Thursday, December 27, 2007

When A Forest Is Not a Forest

A dense growth of trees and underbrush covering a large area - The American Heritage Science Dictionary

A large tract of land covered with trees and underbrush - Unabridged (v 1.1)

A large area covered with trees and undergrowth - Oxford dictionary

Judging by these definitions could one call the area shown in below image as a forest?

If the Union Ministry of Environment and Forests (MoEF) has its way, then this dense growth of trees and underbrush (Law College land, Pune city) cannot be called a forest and can be exploited by commercial interests without permission from MoEF. The reason is an attempt to define forests in a way that excludes the common sense definitions of forest, three of which I quoted above. According to the new proposed definition, only those areas notified by the government as forests in any Act or recorded in any government documents as forests can be considered a forest. Other dense growths of trees and underbrush not under government control need not apply although the Supreme court has allowed the common sense definition to be considered irrespective of ownership. Only the Indian bureaucracy can come up with such an absurdity. Consider the situation in the image below.

Here the entire area in the image (reserved hills of Pune city) is a notified forest regardless of whether it is actually covered with trees or is barren. I have no problems with this. Afforestation can rejuvenate barren lands. With global warming threatening India, such large scale afforestation programs on barren forest land can contribute in mitigating climate change in many ways. So then why not protect already dense growths of trees which happen not to be official forests? If these lands lose protection as they will if this perverse definition is adopted, they will no doubt be stripped of their green cover in no time. According to the Forest Survey of India, around 2.5% of the total land area of India is covered by Trees outside Forests, i.e. woodlands, sacred groves, and other clumps of trees not officially under government control. This comes to around 80,000 sq km, which is an awful lot of greenery with no potential protection from the government.

Governments like blanket rules. So much easier to implement than to let scientists examine case by case whether an area is ecologically sensitive and should be protected regardless of whether it is an official forest or not. Doing that would be giving Indian scientists too much power. Never! Inch by inch, Act by Act, definition by definition the Indian government is abdicating its responsibility to conserve and manage India's forests and biodiversity. Our basic philosophy of forest management has not changed since the days of the British raj. They looked upon Indian forests as a resource to be exploited. Forest management working plans were written with this in mind. The focus has been and still is on timber and mono-culture plantations and not on conservation and biodiversity. Successive Indian governments have been no more enlightened in their thoughts and actions. Do you think the timber and mining industry has any say in the matter of this new "definition". These are worrying times for the environmental health of our country.

Wednesday, December 19, 2007

The End of Darwinian Evolution?

It’s hard to make predictions, especially about the future- American baseball player Yogi Berra, or was it Mark Twain who made this comment? Either way, it’s hard to disagree. Maybe that’s why I chose to study geology. So much easier to figure out what happened in the past! Darwin’s Last Gasp was the provocative title of an editorial in the Times of India a few days ago. Mukul Sharma writes:

With globalization in progress the different races are no longer going to be evolving away from each other. Unlike what happened earlier when humans dispersed to separate regions and developed unique gene pools that made them less alike, the trend now is being reversed with a tendency of merging into a single mixed humanity.

The other reason why Darwinian evolution may finally have to give up on its mechanisms is because natural selection is about to be bypassed altogether by genetic manipulation technology. Ultimately - say in about another 50 years or so - artificial selection using genetic engineering techniques will make evolution forever irrelevant, at least as far as our species is concerned.

The research that prompted this article suggested that human adaptive evolution fueled by the advent of agriculture and a population explosion has accelerated over the last ten thousand years or so. That may well be so says Mukul Sharma, but not anymore. Take his first assertion. Humans are migrating in large numbers and mixing up the gene pool and that’s the end of Darwinian evolution for humans. Is it the end of evolution or the end of evolution through natural selection commonly known as Darwinian evolution and what’s the difference between the two? Most people take evolution to mean adaptive evolution through natural selection i.e. a change over generations to a better adapted state. It is this kind of evolution that the research on accelerated evolution concentrated on. Biologists have a more inclusive definition which is changes in the frequency of alleles in a population from one generation to the next. Evolution is a process that causes heritable changes in the properties of populations over generations. Individuals don’t evolve. Modern population migrations cause great demographic changes especially given the declining fertility rates in many western nations. So, say with Indians immigrating to England in large numbers, northern European genes will decline in frequency relative to south Asian ones. The genetic structure of the population will change over generations i.e. it will evolve. Even without migration, populations can evolve without natural selection taking place. This is by a process known as random genetic drift. Biologists acknowledge that the vast majority of mutations may not be advantageous but neutral or almost neutral, meaning they do not affect reproductive fitness. Natural selection is blind to such neutral changes and the frequency of such genes can fluctuation randomly over generations until just by chance one allele completely replaces the alternate version i.e. the mutation becomes fixed in the population. So mixing of populations won’t stop humans from evolving even in the absence of natural selection. And it certainly has not stopped acting in the poorer countries where enormous differences in mortality rates still exert strong directional selection pressures for change.

The notion that natural selection has stopped working on human populations is mainly related to advances in medical technology and the overall improvements in standards of living. This undoubtedly has led to a relaxation of mortality selection, the most familiar form of natural selection. People who used to die before reproducing due to disease and poor health linked to bad genes now don’t die in the same numbers. Such faulty genes therefore don’t get eliminated from the gene pool. For example the frequency of genetically determined red-green color blindness is about 5-10% higher in western urban males than in traditional hunter gatherer or non-industrialized farming societies living today. This is an indication that selection has been relaxed in western populations. But natural selection works on humans (and other organisms) in several other ways at various stages of our life cycle, and these have not been affected by medical advances so far. These other forms of natural selection are 1) selection at the gamete stage, 2) selection at the embryo stage and 3) sexual selection at the reproductive stage. There is some evidence that selection can weed out defective sperm mostly based on the extreme gymnastic contortions sperm cell have to perform within the female reproductive system. It is possible this is selection for the quality of sperm. And there is also some evidence that there are more mutations in early-stage cells than in the final fertilized egg, suggesting that mutations are being weeded in the female gamete as well. Out of several hundreds of million sperm cells, only a few taste success, and out of 5-7 million oocycts only a few hundred or so become eggs, so selection most probably is playing a role eliminating faulty cells at this stage. How would selection work at an embryonic stage? About 60% of our genes are expressed at this stage, ones involved in basic cellular physiological functions and those involved in development. Again bad genes which are expressed at an early stage in the embryo will cause faulty development of the embryo and likely death. The estimate is that about 80% of conceptions that are lost before birth are likely the result of natural selection. Finally there is sexual selection. If individuals have the ability to screen potential mates for bad genes, then such choice may lead to elimination of these genes as bearers of these genes remain without a partner. Do humans have such abilities? As usual Darwin got there first by referring to a French and Scottish study which showed that single men had twice the natural death rate as married men at years 20 to 30. Similar patterns exist in Asia, Europe and America and being single is apparently one the biggest risk factors for human beings. This may off course mean that marriage improves health, but the other explanation that health improves your chances of marriage is also highly probable. It is likely we make conscious choices or get unconsciously influenced regarding the genetic quality of potential mates.These forms of natural selection will continue to affect us humans even during demographic changes, population mixing and the current medical technologies.

Mukul Sharma’s second assertion is that “artificial selection using genetic engineering techniques will make evolution forever irrelevant, at least as far as our species is concerned”. In making this assertion he misses the altogether important point that artificial selection is also a mechanism of Darwinian evolution and contrary to making evolution irrelevant it has the potential of transforming it into an even more potent force. Darwin himself began his one long argument using artificial selection carried out by pigeon breeders and domestication of cattle to ram home the point that populations can change very rapidly through such means. Darwin thought of natural selection as acting through the differential survival and reproduction of individuals. Artificial selection if society goes in for it will change human populations not by eliminating individuals or banning some from reproducing but by preferential representation of certain genes by making changes at the early gamete stage of the life cycle. Initially such selection will focus on disease genes but there could be other types of changes possible. Recently I read an article about the super rich in Newsweek magazine. The tendency is to form exclusive clubs and networks and isolate oneself socially and culturally from the rest of the plebeian population. If this trend of cultural isolation continues then how long until certain groups opt for genetic isolation through artificial selection? Will we see evolution of enhanced features or abilities in certain groups? All this is speculation. Most predictions about the future including the ones I am making will be wrong. Humans may decide to regulate the use of genetic engineering for certain medical applications only, or it may go the other way, where cultures may decide to isolate themselves from other groups and go in for strong directional evolution in many traits through artificial means. An as yet undiscovered pathogen may evolve to which our medical knowledge have no answer to, restoring strong mortality selection.

