Dr. V.V. Peshwa, Geologist Extraordinaire, 1939-2024

My Guruji, Dr. V. V. Peshwa passed away on August 27, 2024. He was my thesis advisor during my Master's education in Pune. His career as a faculty with the Department of Geology, Pune University (now Savitribai Phule Pune University), was full of distinction and dedication to the noble cause of teaching. Field geology, remote sensing, and mineralogy. He had a mastery over these subjects and taught them with extraordinary clarity. His lectures on mineral optics, delivered without the aid of notes, remain some of the most lucid explanations I have heard on any aspects of geology.  

Dr. Peshwa also set up the remote sensing lab at Pune University in the early 1970's,  having received a specialized Master's degree from the Netherlands. Over the years he amassed a vast collection of aerial photographs and satellite imagery of Indian landscapes, teaching with great panache the fine skills of image interpretation. He was a formidable researcher too, with publications in igneous and metamorphic petrology, remote sensing of the Deccan Basalts and Proterozoic sedimentary basins, and on geohazards. 

I will recount two incidents from my association with him. I had to choose a thesis guide at the end of my first year of Master's course at Pune. I asked Dr. Peshwa if he was willing to be my guide. As was his style, he promptly said no! I was unsure how to persuade him, but fortunately my senior, Anand Kale, came up with a brilliant plan. I was told to sit on a chair outside his room and poke my head inside every few minutes until he said yes. I agreed, and like a security guard sat outside his room all morning. Towards early afternoon Dr. Peshwa had given up trying to ignore this motionless sentry outside his door and agreed to my request, but on one condition. I had to go and map an area in Andhra Pradesh in the Cuddapah Basin.  He had some aerial photos of this place and wanted someone to study a fold structure that was spectacularly exposed near Nandyal town. The imagery below is from ISRO Cartosat.

Folded Cuddapah Group and Kurnool Group sediments south of Gani.

Dr. Peshwa accompanied me during my second trip to the field area. It was mid January and one early morning we set off to the low range of hills, about an hour walk from where we were staying. We worked till the afternoon, and by around 3 pm decided to call it a day. We were running out of water and were famished. We thought we should walk to the next village which was just 15 minutes away, have a snack and then turn back to our camp in Gani village. To our surprise every shop in the village was closed. Dejectedly we started walking to Gani. After a while we spotted a man on a bicycle coming in our direction. We recognized him as a shopkeeper from Gani. He stopped and explained that it was the auspicious day of Pongal and everything was closed. He slipped his hand into a bag and gave us two round dry buns to eat and cycled away. We tried to bite into them, but they was rock hard, harder than the Cuddapah quartzites we were trying to break with a hammer. We collapsed with laughter and trudged along, where our host was waiting for us with a hot sumptuous meal! 

For all his exuberance and light heartedness, Dr. Peshwa never compromised on the quality of work he expected from his students. He supervised with an eagle eye my petrographic analysis, read every word of my thesis, and even sent me back to the library because he thought my literature search was not exhaustive enough. He gave me full independence to follow my interest in carbonate sedimentology, but cautioned me to remain within the bounds of data. He did not like grand theorizing or explanations by 'arm waving'. Some might call him conservative, but it made us into careful researchers, and brought a rigor to our work. 

He remained active in geology long after his retirement, accompanying younger faculty and students to the field and acting as their mentor and advisor. I live near his house and used to stop by once in a while for a chai and long conversations about geology. He will be missed greatly. The picture below shows Dr. Peshwa, seated center, on his 80th birthday.

Now, only all those memories remain to serve as inspiration and to help us stay true to what the rocks are telling us.

Jyotirao Phule On Watershed Management

Jyotirao Phule (1827-1890) was a social reformer from Maharashtra who worked for the emancipation of the lower castes and for improving the lives of peasant agriculturists. In Shetkaryacha Asud (The Cultivator's Whipcord), written in 1883, he describes the plight of poor farmers and offers some advice on improving yield through land management practices. 

An excerpt- 

The essence of leaf, grass, flower, dead insects and animals, is washed away by summer rain, therefore our industrious government should, as and when convenient, use the white and black soldiers and the extra manpower in the police department to construct small dams and bunds in such a way that this water should seep into the ground, and only later go and meet streams and rivers. This would make the land very fertile , and the soldiers in general, having got to working in [the] open air, will also improve their health and become strong. 

.....Therefore the government should maintain these bunds in good condition, especially the backwaters. The government should conduct surveys of all the lands in its territory, employing water specialists, and wherever it is found that there is enough water to be drawn from more than one source, these places should be clearly marked in the maps of the towns, and the government should give some awards to farmers who dig wells without its assistance. Also the government should allow the farmer to collect all the silt and other things extracted from rivers and lakes, as in the older times, and it should also return all the cow pastures to the villages, which it has included in its 'forest'. 

Phule covers many of the interventions that are recommended by watershed management specialists today. The last line of the passage I have quoted is telling. Preventing villagers from using what was traditionally considered 'village commons' has always been contested by the people. Phule also called for the destruction of the "oppressive Forest Department". The conflict between agriculturists, forest dwellers, pastoralists, and the forest department continues to this day. 

This essay, translated from Marathi to English by Aniket Jaaware, has been republished in Makers of Modern India, a compilation of essays written through the 19th and 20th century by influential Indian political activists and social reformers. The collection is edited and introduced by historian Ramachandra Guha.

