Why in News?
What are Sentinel Species?
Definition
Characteristics of Sentinel Species
Classic Examples of Sentinel Species
Frogs (Most Common Example)
Canaries in Coal Mines (Historical Example)
Honeybees
Polar Bears
Certain Fish Species
Emperor Penguins (Current Example – April 2026)
Static-Dynamic Linkage
Source/Reference:
https://www.thehindu.com/sci-tech/science/what-are-sentinel-species/article70853746.ece/amp/
Why in News?
A study by 23andMe (published in Nature, April 2026) of nearly 28,000 users found that genetic variations in GLP1R and GIPR genes influence weight-loss efficacy and side effects of GLP-1 drugs (e.g., semaglutide, tirzepatide).
Separately, a single mutation in non-coding DNA (Enh13) caused complete male development in XX mice embryos, highlighting the role of the 98% non-coding genome in development and disease.
GLP-1 Drug Response Study (23andMe / Nature)
Key Findings on Weight Loss (GLP1R gene mutation):
Key Findings on Side Effects (GLP1R & GIPR mutations):
Significance:
Sex Reversal Study (Bar-Ilan University / Nature Communications)
What Happened?
Significance of Non-Coding DNA Finding
Static-Dynamic Linkage
Source/Reference:
Why in News?
What is Keytruda?
Basic Profile
Mechanism of Action
How Immunotherapy Differs from Chemotherapy and Radiation
Chemotherapy / Radiation
Immunotherapy (Keytruda)
Other Immunotherapy Types
CAR-T Cell Therapy
mRNA Cancer Vaccines
Availability in India
Monoclonal Antibodies Available
Indigenous CAR-T Therapy
Cost & Access in India
Pricing
Patient Access Programme
Government Support
Patent Expiry (2028)
India’s Cancer Burden: Why This Matters
Current Statistics
Trend (GBD 2023)
Comparison with Australia
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Source/Reference:
Why in News?
Background of the Case
What Happened?
Procedural History
Centre’s February 2026 Submission
Key Safeguards under FRA (Detailed in Joint Affidavit)
Multi-Tier Verification Process
Gram Sabha and Forest Rights Committee
Role of Forest Department (Rule 12A(1))
Duties of Rights-Holders and Gram Sabha
Legal Framework: Two Key Laws
Forest Rights Act (FRA), 2006
Van (Sanrakshan Evam Samvardhan) Adhiniyam, 1980 (Forest Conservation Act, 1980)
The Core Legal Question: Does recognition of individual rights under FRA automatically exempt the need for prior approval under Forest Conservation Act for construction of dwelling houses on forest land?
Static-Dynamic Linkage
Source/Reference:
Why in News?
What are Shadow Libraries?
Definition
Key Platforms
Characteristics
Why Do People Use Shadow Libraries?
The Access Problem
User Voices
The “Serials Crisis”
The Shifting Landscape: 2026 Developments
Anna’s Archive Scrapes Spotify (Late 2025)
Legal Response
AI Training Controversy
Internal Conflicts Within Shadow Libraries
No Unified Philosophy
The Legal Alternative: Open Access in India
Diamond Open Access
Key Initiatives
Open Access India’s View
Static-Dynamic Linkage
Source/Reference:
Why in News?
What are Morel Mushrooms (Morchella)?
Basic Profile
Market Value
Traditional Harvesting Challenges
The Scientific Breakthrough
Research Process
Cultivation Methods
Patent Status
Why Was Cultivation So Difficult?
Major Scientific Challenges
How They Overcame It
Significance and Impact
Economic Significance
Strategic Significance for J&K
Ecological Conservation
Beneficiaries
Static-Dynamic Linkage
Source/Reference:
UPSC Mains Subject: GS Paper III – Environment & Ecology (Climate Change) | GS Paper I – Society (Health)
Sub-topic: Climate-Health Intersection; Urban Heat Islands; Occupational Hazards
Introduction
Climate change is intensifying heat stress by combining high temperatures with humidity, limiting sweat evaporation. New research lowers the safe wet-bulb threshold to ~31°C, exposing vulnerable groups and highlighting gaps in India’s climate adaptation.
Main Body
Understanding Wet-Bulb Temperature
What It Measures:
The Science:
Traditional Threshold:
New Finding (Nature Communications):
India’s Lived Reality: Heat Indices Pushing Limits
The Navi Mumbai Tragedy (Three Years Ago):
Key Insight:
Urban Heat Islands: Concrete, Sparse Trees, No Nighttime Relief
What Creates Urban Heat Islands:
The Consequence:
Social Conditions: Heat as Occupational Hazard
Vulnerable Workers:
The Problem:
Heat Action Plans: Inadequate and Not Attuned
Current Gaps:
What Is Needed:
Way Forward
For Urban Planning:
For Heat Action Plans:
For Worker Protection:
For Early Warning Systems:
Conclusion
The new study in Nature Communications reframes India’s climate challenge: the safe wet-bulb limit for human endurance may be 31°C, not 35°C—and this lower threshold can be unforgiving for the elderly and outdoor workers. The Navi Mumbai tragedy, where 13 died at just 35°C dry temperature, underlined the need to redraw metrics of well-being during summer. Yet planning remains slow.
Concrete-dense urban heat islands offer no nighttime relief. Heat action plans are based on dry-heat thresholds, not the more dangerous heat-humidity combination. Protecting people requires granular knowledge, localised planning, and recognition that heat is now an occupational hazard for millions of workers. India’s cities do not have time to lose.
UPSC Mains Practice Question
UPSC Mains Subject: GS Paper III – Economy (Globalisation) | GS Paper II – International Relations
Sub-topic: Geopolitical Risks; Energy Security; Demographic Dividend; Supply Chain Resilience
Introduction
The assumption that wars are a near-impossibility in an age of hyper-economic interdependence lies in tatters. The first wave of globalisation (1870s onwards) made the US an economic superpower. The second wave (post-1989) enabled China’s emergence as the “world’s factory.” This decade ought to have been India’s—favourable youth demographics, digitisation (Jan Dhan-Aadhaar-Mobile), formalisation (GST, demonetisation), and infrastructure investments.
Yet, the demographic dividend has not materialised due to successive disruptions: Covid, wars in Ukraine and Iran, and US unilateral tariffs. Today, war has shrunk India’s political and economic space for easy solutions.
Main Body
India’s Missed Demographic Dividend
What India Had Going for It:
What Went Wrong:
The Result:
The Comparison:
Globalisation’s Foundational Assumptions Upended
What Globalisation Was Built On:
What Has Happened:
The Consequence:
What Indian Policymakers and Firms Must Do
Factor Geopolitical Risks into Growth Strategies:
Stay the Course on Reforms:
No More Low-Hanging Fruit:
Urgent Policy Reforms That Can No Longer Wait
Fertiliser Subsidy Regime:
State Discom Losses:
Way Forward
For Energy Security:
For Supply Chain Resilience:
For Structural Reforms:
For Macroeconomic Stability:
Conclusion
India was poised for a growth surge, but Covid, wars, and protectionism have constrained its trajectory. With global interdependence no longer a safeguard, policymakers must embed geopolitical risk, diversify supply chains, accelerate reforms, and address structural issues like fertiliser subsidies and discom losses—there are no easy solutions left.
UPSC Mains Practice Question