Палеоэнтомологические исследования пермо-триасового вымирания Еськов Кирилл

Summary

This transcript delves into the study of mass extinctions, particularly the Permian-Triassic boundary, focusing on new research from entomology. It challenges traditional views by suggesting that the extinction event was not as abrupt or catastrophic as once thought. Instead, it was a prolonged process over millions of years, driven by internal biological factors. The speaker emphasizes the importance of insect fossils in understanding biodiversity shifts and refutes the idea that volcanic eruptions alone caused the extinction, proposing that gradual ecological changes were more significant.

Takeaways

• 😀 The topic of mass extinctions is captivating to many people, especially when discussing the most famous one: the extinction of the dinosaurs at the boundary of the Mesozoic and Cenozoic eras.
• 😀 The greatest mass extinction, according to some paleontologists, occurred at the boundary between the Permian and Triassic periods, marking the end of the Paleozoic era, with an estimated 90% of marine life being wiped out.
• 😀 A 2003 monograph by British paleontologist Ben presents a controversial perspective on the Permian-Triassic extinction event, suggesting that life on Earth did not nearly perish as previously believed.
• 😀 Russian paleontologists, especially Alexander Pavlovich Ranin, have recently challenged traditional views on mass extinctions, offering new insights based on their extensive research on continental fossil records.
• 😀 Insects are one of the most abundant groups on Earth and their study has provided crucial evidence for rethinking extinction events. Unlike marine fauna, insect fossil records offer clearer insights into continental biodiversity.
• 😀 The mass extinction event at the boundary of the Permian and Triassic periods was likely influenced by a significant volcanic eruption in the Siberian Traps, but this catastrophic event was only a part of a larger ongoing ecological transition.
• 😀 Despite the volcanic eruptions, the patterns of life disruption were more gradual, spanning millions of years, rather than the sudden catastrophe often depicted in traditional extinction theories.
• 😀 Russian paleontologists have an excellent fossil record of continental fauna from the period around the Permian-Triassic boundary, helping to better understand the ecological shifts that occurred during the extinction.
• 😀 The extinction crisis, though severe, was not as abrupt as previously thought. The decline in biodiversity was more extended and less sharp than earlier models suggested.
• 😀 Modern studies based on insect fossils reveal that, although biodiversity suffered at the Permian-Triassic boundary, the rate of extinction was not significantly different from the background extinction rates that occurred over millions of years.
• 😀 Comparing different methods of measuring extinction (e.g., classical versus cumulative diversity curves) has shown that traditional models exaggerate the sharpness of the extinction event and that the real changes were more gradual and biologically driven.

Q & A

What is the most popular mass extinction event among the public?

The most popular mass extinction event among the public is the extinction at the boundary between the Mesozoic and Cenozoic eras, specifically the extinction of the dinosaurs at the end of the Cretaceous period.

Which mass extinction is considered the largest according to the speaker?

The largest mass extinction, according to the speaker, is the Permian-Triassic extinction, also known as the Great Dying, which occurred at the boundary between the Paleozoic and Mesozoic eras.

What was the main focus of the studies by paleontologist Ben and entomologist Alexander Pavlovich Ranin regarding mass extinctions?

Ben's study in 2003 focused on the Permian-Triassic extinction and the dramatic ecological collapse, while Alexander Pavlovich Ranin argued against the idea that life nearly died out, suggesting a more gradual process.

Why do the scientists focus on insect fauna when studying mass extinctions?

Insects are used because they are the most diverse group of organisms on Earth, and their fossil records offer a more representative view of biodiversity compared to marine fauna, which was traditionally the focus.

How do marine faunal data differ from continental faunal data in the study of mass extinctions?

Marine faunal data is easier to track because of continuous stratigraphic layers and clearer fossil sequences, whereas continental faunal data is more complex due to the fragmented and isolated nature of the fossil records.

What is the current dominant theory regarding the cause of the Permian-Triassic extinction?

The dominant theory is that the Permian-Triassic extinction was caused by catastrophic volcanic activity, specifically the eruptions associated with the Siberian Traps, which released massive amounts of volcanic gases and altered the atmosphere.

What new insight has been gained from studying insect fossils in relation to the Permian-Triassic extinction?

Studies of insect fossils suggest that the Permian-Triassic extinction was not as abrupt or catastrophic as previously believed, and the extinction process occurred gradually over tens of millions of years, with a more complex biological mechanism at play.

What is the issue with previous models of mass extinction that focused on marine fauna?

Previous models focused heavily on marine fauna, but these models failed to capture the full scope of biodiversity loss, as the majority of Earth's biodiversity is concentrated on land, not in the oceans.

How did the study of insect fauna change the understanding of the extinction crisis at the Permian-Triassic boundary?

The study of insect fauna revealed that the extinction crisis at the Permian-Triassic boundary was not as sharp or as sudden as previously thought. The changes were more spread out over time, with a much slower process of turnover.

How does the speaker relate the research on mass extinction to historical events like the assassination of Archduke Franz Ferdinand?

The speaker compares the overemphasis on catastrophic events in mass extinction research to the overanalyzing of the assassination of Archduke Franz Ferdinand, suggesting that such studies, while important, miss the broader and more complex long-term processes that contribute to these events.