Campus Memories: Prof. Sohan Modak

I came to know from media reports and Twitter posts that biologist Dr. Sohan Modak passed away on March 23rd. Although I never interacted with him directly I do have some distinct memories of his presence on the Pune University campus when I was completing my Masters in Geology in the late 1980's. On various occasions there were protests and strikes organized by faculty in opposition to some decision regarding University functioning. I don't remember Dr Modak ever making common cause with the rest of the faculty regarding going on a strike. He used to show up to the canteen with large posters which outlined his opinion of the situation. He then used to vociferously appeal to the faculty to get back to teaching. 

On the academic side, many of my college batch mates had opted for a Master's in Zoology. I started hearing a different language from them. There was less emphasis on the rigid divisions between Zoology and Botany. Instead, universal mechanisms underlying all life were being discussed. Gene regulation, chromosome structure, development. All this was new and alien to me, but exciting to hear about none the less. 

Dr. Modak had played a big role in the transformation of biology syllabus I was told. The various tributes now poring in bears this out. 

R.I.P. 

 

Diego Maradona RIP

I will prefer to remember his godly feet. That liquid motion on the football pitch. His short stocky body in perfect balance, skipping, darting, weaving his way through a maze. A slight feint of his right shoulder, a sudden burst, leaving bewildered defenders in his wake.

He had the footballing world at his feet, we gasped in disbelief, as he made the impossible look utterly simple.

He lived a troubled, imperfect life. But in these troubled times we must find it in us to forgive and keep remembering what makes us happy. And that his magical twinkling feet did, bring us joy unconfined.

On that hot, steamy afternoon in the Azteca Stadium, Mexico City, in 1986, Victor Hugo Morales described one of those unforgettable moments of poetry in motion.

Take a look.

Email subscribers can watch it here- Diego Maradona Goal Against England.

Adios Diego.

Interview: Palaeontologist Prof. Ashok Sahni

This is a rich conversation between paleontologist Prof. Ashok Sahni and Dr. Devapriya Chattopadhaya of the Indian Institute of Science Education and Research, Pune.

Email subscribers who can't see the embedded video can watch it at this link: Interview- Prof. Ashok Sahni.

It was so refreshing to hear Prof. Sahni talk candidly about the state of paleontology research in India,  preserving fossil sites, motivating students, the need for Indian scientists to proactively engage with the public about their work, and the importance of building bridges between research and societal needs.

Prof. Sahni comes from an illustrious line of scientists. His uncle was the paleobotanist Dr. Birbal Sahni after whom the Birbal Sahni Institute of Palaeosciences, Lucknow is named. And his father was also a palaeontologist. His mother was not keen on him taking up geology, admonishing him that there were already too many rocks in the house. However, he persisted. 

Definitely worth your time.

Remembrance: Dr V.G. Phansalkar, Palaeontologist

In the February 2020 issue of the Journal of Geological Society of India, Anand Kale has written a very nice tribute to his mentor Dr. V.G. Phansalkar who passed away earlier in December 2019.  It captures very well both the professional aspects of Dr. Phansalkar's career and his endearing personal nature. Dr. Phansalkar was a paleontologist and a stratigrapher who taught with distinction at Banaras Hindu University, University of Pune (now Savitribai Phule Pune University) and Sholapur University ( renamed Punyashlok Ahilyadevi Holkar Solapur University) from 1962 until his retirement in 1999.

Photo credit: Anand Kale. 

I was fortunate to interact with him extensively when I was studying for my masters degree at the University of Pune . He was an original thinker with a penchant for asking that awkward question which you had not thought of or which you were hoping no one will ask. At our department seminars,we students always waited for that moment when Dr. Phansalkar raised his hand to inquire about some aspect of the presentation that he thought could be explored in a new direction. A spirited debate always followed! There was never any malice in his actions, just genuine curiosity and a wish to share his perspective.

During my time as a student in Pune, stratigraphy and sedimentary geology were subjects that were placed in two separate bins and taught as such. Stratigraphy deals with the way strata (sedimentary layers) are laid down and the relationships of bundles of strata across time and between those deposited in different locales at the same time. It is a hugely important subject, providing many of the organizing principles for piecing together the geologic history of a region. Unfortunately, Dr. Phansalkar did not get to teach us this subject. The lecturer who was assigned to teach it did a hack job of it with an insane emphasis on memorizing rock unit names from different parts of the country. Enlightenment came during our paleontology coursework. By interleaving palaeontology and stratigraphy in his lectures Dr. Phansalkar guided us towards understanding stratal layering patterns, sedimentary rock properties, and fossil occurrences as interrelated outcomes of the way sedimentary basins get filled up. I now realize it was an early jargon free introduction to sequence stratigraphy!

Years after my graduation from Pune, on a holiday from my PhD work in the U.S., I paid a visit to my old geology department.  In a conversation with Dr. Phansalkar I happened to mention that I was teaching sedimentary petrology as part of my assistantship duties. He looked at me for just a moment, leaned towards a drawer, and placed a box of limestone thin sections in my hand. Use these to teach he said. They were part of his precious collection of samples from the Cretaceous age sedimentary rocks exposed in the area around Ariyalur in Tamil Nadu. My lab benefited enormously from his thoughtful gift.

His home in Pune is quite close to where I live. In recent years we bumped into each other quite often during his evening walk in the park and on the nearby hill. Long geological stories peppered with humorous anecdotes became a welcome addition to my evening routine. I will miss that now that he is gone.

People often ask me why I took up science outreach. I have no hesitation in saying that it was in no small measure due to educators like Dr. Phansalkar who taught me that knowledge sharing is an immensely fulfilling endeavor to follow.

