spectacular Peacock Tarantula was named on the basis of a single specimen obtained at Gooty (Andhra Pradesh) railway station’s timber yard in 1899. Naturalists doggedly searched the area for the spider. About 102 years later, some distance from Gooty, they found the most beautiful spider in the world in a totally degraded forest. Within five hours. While this re-discovery went totally unnoticed in India, it set the network of European and American animal dealers buzzing. Within a year 12 specimens of the tarantula were smuggled out of the country and the babies hit the pet trade the following year. In 2005 when I visited an exotic pet expo in the United States each baby was worth US $350, down from $1,000 in 2003.
Andaman Lizard
Yet another effortless discovery happened at the field station of the Andaman and Nicobar Islands Environmental Team in 2004. Lizard researcher Shreyas Krishnan heard a splash in the rapidly growing pond outside. A lizard it was, and one that neither he nor any of the numerous visiting herpetologists had ever seen before. Shreyas had discovered not only a species, but a whole new genus.
Large-Billed Reed Warbler
The Large-billed Reed-warbler is the world’s least known bird. A single bird was collected in the Sutlej Valley, Himachal Pradesh, India, in 1867, but many had questioned whether it indeed represented a true species. A live specimen was then trapped by Philip D. Round in March 2006 in Thailand and it was confirmed to be a new species.
This bird was sighted at Narendrapur, 10 kms from Kolkata on 1st April 2007.
Bugun Liocichla
In September 2006, the National Geographic reported that an amateur bird-watcher who was an astronomer, found the first new bird species to be discovered in India in over 50 years.
No specimen was taken, because "we thought the bird was just too rare for one to be killed," said Ramana Athreya, the bird’s discoverer, in a statement.
Because the Bugun liocichla is so distinctive and doesn’t appear to fear humans, experts say it must be extremely rare or it would have been discovered before now.
Smallest Indian Land Vertebrate
A few days back, Science Daily reported that India’s smallest land vertebrate, a 10-millimeter frog, has been discovered from the Western Ghats of Kerala by Delhi University Systematics Biologist, S D Biju and his colleagues.
Adult males are barely 10 mm in length. In this photograph, the frog is placed on an Indian 5 rupee coin. Biju gave a new name for the frog, Nyctibatrachus minimus.
New Frog Family
In 2003, Biju had discovered a bright purple, bloated frog in the Western Ghats that was so unique it merited the establishment of not only a new species but also a new family.
This creature evolved during the heyday of the dinosaurs. Dubbed Nasikabatrachus sahyadrensis, it evolved about 130 million years ago, prior to the break up of India and the Seychelles around 65 million years ago.
Arunachal Macaque
As a well populated country of over a billion people, India seems an unlikely place to discover a new primate species. The last time in the world that researchers spotted a new macaque was in the Mentawai islands of Indonesia in 1903.
Hence the surprise discovery of this new monkey species made headlines over the world.
Macaca Munzala, as it was named, grabbed the attention of ecologists as it is one of the highest-dwelling primates in the world.
Limbless Lizard
In May this year, an Indian zoologist found a new species of limbless lizard in a forested area in Orissa.
"Preliminary scientific study reveals that the lizard belongs to the genus Sepsophis," said Sushil Kumar Dutta, who led a team of researchers from "Vasundhra," a non-governmental organization, and the North Orissa University.
While modern snakes and lizards are derived from a common evolutionary ancestor, they belong today to two entirely separate groups of animals, or orders.
Indian Egg-Eating Snake
Outlook reports: Another herpetological breakthrough was the rediscovery of the Indian Egg-Eating Snake, a toothless specialist. It was first found in Rangpur (now in Bangladesh) in 1863. Subsequently it disappeared altogether. In 2003, a specimen of the long lost Indian Egg-Eater turned up in Maharashtra.
Here’s the Wikipedia entry for the Elachistodon westermanni, as it is called.
New Dinosaur Species
Not a living species, but worthy of inclusion in this collection, a new species of dinosaur was discovered in 2003 along the Narmada river in Gujarat.
