The Common Descent Podcast

Latest Episodes:

Episode 227 - Beaks Sep 27, 2025

Show notes

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, and ant-eaters.

Time markers:
Intro & Announcements: 00:00:00
News: 00:07:00
Main discussion, Part 1: 00:42:40
Main discussion, Part 2: 01:38:25
Patron question: 02:21:50

Check out our website for this episode’s blog post and more: http://commondescentpodcast.com/

Join us on Patreon to support the podcast and enjoy bonus content: https://www.patreon.com/commondescentpodcast

Subscribe to Curiosity Box using our Affiliate Link: https://www.curiositybox.com/CommonDescent
And get 25% off the first box with code descent25

Got a topic you want to hear about? Submit your episode request here: https://commondescentpodcast.com/request-a-topic/

Lots more ways to connect with us: https://linktr.ee/common_descent

The Intro and Outro music is “On the Origin of Species” by Protodome. More music like this at http://ocremix.org

Musical Interludes are "Professor Umlaut" by Kevin MacLeod (incompetech.com). Licensed under Creative Commons: By Attribution 3.0 http://creativecommons.org/licenses/by/3.0

Episode 226 - Dodos Sep 13, 2025

Show notes

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, and cave fish evolution.

Time markers:
Intro & Announcements: 00:00:00
News: 00:05:45
Main discussion, Part 1: 00:33:10
Main discussion, Part 2: 01:06:00
Patron question: 01:56:50

Check out our website for this episode’s blog post and more: http://commondescentpodcast.com/

Join us on Patreon to support the podcast and enjoy bonus content: https://www.patreon.com/commondescentpodcast

Subscribe to Curiosity Box using our Affiliate Link: https://www.curiositybox.com/CommonDescent
And get 25% off the first box with code descent25

Got a topic you want to hear about? Submit your episode request here: https://commondescentpodcast.com/request-a-topic/

Lots more ways to connect with us: https://linktr.ee/common_descent

The Intro and Outro music is “On the Origin of Species” by Protodome. More music like this at http://ocremix.org

Musical Interludes are "Professor Umlaut" by Kevin MacLeod (incompetech.com). Licensed under Creative Commons: By Attribution 3.0 http://creativecommons.org/licenses/by/3.0

Episode 225 - Forests Aug 30, 2025

Show notes

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 ancient deer.

Time markers:
Intro & Announcements: 00:00:00
News: 00:06:00
Main discussion, Part 1: 00:37:30
Main discussion, Part 2: 01:47:10
Patron question: 02:48:35

Check out our website for this episode’s blog post and more: http://commondescentpodcast.com/

Listen to more Plants with Aly on Leaf it to Us!
https://commondescentpodcast.com/leaf-it-to-us/

Join us on Patreon to support the podcast and enjoy bonus content: https://www.patreon.com/commondescentpodcast

Subscribe to Curiosity Box using our Affiliate Link: https://www.curiositybox.com/CommonDescent
And get 25% off the first box with code descent25

Got a topic you want to hear about? Submit your episode request here: https://commondescentpodcast.com/request-a-topic/

Lots more ways to connect with us: https://linktr.ee/common_descent

The Intro and Outro music is “On the Origin of Species” by Protodome. More music like this at http://ocremix.org

Musical Interludes are "Professor Umlaut" by Kevin MacLeod (incompetech.com). Licensed under Creative Commons: By Attribution 3.0 http://creativecommons.org/licenses/by/3.0

Episode 224 - Bipedalism Aug 16, 2025

Show notes

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 markers:
Intro & Announcements: 00:00:00
News: 00:07:35
Main discussion, Part 1: 00:35:15
Main discussion, Part 2: 01:10:50
Patron question: 02:05:55

Check out our website for this episode’s blog post and more: http://commondescentpodcast.com/

Join us on Patreon to support the podcast and enjoy bonus content: https://www.patreon.com/commondescentpodcast

Subscribe to Curiosity Box using our Affiliate Link: https://www.curiositybox.com/CommonDescent
And get 25% off the first box with code descent25

Got a topic you want to hear about? Submit your episode request here: https://commondescentpodcast.com/request-a-topic/

Lots more ways to connect with us: https://linktr.ee/common_descent

The Intro and Outro music is “On the Origin of Species” by Protodome. More music like this at http://ocremix.org

Musical Interludes are "Professor Umlaut" by Kevin MacLeod (incompetech.com). Licensed under Creative Commons: By Attribution 3.0 http://creativecommons.org/licenses/by/3.0

Episode 223 - Mutations Aug 02, 2025

Show notes

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 & Announcements: 00:00:00
News: 00:09:25
Main discussion, Part 1: 00:40:50
Main discussion, Part 2: 01:35:00
Patron question: 02:28:55

Check out our website for this episode’s blog post 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 connect with us: https://linktr.ee/common_descent

The Intro and Outro music is “On the Origin of Species” by Protodome. More music like this at http://ocremix.org

Musical Interludes are "Professor Umlaut" by Kevin MacLeod (incompetech.com). Licensed under Creative Commons: By Attribution 3.0 http://creativecommons.org/licenses/by/3.0

Episode 222 - Shrews Jul 19, 2025

Show notes

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 rocks.