Papers: Carbonate Sedimentology Tribute To Robert Ginsburg

Dr. Robert Ginsburg, who spent much of his career studying the geological evolution of the Florida Keys died recently. The Depositional Record has an open access special issue in his honor packed with papers on the modern and ancient carbonate rock record.

In Precambrian times (before 542 million years ago), the precipitation of calcium carbonate on the sea floor was influenced by the activity of microbes. Beginning around 530 million years ago, complex multicellular organisms evolved the ability to secrete calcium carbonate as a protective shell.  Since then, limestones have been forming by the aggregation of skeletons of marine organisms. They tell us about past biodiversity and the conditions in which these ancient organisms lived. Understanding the controls on the origin and accumulation of these sediments using present day examples provides useful analogues to interpret the past. Limestones (CaCO3) and dolostones (CaMg(CO3)2) are also important petroleum reservoirs.

The satellite image shows a portion of the Florida Keys carbonate platform.  It is made up of a low energy shoreline with plant stabilized mud flats, quiet sea grass covered lagoons, and towards the southern reaches, an arcuate coral reef system. The sunlight waters provide ideal conditions for a complex community of shell secreting organisms. Broken down shell fragments accumulate either in-situ or are distributed across the platform by waves and currents. Dr. Ginsburg wanted to know the details of these processes.

In the published issue, there are quite a few papers on carbonate depositional environments and the sediment production and distribution processes in action in the Bahamas shallow marine region. These are supplemented by examples from other parts of the world, including the Florida Keys.

... and don't forget to read the warm humorous tribute celebrating the life and work of Dr. Ginsburg written by Eugene Shinn.

"But, what would be his dissertation subject? Someone came up with a catalogue advertising Fellowships at the University of Miami in Florida. When he asked Jack Hough about Miami, Jack admitted he had never heard of the place. In fact, no one that far north had heard of the University of Miami. Bob drove south for the interview anyway. He was on a mission, an idea he wanted to test. He wanted to determine the process by which sediment became rock. It seemed straightforward enough. All you had to do was dig a hole or push a core tube a few feet into the sediment until it stopped. That would be the zone of transition from sediment to rock. He got the Fellowship (about $3,000) and began his research. Of course, the problem turned out to be more difficult than expected, so difficult in fact that many scientists are still working on it today".

One of his seminal contributions was a proposal to explain the cyclic nature of carbonate sedimentary deposits.  It is observed that many thick limestone sequences are made up of a repeated pattern of relatively deeper water subtidal sediments overlain by shallower water intertidal sediment. These couplets are stacked to form deposits that can be hundreds to even thousands of feet thick. Dr. Ginsburg suggested that this pattern arises due to the cyclical shifts in the reduction and expansion of source areas of carbonate sediment.

At times when the open sea area is large, healthy organic growth produces a large supply of skeletons. Breakdown of these skeletons produces carbonate mud. This mud is transported by currents and trapped along the shores causing accretion of tidal mud flats, which grow towards the open sea. This spread of tidal flats in turn eventually shrinks the size of the source region, reducing sediment supply and stopping tidal flat growth. Sediment production in this system then falters. Natural subsidence of the basin reestablishes water depths for optimum organic growth, again resulting in healthy sediment production, and the cycle restarts.

Here is the abstract of Dr. Ginsburg's model published in AAPG Bulletin in 1971.

Title: Landward Movement of Carbonate Mud: New Model for Regressive Cycles in Carbonates:

Repeated regressive cycles are characteristic of the Paleozoic shallow-water carbonates of North America; similar cycles are present, although less abundant, in Mesozoic and Cenozoic strata worldwide. Several of these cyclic carbonates contain major hydrocarbon reservoirs: Permian, Central Basin platform; Mississippian, Saskatchewan; Ordovician and Silurian, Montana. Studies of comparable recent deposits in Florida, the Bahamas, and the Persian Gulf suggest an alternative to the accepted tectonic explanation of these cycles.

The Florida Bay lagoon and the tidal flats of the Bahamas and Persian Gulf are traps for fine sediment produced on the large adjacent open platforms or shelves. The extensive source areas produce carbonate mud by precipitation and by the disintegration of organic skeletons. The carbonate mud moves shoreward by wind-driven, tidal or estuarine like circulation, and deposition is accelerated and stabilized by marine plants and animals.

Because the open marine source areas are many times larger than the nearshore traps, seaward progradation of the wedge of sediments is inevitable. This seaward progradation gives a regressive cycle from open marine shelf or platform to supratidal flat. As the shoreline progrades seaward the size of the open marine source area decreases; eventually reduced production of mud no longer exceeds slow continuous subsidence and a new transgression begins. When the source area expands so that production again exceeds subsidence a new regressive cycle starts.

The seaward progradation suggested by this model should be observable in ancient deposits.

This explanation of cyclicity is known as the autocyclic model, since all the feedbacks are internal to the system. The alternative explanation is called the allocyclic model. In this case, lithologic repeats are thought to result from changes in sea level caused by the growth and decay of polar ice caps due to cyclic changes in the solar radiation received by the earth (Milankovitch Cycles).

Dr. Ginsburg's work still generates a lot of debate.

Dive in!

Interview- Rosemary And Peter Grant On Watching Evolution In Action

Source: Quanta Magazine; Courtesy Peter and Rosemary Grant

Daphne Major in the Galapagos chain.

Yes, 40 years of field research on that half a square km size island, tracking, generation after generation, changes in body and beak size of different species of ground finches.  Lately, they have supplemented their morphologic and bird song data with genomic analysis to get an understanding of the genetic underpinnings of morphologic change.

