DeepSummary
The podcast episode discusses the discovery of a species of predatory worms called Selkirkia that lived 25 million years longer than previously thought. During the Cambrian period, around 500 million years ago, the ocean was teeming with diverse and alien-looking marine life forms, including these worms with teeth and spines covering their throats. Researchers believed these worms went extinct at the end of the Cambrian, but a recent paper in Biology Letters revealed fossils of a new Selkirkia species dating back to the early Ordovician period, 475 million years ago.
The discovery of this time-traveling worm challenges the traditional boundaries between geological time periods and suggests that some ancient life forms may have persisted for much longer than expected. Karma Nanglu, a postdoctoral fellow at Harvard and one of the paper's authors, explains that this finding expands the longevity of the Selkirkia group to an impressive 40 million years, during which they maintained their simple yet effective lifestyle of building tubes and ambushing prey.
While this discovery raises questions about the fuzziness of time period boundaries and the potential for other ancient groups to have survived longer than thought, Nanglu emphasizes the intrinsic value of studying these fossils. Understanding the origins of modern marine life and appreciating the beauty and diversity of these ancient creatures inspires curiosity and wonder about the natural world.
Key Episodes Takeaways
- A new species of predatory worms called Selkirkia was discovered in fossil records dating back to the early Ordovician period, 475 million years ago, challenging the belief that they went extinct at the end of the Cambrian period around 500 million years ago.
- This discovery expands the known longevity of the Selkirkia group to an impressive 40 million years, during which they maintained their simple lifestyle of building tubes and ambushing prey.
- The finding raises questions about the boundaries between geological time periods and whether they are as distinct as previously thought, with some ancient life forms potentially persisting across multiple periods.
- Studying ancient fossils like the Selkirkia worms allows researchers to understand the origins of modern marine biodiversity and appreciate the diversity and beauty of these ancient creatures.
- While conservation paleobiology focuses on more recent timescales to inform predictions about climate change, studying deeper time periods like the Cambrian and Ordovician offers intrinsic value in understanding the fundamental origins of life on Earth.
- The Cambrian period, around 500 million years ago, witnessed a rapid increase in biodiversity known as the Cambrian Explosion, with the appearance of most major animal groups seen in modern environments.
- The Ordovician period, following the Cambrian, saw the emergence of more complex modes of life, increased speciation rates, and the expansion of life into the water column.
- The discovery of the time-traveling Selkirkia worm challenges the traditional narrative of distinct evolutionary events happening in separate geological periods, suggesting more continuity and overlap across these boundaries.
Top Episodes Quotes
- “And worms in particular are definitely gross. Like, I'm not going to deny that for a second. They can smell like chemicals or sometimes they're covered in mucus, but they're also colorful. Some of them look ghostly. Some of them are under the sort of sea floor, but there's also, like, a real understated, sort of underappreciated beauty to them.“ by Karma Nanglu
- “Well, it really plays into a much larger debate that's going on research at the time or at this time, rather. So we have events, like a really classic narrative during the ediacaran period. That's when life sort of got big, it got macroscopic, and the cambrian explosion fills out most of the diversity that we see in modern environments as well. And then during the Ordovician, we get much more complicated modes of life. We start to get increase in speciation rates. Things start moving up into the water column more. So that's the traditional narrative. But some researchers have sort of questioned how much some of these events actually represent completely separate phenomena.“ by Karma Nanglu
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Episode Information
Short Wave
NPR
4/17/24
Researchers thought these tiny terrors died out at the end of the Cambrian period. But a paper published recently in the journal Biology Letters showed examples of a new species of this worm in the fossil record 25 million years after scientists thought they'd vanished from the Earth. One of the authors of the paper, Karma Nanglu, tells us how this finding may change how scientists understand the boundaries of time.
Curious about other weird wonders of the ancient Earth? Email us at shortwave@npr.org.
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