Great White Sharks’ DNA Puzzle Stumps Scientists

Quick Summary

• Scientists have discovered stark differences between the nuclear DNA and mitochondrial DNA of white sharks,invalidating previous theories about migration-driven genetic variation.
• A study reveals that during the last ice age, 10,000 years ago, great whites were restricted to a single population in the southern Indo-Pacific Ocean before expanding globally.
• By 7,000 years ago, thes sharks began splitting into genetically distinct groups; three major populations exist today: Southern Hemisphere (Australia/South Africa), Northern Atlantic, and Northern Pacific.
• Despite their global distribution, white shark numbers remain low-estimated at around 20,000 individuals worldwide.
• Previously accepted explanations for genetic discordance linked to male-female migration patterns (philopatry) or reproductive skew are refuted by new findings from extensive nuclear and mitochondrial DNA analyses.
• There is speculation that natural selection could explain mitochondrial variation but remains unverified as it woudl require extraordinarily strong selective pressures.

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Indian Opinion Analysis

This discovery sheds light on the evolutionary history of an apex marine predator while highlighting its ongoing vulnerability due to small population sizes and genetic isolation risks. For India-with its vast coastline-it underscores the importance of preserving marine ecosystems amid climate change impacts revealed through this study’s past insights into habitat reductions during the last ice age.

Though not directly related to Indian waters per se given no mention in observed data on specific regions like Goa or Tamil Nadu coasts… broader regional Conservation Policy