Is there a possibility of even more fundamental changes to our genome? Evolutionary biologist Mark Ridley has speculated that our current level of biological complexity is limited by mutational load mainly through copying errors when our DNA gets replicated. Nearly 2 billion years ago repair enzymes evolved that reduced copying errors from about 1 in 10,000 to about 1 in 10,000 million. This enabled an increase in biological complexity. There is a hint that our mutation rates are very high. For humans it takes on average about five estrus cycles for a fertile male and a fertile female to produce a baby. This indicates, although is not proof, that the four unsuccessful attempts are related to genetic errors mostly copying errors. Could we fashion an even more efficient repair enzyme, one that reduces the error rate even further multi-fold fueling evolution of humans towards even greater complexity? The only certainty is change. I would wager (to be settled by my potential descendants :-) ) that 5,000 years from now our descendants will be as different from us as we are from our ancestors who lived 10-15,000 years ago.

Monday, December 17, 2007

More Chest Beating About Climate Change

Finally what has been and has not been achieved at the recently concluded climate change conference in Bali? Going by the infantile jingoistic Indian media, this was the place where India stepped up to the plate and saved the world from a global meltdown perhaps literally. The Times of India has a lot of space devoted to how India lead by knight in shining armor Kapil Sibal forced the U.S to change its position and cornered Europe into supporting the Indian position.

Some excerpts from the Times of India:

"India beams as climate deal clinched"

"India led by science and technology minister
Kapil Sibal, clinched an almost impossible deal at the UN conference on climate change in Bali"

"At this point,
Sibal intervened to put forth the Indian position yet again. It's unusual at such a forum and the aggressiveness of the minister shocked many.....America had been cornered"

" It was a hard-fought win, but we have secured India's position....."

Infantile stuff, more like what you see in England's gutter press after that rare football victory against Germany. So what is this deal that the Indian media is crowing about?

Apparently now further talks will take place on two tracks, one comprising those countries who have agreed to mandatory emission reductions, essentially building on the talks of the Kyoto protocol, and the second track comprising those countries who have not agreed to emission reductions. This two track formula is important as it leaves the door open for countries to join mandatory reductions. Agreeing to this formula, prevented a total collapse of talks. This means that negotiations would now continue beyond the Bush administration and hopefully will deal with a new, more cooperative U.S. administration.

Reading plainly it means that no binding agreement was reached on any issue! Its like that old joke about the four procrastinators who after a long meeting agree unanimously to meet again.

What does this mean for India?

No binding targets in reducing emissions

Vague promises to transfer subsidized new clean technology to India and other developing nations

But India has agreed to seek ways to make "measurable, reportable and verifiable emission cuts"

No money to upkeep forests using clean development mechanisms such as carbon credits.

Doesn't sound like too much of a victory to me. Sunita Narain the director of Centre for Science and Environment in Delhi in an interview with CNN-IBN was also pessimistic stating that technology transfer is an old issue being rehashed at this conference. So far 15 years of talks and not a dollar has been transferred. We still have to at some point start making those emission cuts. And that bit about no money to upkeep forests sounds very foreboding.

Some thoughts on human behavior. Can we really think that U.S negotiators are that stupid and ill prepared or even allowed to "change their minds" at the last minute? The clouds of discontent have been brewing for a long time internationally and lately within the U.S. The Bush administration is in its last year. Does one really think that U.S negotiators were oblivious to all this and came to the conference really believing that they could swing everything in their favor? I suspect they were ready to support the consensus all along but held on to see how much their luck lasts. Sure some pressure works, but this pressure has been building for a long time both internally and most notably the threat from EU to boycott a U.S sponsored meeting on climate change in Hawaii. A country which declares war against the wishes of the entire world is not going to be bothered by a few boos and shouts. Negotiators do have some latitude but it is naive to believe that they will be pressured at the last minute into taking a position that is not allowed by the brief given to them. But the Indian media will have us believe that Kapil Sibal changed all this. I don't mean to disparage the efforts of Mr. Sibal. By all accounts he did a stellar job. But a little more balanced reporting please.

Finally and more importantly than the antics at Bali, is India going to base future emissions policy on technology transfer promises, something that still needs painful long negotiations to achieve? Would that mean a neglectful attitude from the government towards alternative renewable energy? Does that mean a surge in coal plants to generate electricity on the premise that clean technology is on its way but may not happen at all or for some time? Does that mean more tracts of our forests to be given to commercial exploitation on the pretext that we are not receiving funds to protect them? We should not deceive ourselves into thinking that Bali was a great victory. If anything it might lull us into a complacency that might prove disastrous.

Wednesday, December 12, 2007

Radioactivity and India's Water Resources

From EurekAlert Earth Sciences Feed:

"Ice cores drilled last year from the summit of a Himalayan ice field lack the distinctive radioactive signals that mark virtually every other ice core retrieved worldwide. That missing radioactivity, originating as fallout from atmospheric nuclear tests during the 1950s and 1960s, routinely provides researchers with a benchmark against which they can gauge how much new ice has accumulated on a glacier or ice field."

What that means is that Himalayan ice fields are melting away rapidly, so rapidly that the characteristic signal of the 1950's atomic tests has been literally washed away with the melting ice. Much of the Indo-Gangetic plains depends upon glacial meltwater as a source of freshwater that feeds the massive north Indian rivers. If that supply dwindles then water shortages loom ahead. How big is India's water problem. A recent report released by the planning commission has this assessment:

“Currently, total water use (including ground water) is 634 BCM (billion cubic metres), of which 83% is for irrigation. The demand for water is projected to grow to 813 BCM by 2025 and 1447 BCM by 2050, against utilisable quantum of 1123 BCM – 690 BCM from surface water and 433 BCM from ground water. Clearly, the overall demand will outstrip availability in another 35 to 40 years, while ground water in particular will come under even greater pressure in the intervening years.”

So we are headed for a shortfall. The planning commission report provides several recommendations for narrowing the deficit including, artificial recharge of groundwater, extra storage of surface water, and improved efficiency of groundwater use by changes in groundwater law. The troubling part of the report is that it makes no mention of climate change and what effects melting glaciers, erratic monsoons, increase in frequency of droughts, all the expected fall outs of global warming may have on water availability. Has the utilizable quantum of 1123 BCM – 690 BCM from surface water and 433 BCM from ground water been calculated taking into account the expected fall in supply due to shrinking glaciers and erratic monsoons? If the pattern of rainfall changes from a slow steady fall to infrequent high intensity rains, how will that affect groundwater recharge? With glacier shrinking, the surface water availability will increase in the short term but decrease over the medium to long term. Has that been factored in? If rainfall pattern changes over large areas to shorter high intensity pattern, how should we best utilize the increased surface water flows? I did not read the entire report, but did read the conclusions and also did a word search for the terms melting / shrinking glaciers, global warming, climate change and came up with zilch. Sounds like the report assumes unchanging conditions that control water availability.

There already have been accusations that the government has massively overestimated the available water today. Though these new estimates have also been criticized (water debate), any planning commission report which may influence water use policy that does not take into account the changing water availability scenario due to climate change is cause for major concern.

Friday, December 7, 2007

Pleistocene Stone Tools From Near Pune

Some exciting news about 60 km from where I live in Pune. Archaeologists from Deccan College, Pune have discovered stone tools at Morgaon. These tools of Early to Middle Pleistocene age have been dated to about 800,000 years based on magneto-stratigraphic dating of volcanic ash deposits associated with these tools. These tools belong to the lower Paleolithic Acheulean industry, a style of tool making where both surfaces of the tools are flaked to produce symmetrical hand axes of distinctive pear and disc shapes.