Rosemary and Peter Grant interviewed about their epic evolution watch:

"The diminutive island wasn’t a particularly hospitable place for the Grants to spend their winters. At less than one-hundredth the size of Manhattan, Daphne resembles the tip of a volcano rising from the sea. Visitors must leap off the boat onto the edge of a steep ring of land that surrounds a central crater. The island’s vegetation is sparse. Herbs, cactus bushes and low trees provide food for finches — small, medium and large ground finches, as well as cactus finches — and other birds. The Grants brought with them all the food and water they would need and cooked meals in a shallow cave sheltered by a tarp from the baking sun. They camped on Daphne’s one tiny flat spot, barely larger than a picnic table.

...They visited Daphne for several months each year from 1973 to 2012, sometimes bringing their daughters. Over the course of their four-decade tenure, the couple tagged roughly 20,000 birds spanning at least eight generations. (The longest-lived bird on the Grants’ watch survived a whopping 17 years.) They tracked almost every mating and its offspring, creating large, multigenerational pedigrees for different finch species. They took blood samples and recorded the finches’ songs, which allowed them to track genetics and other factors long after the birds themselves died. They have confirmed some of Darwin’s most basic predictions and have earned a variety of prestigious science awards, including the Kyoto Prize in 2009".

indefatigable to the end..

"Do you plan to go back to Daphne?

RG: We stopped intensive work after 40 years, but we do plan to go back.

PG: The oldest person died at 122 years old. That means we have 40 more years".

Ground finches are off course the birds that Charles Darwin famously observed when on tour to the Galapagos, but infamously didn't mention in his book since he never labelled his samples according to their island location. He did borrow correctly labelled samples from other sailors and then had the ornithologist John Gould classify them. Gould's finding was that the islands finches were a group of sibling species despite their widely varying body and beak size and shape.

Habitats varied on different islands. Darwin realized that sometime in the distant past one ancestral population of finches must have immigrated from the South American mainland and then diverged into several morphologically distinct species, each a fit to its habitat. That was one of the threads of reasoning he weaved into a more comprehensive theory of common descent and evolution through natural selection.

The book, Beak of the Finch by Jonathan Weiner, is a bit dated but is still a riveting account of Rosemary and Peter Grant's research.

Update: @avinashtn alerted me to the Grant's book "40 Years of Evolution".

Life Began As Clay Crystals

There is a fine article on BBC Earth by Martha Henriques on the work of chemist Graham Cairns-Smith and his theory that life may have begun as clay crystals. Cairns-Smith reasoned that clay minerals are made up of sheets of atoms bonded in a regular lattice pattern that is stacked in layers.  Pieces of this latticework break off, forming offspring crystals often with minor dislocations to the latticework. These offspring crystals grow ..break off with more minor changes... grow.. and so on. Organic molecules like the precursors of DNA might have used such a "replicating entity" as a scaffolding to build an organic replicating system.

His idea stood at the intersection of geology, chemistry and biology and his wife Dorothy recalls the reaction he got from his peers:

"He could never get funding," Dorothy says. A major stumbling block to securing research grants was that his work straddled too many different disciplines.

One time we went to California, and Graham gave lectures to the Menlo Park Geology Survey," says Dorothy. "They all said, well, your geology's fine but I don't think your chemistry's right. Then he gave a lecture to NASA on the chemistry side and they said, well, your chemistry's fine but I'm not sure about your biology. And then he lectured to Berkeley and they said, well, your biology's fine but I'm not sure about your geology".

Nowadays such grand problems are tackled by multi-disciplinary teams of sub sub specialists. If a chemist is asked to talk on the geology aspects,  he just forwards the email of his teammate.

The Unconformity At Rathivade

My friend Pradeep Sarkar died last Tuesday June 7th. He got up that morning and complained of shortness of breath. In a few minutes it was all over. He leaves behind a shattered family, a wife and a son, and a large number of stunned friends, colleagues and students.

I met Pradeep when he joined the faculty at Fergusson College, Pune, during my second year B.Sc. He had a way with students and his enthusiasm for geology rubbed on to others. A boring summer vacation was looming ahead.  Having already decided to major in geology, Anil Lalla, Nalin Nair and myself asked him if he was going for fieldwork to the Konkan coast. As it happened he was and to our delight he invited us to go along with him.

We traveled to the little town of Malvan in the Sindhudurg district in southern Maharashtra. His research involved mapping the Precambrian geology with emphasis on understanding sedimentary structures and environments of deposition of the mid-late Proterozoic Kaladgi Group. Peninsular Gneiss, Greenstone schist belt, deformed conglomerate, trough cross bedding, fining up sequence. We had read and heard about these magical geological features in class. Pradeep made them come alive in the field in the week of our arriving at Malvan. He taught us how to read a toposheet and how to overlay the geology on it. He taught us how to measure and describe lithological sections. He taught us how to scan the horizon and see beyond.

In the evenings after fieldwork we used to go to the rocky  Malvan beach where the Kaladgi Group sediments were exposed. He used to point out to us ripple marks and bedforms made by the action of waves on a sandy sea floor more than a billion years ago. Sometimes we walked a little out of the way, outside town, to one of his favorite spots. A bridge over a small estuary; there we stood watching the rise or ebb of tides, taking in the salty breeze, waiting for the Arabian Sea sunset. Malvan would remain very close to his heart long after he finished his PhD work. He ended up marrying a local girl, the daughter of the lodge he always stayed in.

