Palaeo After Dark

Well, it has finally come to this. After almost 150 episodes under our belts, we've finally produced a podcast where almost no one read any of the papers. This episode was supposed to be about squamate (lizards and snakes) evolution. In particular, we were supposed to look at two papers that tried to determine when squamates must have first diversified. And... we kind of accomplish that. Meanwhile, James shares his weak points, Amanda demonstrates a super power, and Curt laments falling asleep on the couch being the only person to read these papers. We swear the next one will be better.... maybe.


Up-Goer Five (Curt Edition):

Our friends were supposed to talk about these papers that they read. However, they didn't read these papers and so they spend some of the time trying make it up as they go along. The papers that the friends were supposed to read were about cold, cute things with dry skin and four legs (most of the time). Both of these papers suggest that these cold, cute things probably came about well before we thought they did. In fact, we probably had the first cold, cute things just around or before the time a really bad thing happened that hurt all living things around the world. It was the worst of the bad things to have ever happened. These papers suggest that these cold, cute things might have done alright during these really bad times, and that may be the reason why there are so many cute, cold things around the world today.



 Tałanda, Mateusz. "An exceptionally preserved Jurassic skink suggests lizard diversification preceded fragmentation of Pangaea." Palaeontology (2018). 

 Simões, Tiago R., et al. "The origin of squamates revealed by a Middle Triassic lizard from the Italian Alps." Nature 557.7707 (2018): 706. 

Direct download: Podcast_143_-_Squamate_Talk.mp3
Category:general -- posted at: 3:00am EDT

The gang discusses two papers that look at the origins of the latitudinal diversity gradient, the tendency for higher species diversity in the tropics and lower diversity closer to the poles. Specifically, these studies use comprehensive phylogenetic analyses of modern taxa to try and determine if the current diversity gradient is caused by increased speciation or decreased extinction at the equator. Meanwhile, Amanda shares diseases with her cat, James decides to "treat" himself to a Lime-A-Rita, and Curt just re-enacts scenes from other media.


Up-Goer Five (James Edition):

The group looks at two papers that are interested in where animals live. They are looking at a well known thing where more animals live near the middle of the world than at either end. However, it is not clear whether there are more animals in the middle of the world because they have been there longer and so the number of animals has just built up over time, or whether animals in these areas make more types of animals more quickly.

The first study looks at animals that have no legs and live in the water that you can not drink and breath water. This study finds that animals that live in the middle of the world actually make other animals slower than animals that live at either end of the world do, so the reason there are more animals in the middle of the world is probably because they have been there longer. The second study looks at animals with hard outer skin that have six legs and live in big families. This study finds that there is no change across the world in how quickly these animals make more animals, which is different from the first study. However, this does mean that the reason there are more animals in the middle of the world is because they have been there longer, so this agrees with the first study!



 Economo, Evan P., et al. "Macroecology and macroevolution of the latitudinal diversity gradient in ants." Nature communications 9.1 (2018): 1778. 

 Rabosky, Daniel L., et al. "An inverse latitudinal gradient in speciation rate for marine fishes." Nature (2018): 1. 

Direct download: Podcast_142_-_The_LDG.mp3
Category:general -- posted at: 3:00am EDT