All plants need water, but some take it to the extreme. This episode, Dr. Aly Baumgartner joins us to explore the many life strategies of plants that live in the water. We’ll discuss the adaptations that allow them to lead an aquatic lifestyle, their evolutionary history as seen through genes and fossils, and the benefits that keep leading plants back to water. In the news: fish diversity, ammonite survivors, gut microbes, and hiding dinosaurs. Time markers: Intro & Announcements: 00:00:00 N...
Jan 18, 2026•2 hr 38 min•Ep. 356
From deep-sea trenches to your home garden, gastropods (snails and slugs) are among the most diverse and successful groups of animal life in Earth history. This episode, we’ll explore what makes these animals distinctive, we’ll touch on their extraordinary fossil record, and we’ll investigate the many evolutionary experiments gastropods have undergone in their anatomy and lifestyle. In the news: squishable ants, false saber-tooths, bee burrows, and baby ankylosaurs Time markers: Intro & Anno...
Jan 04, 2026•2 hr 24 min•Ep. 350
Happy New Year! Please enjoy our annual question-answering marathon, now longer than ever! Thank you so much to everyone who listens, shares, and supports the podcast. Check out our website blog posts and more: http://commondescentpodcast.com/ Join us on Patreon to support the podcast and enjoy bonus content: https://www.patreon.com/commondescentpodcast Got a topic you want to hear about? Submit your episode request here: https://commondescentpodcast.com/request-a-topic/ Lots more ways to connec...
Dec 31, 2025•5 hr 52 min•Ep. 349
Of all the highly successful and capable flying insects in the world, few are as successful or capable as those in the order Diptera. This episode, we’re joined by special guest Brandon Strauss to discuss the distinctive anatomy and varied habits of flies, mosquitoes, and their many two-winged relatives. Then, we’ll peer into the past for a glimpse at the fossil record and dynamic evolutionary history of the group. In the news: long-nosed crocs, river mosasaurs, stampeding sea turtles, and giant...
Dec 21, 2025•2 hr 42 min•Ep. 348
Today, bony animals are some of the most diverse organisms on Earth, but it wasn’t always that way. This episode, we explore what features distinguish vertebrates from their closest relatives, and we dive into the abundant evidence from genetics, embryology, and the fossil record that gives us a glimpse at how our distant ancestors came to be. In the news: swimming hands, early life, Dunkleosteus jaws, and Neanderthal noses Time markers: Intro & Announcements: 00:00:00 News: 00:05:35 Main di...
Dec 07, 2025•2 hr 16 min•Ep. 347
Nearly 400 million years ago, an unusual group of fish gave rise to the first land-dwelling vertebrates. Since then, their descendants have repeatedly moved back into the water. This episode, we explore the many ways these species adapt to the challenges of turning a terrestrial body into one that can survive at sea, and we investigate some of the most famous and confusing cases from the fossil record. In the news: post-extinction oceans, croc eggs, damaged dino tails, and meat-eating dung beetl...
Nov 23, 2025•2 hr 43 min•Ep. 346
The dome-headed dinosaurs are some of the most iconic ancient reptiles, but they’re surprisingly unexplored compared to other dinos. This episode, we explore what makes these dinosaurs unique, what limits our understanding of them, and the many confounding mysteries that paleontologists have been scratching their heads over, including the question of what exactly they were doing with those thick heads. In the news: the I Know Dino children’s book, giant reptile locomotion, and dinosaur hooves. T...
Nov 09, 2025•2 hr 16 min•Ep. 345
In this special guest episode of Silver Screen Science, we're joined by Sabrina and Garret of I Know Dino to discuss the science and scientists of the newest installment in the Jurassic franchise: Jurassic World: Rebirth! Find more Common Descent: http://commondescentpodcast.com/ Join Common Descent and I Know Dino on Patreon to support the podcast and enjoy bonus content: https://www.patreon.com/commondescentpodcast https://www.patreon.com/cw/iknowdino Lots more ways to connect with us: https:/...
Nov 05, 2025•1 hr 39 min•Ep. 344
Welcome … to Cute-E! During our Spook-E series, we speculate on the evolution of monsters from myth and popular media, but we leave out fiction’s more adorable creatures. In Cute-E, we choose cuddlier critters and discuss how they – or something like them – could evolve here on Earth, pulling inspiration from real-world species across our planet’s history. This year’s theme is Monsters of Nintendo. This episode, we pluck precious partners from the soil. What could be the evolutionary background ...
Nov 01, 2025•59 min•Ep. 338
Generally speaking, it’s not a good idea to mess with ants. But several lineages of animals have evolved to be ant-eating specialists. This episode, we discuss anteaters, the suite of adaptations that allow them to focus on ant-eating, and the variety of other species that have evolved similar adaptations for the same purpose. We explore the evolutionary history of ant-eating mammals and even dinosaurs through the fossil record and genetic evidence. In the news: butt-drags, ancient leeches, Nean...
