Thursday, April 15, 2021

The Games Lizards Play

I did mean evolutionary games played out over long periods of time, where for example, three colored varieties of one lizard species keep cyclically oscillating in their numbers. Why should this happen? The answer lies in the children's game 'rock- paper- scissors', an analogue for understanding evolutionary strategies for reproductive success.

This is a really fine essay in The Wire Science by evolutionary biologist Raghavendra Gadagkar on the ecology and evolutionary biology of rock lizards. Dr. Gadagkar started out as a molecular biologist but changed course and got interested in the biology of large animals, choosing lizards as one of his research subjects. 

He describes the various life strategies lizards evolve, dependent on ecology and population dynamics. His colleagues Maria Thaker and her student Anuradha Batabyal too are engaged in work on Indian rock lizards. He points out some aspects of their work-

"Ecologists generally take great pride in studying forests and exotic places, the more pristine the better; few study the ecology of their backyard, the trees lining their streets and the lizards that run around them. It is somehow considered too silly for a serious scientist to be doing so.

Much of Anuradha and Maria’s research on rock lizards defies this stereotype. They extract rigorous scientific questions that can only be answered by studying urban animals and comparing them with their rural or forest counterparts. When animals move into urban habitats, they face new challenges, just as we do when moving from villages into cities – new enemies, new resources, and rapid spatial and temporal changes in the environment, requiring a new survival toolkit. How do lizards deal with these problems?
"

It gladdens my heart to see such science coverage in a major Indian news portal. And what about the last sentence? .." I think it’s time we changed the canonical image of the scientist from that of an elderly, bearded man in a white coat to one of an intrepid young woman in the wilderness!"

That this is an admission made by an elderly bearded man makes me even happier.

More Fun Than Fun: My Favourite Lizard Stories- Raghavendra Gadagkar.

Sunday, March 28, 2021

Himalaya Overview, African Population History, Iceland Volcano

 From past couple of weeks:

1) This is a fine synthesis of geological, geophysical, seismic and geodetic data of the growing Himalaya mountains. The review examines the interplay and feedbacks between seismic cycles and tectonic deformation. Earthquakes result in rock deformation and faulting. Tectonic structures developed this way over million of years, in turn, influence stress accumulation and the extent and location of earthquakes.

Building the Himalaya from tectonic to earthquake scales.

2) Holocene-age ancient DNA and genetics of extant populations is increasing our understanding of African population history.

The deep population history in Africa

3) The remarkable drone footage of the ongoing eruption of Geldingadalir volcano in Iceland.


Email subscribers who can't see the embedded video can view it here- Iceland Volcanic Eruption.

Friday, February 19, 2021

Fossil Dickinsonia in Bhimbetka Sandstones: Nature India Article

 My short piece published in Nature India on the surprising report of Ediacaran age fossil Dickinsonia in the Bhimbetka caves near Bhopal, Central India, and its geological and biological significance.

an excerpt:

"The biological affinity of Dickinsonia is controversial. Most scientists tend to accept it as an early animal. Some like Gregory Retallack, co-discoverer of this fossil, think of it to be a large algae or lichen. He argues that the mainstream view that Dickinsonia was a marine animal is based on weak evidence, while his own detailed work shows that Dickinsonia was a land creature, forming biogenic crusts on soils. Interestingly, the Bhimbetka rocks were deposited in a mostly terrestrial setting, more in alignment with Retallack's interpretation. Importantly for geology, its restricted time span, being found only in rocks between 555-550 million years old, makes it a diagnostic age indicator. So far, no animal fossils have been found in the Vindhyan rocks. This finding may inspire geologists to start searching contemporaneous Indian basins afresh for such subtle clues".

Fossil from dawn of animal life found in India’s famous caves.

Wednesday, February 17, 2021

Readings: Chamoli Debris Flow Disaster, Uttarakhand

The Himalaya are geologically and ecologically fragile. Despite this, the Indian government has repeatedly ignored advice from its scientists and has gone ahead with major infrastructure projects, which have not been assessed rigorously for the inevitable impact they will have on the surrounding environment, people and livelihoods.

The February 7 2021 Chamoli debris flow that destroyed two dams and killed scores of people with hundreds still missing is the latest example of how the natural tendency of Himalayan slopes to fail combines with steel and concrete to cause enormous damage. 

Here is a short list of readings of this event and Himalaya infrastructure projects.

1) Dr. Dave Petley has put together a sequence of events based on crowd sourcing satellite imagery. This was a remarkable example of experts collaborating to pinpoint the location and cause of this debris flow within just a day. 

The catastrophic landslide and flood in Chamoli in Uttarakhand: the sequence of events.

 2) M. Rajshekar explores the messianic drive of the Central and the Uttarakhand government to build dams in the Himalaya. 

Modi said he would revive Ganga but his government is doing the opposite by reviving dams

3) R.Shreedhar, an experienced earth scientist working in the Himalaya writes a fine essay about the neglect of science and the political economy of Himalaya dam building.

The Science and the Political Economy of the Rishi Ganga Flood.

4) The title of this essay by Nivedita Khandekar says it all.. "We have learnt nothing from the 2013 Uttarakhand Disaster".

We have learnt nothing from 2013 Uttarakhand disaster.

 

Sunday, January 31, 2021

Mammalian Evolution, Earth Biosphere, India Geology Outreach

 Sharing these interesting items:

1) Simone Hoffman writes about one of the fundamental transitions in mammalian evolution, the transformation of bones of the lower jaw into those of the middle ear.

Lend an ear to a classic tale of mammalian evolution.

2) How has the earth's evolving biosphere from early microbes to megascopic land plants impacted the biogeochemistry of the earth? A great review article by Noah Planavsky and colleagues. Read this one quickly. It is open access for now, but might go behind a paywall in the next few weeks.

Evolution of the structure and impact of Earth’s biosphere.

3) Live History India anchored by Mini Menon has produced a great geology outreach video. Four geology enthusiasts talk about India's varied geology, how to raise awareness among our citizenry about the importance of geology in our lives, and the urgent need to protect sites of exceptional geological significance. Dr. Pushpendra Ranawat, Bidisha Bayan, Dr. Reddy, and Aliya Babi are the guests. 

Do make the time and watch this. Email subscribers who can't see the embedded video can watch it here - India: What Lies Beneath.