We remained good friends throughout. After I left India to pursue graduate studies we struck up a lively correspondence. I used to mail him research papers. His interests were moving toward studying calcrete, calcium carbonate deposits found as nodules and veins in the semi arid eastern Deccan plateau. On my return to India a few years back we renewed our meetings. During short chai sessions at the local tapri he used to hold court, talking excitedly of his research and teaching commitments. He wanted to see some of my PhD samples of Ordovician carbonates and maybe hold a lab session with graduate students. I agreed to meet him in his lab. Alas, that day never came. His work load was such that he just never got around organizing it.

Last week on June 10th I attended a sad but memorable condolence meeting for Pradeep. Friends and colleagues talked touchingly on the many memories they had of time spent with him. He leaves behind a legacy of 3 decades of excellence in teaching and of inspiring countless students to take up geology as a career.

When I heard the news of his passing on June 7th, my mind skipped back to that field trip and I found myself thinking about the unconformity near the village of Rathivade some distance away from Malvan. Amidst monsoon showers and sunny interludes we walked through the Konkan countryside. In a stream bed we came across something he had badly wanted us to see- The Great Eparchaean Unconformity. There scattered along were patches of Archean gneiss. Along the stream bank overlying the gneiss were mid Proterozoic Kaladgi sediments. By the time I had walked to the stream edge, Pradeep had rushed in and was already standing knee deep in water. It is an important feature of Indian geology he explained.... this unconformity. Etched on the surface of Peninsular India, it speaks of a change from a hot tectonically active Archean earth in which was formed the gneiss, to a cooler more stable Proterozoic world, where, on large cratonic basins in shallow seas, thick sequences of sandstones and limestones accumulated. This unconformity- he told us-  marks a long period of quiescence between these two phases of formation of the earth's crust, maybe a 300 -500 million year break.

With amazement we stared at him. 

Since then, at different times and places, I met and was influenced by other good teachers and mentors who kept my interest in geology alive. But it all began during that late summer in June 1986 when the generosity of a young PhD scholar opened the eyes of three geology enthusiasts to the wonders of this earth.

 Pradeep Sarkar 1960-2016

Quote: Stephen Jay Gould On Paleontology

This study of periodicity of mass extinction was published last month-

Periodic impact cratering and extinction events over the last 260 million years - Michael Rampino and Ken Caldiera.
 
The claims of periodicity in impact cratering and biological extinction events are controversial. A newly revised record of dated impact craters has been analyzed for periodicity, and compared with the record of extinctions over the past 260 Myr. A digital circular spectral analysis of 37 crater ages (ranging in age from 15 to 254 Myr ago) yielded evidence for a significant 25.8 ± 0.6 Myr cycle. Using the same method, we found a significant 27.0 ± 0.7 Myr cycle in the dates of the eight recognized marine extinction events over the same period. The cycles detected in impacts and extinctions have a similar phase. The impact crater dataset shows 11 apparent peaks in the last 260 Myr, at least 5 of which correlate closely with significant extinction peaks. These results suggest that the hypothesis of periodic impacts and extinction events is still viable.

This idea is not new and I remembered Stephen Jay Gould's essay "The Cosmic Dance of Siva" (in The Flamingos's Smile) which describes one of the early such hypothesis followed by his trademark meditations of the role of paleontology in understanding the nature of evolution  and the history of life. Gould was always irked by the opinions held by many that paleontology is a dusty sort of a science, where people spend their careers fighting over species names, and that they have nothing important to say about the theoretical aspects of evolution. A large part of his popular science writing effort was devoted to demolishing  this notion. He was very successful in it with essay after essay beautifully demonstrating the utmost importance of paleontology in highlighting life's little oddities as well as its grand patterns.

Paleontology in the early 1970's underwent something of a change in attitude. Decades before "big  data" became a buzzword, researchers led by David Raup, Jack Sepkoski,  Leigh Van Valen and Tom Schopf, to name a few,  began amassing enormous data sets on fossil characteristics and species distributions and subjected them to rigorous statistical analysis in an effort to elucidate distribution of biodiversity and macro-evolutionary trends. Gould's own work was substantial. Ideas such as "punctuated equilibrium" (with Niles Eldridge) which relies on the fossil record to tease out patterns in the mode and tempo of evolution, were met with admiration as well as fierce criticism as was his thinking on the role of contingency and chance and the limits of natural selection and adaptive evolution as explanations for life's historical trajectories. His theoretical forays did make paleontologists think more broadly about their data and what it tells us about evolution but my take is that it didn't cause a revolution in evolutionary theory as was made out by the media and by Gould's  rhetoric. But he did elevate the status of paleontology and that can only be good for science.

He writes:

Most hot  ideas turn out to be  wrong. I can only hope that I will not be remembered as the man who campaigned with a name for the nonexistent (surely worse than a moon for the misbegotten). Some chances are certainly worth taking. If Thalia smiles and Siva exists, think what it all will mean for my beloved science of paleontology. We have labored so long under the onus of boredom and dullness. We are guardians of life's history, but we are often depicted as mindless philatelists of stone; specialists in tiny corners of space, time, and taxonomy; purveyors of such arcane names  as Pharkidonotus percarinatus in extended orgies of irrelevant detail. The editors of Britain's leading scientific journal wrote of us in 1969: "Scientists in general might be excused for assuming that most geologists are paleontologists and most paleontologists have staked out a square mile as their life's work." 

That impression has changed since to include paleontology as an important contributor to evolutionary theory. For that, the field owes him a debt.

J Tuzo Wilson's Hawaiian Dream

Again via Twitter I came across this collection of essays on eminent geologists titled Rock Stars, produced by The Geological Society of America History of Geology Division.

