The Common Descent Podcast

We talk about fossils a lot on this podcast – every episode, in fact – but we rarely take the time to discuss how fossils get the way they are. This is a crucial subject, because the fossilization process is a filter, and nothing comes through the filter unaltered, and many things don’t come through at all. In this episode, we talk about how fossils typically form, how we study this process, and w...

Seahorses are very strange fish, with their upright posture, tube-like mouths, and various other unusual features. Along with their cousins in the family Syngnathidae, seahorses have been the subject of much research into how they came about their bizarre body plans and lifestyles. In this episode, we discuss a bit of what we know of how seahorses (and their relatives) do what they do, and how the...

Our highest-level supporters on Patreon get their own special mini-episode on a topic of their choosing! We released the first five in a compilation a while ago, and now that we’ve done five more, here’s another compilation for everyone to enjoy. Special thanks to our Patrons for their generous contributions, and thanks also to our special guest, Laura! 00:00:00 Intro 00:02:15 Crinoids for Lewis 0...

Every plant starts somewhere, and often that somewhere is inside a seed. Seeds are among the most diverse and important evolutionary innovations of plants, allowing species to survive, thrive, and travel between generations in extraordinary ways. This episode, Aly joins us to discuss how seeds do what they do, how seeds have evolved over time, and how seeds are invaluable resources for paleontolog...

Paleoartist Rob Soto has created some fantastic artwork for the podcast over the years. Most recently, for our Five Year Anniversary celebration, he produced our Five Year logo and a series of movie-poster-style depictions of famous fossil localities, all now available on our merch store! In this special episode, we continue our Five Year celebration by sitting down with Rob to discuss his backgro...

Blood is nutritious, easy to digest, and not hard to come by, so it’s unsurprising – if a bit unsettling – that thousands of species have evolved a taste for the stuff. From birds to bats to bugs, the diversity of sanguivores includes a wide variety of body plans, feeding strategies, and unique evolutionary histories, all converging upon a similar set of behaviors and features honed for a diet of...

None of us are alone. Like, in the literal, biological sense. Symbiotic relationships – close interactions between unrelated organisms – are a defining feature of life on Earth. Each of our bodies has its own share of parasites, hitchhikers, and tiny helpers, and some of the most prominent ecosystems on Earth function only by virtue of the symbiotic relationships at their foundations. In this epis...

Episode 132 – Mary and Louis Leakey Happy Darwin Day! Mary and Louis Leakey are two of the biggest names in the history of paleoanthropology and human evolution, and they’re one of history’s most impressive scientific duos. In this episode, our special guest takes us through the tales of the Leakey’s most important scientific work, their personal lives, and the ongoing impact they’ve had on modern...

Volcanoes are fascinating, devastating, and fundamental to Earth systems. Volcanic eruptions can transform ecosystems, landscapes, and even the atmosphere, and at their most extreme, the effects of volcanism can be global and long-lasting. In this overstuffed episode, we discuss the many forms and features of volcanic activity, and we take a look at the complex and dramatic interaction between vol...

With every breath you take, you’re collecting information about your surroundings. We humans are actually pretty skilled smellers, as these things go, but olfactory abilities vary widely across the animal kingdom (and beyond). In this episode, we discuss how smelling works, what smelling is good for, and how scientists explore the evolutionary history of smell. In the news: giant ichthyosaurs, gia...

Happy New Year! Thanks as always to everyone who submitted questions for the Q&A. Thanks to everyone for listening, sharing, and supporting the podcast this year and for our whole run of nearly five years. We make the podcast, but you, our audience, make the podcast possible. More to come. See you in 2022. Check out our blog for bonus info and pictures: http://commondescentpodcast.wordpress.com/ J...

Today, rhinos are famous for their large size and impressive horns (and their distressing conservation status, sadly), but modern rhinos are only a small sample of what rhinos have been over time. Thanks to a surprisingly good rhino fossil record, we have a pretty good picture of how these animals got started and of the surprising forms they’ve taken since, from horse-like runners to hippo-shaped...