Time markers:
Intro & Announcements: 00:00:00
News: 00:09:35
Main discussion, Part 1: 00:45:25
Main discussion, Part 2: 01:40:50
Patron question: 02:12:35

Find Derek online at @DenoudenDerek

Check out our website for this episode’s blog post and more: http://commondescentpodcast.com/

Join us on Patreon to support the podcast and enjoy bonus content: https://www.patreon.com/commondescentpodcast

Check out our friends’ new data management app, Cnidarity: https://cnidarity.com/

Got a topic you want to hear about? Submit your episode request here: https://commondescentpodcast.com/request-a-topic/

Lots more ways to connect with us: https://linktr.ee/common_descent

The Intro and Outro music is “On the Origin of Species” by Protodome. More music like this at http://ocremix.org

Musical Interludes are "Professor Umlaut" by Kevin MacLeod (incompetech.com). Licensed under Creative Commons: By Attribution 3.0 http://creativecommons.org/licenses/by/3.0

Episode 221 - Legless Lizards Jul 05, 2025

Show notes

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 tusk boomerang, and night lizards.

Time markers:
Intro & Announcements: 00:00:00
News: 00:06:25
Main discussion, Part 1: 00:41:50
Main discussion, Part 2: 01:33:55
Patron question: 02:16:35

Check out our website for this episode’s blog post and more: http://commondescentpodcast.com/

Join us on Patreon to support the podcast and enjoy bonus content: https://www.patreon.com/commondescentpodcast

Happy Disability Pride Month!
AmeriDisability https://www.ameridisability.com/
National Disability Rights Network https://www.ndrn.org/

Got a topic you want to hear about? Submit your episode request here: https://commondescentpodcast.com/request-a-topic/

Lots more ways to connect with us: https://linktr.ee/common_descent

The Intro and Outro music is “On the Origin of Species” by Protodome. More music like this at http://ocremix.org

Musical Interludes are "Professor Umlaut" by Kevin MacLeod (incompetech.com). Licensed under Creative Commons: By Attribution 3.0 http://creativecommons.org/licenses/by/3.0

Episode 220 - Terrestrial Crocs Jun 21, 2025

Show notes

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 tropical archosaurs.

Time markers:
Intro & Announcements: 00:00:00
News: 00:07:25
Main discussion, Part 1: 00:44:20
Main discussion, Part 2: 01:23:20
Patron question: 02:17:25

Check out our website for this episode’s blog post 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 connect with us: https://linktr.ee/common_descent

The Intro and Outro music is “On the Origin of Species” by Protodome. More music like this at http://ocremix.org

Musical Interludes are "Professor Umlaut" by Kevin MacLeod (incompetech.com). Licensed under Creative Commons: By Attribution 3.0 http://creativecommons.org/licenses/by/3.0

Episode 219 - Beringia Jun 07, 2025

Show notes

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 & Announcements: 00:00:00
News: 00:09:10
Main discussion, Part 1: 00:35:25
Main discussion, Part 2: 01:02:15
Patron question: 01:40:40

Check out our website for this episode’s blog post and more: http://commondescentpodcast.com/

Join us on Patreon to support the podcast and enjoy bonus content: https://www.patreon.com/commondescentpodcast

Some LGBTQIA+ organizations in the southeast US:
Trans Aid Nashville: https://www.transaidnashville.org/
Out Memphis: https://www.outmemphis.org/
Southerners on New Ground: https://southernersonnewground.org
Shoutout to Vic Michaelis for these links: www.instagram.com/vicmmic/

Got a topic you want to hear about? Submit your episode request here: https://commondescentpodcast.com/request-a-topic/

Lots more ways to connect with us: https://linktr.ee/common_descent

The Intro and Outro music is “On the Origin of Species” by Protodome. More music like this at http://ocremix.org

Musical Interludes are "Professor Umlaut" by Kevin MacLeod (incompetech.com). Licensed under Creative Commons: By Attribution 3.0 http://creativecommons.org/licenses/by/3.0

Episode 218 - Lungs May 24, 2025

Show notes

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 cicadas.

Time markers:
Intro & Announcements: 00:00:00
News: 00:05:50
Main discussion, Part 1: 00:31:30
Main discussion, Part 2: 01:21:35
Patron question: 02:05:35

Check out our website for this episode’s blog post and more: http://commondescentpodcast.com/

Listen to our new podcast, Leaf it to Us!
https://linktr.ee/leafittouspod

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 connect with us: https://linktr.ee/common_descent

The Intro and Outro music is “On the Origin of Species” by Protodome. More music like this at http://ocremix.org

Musical Interludes are "Professor Umlaut" by Kevin MacLeod (incompetech.com). Licensed under Creative Commons: By Attribution 3.0 http://creativecommons.org/licenses/by/3.0

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