I haven't gone through all of them yet, but there is a lovely piece on J. Tuzo Wilson, the geophysicist most famous for his work on the then incipient field of moving continents and oceanic crust aka plate tectonics.

We know Wilson from geology coursework on the "Wilson Cycle", the opening and closing of ocean basins over hundreds of millions of years. But Derek York who has written the essay has more insights. He remembers that Wilson had a knack of solving problems by visualizing rather than working equations. One of his famous insights into the origin of the Hawaiian island chain came to him this way-

Tuzo’s mind had a fascinating way of solving problems. Unlike most physicists, who find their solutions via mathematics, Tuzo solved problems almost entirely with visual images and then presented the solutions in extremely clear prose. He had a remarkable ability to look into the heart of extreme complexity and see simplicity itself. The nearest mind that I can think of to compare with Tuzo’s was that of Michael Faraday who, instead of integrating differential equations to calculate the electric field, imagined a charged particle to be an octopus with tentacle-like lines of force reaching out into the space around it.

To solve the problem of the origin of the Hawaiian Islands, for example, Tuzo imagined someone lying on his back on the bottom of a shallow stream, blowing bubbles to the surface through a straw. The bursting bubbles were the Hawaiian Islands, and they lay in a line because they were swept along the surface by the moving stream. Thirty years later, leading geophysical theorists use supercomputers to solve horrendous equations that Tuzo”solved” in the visualizing region of his brain.

In today's jargon, the moving  stream is a tectonic plate in motion and the bubbles are rising molten material originating ultimately from a fixed heat source in the mantle. 

Another famous Wilson piece of reasoning was the sense of movement on transform faults linking mid ocean ridges. He predicted that for earthquakes occurring underwater in the middle of the ocean "rocks everybody believed had moved right to left during the earthquake had moved left to right, and vice versa".

What did he mean by that? Well, the sense of motion along transform faults which connect strands of mid-oceanic ridges is opposite to what one would expect from a classical strike slip fault. See the image below.

Fig. A is a bed offset by a sinistral strike slip fault with a left lateral motion.  This means that the piece of crust north of the fault  has moved towards left.

Fig.B shows strands of a mid oceanic ridge. The red line linking the ridges is the transform fault. Notice however that the sense of motion along the transform fault is opposite that of a classical strike slip fault  i.e. the piece of  crust north of the transform fault is moving towards the right as it would  since the ridge is producing new oceanic crust and pushing older crust away.

There are other interesting essays, I enjoyed the one on Lawrence Sloss And The Sequence Stratigraphy Revolution.

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Indian Rationalist Narendra Dabholkar Shot Dead In Pune

Crushingly sad news from Pune, India. Yesterday morning two unidentified gunmen shot dead Dr. Narendra Dabholkar (pictured on left) who for many years had been the public voice of reason, fighting against the superstition and pseudo-science that permeates Indian society. The murder followed a persistent campaign by Dr. Dabholkar to get the Maharashtra state government to pass an anti-superstition bill.

The International Humanist and Ethical Union has a short article  on Dr. Dabholkar and his work.

I often hear people say that differences in belief systems and ideology must be debated peacefully and not result in violent outcomes. I think that really underestimates the power belief systems like religion have over human behavior. Much violence throughout human history has been because people hold what they see as nonnegotiable belief systems which then piggyback and amplify an inherent human tendency to divide people into an "us versus the other". Letting go of such strongly held beliefs becomes a question of self-preservation.

Besides, there is an economic angle to this too. Godmen and clairvoyants in India rake in enormous amounts of money channeled to them by an adoring gullible public. They have dedicated television channels where long distance blessings can be purchased. " Our daughter has been sick for the last 8 months" - "Make sure to  sew buttons of the same color on your husband's shirt.. Your daughter will be cured" is the kind of profound advice I have heard being given and which the believers willingly lap up.

Dr. Dabholkar's work threatened to put the brakes on this lucrative business.

Science Writing In India And Some Thoughts On Punctuated Equilibrium

Kind of a hodge podge title but I didn't feel like writing two separate posts.

Current Science had a special focus a couple of weeks ago on science writing in India. Seema Singh has written quite well about her struggles to become a better science writer. She summarizes the state of science writing in India:

Science is just about reviving in India. People mention that the first time in three decades such a coordinated effort is being mounted to infuse funds and sparkle in Indian science. But there still are not too many stories that can be told with a single-sentence punch line. In which case, the art of chronicling the process becomes even more important. Now, whether the body of knowledge will help here, or the skill of storytelling, is left to my mind, to individual communicators, specialists or non-specialists. For me, personally, it is about homework and humility, intricate osmosis of critical inquiry and sensitivity, the spirit of curiosity, sense of wonder, and, of course, fact checking.

That's an important point about what and how science gets covered. Far too often, the media either exults in and tries to claim an Indian connection to a notable piece of research by an Indian scientist who left the country 20 years ago, or features scientists based in India only during satellite launches, nuclear power plant protests or major earthquakes. Science as an activity and scientists in their day to day working avatar are rarely featured.  A trigger to change this could come from within too. Few Indian scientists today are using social media platforms to initiate a conversation with the public. There has been a small increase in the number of Indian scientists who do blog with biologists and ecologists (1, 2) taking the lead, but my impression is that far too many write about everything else but their research.

Seema Singh also writes about her interesting encounter back in 2001 with evolutionary paleontologist Stephen Jay Gould who popularized the field of evolution like no other writer except perhaps Richard Dawkins. Gould along with Niles Eldredge proposed the controversial and widely misunderstood theory of punctuated equilibrium. Seema Singh describes it thus: ... which propounded that evolution takes place in rapid spurts of species differentiation, not in continuous transformations.