Oct 26, 2025•2 hr 21 min•Ep. 343
Welcome ... to Spookulative Evolution. Spook-E Season is back! All throughout October, we pick monsters from myth and media and speculate how they – or something like them – could evolve here on Earth, pulling inspiration from real-world species across our planet’s history. This year’s theme is Monsters of Nintendo! This episode, we take the hunt across the stars. What biological explanation can we find for jellyfish-shaped parasites with a complex and terrifying life cycle? Our creatures to cre...
Oct 25, 2025•1 hr 9 min•Ep. 337
Welcome ... to Spookulative Evolution. Spook-E Season is back! All throughout October, we pick monsters from myth and media and speculate how they – or something like them – could evolve here on Earth, pulling inspiration from real-world species across our planet’s history. This year’s theme is Monsters of Nintendo! This time, we’re sailing with the scourges of DK Isle. What circumstances might lead to the evolution of crocodile-faced humanoid pirates? Our creatures to create this time: Kremling...
Oct 18, 2025•1 hr 3 min•Ep. 336
Located in southeastern Alberta is a stretch of gorgeous badlands that are home to some of the world’s absolute best Late Cretaceous fossils. This episode, we explore how Dinosaur Provincial Park earned its designation as a UNESCO World Heritage Site, we list off some of the famous dinosaurs who once lived there, and we discuss a fraction of the many fossil discoveries that have been made at the Park since the late 1800s. In the news: Cretaceous crocs, baby pterosaurs, late megaraptorans, and ea...
Oct 12, 2025•1 hr 55 min•Ep. 342
Welcome ... to Spookulative Evolution. Spook-E Season is back! All throughout October, we pick monsters from myth and media and speculate how they – or something like them – could evolve here on Earth, pulling inspiration from real-world species across our planet’s history. This year’s theme is Monsters of Nintendo! This episode, we take a trip to the Kingdom of Hyrule. How might nature develop an octopus-like monster with a penchant for projectiles? Our creatures to create this time: Ocotoroks....
Oct 11, 2025•57 min•Ep. 335
Welcome ... to Spookulative Evolution. Spook-E Season is back! All throughout October, we pick monsters from myth and media and speculate how they – or something like them – could evolve here on Earth, pulling inspiration from real-world species across our planet’s history. This year’s theme is Monsters of Nintendo! This episode, we begin with a baddie from the Mushroom Kingdom. What evolutionary path might generate a pipe-dwelling plant-like predator? Our creatures to create this time: Piranha ...
Oct 04, 2025•1 hr 6 min•Ep. 334
The faces of vertebrate animals are often soft and full of teeth, but there is a common alternative. Birds, turtles, and many more groups have developed toothless snouts covered in a tough sheath. This episode, we’ll explore the defining features of beaks and their various functions. And we’ll take a tour through animal life past and present to investigate the reasons behind the repeated evolution of beaks among dinosaurs and beyond. In the news: Life on Mars, ancient sharks, mammoth microbes, a...
Sep 28, 2025•2 hr 27 min•Ep. 341
Dodos are probably the single most famous case of recent human-induced extinction. First documented in the late 1500s and extinct within a century, dodos have become a global reminder of the devastating potential of human activity. This episode, we review the brief history of human interactions with dodos, and we explore what recent research and fossil evidence has taught us about these birds and their closest relatives. In the news: Cretaceous crocs, extra-spiky dinosaurs, turtles of the sea, a...
Sep 14, 2025•2 hr 5 min•Ep. 340
Forests are among the most widespread and diverse biomes on our planet. This episode, we’re joined by our favorite paleobotanist, Dr. Aly Baumgartner, to explore what defines a forest, how these habitats function, and how they differ around the globe. Then, we’ll take a trip into the past to discuss how paleontologists study ancient forests and how these biomes have changed over hundreds of millions of years. In the news: ocean sediments, early penguins, island foxes, Canadian dragonflies, and a...
Aug 31, 2025•2 hr 56 min•Ep. 339
Most vertebrate animals on land get around on all fours, but some of us have committed to two-legged locomotion. This episode, we explore the various ways animals have evolved bipedalism and the many benefits that come with it. We’ll also take a look at how we identify bipedal animals in the fossil record, and we’ll zoom in on the evolutionary story behind Earth history’s most successful bipeds. In the news: potato origins, trilobite legs, bone worm burrows, and australopithecine sexes. Time mar...
Aug 17, 2025•2 hr 15 min•Ep. 333
Mutation. It is the key to our evolution. As our cells constantly divide and reproduce and replicate our DNA, errors and inconsistencies develop, leading to the incredible variation of life that drives evolutionary change. This episode, we explore the genetic mechanisms behind mutation and we discuss how scientists study mutations to understand the evolutionary history of life on Earth. In the news: Neanderthal tools, caiman food, dancing dinosaurs, and ancient integument. Time markers: Intro &a...