It has been named Rajasaurus narmadensis, or the regal reptile from Narmada. The age of the bones meant that Rajasaurus was a contemporary of Tyrannosaurus rex and therefore one of the last species to live before the dinosaurs were wiped out.
(Credits: This was inspired by the Outlook article referenced in the post, from which I decided to do further research. Photographs are from the articles linked to from the post)
On the day when a court in Jodhpur sentenced Bollywood actor Salman Khan to five years imprisonment, scientists at the Hyderabad-based Laboratory for the Conservation of Endangered Species (LaCONES) celebrated a unique achievement. They had successfully given birth to a black buck antelope, named ‘Blacky’, using Artificial Insemination. For Hyderabad, which has been in the news for all the wrong reasons lately, this is at least a different kind of news – especially since the black buck is the State animal of Andhra Pradesh.
Artificial Insemination
This is reportedly the world’s first fawn conceived through a non-surgical, intra-vaginal insemination procedure, for which the scientists had to collect 85 ejaculations from five males and insert them in three female blackbucks, out of which one successfully gave birth to Blacky. The Government gave permission to experiment with blackbucks only after LaCONES had successfully produced ‘Spotty’ – a common spotted deer, in March of last year.
While LaCONES is working on technology to help save endangered species, it is interesting to note that it was itself facing a threat of extinction in 2002. President Abdul Kalam finally inaugurated it (PDF) in Feb 2007.
Next on the radar are endangered species like vultures and Nicobar pigeons. (Why are such initiatives important? For e.g., vultures in India have declined by up to 95% in the recent past. Carcasses of dead animals are now eaten by rats or dogs, rather than vultures, that helps spread rabies. India has one of the world’s highest rate of rabies). The scientists are ambitious to talk of even using the technique to address the catastrophic decline of Indian tigers.
Cloning
Scientists at LacoNES are working on India’s first reproductive cloning experiment using rabbits. They have developed cloned embryos so far. Transplanting them successfully into surrogate mothers is the next step. We may soon have the first Indian dolly from this lab!
Was it pure coincidence that it was the Centre for Cellular and Molecular Biology (CCMB), the institute that owns LaCONES, whose DNA analysis was used as evidence in Salman Khan’s case?
Photo Credit: Outlook Magazine
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A week back, the Government of India issued a press release that referenced the Golden Triangle Partnership Scheme. Now, the Economist has a more elaborate article on it:
India, too, has a long tradition of herbal medicine, and its government is keen that this tradition should be brought into the mainstream, to the profit of the country’s burgeoning drug industry. To that end, it is spending about $40m on what is known as the Golden Triangle Partnership, to assess the country’s herbs scientifically, and select those suitable for serious investigation.
Most Indian herbal remedies are based on the Ayurvedic system of medicine, although Tamil-based Siddha and Unani, which has Persian roots, are also used extensively. Proving their worth is a daunting task. There are 80,000 Ayurvedic treatments alone, involving the products of some 3,000 plants. More than 7,000 firms make herbal compounds for medical use. Establishing the active ingredients and exactly how they work would thus take some time.
The Golden Triangle Partnership is not, however, looking for new molecules to turn into chemically pure drugs. Instead, it proposes to make herbal medicine itself more scientific by conducting clinical trials of traditional treatments for more than 20 medical conditions. These include arthritis, diabetes, irritable bowel syndrome, malaria and psoriasis.
To do that means getting the country’s drug companies to take part in what is, for them, the non-traditional activity of traditional medicine. One of these firms, Ranbaxy, has already opened a small research and development division for herbal medicine and is beginning to look at remedies for conditions such as diabetes.
What are the exact means and objectives of this effort?
To encourage such developments the project’s partners are trying to identify how the potency of herbs varies with exposure to the sun, the type of soil in which they are grown, and when and how they are harvested. With that information, they can define standard doses and clinical trials can begin. If the trials succeed, the treatments that result should be patentable—unlike the traditional formulations.