I wanted to expand on this.

Benjamin Franklin And Erasmus Darwin: Musings About Geology and Evolution

I am reading When You Were A Tadpole and I Was A Fish  by Martin Gardner. It is a collection of essays on science and culture. There is a really good one on the complex personality of Isaac Newton, another one on Ann Coulter's rants against evolution and quite a bit of writing on debunking paranormal claims. I haven't yet finished the entire book with some chapters on literature and religion still unread. I am not sure they will hold my interest as there is more critical dissection of literary figures like Chesterton and a long explanation on why he (Mr. Gardner) is not an atheist than I care to read about.

In one of the chapters Mr. Gardner gives a list of anticipations made by famous figures about how the world works which have turned out to be right, although not in all details. The larger point he is making throughout the book is the lack of evidence for clairvoyance. People are making predictions all the time. Most of them turn out to be wrong. We however tend to remember and wonder only at the tiny fraction that turn out to be correct.

He off course does not categorize Benjamin Franklin and Erasmus Darwin as people making loose predictions. They were both far better thinkers than your run of the mill soothsayers and fortune tellers. Their musings were serious attempts to understand natural processes and were not just opportunistic attention grabbing stunts.

This is Benjamin Franklin in a letter to Abbe Soulaive, September 22, 1782:

"Such changes in the superficial parts of the globe seemed to be unlikely to happen if the Earth was solid to the centre. I therefore imagined that the internal parts might be a fluid more dense, and of greater specific gravity than any of the solids we are acquainted with; which therefore swim in or upon that fluid. Thus the surface of the globe would be a shell, capable of being broken and disordered by the violent movements of the fluid on which it rested."

OF Flies Mice And Men- Francois Jacob 1920 -2013

The great French biologist Francois Jacob died on April 19th 2013. I started this post and left it lingering in draft. I want to post it now.

 Carl Zimmer at The Loom  has an essay which outlines one of the key moments of Jacob's career- when he realized how cells turn genes on and off.  That formed the basis of understanding gene regulation and laid the foundation of the field of developmental biology. For that work he shared the Nobel Prize in 1965 with Andre Lwoff and Jacques Monod.

Francois Jacob also wrote beautifully about evolution. His description of evolution as a tinkerer has become a popular way to think about how evolution builds novelties and puts together complex structures and traits. From his elegant essay on evolution and tinkering published in Science in 1977 :

Natural selection has no analogy with any aspect of human behavior, However, if one wanted to play with a comparision, one would have to say natural selection does not work as an engineer works. It works like a tinkerer - a tinkerer who does not know exactly what he is going to produce but uses whatever he finds around him whether it be pieces of string, fragments or wood, or old cardboards; in short it works like a tinkerer who uses everything at his disposal to produce some kind of workable object. For the engineer, the realization of his task depends on his having the raw materials and the tools that exactly fit his project. The tinkerer, in contrast, always manages with odds and ends. What he ultimately produces is generally related to no special project, and it results from a series of contingent events, of all the opportunities he had to enrich his stock with leftovers. As was discussed by Levi Strauss (5) none of these materials at the tinkerer's disposal has a precise and definite function. Each can be used in a number of different ways. In contrast with the engineers's tools, those of the tinkerer cannot be defined by a project. What these objects have in common is "it might well be of some use". For what? That depends on the opportunities.

I enjoyed reading his books; The Statue Within and Of Flies Mice and Men.

Here is a passage from his book Of Flies Mice and Men where he describes the fear and excitement of changing course midway through his career:

The word "courage" is not too strong. The daily interaction over years with a living organism, however humble, entails a certain familiarity. You could almost say that you acquire a certain tenderness for it. After 15 years of working with a particular colon bacillus, I had accumulated hundreds of mutants. In each of these mutants, one or another of the cellular functions, many of them indispensable to the life and reproduction of the bacteria, had been altered. To abandon this work and all that it offered; to renounce the kind of intimacy that comes with the knowledge of little unwritten quirks, the folklore that surrounds the work of any one organism; to start again from zero with another, unknown organism whose idiosyncrasies I would have to discover - all this was a considerable sacrifice. It was a little like leaving a loved one . But, at the same time, the new project was an exciting one. It would mean entering an unknown world, beginning a new life, becoming young again....

An Account Of Natural Selection By A Victorian Gentleman

Who wrote this...Darwin or Wallace?

There is a law universal in nature, tending to render every reproductive being the best possible suited to its condition that its kind, or organized matter, is susceptible of, which appears intended to model the physical and mental or instinctive powers to their highest perfection and to continue them so. This law sustains the lion in his strength, the hare in her swiftness, and the fox in his wiles. As nature, in all her modifications of life, has a power of increase far beyond what is needed to supply the place of what falls by Time's decay, those individuals who possess not the requisite strength, swiftness, hardihood, or cunning, fall prematurely without reproducing—either a prey to their natural devourers, or sinking under disease, generally induced by want of nourishment, their place being occupied by the more perfect of their own kind, who are pressing on the means of subsistence . . .

There is more beauty and unity of design in this continual balancing of life to circumstance, and greater conformity to those dispositions of nature which are manifest to us, than in total destruction and new creation . . . [The] progeny of the same parents, under great differences of circumstance, might, in several generations, even become distinct species, incapable of co-reproduction.

The answer is neither.

