The gang discusses two papers that look into the timing of evolution of the “crown group”. The first paper looks at fossil glass sponges, and the second paper looks at the phylogeny of lampreys. Meanwhile, James gives some sound advice, Amanda has ambitious hobby plans, and Curt imagines the perfect media crossover.

Up-Goer Five: (Curt Edition)

The friends talk about two papers that look at groups of animals and try to see when the things that we see today in these groups may have first happened in the past and what we can tell us about why those things might have happened. The first paper looks at a group of animals that are made up of many single parts that can all act on their own and these animals get food out of water in a very simple way. This paper finds some very old animals that look a lot like some groups of these animals we see today. This would mean that this group may have been around a lot longer ago than we think.

The second paper looks at a group of animals that are long without much going on and a round mouth and live in the water. This group has animals that live in different places that have made people ask why. This paper looks at how all of these animals changed over time and uses that to see when the animals that we see today may have first been around. They find that these animals may have first appeared during a time that was really hot, and that might be why the animals are where they are today.

References:

Botting, Joseph P., et al. "Advanced crown‐group Rossellidae (Porifera: Hexactinellida) resembling extant taxa from the Hirnantian (Late Ordovician) Anji Biota." Papers in Palaeontology 11.1 (2025): e70000.

Hughes, Lily C., et al. "Phylogenomic resolution of lampreys reveals the recent evolution of an ancient vertebrate lineage." Proceedings B 292.2038 (2025): 20242101.

The gang celebrates the research of the late Elisabeth Vrba by talking about two of her papers, as well as her research more broadly. And, despite their best efforts, they get easily distracted on tangentially related side discussions.

Up-Goer Five (Curt Edition):

The friends talk about two papers from someone who they want to remember the memory of because that person is no longer with us. They talk a lot about this person's work, and some other things that come up as they are talking. The big things these two papers look at are how small things working together can build things that are bigger than themselves, and how those bigger things can be changed by the small things but not in a way where the big things can be known just by looking at the small things. The big things have stuff in them that come up from the way the small things work together to build something bigger than themselves.

References:

Vrba, Elisabeth S. "Macroevolutionary trends: new perspectives on the roles of adaptation and incidental effect." Science 221.4608 (1983): 387-389.

Vrba, Elisabeth S. "Mammals as a key to evolutionary theory." Journal of mammalogy 73.1 (1992): 1-28.

The gang discusses two papers that look at some exceptional soft-tissue preservation during the Silurian. The first paper potentially identifies a unique type of pterobranch, and the second paper looks at some early molluscs. Meanwhile, James has seen some movies, Amanda has a skibidi day, and Curt’s soul dies.

Up-Goer Five (Curt Edition):

The friends talk about two animals from a long time ago that are only found as soft parts and that makes it hard to find the parts of them that were in the ground a long long time ago. The first paper looks at an animal that is not well known in the past but is close to another animal that is better known. These soft parts are weird and people did not know what they were for a long while. This paper makes the case for this being one of this group of animals that all live in long empty round things together. They also say that this one may have lived moving in the water even though the ones today all sit at the bottom of the water on the ground.

The second paper looks at another group of animals that many today have a hard part on them and some of them turn their body when they grow. The animals that they are looking at do not do these things. They have hair and are long. These are animals are from a group that we think might be close to what the early animals in this group today would have looked like. The friends talk about this paper because they gave the animals funny names.

References:

Briggs, Derek EG, and Nicolás Mongiardino Koch. "A Silurian pseudocolonial pterobranch." Current Biology 33.23 (2023): 5225-5232.

Sutton, Mark D., et al. "New Silurian aculiferan fossils reveal complex early history of Mollusca." Nature (2025): 1-6.

The gang discusses two papers that look at some exceptionally preserved juvenile fossil specimens and the interesting clues these fossils give to the ontogeny of extinct groups. The first paper is the current oldest preserved tadpole, and the second paper is an exceptionally preserved mummified sabre-toothed cat. Meanwhile, Amanda becomes light, James is visited, and Curt is left in the dust and the filth.

Content warning: This episode contains covers some potentially dark material given that these fossils are juveniles. The following time stamps represent some of the more sensitive moments in which the group make morbid jokes about the subject matter.

6 min 3 sec to 6 min 39 secs.

58 min 13 seconds to 58 min 29 secs

Up-Goer Five (Curt Edition):

The friends talk about two papers that show some kids from animals groups that are no longer around. These papers are cool because they show how animals from a long time ago changed as they got older. The first paper looks at the kid of an animal group that changes a lot from a thing that moves through water to a thing that jumps on the ground. This kid is somewhere in the middle of jumping and moving through water. This is the oldest of this type of kid we have found so far. The group today is different because they go through this really big change. This paper shows that they were going through this really big change a long long time ago and shows that this change probably happened early on in their time line.

The second paper looks at a kid that is from a group of animals with hair and long teeth. This kid was in ice and so we have a lot of things that we would not get that are soft. This is the first time we have seen the soft parts for this age of this animal and it shows us that lots of things we see in the grown animals were also there when they were kids.

References:

Chuliver, Mariana, et al. "The oldest tadpole reveals evolutionary stability of the anuran life cycle." Nature (2024): 1-5.

Lopatin, A. V., et al. "Mummy of a juvenile sabre-toothed cat Homotherium latidens from the Upper Pleistocene of Siberia." Scientific Reports 14.1 (2024): 28016.