A bit sarcastically, the article is titled “Growing wiser“. Yes, on the whole, I think the objective is great. The more we are able to make alternative product development a scientific process, the better. At present, anyone can package anything and sell it as an Ayurvedic product, with no tests or checks. The Government promised Rs. 5 lakhs (INR 500,000) to all ayurvedic firms encouraging them to go in for Good Manufacturing Practices (GMP) certification, but I’m not sure how much of it went to the bureaucrats for bribes in getting the certification.
While this is all good, I’m not sure about the patentability of Homeopathic treatments. How can a therapy that increases the potency of a substance by diluting it further with water, and thus contradicts the laws of chemistry and physics, get patents? Will it convince the skeptics?
I’m not against alternative medicine. In fact, I would love it to be more scientific and less misused. It may be a huge economic opportunity for India if we’re able to patent and export alternative medicinal remedies that have gained scientific acceptability. I’m just not too optimistic about it yet.
Image Credit: UK Skeptics
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I learnt this from an army lieutenant, and didn’t find any reference to it on the Internet, so am writing about it. I have often met people who discuss about how we take things for granted, and never realize their value unless we miss them. Typical examples include electricity and water. But what about color?
Indian army soldiers, who’re deployed on Siachen, have numerous newspaper, magazine, and such stuff posted on their cabin walls. They’re supposedly mad about any such clips, and bring them along whenever they’re back to Siachen from the mainland. Their walls are littered with photographs, newspaper clippings, magazine cutouts – anything that is colored.
Why? Because the whole world in Siachen is only the white of the snow. They don’t get to see color at all.
Do we ever even think about such things?
Technorati Tags: siachen, color, india
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An important scientific finding was reported a couple of weeks back, that has very important implications.
Palaeontologists and molecular biologists have disagreed with each other regarding the origins of modern Homo sapiens. Since 1987, molecular biologists have believed, using DNA evidence, that Homo sapiens evolved in Africa and then spread out to other parts of the world. Paleontologists, on the other hand, said that modern humans evolved separately in different regions of the world, from the earlier Homo erectus.
Until now.
In a recent study in Nature, Andrea Manica of the University of Cambridge and his colleagues show that the skull data and the genetic data actually agree with each other. They studied 4,666 male skulls and 1,579 female ones, drawn from 105 groups of people from all six inhabited continents, and showed that they varied in the same way as human genetic data do.
The Economist reports:
One of the main lines of evidence for the “Out of Africa” hypothesis, as it is usually known, is that the most genetically varied human populations are in that continent—particularly in the south and east of it. The farther you go from Africa, the less genetic variety there is, because in a rapidly dispersing population genetic variety is lost faster by random failures to breed than it is replenished by evolution.
If the “Out of Africa” hypothesis is right, that decreasing variability should be reflected in skull shape—since this is ultimately under genetic control. As far as skulls are concerned, there is one confounding variable: climate. Things such as nostril size vary with temperature and humidity in ways that suggest evolution is at work. Since Dr Manica was looking for effects other than those produced by natural selection, those things had to be eliminated. Which he did.
Using what was left, he estimated the amount of diversity in groups of skulls from different parts of the world using a statistical technique called multiple-regression analysis, and compared the resulting map with a similar map of genetic diversity. The two matched perfectly. There was no room for the influence of local populations of Homo erectus.
Also see National Geographic’s report here. Even if there is one notable skeptic of the study, I find this reassuring for two reasons:
First, this is the beauty of science at work. We have two scientific disciplines contradicting each other. And when sufficient data from both streams is analyzed and known influencing factors accounted for, the data from the two independent streams matches almost miraculously. This is the true scientific method at work.
Second, and more important, this finding effectively kills the concept of “race”. We have all come from the same place, evolved from the same species. There are no separate origins, and hence no different races of people. Race is a product of the imagination of Homo sapiens, not a natural occurrence.