Image to the left shows the Acheulean tools from Morgaon (source Times of India). The age of these tools indicate that these tools were made by representatives of the now extinct species Homo erectus. This is an inference based on our overall understanding of human evolution and not due to the preservation of Homo erectus remains alongside the stone tools at this site. In India remains of Homo erectus are extremely rare. In fact, only one unequivocal fossil from the Narmada basin has been discovered. There could be many reasons for this such as the low preservation potential of terrestrial species to begin with or these fossils are preserved in very specialized geological contexts, or an interesting suggestion by anthropologist Parth R. Chauhan that hominin fossils many not be recognized as such since most such work in India is carried out by geologists or archaeologists and not physical anthropologists who are better trained to recognize hominin fossils. There is however quite a rich archaeological record of stone tools in India. The oldest unequivocal evidence is from Isampur in Karnataka, where again Acheulean style tools of around 1.2 millions years ago have been discovered. The Paleolithic tool finds in India have been nicely summarized here. Whatever the reasons for the lack of fossils, this presents a good example of the sometimes infuriating situation a field of study can find itself in. An abundance of one type of evidence and a virtual lack of a complimentary type. In this case, a rich collection of tools, but no signs of its maker. The lack of hominin fossils has certainly hampered studies of human evolution in the south Asian context. Tools indicate an early presence of the genus Homo in India (at least 1.2 million years ago), but we know little of the subsequent evolution of this species in India in terms of morphological changes interpreted in the context of changing climates and environments. Did Homo erectus evolve into a more modern form, know as the archaic modern human morphology as has been observed in Europe and Africa? Can the changing tool technology through the Indian Paleolithic record be interpreted in the context of such evolutionary changes? There is a potential here to make important contributions to the Multi-Regional vs Out-of-Africa debate on modern human origins, but at present that potential is unexploited.

In any case this is an exciting and important discovery. It supports our overall understanding of the evolution and migration of populations of Homo erectus which is considered the first member of the human family to have migrated out of Africa. The earliest evidence of this genus is from Africa dated to nearly 2 million years ago. The earliest evidence outside Africa is from Dmanisi in Georgia (central Asia) dated to about 1.7 million years ago. The Isampur tools indicate that populations of Homo erectus migrated into India at least 1.2 million years ago maybe even earlier. This latest discovery adds to our slowly increasing knowledge of the distribution of Homo erectus populations in India and the variation in stone tool technology prevalent at that time. It is another piece in an accumulating database, but by no means an earth-shattering find.

The Indian media should view this discovery as such and not launch into breathless, nationalistic "we got here first" or " we have the oldest stone tool technology" interpretations. There are hints this is already happening. From the front page of Times of India:

"The evidence - mostly Acheulean artefacts and tools made of basalt stone - comes relatively close to that of the oldest evidence of such tools found in Africa and dating 14 lakh years". How is a gap of more than half a million years close? And don't forget Isampur in Karnataka, which has already pushed back the date of Acheulean stone tools in India to 1.2 million years.

Monday, December 3, 2007

Bottoms Up to Prevent Climate Change

The Times of India science reporter Narayani Ganesh has this prescription for combating climate change:

What if we shifted the entire responsibility on to the shoulders of one well-known person, say someone like R K Pachauri, who heads The Energy Research Institute and the Nobel prize-wining Intergovernmental Panel on Climate Change? He could institute a climate hotline, a blog, office, radio talk-in show, agony uncle column or any other kind of public interface system that would encourage people to respond to, complain of, discuss, give ideas, share experiences and counsel/get counselled on anything related to saving the planet and ourselves from the scourge of global warming. Collection boxes - on the lines of those displayed by organisations like the Red Cross, CRY or PETA - placed at strategic points and monitored carefully could help assuage the guilt of individuals while galvanising fund-raising on a fairly large scale.

Ganesh is frustrated with the government's response to climate change and wants a bottoms up approach whereby eminent scientists will raise awareness by writing columns and funds for research in alternative energy are raised by placing collection boxes. Will this strategy work? I can imagine people responding to columns with plenty of suggestions and advice but will something like this change habits and behavior and genuinely lead to reduction in emissions? Recently the British rock band Radiohead allowed online downloads of their latest album on a voluntary payment basis. Fans could pay as little or as much as they wanted. Nearly two thirds payed nothing and the rest on average less than $3 for an album that cost about $16. If offered a free lunch people grab it with both hands. Radiohead's collection box remained nearly empty. Free lunches abound in India. The government doles out free electricity, subsidizes fuel, water, gas and roads and most people make full use of this largesse and seem not to be racked with guilt. Urban India is consumed by consumerism and a rural population is aspiring for that. We Indians have grown so used to these government handouts that columns and blogs by an over-hyped UN administrator and a few collection boxes are likely to be ignored.

A bottom's up approach, people's participation in minimizing climate change have a feel good quality to it. People appear altruistic and can feel less guilty without actually bearing any significant costs, which is why politicians will likely support such schemes. On the other hand, schemes that will make a real difference in reducing emissions, such as fitting carbon scrubbers to coal plants, charging more for electricity, tolling roads, introducing congestion charges for vehicles in urban centers are highly unpopular and unlikely to be introduced at least for some time. So, India will go through a strange phase whereby politicians will actively encourage useless schemes like scientists writing columns and collection boxes to raise funds for "research", while distancing themselves from regulations that impose limits on emissions. Our emissions and accompanying pollution will keep growing. Unless there is a political will to take tough decisions, a top-down imposition, the 3 Indians out of a 1000 with Internet connections, will have to make do reading Mr. Pachauri's blog on preventing climate change. Bottom's Up for that! :-)

Saturday, December 1, 2007

Earthquakes in South Maharashtra

The Amateur Seismic Centre, Pune website keeps a track of earthquake activity in south Asia. From their list of recent earthquakes these four:

24th November Chandoli region Mag: 4.3 10.57 a.m
24th November Chandoli region Mag : 3.8 11.35 a.m
24th November Chandoli region Mag: 3.8 12.35 p.m
24th November Chandoli region Mag: 2.8 3.53 p.m

Chandoli region lies in southern Maharashtra, which shows elevated levels of seismic activity as seen in figure below.

Source: Amateur Seismic Centre, Pune;

Two distinct clusters are seen in south Maharashtra, one centered along the western ghats in Satara and Kolhapur districts and another to the east around Latur. Both these areas have experienced devastating earthquakes in recent times. In 1967, the Koyna earthquake caused few hundred deaths and structural damage and then in 1993 the Killari earthquake in Latur district caused thousands of deaths and enormous structural damage.

Earthquakes as we learn in school are caused mostly in and around plate boundaries. There rock masses along faults are under frictional stress, i.e. friction between the rock masses on either side of the fault inhibits slip or motion. Plate movements and pore pressures keep adding shear stresses to this rock mass to the extent that the shear stress exceeds a critical value that overcomes the frictional stress. When that happens the rock masses suddenly lurch past each other releasing energy and causing an earthquake. But southern Maharashtra is far away from plate boundaries. What are causing these intra-plate earthquakes? Figure below (source: Sheth 2006) shows zones of structural weakness in south Maharashtra.

The Dharwar trend refers to very ancient zone of crustal weakness, one that formed during orogenic activity and associated rupturing and faulting of the crust in Precambrian times maybe around 2 billion years ago. This zone of weakness is buried in south Maharashtra below the Deccan volcanic pile (brown region) which is around 65 million years old. When plate motions caused India to split from Africa first, then Madagascar and then Seychelles, a process that occurred episodically starting around 170 million years ago and continuing to about 60 million years ago, the tensional forces involved created a series of faults and zones of weakness along the western margin of the Indian continent. Preexisting zones of weakness were more likely to fail during crustal stresses, hence the coincidence of the Dharwar trend with later zones of weakness such as the Koyna fault or rift zone. The Kurduvadi rift also probably coincides with a deep zone of crustal weakness, currently buried under the Deccan traps. The Killari earthquake does not coincide with the Kurduvadi "rift" but may represent a similar zone of crustal weakness further to the east of the Kurduvadi zone. The enhanced seismic activity resulting in the clusters of earthquakes in south Maharashtra occur in the vicinity of these zones of structural weaknesses and need to be understood within the context of the tectonic forces acting presently within these zones.

