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HOW DO TIBETANS & ANDEANS FLOURISH IN THIN AIR?

Relevance:

• Anthropology Optional: Man’s physiological responses to environmental stresses: hot desert, cold, high altitude climate
• GS 3 – Science and Technology- developments and their applications and effects in everyday life.

Why in the News?

• Unique case of convergent evolution: People in the Andes & Tibet, despite being separated by vast distances, developed similar genetic adaptations to thrive in thin air.
• Unlocking the secrets of high-altitude adaptation: The paper led by Elijah S Lawrence in Science Advances, the journal of the American Association for the Advancement of Science research, sheds light on how humans can survive and even thrive in extreme environments.
• Potential medical implications: Understanding these genetic adaptations could lead to new treatments for altitude sickness and other conditions related to oxygen deprivation.

Convergent Evolution in High Altitude Adaptation:

• People living above 4,000 meters in the Andes and Tibet have independently developed similar genetic responses to mountain sickness.
  • Despite historical and geographical divisions, both groups exhibit nearly identical genetic mutations.
• These mutations, occurring 20,000 years apart in the Andes and Tibet, enable humans to thrive in low-oxygen environments.

EPAS1 Gene Adaptations in Tibetans and Andeans

• Common Genetic Site:
  • Adaptations in Tibetans and Andeans are centered around changes in the EPAS1 gene.
  • The EPAS1 gene is extensively studied for its role in responding to hypoxia, the primary cause of mountain sickness.
• Physiological Responses:
  • The genetic adaptations trigger responses such as increased production of red blood corpuscles and alterations in blood vessels.
  • These responses aim to enhance perfusion and oxygenation, providing superior adaptation to high-altitude environments.
• Efficient Oxygen Transport and Metabolism:
  • Individuals with these genetic mutations showcase improved efficiencies in both oxygen transport and metabolism.
  • This enables them to function effectively in high-altitude atmospheres, where others may experience pulmonary and cardiovascular distress.

Genetic Relatedness Between Himalayan and Andean Populations:

• Despite the geographical separation, the Tibetans and Andeans may not be as unrelated as their locations suggest.
• Tibetans are believed to have inherited their EPAS1 gene variants from the Denisovans, a group of hominins discovered in the Altai mountains in Siberia.
• Denisovan Influence
  • The Denisovans are poorly represented in the fossil record compared to Neanderthals, but they have left genetic traces in modern human populations.
  • While the evidence for Denisovans is fragmentary, it’s conceivable that some of their population migrated southward, leaving genetic imprints in India, and possibly eastward across Beringia into the Americas.

Differential Mechanisms

• In Tibetans, the effects of EPAS1 gene adaptations are epigenetic, operating through pathways outside the genome.
  • These adaptations do not seem to involve the coding sections of the EPAS1 gene, responsible for determining amino acids expressed during protein synthesis.
• Conversely, in Andeans, the genetic alterations in the EPAS1 gene occur in a coding region.
  • These changes are inherent in the genetic code, indicating a distinct mechanism compared to the epigenetic effects observed in Tibetans.
• Significance of EPAS1 Variant in the Andes
  • The discovery of an EPAS1 variant in the Andes population addressing hypoxia is both theoretically and practically significant.
  • Theoretically, it contributes to the understanding of human taxonomies by comparing and contrasting genetic adaptations across populations.
  • Opportunities for such comparisons are limited among humans, underscoring the importance of such findings in expanding scientific knowledge.

Alien Contact

• The human sciences are likely to celebrate significantly upon the contact with space aliens.
• The diversity of alien species would provide ample opportunities for comparison and contrast with humans, enriching scientific understanding.
• Potential Alien Differences
  • The greater the divergence between humans and aliens, the more valuable the scientific insights would be.
  • However, if aliens closely resemble humans, it would satisfy politicians and diplomats seeking familiar interactions but disappoint scientists hoping for novel discoveries.
• Comparison in the Absence of Aliens
  • Without contact with space aliens, scholars studying humanity focus on comparing human variations.
  • This includes examining cultural, technological, and biological differences among human populations.

Two Forms of Race

• A cultural and political construct based on notions of superiority and inferiority, which is imaginary and condemnable.
• The other form of race is biological and factual, reflecting evolutionary adaptations to different environments.

Biological Race

• Evolution has led to the development of distinct biological races among human populations, shaped by historical and geographical factors.
• These races exhibit varied responses to their environments, such as differences in prevalence and reactions to conditions like nut allergies and cancer.
• Cancer susceptibility and responses to treatment can vary among racial groups, highlighting the importance of understanding biological race in healthcare and medical research.
• Biological Significance of Race in Medicine:
  • Ewing’s sarcoma, for example, predominantly affects white boys and rarely occurs in colored girls, indicating racial disparities in disease susceptibility.
  • Previously, race was considered biologically meaningless in medical literature, but it is now recognized as a valuable factor in medical guidance and understanding.

Benefits of Understanding this relationship

• Discovery of the Adaptation
  • The discovery of two distinct races adapting to high altitudes through the same genetic site is remarkable.
  • This adaptation is also observed in the coelacanth, a lobe-finned fish, suggesting an ancient mechanism for coping with low oxygen levels in sea water.
• Environmental Adaptation
  • Understanding the role of the EPAS1 gene in hypoxia adaptation gains importance in the context of an overcrowded planet.
  • As glaciers melt and highlands become more habitable due to climate change, populations with adaptations to high altitudes may become increasingly valuable.
• Implications for Space Exploration:
  • As governments and corporations explore manned space missions, individuals adapted to high altitudes could be in demand due to their ability to thrive in low-oxygen environments.
  • This creates a political irony, where the genetic advantage of high-altitude adaptation, such as the prevalence of the EPAS1 variant in Tibetans compared to Han Chinese, could influence recruitment for space missions.
• Potential Political Implications:
  • With around 90% of Tibetans possessing the EPAS1 variant compared to only 9% of Han Chinese, this genetic difference could play a role in decisions regarding space exploration, such as Mars base planning, potentially favoring Tibetan minorities in recruitment due to their genetic edge.

Source: https://www.newindianexpress.com/opinions/2024/Feb/16/how-do-tibetans-andeans-flourish-in-thin-air

Mains question

Discuss the genetic adaptations to high altitudes. Evaluate the implications of such adaptations in diverse geographical regions. (250 words)