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In September 2000, a military laboratory in the garrison town of Tezpur in northeastern India announced that it had identified the hottest chili in the world. After some disputing claims and questions of authenticity, it was scientifically proven by New Mexico State University’s Chile Pepper Institute, where spiciness is a religion. The Guinness Book of World Records also heralded the discovery.
The Hottest Chili
The chili is known as “Bhut Jolokia” (translated as “Ghost Chili”), or “Naga Jolakia”, after the Naga warriors from Nagaland in northeastern India. The hotness of chili is measured using the Scoville scale. For a list of Scoville ratings of different chilies and sauces, see this. For a quick summary: Classic Tabasco sauce ranges from 2,500 to 5,000 Scoville units. Your basic jalapeno pepper measures anywhere from 2,500 to 8,000. The previous record holder, the Red Savina habanero, was tested at up to 580,000 Scovilles.
The Bhut Jolokia crushed those contenders, testing at 1,001,304 Scoville units.
Eating Bhut Jolokia
The news is few months old, but was revived recently by an Associated Press reporter who dared to eat one full bhut jolokia (read the full experience, it would be unjust to read just a snippet). Incidentally, another news broke out last month of a 17-month old toddler, who happily devours a handful of them at a time, without batting an eyelid – since he also smears his eyes with them. Fortunately, his illiterate parents do not wish to send him to make world records, unlike some other highly literate ones.
While all this has been making the news rounds, my interest in this story came from multiple angles.
North-Eastern Region of India
For a change, there is some good news from and for North-Eastern India. For complex reasons, the people from this region are not treated at par with others in the rest of India. The world record status has given them a sense of pride.
The economy of the region is precarious, with tea-making on a steady decline. There are some hopes that the exports of this hot chili will help – not in a revolutionary way, but any help is good news for now.
Globalization
What? Aren’t we talking about chilies? Yes, we are. Remember, LIFE Magazine included the discovery of the potato in the 100 Most Important Events of the past 1000 Years. Similarly, some interesting facts from a nice article in Time:
- The remarkable spread of the chili is a piquant chapter in the story of globalization. Few other foods have been taken up by so many people in so many places so quickly.
- In terms of keeping billions of people fed, the chili can hardly compare to rice or corn or even potatoes, of course. But by adding spice to such staples, by making even the poorest food rich in flavor, the chili has become one of the most important ingredients in the world. For hundreds of millions of poor, chilies are the one luxury they can afford every day, a small burst of flavor in the slums of Asia or the parched grazing land of West Africa.
- Chilies are native to South America, where people have been cultivating and trading them for at least 6,000 years. (Six thousand years?!)
- In 2001 UK’s then Foreign Minister Robin Cook called chicken tikka masala the country’s national dish.
- In the US, Mexican food is ever more popular; salsas and chili sauces have outsold tomato-based ketchup since the early 1990s.
Science
Why do we like chili?
The heat in chilies turn on the pain receptors in our mouth and on our tongue. It’s essentially a defense mechanism designed to stop (us) animals devouring the (chili) pod. Our body reacts as if it’s a poison.
At a very low level, our body’s nervous system releases endorphins, a type of mild natural opiate, to ease the sting. It’s that mix of pleasure and pain that makes eating chilies such a wonderful experience.
No, eating chilies cannot become an addiction. And if you still have questions, here’s a Chili FAQ.
Photo Credits: Manish Swarup, AP
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After the Christian fundamentalists’ ape-like antics during the Hindu priest’s opening the Senate morning session, comes a more worrisome portent.
The Denver Post reports that evolutionary biologists and university professors teaching evolution have been receiving death threats from a Christian fundamentalist.
At Panda’s Thumb (an excellent scientific resource for defending the theory of evolution), you can read excerpts of threatening emails received by the professors.
Observe how this contrasts with Islamic fundamentalist terrorism:
- Terrorism strikes the general public; these threats are against specific distinguished men of learning and science
- Terrorism is organized, inspired by a fanatical leader; this is an individual fanatic, inspired by organized religion
Evolution says that in the long term, the fittest species survive. Will they, in this case?
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An Unquiet Mind by Mahendra Palsule is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License.