Quote: Darwin On Marriage

Apart from evolution much pondering on the pro's and con's of marriage:

For

"It is intolerable to think of spending one's whole life, like a neuter bee, working, working, and nothing after all," he writes, "No, no won't do – Imagine living all one's day solitarily in smoky dirty London."

"Cheer up. One cannot live this solitary life, with groggy old age, friendless and cold, and childless staring one in ones face, already beginning to wrinkle. Never mind, trust to chance… There is many a happy slave."

Against

"Eheu!! I never should know French, – or see the Continent – or go to America, or go up in a Balloon, or take solitary trip in Wales – poor slave."

read more on this post by James Randerson  The Private Life of Charles Darwin @ Guardian's Notes&Theories.

On Darwin's Bad Days And Long Ponderings

On Krulwich Wonders, Robert Krulwich mines Darwin's correspondence with Charles Lyell in which he complains of bad days and feeling poor and stupid. The great man was not worrying about natural selection but rather an upcoming book on orchids!

There is more on Darwin's tendency to be anxious and careful about his ideas and data:

In his short biography of Darwin, David Quammen writes that he was "nerdy, systematic, prone to anxiety." He was not quick, witty, or social. He spent decades working out his ideas, slowly, mostly by himself, writing letters and tending to a weak heart and a constantly upset stomach. He was a Slow Processor, who soaked in the data, thought, stared, tried to make sense of what he was seeing, hoping for a breakthrough. All around were snappier brains, busy being dazzling, but not Darwin's, which just plodded on until it finally saw something special, hiding in plain view.

Plodded on until it finally saw something special, hiding in plain view.

To that I will add that most people can't see something special, hiding in plain view. Inspiration often comes to the prepared mind and Darwin through his meticulous observations and prolonged days of thinking had a prepared mind, one that was not ideologically constrained but one that could accommodate and not summarily reject more radical notions of nature and change.
 
I am reading right now from  Darwin's Timeline which summarizes chronologically his life. There is a section on his life and work in London after he returned from his epic voyage on the Beagle in 1836. In it are two incidents which sowed the germs of two of the most important ideas on the nature of life and evolution; common descent and natural selection.

The first was in the months of 1837 when ornithologist John Gould on examining the collection of birds from Galapagos announced that what were cursorily identified as finches, wrens and blackbirds were all actually closely related varieties of finches. Why the confusion? Because the birds all had distinctly different shaped beaks. The prevailing world view of nature was that organisms could be grouped into different "kinds" distinguished by large differences in some trait or a collection of traits. Taxonomy was a flourishing field then and that species could be organized into hierarchically related groups was well understood. But that was seen to be the Creator's way of ordering the natural world.

Darwin on receiving Gould's interpretation that these birds were really closely related varieties of just one "kind" i.e. a finch began thinking on a different interpretation of the tree of life, on ways by which one species may change or transmutate into several species differing in one character, in this case the beak. His own collection of finches from the Galapagos was a mess. He had not labelled the birds by the island he collected them from. Fortunately, some other sailors on the Beagle had and using their collection Darwin could place the variation of beaks in a geographic and ecologic context. Perhaps few finches made their way from the South American mainland and populated different Galapagos islands? Isolated on different islands,  some force may have led to the differentiation of beak shape, each specific to a particular island ecology. That is common descent and adaptive radiation as we understand it today. More than natural selection, common descent is probably Darwin's most original contribution to biology.

The second "moment" for Darwin came in October 1838 when he read Thomas Malthus's essay on human population growth. Malthus argued that human populations grow until there is a resource scarcity, thereafter which a struggle for existence ensues and the weak die off. Darwin recognized that resources are limited in nature and a struggle for existence must be taking place wherein some organisms survive to reproduce while those not possessed with the right characters die out without reproducing. Populations will gradually change in character as generation after generation passes through this nature's filter, a process he called natural selection.

The Darwin Timeline is fascinating to read.  In all those months of thinking and rethinking there would have been bad days and days of frustration as Robert Krulwich points to. But Darwin was truly great not just because he had a couple of great ideas but because he took a firm grip on them and had the intellectual courage not to let go even as he increasingly realized that his theory would demolish cherished notions of our place in the universe.

Richard Muller On Reconfirmation Of Temperature Data

NPR Science Friday hosts Berkeley professor Richard Muller whose Berkeley Earth Surface Temperature project investigated whether measured temperature data collected and reported by climate scientists was flawed. His conclusion is that the previously measured data faithfully records that the earth has been warming and that humans are primarily responsible for the temperature increase:

FLATOW: So tell us about your change of mind and heart about this issue.

MULLER: Well, if you had asked me a year ago, I might have said I didn't know whether there was global warming at all. But we had begun a major study, scientific reinvestigation. We were addressing what I consider to be legitimate criticisms of many of the skeptics.

But about nine months ago, we reached a conclusion that global warming was indeed taking place, that all of the effects that the skeptics raised could be addressed, and to my surprise, actually, the global warming was approximately what people had previously said.

It came as a bigger surprise over the last three to six months when our young scientist, Robert Rhode, was able to adopt really excellent statistical methods and push the record back to 1753. With such a long record, we could then separate out the signatures of solar variability, of volcanic eruptions, of El Nino and so on. And actually, to my surprise, the clear signature that really matched the rise in the data was human carbon dioxide and other greenhouse gases. It just matched so much better than anything else. I was just stunned.

Prof. Muller also talks about the urgent need for a policy that provides incentives and financial assistance to switch to natural gas thus cutting down on the need to burn coal. Clean fracking is his rallying point!

Also the Guardian has a long article on Richard Muller and his work.