Beginning around 55 million year ago, the northward moving Indian plate collided with the Asian plate. The northward movement was met by resistance from the Asian continent and so the Indian continent has been under compressional stresses since. At first, the thought that a continental collision in northern India can have an effect on earthquakes in south Maharashtra about 1500 kms away seems absurd, but two types of evidence are available. The first is the nature of the earthquakes themselves. The mechanism of earthquakes are investigated by deriving a fault plane solution, which is an analysis of particle motions in the earth during the passage of the P or longitudinal waves which radiate in all direction from the hypocentre. The hypocentre is the point of origin of the earthquake and coincides with the point in the fault where the first slip of the rock masses occur. So, a fault plane solution tells us the direction of motion of the rocks along the fault. Such as analysis on the Koyna earthquake (Rao et al 1974) and the Killari earthquake (Mandal et al 1997, Gahalaut et al 2002) shows that the slip in case of Koyna is a strike-slip motion (rocks move past each other with very little vertical motion) while in the case of Killari it is a reverse thrust motion (fault block on the hanging wall move up relative to the footwall). Both these types of motions indicate compressive stresses.

The second type of evidence is from the Neogene deformation (23 million years to recent) of the Indian peninsular region around the Deccan traps. In the vicinity of Mahabaleshwar , the Deccan traps are folded into a south plunging regional anticline (Widdowson & Cox 1996). To the north in the Satpura, the high topography of the Pachmari hills has also been interpreted as being due to recent crustal warping and uplift (Venkatakrishnan 1984, 1987). And in the south, crustal arching along the Mangalore -Chennai axis (Subrahmanya, 1994) has resulting in the NE and SE flow of rivers on either side of the arch (see figure below; source Sheth 2006).

All this deformation has been interpreted to be of Neogene age on geomorphological evidence such as youthful steep topography and antecedent drainage (evidence summarized in Sheth 2006) and indicates a compressional stress regime in the Indian peninsula.

The fundamental zones of crustal weakness along which south Maharashtra earthquakes occur originally developed in the Precambrian and are 2-3 billion years old. These zones have been periodically re-activated first as tensional fractures and faults when India broke up from Madagascar and Seychelles and later as strike-slip and reverse faults as manifestations of the compressional stresses periodically building up in the Indian peninsula. There is a very ancient geological control on the Koyna and Killari earthquakes.

Finally a few thoughts on that nagging question: Did the Koyna dam cause the Koyna earthquake in 1967? The popular notion at that time was that the impounding of water in the reservoir imposed stresses on the crust caused the earthquake. But calculations of rock mechanics show that the increase in pore pressures at depth due to loading of even a few hundred metres of water is very small, orders of magnitudes less than required to cause rock failure by itself. However, if the tectonically created stress along faults are already at a critical level, then a small increase in pore pressure due to impounding of water may act as a tipping point causing slip along the fault. This seems to be the case at Koyna. The deep crustal faults appear to be at a critical level of stress and the pattern of seismicity correlates with the loading and unloading cycles of the reservoir (Pandey and Chadha 2003). Under the right circumstances of crustal stresses, dams may induce earthquakes but are not a primary cause. This is of significance in understanding the risk imposed by the various proposed dams in the Himalayas. There faults and tectonic instability is unavoidable. Understanding the stress regime along individual faults in the vicinity of the proposed dams is of critical importance.


Gahalaut V.K, Kalpna and P. S. Raju 2003; Rupture mechanism of the 1993 Killari earthquake, India: constraints from aftershocks and static stress change; Tectonophysics, Volume 369, Issues 1-2, 3 July 2003, Pages 71-78

Mandal P, Manglik A and Singh R.N., 1997; Intraplate stress distribution induced by topography and crustal density heterogeneities beneath the Killari, India, region; JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 102, NO. B6, PAGES 11,719–11,730

Pandey Ajeet P and Chadha R. K. Surface loading and triggered earthquakes in the Koyna–Warna region, western India; Physics of the Earth and Planetary Interiors, Volume 139, Number 3, 31 October 2003 , pp. 207-223(17)

B. S. R. Rao, T. K. S. Prakasa Rao and V. S. Rao 1974; Focal mechanism study of an aftershock in the Koyna region of Maharastra State; Journal Pure and Applied Geophysics

Subrahmanya, K. R., 1994, Post-Gondwana tectonics of peninsular India: Current Science, v. 67, p. 527-530

Venkatakrishnan, R., 1984, Parallel scarp retreat and drainage evolution, Pachmarhi area, Madhya Pradesh, central India: Journal of Geological Society of India, v. 25, p. 401-413

Venkatakrishnan, R., 1987, Correlation of cave levels and planation surfaces in the Pachmarhi area, Madhya Pradesh: A case for base level control: Journal of Geological Society of India, v. 29, p. 240-249

Widdowson, M., and Cox, K. G., 1996, Uplift and erosional history of the Deccan Traps, India: Evidence from laterites and drainage patterns of the Western Ghats and Konkan coast: Earth and Planetary Science Letters, v. 137, p. 57-69

Monday, November 26, 2007

Skin Cells and Ethics

This from the Times of India

"Using deactivated viruses, the scientists managed to transport four key genes into the nucleus of the skin cells which reprogrammed them into cells virtually identical to embryonic stem cells.......Of far greater import, though, is the fact that till today the only way stem cells could be obtained was from embryos which had to be destroyed while they were harvested. The new discovery neatly sidesteps this hassle area and deftly diffuses the huge political firestorm generated over the morality of stem cell research. The method avoids the use of human reproductive materials altogether - no egg, no embryo and no cloning technique at all".

The editorial describes a technique which used a retrovirus to insert four genes into the genome of an adult skin cell which induces the skin cell to be reprogrammed to behave like embryonic stem cells. As far as the researchers could tell the reprogrammed skin cell behaves just like an embryonic stem cell potentially capable of diversifying into different specialized cell types. It then comes to the conclusion that this discovery means a freedom from using embryonic stem cells for research.

TOI has come to a somewhat hasty conclusion. The four genes that the researchers used to reprogram the skin cell genome were first identified through research on embryonic stem cells. The implication is that research on any novel methods to induce adult cells into becoming pluripotent and on developing into specialized cells without developmental defects or the risk of inducing diseases like cancer will rely on a deeper understanding of how embryonic stem cells work naturally. We don't understand this process completely yet and so there is no getting away from embryonic stem cell research at least for the near future.

TOI then claims

"But at least as far as ethical bans and restrictive government funding are concerned, they've been blown away".

Which government's views is TOI talking about? India already funds embryonic stem cell research and therapeutic cloning. Unlike the United States, destruction of embryos for research purposes has not posed any major ethical dilemmas and therapeutic cloning is widely supported by civil society. TOI's concerns don't reflect those of Indian society at large.

Tuesday, November 20, 2007

LiveScience Ignores Basic Genetics


"Researchers find that males can respond quicker than females to sexual selection, resulting in glitzier garbs like the male peacock's tail feather, which outshows any drab peahen". This appeared as an accompaniment to an article discussing research which showed how males with a "simpler" genetic arrangement of XY sex-determining chromosomes may evolve faster than females with a XX arrangement.

I posted on this a couple of days ago commenting:

"Sexual selection though may not be the best example to illustrate the connection between "simple genetic variability" and faster evolution. The reason is the peacock' s tail. This particular study uses the fly Drosophila melanogaster which has an XY (male) / XX (female) sex determination system. But in birds, the system is different. It is the males which are ZZ and females ZW. So, females have a "simple genetic system" yet it is the peacock that evolves the elaborate tail."

The genetic explanation put forth by these researchers to explain why sexual selection commonly occurs via males clearly cannot be extended to birds. Yet LiveScience one of the biggest science portals ignoring basic genetics have a photo of a peacock and a caption clearly meant as an example supporting the researchers hypothesis.

