StarTalk Podcast: Cosmic Queries – Sharks, with Neil deGrasse Tyson & Jordan Klepper

Megalodon Myths

The megalodon, a giant prehistoric shark, often sparks curiosity about its possible existence today. Jasmin Graham explains that while the ocean remains largely unexplored, the megalodon's extinction is supported by the evolution of its prey, such as whales, which grew larger after the megalodon's disappearance 1. She notes that the megalodon was not a deep-sea dweller, making it unlikely to remain hidden in unexplored ocean depths. Neil deGrasse Tyson humorously defends the creative liberties taken in movies like "The Meg," questioning the accuracy of their portrayal of the megalodon 2.

You can't hide a huge animal.

--- Neil deGrasse Tyson

Jasmin adds that while we lack complete fossil evidence, the likelihood of the megalodon having more gill slits than its relatives is slim.

   

Evolutionary Insights

Understanding shark evolution offers valuable insights into marine ecosystems. Jasmin Graham shares her journey into shark science, highlighting their unique adaptations like cartilage-based skeletons and strong teeth, which make them efficient predators 3. She explains that marine mammals, once land-dwellers, returned to the ocean, showcasing evolutionary adaptability. This adaptability might allow sharks to thrive despite climate change, potentially leading to increased intelligence 4.

It's a perfect design, perfect killing machine.

--- Neil deGrasse Tyson

Neil deGrasse Tyson notes that such evolutionary traits have made sharks formidable hunters in the marine world.

   

Greenland Sharks

The Greenland shark captivates scientists with its potential lifespan of over 500 years. Jasmin Graham discusses the methods used to estimate their age, such as carbon dating and vertebrae calcification, acknowledging the challenges in obtaining precise data 5. These sharks exhibit indeterminate growth, meaning they continue to grow throughout their lives, albeit at a slower pace as they age.

The bigger the shark, the older it is.

--- Jasmin Graham

While the exact age of Greenland sharks remains uncertain, they are undoubtedly among the longest-living vertebrates, offering a fascinating glimpse into the mysteries of marine life.