A groundbreaking new study using advanced Artificial Intelligence (AI) has rewritten the history of sharks. The research reveals that the giant asteroid strike that wiped out the dinosaurs 66 million years ago had a surprisingly small effect on sharks and rays.
Researchers from Swansea University led the project, using a special “deep-learning” AI model to analyze the largest collection of shark fossils ever assembled.
The new AI tool has significantly improved our understanding of shark evolution over the past 145 million years. Studying the distant past is notoriously difficult due to the incomplete and “messy” nature of fossil records.
However, this AI was able to “fill in the gaps,” correcting errors and identifying subtle patterns missed by human researchers. As a result, it created the most accurate timeline to date.
The resulting data challenge prior scientific beliefs about the resilience of sharks. Unlike the dinosaurs, which suffered a total mass extinction on land from the asteroid impact, sharks and rays proved incredibly resilient.
Surprisingly, the global disaster caused a drop of only about 10% in shark and ray species. This permitted them to survive and continue to thrive long after the dinosaurs vanished.
However, the news is not all in favor. The number of different shark and ray species was highest around 50 million years ago, according to this research. Since then, the number has slowly dropped. The oceans have naturally lost more than 40% of their shark and ray species over the last 50 million years.
Lead author Dr. Catalina Pimiento cautions that today’s sharks are already in a weak state. Because their numbers have been shrinking for millions of years, they are starting from a “reduced baseline.”
The implication is that these species are in greater danger than previously understood when confronting modern human-caused dangers such as overfishing and climate change. They have already been significantly weakened in their evolutionary capacity. This highlights the importance of safeguarding the remaining few.