How can science reporting from such a portal become so awry and careless? The original paper clearly made no mention of peacocks or birds, but relied on fruit fly genetics to tease out the results. The mindless extrapolation to birds is a creation of the media. Is this the fault of the science writer, in this case Jeanna Bryner, or was there some editorial oversight insisting that a photo of a splendid peacock's tail will go along nicely with the sexual selection theme?

Its website claims that "It has become a trusted news source and its content is syndicated regularly on major news portals such as Yahoo!, MSNBC, Fox News and AOL." With such major goof ups I am not so sure I can trust them for my daily dose of science news. Readers of Yahoo!, MSNBC, Fox News and AOL also be warned!

Sunday, November 18, 2007

Simple Males Evolve Faster

A press release titled Males being "simple" evolve faster appeared in the Times of India. It covered a research paper Simpler mode of inheritance of transcriptional variation in male Drosophila melanogaster: published in PNAS. The researchers pointed out that since males are hemizygous i.e . have X and Y sex chromosomes they have more additive genetic variation (variation in traits are due to variation in genes without dominance effects or gene interaction effects), while females with XX sex chromosomes exhibit non-additive genetic variation. Since males have only one X chromosome, they may -unlike females - lack the complementary allele on the corresponding sex (Y) chromosome. In females any beneficial mutation may not necessarily be expressed as the effect of that gene may be masked by the complementary allele, meaning the trait is expressed through dominance. This would mean that it will be hard for that particular version of the gene to increase in frequency since you would need two copies of that gene (recessive) for it to be expressed and subjected to natural selection. In contrast, since males have just one copy of many sex-linked genes, any beneficial mutation will be expressed and face selection, leading to a rapid frequency increase of the gene over few generations. Therefore this type of sex-linked genetic variation in males responds more quickly to selection than the one found in females. More response to selection pressure, faster evolution. Biologist David Rand, of Brown University explains it well "This research shows how recessive and dominant traits are important in determining variation in populations. The best way to think of it is males play with one card, but females get to play one and hold one. If males have got a good trait, it's promoted; something bad, it's eliminated. In females you can have a bad card, but a good card can protect it. As a result, females can carry deleterious traits but not express them."

Interesting stuff. The researchers then add that sexual selection usually operates via males due to this difference in the type of genetic variability. Sexual selection leads to dimorphism, i.e. males and females develop divergent morphologies. In many species it is the males that become bigger or develop large antlers or bright ornamentation. The usual explanation for this: Males have more variable reproductive success than females and tend to be more promiscuous. Females due to a large investment in the gamete are more choosy. So males compete for female attention leading to bigger, stronger, showier males over time. The researchers of this study argue that the simpler genetic inheritance system coupled with the more variable reproductive success of males would help males evolve via sexual selection pressures more rapidly.

Sexual selection though may not be the best example to illustrate the connection between "simple genetic variability" and faster evolution. The reason is the peacock' s tail. This particular study uses the fly Drosophila melanogaster which has an XY (male) / XX (female) sex determination system. But in birds, the system is different. It is the males which are ZZ and females ZW. So, females have a "simple genetic system" yet it is the peacock that evolves the elaborate tail. Even in species where sexual selection operates via XY males, does that really mean males are evolving faster than females as the titles of virtually all press releases implied? Sexual selection in males is fueled by female choice, which is a genetically determined trait. Which means that female discrimination for a mate and male ornamentation will evolve in tandem at the same pace.

Wednesday, November 14, 2007

Deccan Volcanism and Mass Extinctions

Science and the scientific method is about eternal vigilance, the need to question even well "proven" theory, to prevent theory from turning into dogma, to make sure that "mainstream thinking" does not fossilize into inertia and a reluctance to question "established facts". This post is about how one such well established theory may turn out to be wrong.

During the Paleozoic period the earth has seen five mass extinctions, great dyings, where a significant proportions of the earth's biota has gone extinct within a short period of time. These five extinctions took place in the Ordovician-Silurian, Late Devonian, Permian-Triassic, Triassic-Jurassic, and Cretaceous-Tertiary. Of these, the Permian-Triassic was the mother of all extinctions in which about 95% of species perished. The most famous however is the Cretaceous-Tertiary event in which about 50% of all species including the non-avian dinosaurs went extinct. The reason for a high public profile has been the dramatic explanation for this extinction and also some very famous victims. In the early 1980's physicist Luis Alvarez, his son geologist Walter Alvarez, and chemists Frank Asaro and Helen Michels discovered a high concentration of iridium in rocks at the Cretaceous-Tertiary boundary (K-T). Since iridium is rare in the earth's crust but is common in asteroids, the scientists suggested that the earth was hit by a large asteroid around 65 million years ago, causing environmental stresses and the late Cretaceous extinction. In 1991 in the Yucatan peninsula in Mexico, a large impact crater named the Chicxulub Crater was discovered. This was dated to around 65 million years. The cause was assumed to be found and it became accepted wisdom that the Cretaceous dying was caused by the Chicxulub impact event. The theory quickly took hold over public imagination. The dinosaur story was retold through countless documentaries, popular articles and books, one of the most famous being T rex and the crater of doom by Walter Alvarez. There was just something satisfying about these fearsome creatures who dominated terrestrial ecosystems for over 150 million years being wiped out suddenly by a weapon of mass destruction from outer space.

But nature is never that simple. The facts as always are messy and the Cretaceous extinction story has gotten messier. Mounting evidence reported in various media outlets in the past few months to week here, here and here suggest that the late Cretaceous extinction was not caused by the Chicxulub impact event but had multiple causes including the gigantic Deccan volcanic eruption at the end of the Cretaceous. I live in the Deccan volcanic province and so this a exciting news to me. All those basalt layers that I see everyday may have played a role in changing earth history. The champion of this hypothesis in palaeontologist Gerta Keller who over the last few years has assembled some impressive evidence in support of her theory. First is the debunking of the conventional wisdom that the Chicxulub impact event caused the mass extinction. Keller and her research team drilled and recovered cores from the impact site in Mexico and from another site along Brazos river in Texas, some 1700 km from the impact site. Their detailed analysis of the sedimentological, geochemical and palaeontological aspects of the cores revealed that a) the impact took place almost 300,000 years before the K-T mass extinction b) the impact is recorded by characteristic sedimentary rocks known as breccia (rock containing pulverized and fragmented pieces) and as layers rich in glass spherules which form by the heat and shock of the impact. An analysis of the biota in the sediment below and above this impact layer shows no evidence of accelerated extinction or stressed ecosystems. It appears that the Chicxulub event had little impact on the earth's biota let alone trigger a mass extinction.

Second, Keller has now managed to come up with evidence tying the Deccan volcanics to this mass extinction and this evidence comes from Rajamundhry, Andhra Pradesh, India. A small digression at this point. Travelling to Rajamundhry is a fantastic experience because of the wide bridge across the Godavari River as you approach Rajamundhry from Hyderabad. I crossed it by train at sunset, and the Godavari is an awesome sight. Image below shows the railway bridge.

Back to volcanics. There always have been suggestions that the Deccan volcanics played a role in the late Cretaceous mass extinctions, but due to large uncertainties in establishing the time span of the main eruptive phase it was difficult to establish a link between the volcanism, environmental stresses and extinction. Recent dating of the Deccan basalts indicate that 80% of the volcanism took place in what is known as C29R magnetic polarity zone, which spans the K-T boundary and the mass extinction event (R means that the earth's magnetic field had reversed polarity at that time).