Far below the ocean surface is a vast environment of cold, darkness, very scarce food, and surprisingly diverse life. Deep sea life is quite mysterious, in part because of their unusual adaptations for surviving in such tough habitats, and also because it’s very difficult to study organisms of the deep, modern or fossil. In this episode, we discuss what is known about the adaptations, evolutionary...

Surprise! A special short(ish) episode of Silver Screen Science to discuss the Prologue/Trailer for Jurassic World: Dominion! Time markers: Science Discussion: 00:00 More Thoughts: 25:00 We're now taking questions for our End of the Year Q&A! Submit your question here: https://forms.gle/Q3jHtLSp5CdFuAuL9 Join us on Patreon to support the podcast and enjoy bonus content! https://www.patreon.com/com...

Located across a wide area of the Upper Great Plains of the United States, the Hell Creek Formation is one of the world’s premier locations for studying the Age of Dinosaurs, especially trends of evolution – and extinction – at the very end of the Mesozoic Era. In this episode, we discuss the ancient history and scientific history of the region, including some famous finds and groundbreaking resea...

Evolution loves to plagiarize. You might be surprised at just how useful it can be for an organism to copy the signals, sights, sounds, and smells of others. Mimicry is all about making use of miscommunication. In this episode we’ll discuss the astounding diversity of modern mimics, the rare examples of fossil mimics, and the complex and confusing evolution patterns of mimicry. In the news: Cambri...

Orchids are among the most diverse and widespread group of plants on Earth today, not to mention one of the most popular among plant enthusiasts. This episode, we discuss what makes orchids so unique and strange, as well as the many mysteries surrounding their evolution and deep history. As with all our plant episodes, Aly is on hand to tell us all about why orchids are so fascinating. Featuring s...

Welcome ... to Spookulative Evolution. October is here, and that means it’s time for Spook-E! Each episode throughout this month, we’re choosing a famous monster and discussing how it – or something like it – might evolve under the rules of evolution and natural selection, pulling inspiration from organisms of the real world. This year’s theme: monster plants. This episode, we face a more modern m...

Welcome ... to Spookulative Evolution. October is here, and that means it’s time for Spook-E! Each episode throughout this month, we’re choosing a famous monster and discussing how it – or something like it – might evolve under the rules of evolution and natural selection, pulling inspiration from organisms of the real world. This year’s theme: monster plants. This episode, we evaluate a famous an...

An Earth covered in ice might sound far-fetched, but there’s reason to think it has actually happened in the past – more than once. In this episode, we examine the Snowball Earth hypothesis and the geologic evidence and climate models that back it up, as well as some of the major lingering questions: Just how snowy is the snowball? How could this start? How could it end? And how did life fare on a...

Welcome ... to Spookulative Evolution. October is here, and that means it’s time for Spook-E! Each episode throughout this month, we’re choosing a famous monster and discussing how it – or something like it – might evolve under the rules of evolution and natural selection, pulling inspiration from organisms of the real world. This year’s theme: monster plants. This episode, we ponder a familiar fa...

Welcome ... to Spookulative Evolution. October is here, and that means it’s time for Spook-E! Each episode throughout this month, we’re choosing a famous monster and discussing how it – or something like it – might evolve under the rules of evolution and natural selection, pulling inspiration from organisms of the real world. This year’s theme: monster plants. This episode, we consider a classic c...

Spiders are among the most diverse, successful, and famous living groups of invertebrates. Today, they’re a worldwide assortment of fascinating predators, and their scarce fossil record provides hints of a history over 300 million years old. In this episode, we discuss the diversity and evolution of spiders, their varied lifestyles, and their most versatile and famous tool, silk. In the news: snak...

The Earth is in motion beneath our feet. The shifting and grinding of the tectonic plates is responsible for the shape of our planet’s surface and – directly or indirectly – nearly all the activity that happens upon it. Plate tectonics has a deep and fascinating history, both as a force that has shaped the Earth for billions of years and as a surprisingly recent foundational scientific theory. In...

Nearly all animals have some form of nervous system, and this system is often monitored and regulated by a brain. We humans are particularly proud of our enormous brains, but these organs come in all shapes and sizes across the animal kingdom, past and present. In this episode, we discuss brain diversity, the sometimes roundabout ways we explore brains in the fossil record, and what we’ve come to...