Evolution of Marine Biodiversity in the Coral Triangle

Overview

The Coral Triangle, also known as the Indo-Australian Archipelago, is celebrated for possessing the highest marine biodiversity on Earth. Despite its ecological importance, the intricate evolutionary history behind this biodiversity hotspot has remained largely unexplored. An international research team has recently illuminated this history, reconstructing how biodiversity in the region has unfolded over the past 40 million years.

Evolutionary History

• The archipelago has shown a significant increase in diversification since the early Miocene, approximately 20 million years ago.
• Around 2.6 million years ago, the number of species reached a plateau.
• No major extinction events were documented during the study period, indicating stable evolutionary progression.

Factors Driving Biodiversity

• Habitat Expansion: Tectonic collisions in Southeast Asia have created extensive shallow marine habitats, fostering increased diversification.
• Thermal Stress Moderation: Approximately 14 million years ago, excessive heat in the region began to moderate, establishing a more favorable environment for biodiversity to thrive.
• Historical Climate: During the Eocene epoch (56 to 34 million years ago), high tropical temperatures hindered biodiversity. However, subsequent cooling periods facilitated the emergence of this biodiversity hotspot.

Current Risks

• The exceptional biodiversity of the Coral Triangle is currently under threat from ongoing anthropogenic warming.
• If these warming trends intensify, the region risks a rapid decline in its unique diversity.

Comparative Insights

• The study offers insights into why the Coral Triangle exhibits greater biodiversity than the Caribbean Sea, primarily due to the absence of significant extinction events in the Coral Triangle region.

Conclusion

The Coral Triangle’s extraordinary marine biodiversity has developed over millions of years, driven by habitat expansion and climatic moderation. Understanding this evolutionary history enhances our appreciation of the region's unique ecological significance and highlights the urgent need for conservation efforts to protect this crucial biodiversity hotspot from the impacts of climate change.

Frequently Asked Questions (FAQs)

Q1. What is the Coral Triangle known for?
Answer: The Coral Triangle is renowned for having the highest marine biodiversity on Earth, featuring numerous species of marine life and unique ecosystems.

Q2. What factors have contributed to the biodiversity of the Coral Triangle?
Answer: Key factors include habitat expansion due to tectonic activity, moderation of thermal stress, and historical climate changes that allowed marine life to flourish.

Q3. How long has the biodiversity of the Coral Triangle been evolving?
Answer: Biodiversity in the Coral Triangle has been evolving over approximately 40 million years, with significant diversification occurring since the Miocene epoch.

Q4. What current threats does the Coral Triangle face?
Answer: The Coral Triangle is threatened by anthropogenic warming, which could lead to a rapid loss of its diverse marine species if climate change continues to intensify.

Q5. How does the Coral Triangle compare to the Caribbean in terms of biodiversity?
Answer: The Coral Triangle has higher biodiversity than the Caribbean primarily due to fewer major extinction events, allowing more species to thrive and evolve.

UPSC Practice MCQs

Question 1: What is the Coral Triangle known for?
A) Highest terrestrial biodiversity
B) Highest marine biodiversity
C) Historical significance
D) Economic resources
Correct Answer: B

Question 2: Which factor is NOT associated with increased biodiversity in the Coral Triangle?
A) Habitat expansion
B) Major extinction events
C) Thermal stress moderation
D) Historical climate change
Correct Answer: B

Question 3: How long has biodiversity been evolving in the Coral Triangle?
A) 10 million years
B) 20 million years
C) 40 million years
D) 56 million years
Correct Answer: C

Question 4: What major threat does the Coral Triangle currently face?
A) Overfishing
B) Pollution
C) Anthropogenic warming
D) Habitat destruction
Correct Answer: C

Question 5: Why does the Coral Triangle have higher biodiversity than the Caribbean Sea?
A) More marine species
B) Fewer extinction events
C) Larger area
D) Different climate conditions
Correct Answer: B