Figure to the left shows the magnetic stratigraphy of the Deccan basalts. Several thousand feet of basalt were erupted in C29R confirming that the volume of basalt erupting at the very end of the Cretaceous over a short period of time must have been enormous, resulting in the release of carbon dioxide and sulphur dioxide in amounts large enough to alter the earth's climate. In Rajamundhry Keller and her team found layers of sediment sandwiched between two Deccan basalt flows. The lower flow was found to have erupted in C29R magnetic polarity, probably coinciding with the K-T event. The sediment above this flow provides a more direct evidence for this connection between the timing of basalt eruption and extinction. They contain early Tertiary post-extinction foraminifera. This biota marks the initial evolution of the foraminifera after the K-T event indicating that the mass extinction must have taken place during the eruption of the main phase of the Deccan volcanics. In detail, the sediments contained foraminifera fossils of early Danian age, which showed that these sediments were deposited in the earliest Tertiary period, and thus were a window into conditions just after the mass extinction and offered to provide a link between volcanism and environmental stresses. Unlike the sequence of fossils spanning the Chicxulub impact layer in Mexico and Texas, the fossils here at Rajamundhry show evidence of stressed ecosystems. The early post-extinction Danian foramainfera are less diverse, tiny, without any ornamentation and show deformities unlike pre-extinction late Cretaceous (Maastrician) foraminifera which are diverse, larger and ornate. This compares well with foraminifera of Danian age elsewhere, suggesting that the conditions recorded in the intertrappean sediments at Rajamundhry are representative of global post-extinction stress. The biota in these sediments suggest that post-extinction recovery of ecosystems was slow. Volcanism continued into the early Tertiary as indicated by the lava flow overlying these sediments. This flow falls in C29N (N means normal polarity) magnetic polarity and occurred about 280,000 years after the K-T event. This continued volcanism Keller suggests may be the reason why ecosystems took so long to recover from the mass extinction. Another small digression. In the figure above of the magnetic stratigraphy, a large part of C29R is made up of the Wai and Lonavala subgroups and the bulk of the C29N by the Mahabaleshwar formation. These are names which must be familiar to readers from Maharashtra. The basalts comprising these subgroups make up the precipitous western ghat escarpment. So, the next time you are standing at Arthur's Seat in Mahabaleshwar (image below), contemplate on the possibility that you are looking at the volcanic pile which altered the course of evolution.

So this is where things stand today. Did I cover everything? Readers may notice a nagging discrepancy. If the Chicxulub impact occured 300,000 years before the K-T boundary, then what caused the irridium anomaly at the boundary? It is no doubt of extraterrestrial origin and so there must have been another asteroid impact that coincided with the peak basalt volcanism. The impact crater has not been found, but expect the story to get even more complicated.

And yes, the Indian media screwed up on this one too. The Times of India (Nov. 8 2007) copied and pasted an article by John Noble Wilford from the New York Times. The article was about some fossil discoveries from post-extinction sediments in New Jersey which showed that some species of Cretaceous ammonoids survived the mass extinction for at least several hundred years. But the connection between the Cretaceous extinction and dinosaurs has become so ingrained that The Times of India in a bombastic subtitle ignored the evidence presented in the article and announced that it was the dinosaurs who lived hundreds of years after the extinction event , for which there is no evidence..... yet.

Friday, November 2, 2007

Images of Alzheimer's

An article in Science Daily about Alzheimer's caught my eye. Brain imaging is rapidly evolving into a powerful tool to diagnose various types of brain disorders. In this study, a positron emission tomography (PET) scan of sugar uptake by the brain allows a more accurate diagnosis of a type of dementia frequently mis-diagnosed as Alzheimer's. This will allow for earlier detection and better treatment of dementia. Modern imaging methods like PET and Magnetic Resonance Imaging (MRI) allows us to peek into our brains and observe the effects of the disease. In multicolor these images can show loss of brain tissue as with MRI and patterns of metabolism as with PET. But these images are clinical. They don't portray the emotional turmoil the patient must be going through, the sense of loss and a steady inexorable distancing from the familiar world. How can a machine capture this personal catastrophe? I was reminded of a different kind of image of Alzheimer's in an article I read several years ago.

In 1997 artist William Utermohlen, was diagnosed with Alzheimer's when he was 60 years old. He captured the ravages of the disease in a series of haunting self-portraits. Soon after his last sketch in 2000, the artist stopped painting. He is now in a nursing home.




Galerie Beckel Odille Boicos, Paris

A picture is worth a thousand words. So true!

Saturday, October 27, 2007

Groundwater, Mountains and Media

An article in India Today, gave me this opportunity to write about geology. I don't write about it enough, but then the media doesn't cover it enough :-)

The October 15th issue of India Today had an article about Dr. Ritesh Arya, a hydrogeologist, who has turned to drilling for groundwater at very high altitudes in the Himalayas. India Today reporter Ramesh Vinayak interviewed him. Dr. Arya has caused quite a sensation by drilling successfully for groundwater at fifteen thousand feet. The Army and the locals are pleased with him. Villages and army posts which had to bring water by tankers, now have flowing water through bore wells. Hurray for Dr. Arya and his geological skills. Mr. Vinayak's reporting on geology is another matter. Here is what he writes about Dr. Arya's research thesis. "At the heart of his ground-breaking thesis is the finding that groundwater resources in the Himalayan region depend on the type of rocks and structural parameters like folds, fissures and fault-line in the rock strata. I am sure Dr. Arya very skillfully interpreted the geology, but I don't see any ground-breaking revelations here. The parameters that control groundwater occurrence and movement are pretty much the same everywhere, no matter what the altitude, i.e. geological properties of rocks and structural features such as fractures, joints, faults. Then Mr Vinayak writes something bizarre," The mountains have groundwater just like the plains but the water movement at high-altitude is controlled by principles of gravity and iso-stacy (wherein the water level is itself up)". Wow! That must have been the physics class I missed in school. I had no idea water responds to gravity differently in the mountains than in the plains. And what is this iso-stacy? The term is isostacy and it is a concept used to explain why topography exists on a continental scale. The lithosphere, which is the rigid outer shell comprising the earth's tectonic plates rides on a plastic asthenosphere. Plastic in the sense that the material deforms by plastic flow. Imagine a block of wood floating in water. The height of the wooden block above water-level is determined by its density and thickness. The lithosphere similarly rides upon the asthenosphere at a height depending upon its density and thickness. As you must have guessed by now, it has nothing whatsoever to do with groundwater. Here's a suggestion for reporters who are blank about science. Why not ask the scientist being interviewed to write a couple of paragraphs?

Okay, enough harassing the media. On to more geology. Groundwater high in the mountains reminded me of my trekking days in college. Where I live in Pune, the popular places to trek were the Sahyadri mountains, and particularly the various 16th century forts strategically placed along the western ghat escarpments. Many of these forts have fresh water wells. People are often surprised to learn that there is groundwater so high up. The popular thinking is that water will just flow down the slope or through cracks and find the lowest level such as adjoining valleys or plains to accumulate. But there can be plenty of groundwater in these western ghats. These are not orogenic mountains like the Himalayas, but were formed during and after the Deccan Trap volcanic eruptions by a combination of the processes of magmatic underplating and denudational uplift. Magmatic underplating refers to the process whereby much of the melt produced in the mantle during such large magmatic events such as the Deccan Traps does not reach the surface but sticks to the underside of the lithosphere. All this hot stuff makes the lithosphere buoyant causing uplift. Most of the uplift is however thought to be denudational uplift (evidence summarized in Sheth 2007) which refers to the process whereby the lithosphere which has been depressed by the weight of the thick volcanic pile rebounds upon removal of the material by erosion causing uplift. This may take place millions of years after the volcanic event. This is analogous to an iceberg floating in water. If you shave off some ice from the top, the iceberg will rise by a proportional amount. Iso-stacy or rather isostacy is in action in the Deccan Traps as well. The Sahyadris are formed of two main types of basalts which occur as alternating layers; amygdaloidal basalt which solidified from more viscous lava and generally forms gentler erosional slopes and compact basalt which solidified from more fluid lava and forms steeper slopes as seen in image below.

Groundwater systems can occur in both types of basalt. My friend Dr. Himanshu Kulkarni has studied these basalt groundwater systems extensively. After two decades of research, some general principles are emerging. Basalts are crystalline rocks with an interlocking fabric of crystals. So, water in these rocks is stored and flows along cracks, joints and fractures. Both, horizontal sheet joints and vertical joints serve as conduits for water flow. Amgdaloidal basalt is generally the more capacious in water storage and high yielding aquifers are those where a layer of amygdaloidal basalt is underlain by the more impermeable compact basalt (Kulkarni et. al. 2000). The figure below illustrates these concepts of basalt hydrogeology.