Aug 03, 2025•2 hr 39 min•Ep. 332
On the outside, shrews might seem like standard tiny mammals, but their anatomy and lifestyle are highly specialized. This episode, with help from special guest Derek den Ouden, we explore the diverse habits of shrews, the anatomical features that set them apart, and how they thrive worldwide despite being perpetually on the brink of starvation. Then, we consider the extinct diversity of shrews in the fossil record. In the news: stubborn bass, choking fish, tomato defenses, and some really old r...
Jul 20, 2025•2 hr 21 min•Ep. 331
Lizards are extremely good at becoming snake-shaped. A long body with small or absent limbs is a shape that has evolved dozens of times across nearly every major lineage of lizards. This episode, we explore the diversity of leglessness in lizards, we discuss which groups have done it and which groups have done it best, and we examine what’s known about the repeated evolution of this unexpected body shape. In the news: giant dusky salamander, very early footprints, a Denisovan skull, a mammoth tu...
Jul 06, 2025•2 hr 30 min•Ep. 330
Today’s crocs are iconic semi-aquatic predators, but their extended family tree features lots of land-dwelling cousins. This episode, we take a tour through croc evolutionary history and explore the many times these reptiles have taken to life on dry land. We’ll examine what features these terrestrial crocs shared, which ones they didn’t, and what their fossils tell us about how the shape of crocs has changed over time. In the news: sauropod guts, Australian biomarkers, butterfly scales, and tro...
Jun 22, 2025•2 hr 28 min•Ep. 329
For over 100 million years, North America and Asia have been connected over the Pacific Ocean through a region called Beringia. The comings and going of plants and animals across this connection have shaped ecosystems of the past and present. This episode, we explore the geologic history of the region and which ancient species have managed to live in and move through Beringia. In the news: early sperm whales, BC plesiosaurs, megatooth shark food, and Arctic nesting birds. Time markers: Intro &am...
Jun 08, 2025•1 hr 49 min•Ep. 328
Take a deep breath and appreciate for a moment the organs that let you do it so efficiently. Lungs are an invaluable tool for life out of the water, and are therefore a favorite topic for paleontologists interested in early animals on land. This episode, we explore the diversity of modern lungs and the few but fascinating insights we have into the lungs of ancient animals, from dinosaurs to the first terrestrial vertebrates. In the news: trilobite sizes, polar forests, early footprints, and cica...
May 25, 2025•2 hr 15 min•Ep. 327
Bears are among the most charismatic and impressive mammals. They have large bodies, very flexible lifestyles, and an extensive fossil record that includes some of the best-preserved and largest fossil mammals of all time. This episode, we explore what makes bears so distinctive and successful, and how their diversity has changed over time. In the news: ancient alligators, rattlesnake venom, late land crocs, pterosaur tracks, and Caribbean crocodiles. Time markers: Intro & Announcements: 00:...
May 11, 2025•2 hr 24 min•Ep. 326
Just about every body of water on Earth, from oceans to puddles, is home to an ecosystem of tiny drifting organisms. This episode, we discuss what sorts of organisms we might expect to find in a swarm of plankton, we’ll explore how plankton is so fundamental to biological and geological systems on Earth, and we’ll take some time to lay out some of the many ways that ancient plankton are a crucial part of the fossil record. In the news: climbing reptiles, croc extinctions, Ashfall rhinos, and ank...
Apr 27, 2025•2 hr 10 min•Ep. 325
Silver Screen Science is our series where we explore how science is portrayed on the big screen. This year, we’re focused on one recurring franchise: Planet of the Apes! Finally, we visit the ongoing prequel franchise with the story of how it all got started: Rise of the Planet of the Apes. Check out our website for blog posts and more: http://commondescentpodcast.com/ Join us on Patreon to support the podcast and enjoy bonus content: https://www.patreon.com/commondescentpodcast Lots more ways t...
Apr 16, 2025•1 hr 7 min•Ep. 324
With several thousand living species, ferns are the second most diverse vascular plants around today, after angiosperms. Ferns are also abundant and well-known in the fossil record. This episode, Aly joins us to explore the dizzying variety of ferns and their ferny-friends, past and present. In the news: When the Earth Was Green, weird wasps, and ancient claws. And also dire wolves. Time markers: Intro & Announcements: 00:00:00 News: 00:04:20 Main discussion, Part 1: 00:46:45 Main discussion...
Apr 13, 2025•2 hr 33 min•Ep. 323
Silver Screen Science is our series where we explore how science is portrayed on the big screen. This year, we’re focused on one recurring franchise: Planet of the Apes! It’s the reboot of the original, a 21st-Century take on the concept – Planet of the Apes (2001). Check out our website for blog posts and more: http://commondescentpodcast.com/ Join us on Patreon to support the podcast and enjoy bonus content: https://www.patreon.com/commondescentpodcast Lots more ways to connect with us: https:...
Apr 09, 2025•59 min•Ep. 322