Source: Advanced Center for Water Resources Development and Management

Such conditions for the formation of a groundwater system are met at many of the high-altitude forts. At Sinhagad, one of the most popular forts near Pune, there are several fresh water wells and storage tanks that have exploited such structural zones of groundwater flow.

In image the brown arrows point to horizontal sheet joints developed at the junction of two lava flows. Such joints among other joint systems form a zone of groundwater flow (blue arrows). The well indicated by the pink arrow captures this flow. The circular green spots are additional water storage tanks.

Groundwater exploration "consultants" have got a bad reputation, sometimes richly deserved, in my part of the country in the state of Maharashtra. People now have smartened up but in the bad old days there were scamsters walking around with a magnetic compass claiming to locate water, and then those who dabbled in dowsing. It was great to read that Dr. Arya relies on sound geological principles for his explorations. In any case, dowsing in the mountains can be dangerous.

What I would like to know is if the principles of dowsing are any different in the mountains than in the plains.


H. Kulkarni, S. B. Deolankar, A. Lalwani, B. Joseph, S. Pawar, 2000; Hydrogeological framework of the Deccan basalt groundwater systems, west-central India; Hydrogeology Journal; Volume 8, Number 4, p. 368-378.

Hetu C. Sheth 2007; Plume-related regional pre-volcanic uplift in the Deccan Traps: Absence of evidence, evidence of absence; Hetu C. Sheth; In

Monday, October 22, 2007

How we think about Race and Intelligence

Media articles and the blogosphere has been abuzz about James Watson's latest indiscretion, stating that Africans are less intellectually endowed than people of European descent. He has been rightly chastised for his really insensitive and unsubstantiated remarks, but that made me think about some other articles and reports about race and intelligence and our reaction to it.

In his book, Guns Germs and Steel, Jared Diamond stresses the genetic equality of humans and explains why Europeans got a head start in achieving technological prowess, leading to their military domination over other cultures. The reasons are to be found in unique combinations of geography, climate, availability of plants that could be cultivated and animals that could be domesticated. Diamond is so mortified about starting a controversy related to group differences that he stays away from even exploring whether culture and religion could have played a role. But here is what he has to say about New Guineans " That is, natural selection promoting genes for intelligence has probably been far more ruthless in New Guinea than in more densely populated, politically more complex societies, where natural selection for body chemistry was instead more potent......That is in mental ability New Guineans are probably genetically superior to Westerners, and they surely are superior in escaping the devastating developmental disadvantages under which most children in industrialized societies now grow up". So, Diamond has no problems accepting that in principle evolution can make one group more intelligent that some other group. Not only that but according to him, at least as far as child rearing goes, New Guinean culture is superior to Western culture. Why was this not met with accusations of racism? Was it because New Guineans and other hunter gatherer societies have been persecuted and any suggestion that they could actually be more intelligent than industrialized people make us feel a little less guilty? Is it okay to say that traditional hunter gather societies are more intelligent than urban societies but not the other way around?

A 2006 study on European Jews (Ashkenazim) settled in the U.S. by Gregory Cochran, Jason Hardy, and Henry Harpending proposed that the high average IQ shown by this group resulted due to occupational constraints imposed on Jews in Medieval times. Jews were forced into trades that required computational skills such as trading and money-lending. This resulted in selection for verbal and mathematical intelligence. A follow up study by David, H. and Lynn, R. compared IQ's of European Jews with Oriental Jews in Israel and found that European Jews have an IQ 14 points higher than Oriental Jews. This according to the authors supported the earlier evolutionary explanation, since Oriental Jews "were permitted to engage in a much wider range of occupations and hence did not come under the selection pressure to develop the high verbal and mathematical intelligence that was present for Ashkenazim". Both the original study and the follow up have received attention and criticism but no howls of protests for example from Oriental Jews or for that matter any other community that they have been racially targeted.

We readily accept that we are more intelligent than our remote ancestors living say a few hundred thousand years ago. That would mean our cognitive evolution was being fueled by selection on existing variability in genes for intelligence. Would there not be such variability in modern populations and did conditions exist in the recent past such that there are discrete differences between groups? Is it even legitimate to research whether groups differ in their intellectual capabilities? In a hysterical editorial the Times of India doesn't think so. They say that some topics such as group differences are best left to sociologists (now that should solve all our problems). According to the Times the job of a scientist is to observe, test and report, which to me is exactly what Cochran et. al. did in their study of Ashkenazim Jews. Their hypothesis has not yet been validated, but there is a clear test available. This will be based on a comparison of IQ's of sibling pairs (to control for environmental differences), one of whom carries the genes that Cochran et. al. have identified as the candidate "intelligence gene" and the other who is a non-carrier. If the carrier is not smarter than the non-carrier, then the hypothesis is wrong. To date, no such specific hypothesis has been presented about innate differences in cognitive abilities between Africans and Europeans. It is reasonable to suppose that any differences are due to social and other environmental factors and the genetic component to the differences measured is negligible. But with the explosion in human genomic data the day might come when someone does present a genetic explanation. Will we be mature enough to let science do the talking?

Some News About My Blogs

I started blogging recently. One reason was that I like writing about science. Another was to point out errors in science reporting especially in the Indian media in the very faint hope that some feedback might reach the media. I send my criticisms directly to newspapers, but the usual trend is that if my article is generally supportive of the media report it has a higher chance of being published. I cannot prove this (I plan to start collecting statistics), but just a trend I have noticed. My post on the editorial in Times of India on Junk DNA was not published in the letters section of the newspaper but received quite a bit of support from the blogosphere. It also caught the attention of the Online Centre for Media Studies, who have posted a synopsis of my post and a link to my blog. It's good to know some feedback is reaching would be and working journalists.

Another piece of news, although somewhat dated. My posts on the Ram Sethu controversy, Adams Bridge and Ram Sethu: A Dummies Guide, received a lot of attention. Again the reaction was mostly supportive, although one memorable comment - either written in jest or due seriousness I am not sure- stands out. I was invited to write an article by the Indian National Interest Review, an online magazine. You can download my article on the Palk Strait here.

Monday, October 15, 2007

Media and Nobel Peace Prize

Spot which one of these newspaper headlines and captions are from Indian newspapers:

Gore Shares Peace Prize for Climate Change Work

PM congratulates Gore for peace prize

2007 Nobel Peace prize awarded to Pachauri's IPCC, Al Gore

Pachauri and Gore share prize for raising awareness on climate change

Gore and U.N. Panel Share Peace Prize

Chidanand Rajghatta had a fine essay in the Times of India about the desperate lengths the Indian media goes to claim an Indian success story. Indian newspapers have been gushing about Pachauri the "man who put emotion into hard science", Pachauri the "efficient administrator and enabler", and Pachauri who stood up to Gore when the two had a brief disagreement in 2002 when Pachauri was elected to head the Inter Governmental Panel for Climate Change (IPCC). Strangely, not one Indian newspaper has tried to find out, even as a matter of curiosity, what Pachauri has contributed to the science of climate change. I agree that his main job was administrative but isn't the media even curious? Wasn't it the research done by hundred's of scientists that enabled the IPCC to take the strong position it did about the urgency of dealing with climate change? Or is the Indian media under the delusion that somehow it was Pachauri heroically fighting opposition who convinced everybody to start acting responsibly on this issue?

In an earlier post I had written about this peculiar mentality of claiming an Indian connection to everything. In the hoopla over Pachauri's "achievement" there was one headline that was particularly revealing about the way we seem to think and link status, success and expertise.

Rajendra Pachauri backed N-deal - Hindustan Times

Now that Pachauri has "won the nobel" let's start asking his expert opinion on just about every subject under the sun. But expertise in one field does not translate into authority in another. Our media just doesn't seem to understand that.

Friday, October 12, 2007

Orissa and Hexavalent Chromium

A list of the most polluted places on earth prepared by Blacksmith Institute, an environmental group appeared in the Times of India, a few days ago. Not surprisingly it included two sites from India; Vapi in Gujarath state and Sukinda in Orissa state. Pollution in Vapi was mostly due to the chemical industry while that in Sukinda has a geological origin, the mining of chromite deposits. Sukinda mines account for a staggering 97% of discovered chromium ore deposits in India. Why is Orissa so unusually blessed or cursed some would say with chromite?

Chromite deposits form by a process of concentration by crystallization in magmas. But not just any magmas. Chromites are almost exclusively restricted to ultramafics, magmas rich in magnesium and iron. Chromite deposits occur in two varieties known as stratiform and podiform. As the terms imply, stratiform means layers of concentrated chromite within the ultramafic rocks, while podiform chromite occurs as lenses or pods of concentrated chromite within the ultramafics. The Sukinda chromites are stratiform. During the late Archean- early Proterozoic period around 2.5 to 2 billion years ago geologists estimate, massive amounts of ultramafic magmas originating in the mantle were injected into the crust in the area that is now Orissa. But why is chromium so concentrated in ultramafic magmas? Chromium is a refractory metal i.e. a metal with a melting point higher than iron and cobalt. It takes a large amount of melting in the mantle to release significant amounts of chromium in to the liquid phase. But large amounts of melting also make the magmas rich in magnesium and iron. So the connection of chromium and chromite deposits with ultramafic rocks.

Stratiform and podiform chromite deposits occur in distinctive tectonic settings. Stratiform deposits occur mostly within ultramafic intrusions in stable continental crust, while most podiform deposits originated in oceanic settings, either within ultramafic rocks associated with mid-oceanic spreading centres or in subduction zone associated back-arc spreading centres. Later, plate tectonic movements have obducted or thrust up these chromite bearing ultramafics to form sections of spectacular mountain belts. The best example in India are the podiform chromites in Ladakh (Karmalkar N.R. et al. 2000), which originated in the oceanic crust between the Indian and Asian continents in the Mesozoic period, and were subsequently thrust up to form the early Himalayan mountains as the Indian plate collided with the Asian plate.

Chromite deposits show an interesting age distribution indicative of the thermal and tectonic evolution of the earth.

Image Source : Stowe (1994). Stratiform deposits occur almost exclusively in the late Archean-early Proterozoic period (2.8 - 1.8 billion years ago), while podiform deposits occur almost exclusively in the Mesozoic and Tertiary periods beginning around 200 million years ago (there are some podiform chromites in late Proterozoic orogenic belts around 800 million years old). Anyone familiar with the geological time scale with readily appreciate that biological evolution has imparted a temporal uniqueness to the sedimentary rock record, enabling geologists to subdivide geologic history into different periods. What is less appreciated is that the thermal and tectonic evolution of the earth has also produced a distinctive rock record (a good idea for a post series). Chromite deposits are one good example. The mid late Archean-early Proterozoic was a period of intense continental crust building. Owing to the high geothermal gradients in the Archean (the interior of the earth was hotter then), there were periods of copious amounts of melting in the upper mantle and lower parts of earlier formed crust. So, were formed large ultramafic complexes and associated chromites. Over time, the earth cooled and large scale melting of the mantle became localized to plate boundaries. The breakup of supercontinent Pangea beginning in the early Mesozoic led to significant worldwide development of subduction zones and associated back-arc spreading centres and the origin of ultramafic hosted chromite. This activity culminated in intense amounts of mountain building activity in the mid-Mesozoic and early Cenozoic. So, podiform chromites occur mainly within tectonically emplaced slices of oceanic rock sequences in this age group. The gap between around 800 million years to 200 million years is one of geology's unresolved problems.

Chromium from Sukinda mines is present as air-borne dust and is also being leached into the groundwater and nearby streams in the form of hexavalent chromium (+6 oxidation state).

In image, the Sukinda syncline is clearly seen. In the core of the syncline the arrow points to the open pit Sukinda chromite mines. The rust color is due to oxidation of the ore. When ingested either through air-borne dust or through water, hexavalent chromium is reduced in our cells to pentavalent and trivalent chromium. This leads to a variety of health problems, including increased risk of cancer. An estimated two hundred and seventy thousand people around Sukinda are at risk or are suffering from chromium related poisoning. The Orissa Pollution Control Board have pleaded impotence, saying “It is unique, it is gigantic and it is beyond the means and purview of the (Orissa Pollution Control) Board to solve the problem,”. In effect they have questioned the rationale for their own existence. The board chairman L.N. Patnaik has predictably rubbished the report, saying that any mining activity will lead to some air pollution, apparently forgetting that chromium is getting into the water supply in massive quantities.

Hexavalent chromium gained recognition because of the movie Erin Brockovic, in which the character played by Julia Roberts campaigned successfully against a polluting industry. In India, maybe this lady on the left can help :-)

Karmalkar N.R., A. G. Dessai and R. A. Duraiswami: Alteration of Chromite from the Dunites of Indus Ophiolite Belt, Ladakh 27-34, Himalaya, India, Gondwana Geological Magazine; V. 15 (1)- June 2000

Stowe, C. W. 1994. Compositions and tectonic settings of chromite deposits through time. Econ. Geol. 89:528 – 546

Wednesday, October 10, 2007

Climate and Point of No Return

The science section of the Times of India has a rather alarming article on global warming. According to Australian scientist Tim Flannery, we may have already emitted greenhouse gases to a threshold value that may cause "irreversible climate change". Flannery remarks that the Intergovernmental Panel on Climate Change (IPCC) report due in November will show that greenhouse gas level by mid 2005 have reached around 455 parts per million, a level not expected until a decade later. The Times of India calls Flannery a "world recognized climate change scientist". I looked up his credentials and found that he is a palaeontologist, an expert on mammals who over the course of his research I am sure has acquired a good knowledge of climate change. But he is not a climate scientist. Don't Indian science reporters ever do any background checks? He may well be right about greenhouse gases already passing some threshold, but with or without immediate thresholds, isn't climate change irreversible on the time scale of the next few hundred years anyway? Owing to the long residence time of CO2 in the atmosphere there is always going to be a lag between our reducing emissions and its effects to be felt in terms of stabilizing the temperature.

This press release reminded me of a cartoon I saw some time back.

Cartoon Creator: Mike Adams; Source:

Flannery's fears may be well founded. We should be doing better than this.

Saturday, October 6, 2007

Tiny Frogs and Fault Rocks

Two news items that caught my eye in the last week or so.

Tiny Frog is India's smallest land vertebrate:
Biologist S D Biju of Delhi University working in the western ghat forests in Kerala discovered a new species of leaf frog which they named Nyctibatrachus minimus. Adult males are barely 10 mm in length and can fit inside a 5 rupee coin (Image source Delhi Univ).

The pleasant surprise was that a press release from an Indian university was picked up by a major science news portal, in this case Science Daily. Indian universities do not have well organized proactive press offices. News of research rarely filters out even in Indian newspapers. Indian scientists for their part have remained largely invisible to the public. We meet them not through their books or articles or on radio and TV talk shows, but only on that tiresome "science day" when hordes of bored school children are made to walk through science exhibits in some government institution. There a government scientist will tell you how fulfilling a career option science is. Despite their best efforts, science as an activity doesn't register among young Indians as something exciting.

Fresh from within the San Andreas Fault:
In 2004, the San Andreas Fault Observatory at Depth, a monumental project to drill right into the world's most famous fault zone began. The San Andreas fault zone marks the boundary between the Pacific plate and the North American plate. The goal was to set up a deep monitoring system to analyse the movements of rocks along the fault zone. After drilling about 2 miles, geologists have recovered about a ton of rock from within the fault zone itself.

It is a magnesium aluminium rich silicate rock known as serpentinite (Image source: Earthscope). Its composition and physical structure will be invaluable in understanding the conditions at depth, and how this major plate boundary behaves and how earthquakes work. In time geologists using this deep monitoring system hope to refine earthquake prediction methods.