The gang discusses two papers that look at the evolution of photosynthesis in different groups. The first paper looks at what might be the first fossil evidence of thylakoids, and the second paper finds evidence for photosynthesizing symbiotes in Devonian fossil corals. Meanwhile, Amanda is making a lasagna, James has a lot of opinions about lasagna (~10 minutes until we actually get to the paper), and Curt is all about those sponges.

Up-Goer Five (Curt Edition):

The friends talk about two papers that look at how some types of living things can make food from the sun. The first paper looks at these very very old things that are very very very small. Inside these things they find very very very small parts of things that are used today by some living things to help make food from the sun. This might be the oldest one of these things that we have ever found, and it makes it so that we can see how things might have gotten better at making food from the sun over time.

The second paper looks at old animals that live in the big blue wet thing that all live close together and make big hard parts that make walls in the water. These old animals are like the ones we see today but they are a group that is not around anymore. Groups today have friends that help make food from the sun for them. This paper looks to see if the old animals had those friends (or friends like them) too. They find that animals today keep some bits of things they do not usually want so that their friends can eat them. This can be seen in the hard parts they make. When they looked at the hard parts of the old group of animals, they saw that they were doing this too. This means that these animals were keeping food for friends just like that animals we see today.

References:

Demoulin, Catherine F., et al. "Oldest thylakoids in fossil cells directly evidence oxygenic photosynthesis." Nature 625.7995 (2024): 529-534.

Jung, Jonathan, et al. "Coral photosymbiosis on Mid-Devonian reefs." Nature (2024): 1-7.

Sausage, Biscuits, Eggey, and Crankshaft make their way into the big mansion. Will they be able to pull off the heist of the century and deliver a perfect Christmas for the raccoons of the junkyard, or will they all go down in a blaze of glory?

"Sergio's Magic Dustbin" and “Silent Night” from Kevin MacLeod (incompetech.com) Licensed under Creative Commons: By Attribution 3.0 http://creativecommons.org/licenses/by/3.0/

Check out “Raccoon Sky Pirates” on itch,io https://hecticelectron.itch.io/raccoon-sky-pirates

Sausage, Biscuits, Eggey, and Crankshaft board the Dumpster Fire and prepare for a holiday adventure... despite the wishes of an unsuspecting populace.

"Sergio's Magic Dustbin" from Kevin MacLeod (incompetech.com) Licensed under Creative Commons: By Attribution 3.0 http://creativecommons.org/licenses/by/3.0/

Check out “Raccoon Sky Pirates” on itch,io https://hecticelectron.itch.io/raccoon-sky-pirates

James, Amanda, Curt, and Ants all get together to plan a holiday raccoon heist. What could possibly go wrong?

"Sergio's Magic Dustbin" from Kevin MacLeod (incompetech.com) Licensed under Creative Commons: By Attribution 3.0 http://creativecommons.org/licenses/by/3.0/

Check out “Raccoon Sky Pirates” on itch,io https://hecticelectron.itch.io/raccoon-sky-pirates

The gang discusses two papers that look at patterns of mosaic evolution, one paper looking at cat evolution and the other paper looking at bird ecomorphy. Which means the gang talks about Amanda’s two favorite taxonomic groups. Meanwhile, Curt enjoys some realistic bird calls, Amanda remains a threat, and James provides relevant “facts”.

Up-Goer Five (Curt Edition):

The friends take a look at how animals change over time and how the parts of the animals might change in different ways at different times. The first paper looks at cats and things that are like cats, and they look at the parts of cats and how they have changed. What they find is that the different parts are changing in different ways across different groups of cats and cat like things.

The second paper looks at the neck of animals that move in the air. The paper is looking to see if the reason why these necks change the way they do are because of how they are trying to get food, which is what people thought might be true but no one has looked to see if it is true. A lot of work is done and it does seem that the necks change in a lot of ways that are different for different groups, but it does seem that a lot of these changes are because of how the animals try and look for food.

References:

Barrett, Paul Z., and Samantha SB Hopkins. "Mosaic evolution underlies feliform morphological disparity." Proceedings of the Royal Society B 291.2028 (2024): 20240756.

Marek, Ryan D., and Ryan N. Felice. "The neck as a keystone structure in avian macroevolution and mosaicism." BMC biology 21.1 (2023): 216.

The gang discusses two papers that detail interesting findings about the soft tissues of extinct arthropods. The first paper does a detailed study of the limbs attached to the trilobite head. The second paper describes the newly discovered head of the ancient myriapod Arthropluera, and discusses the larger implications this fossil has for the evolution of millipedes. Meanwhile, Curt explores new advertising ventures, Amanda unpacks automotive anxiety, and James has no ethical complications to report concerning this podcast.

Up-Goer Five (Curt Edition):

The friends look at two papers that look at parts of dead animals that have lots of parts that repeat over and over again and take off their skin every time they get bigger. The first paper looks at a group of these dead animals that are no longer around but are found a lot in the past. This paper shows that the number of legs in the head is different than we thought it was. They show that there are five legs in the head, and that it was hard to see in a lot of these animals because of the ways that we get these animals in the rocks makes it harder to see.

The second paper looks at an animal that we think is a lot like animals we see today with long bodies and two legs on each part. But we never actually found the head of these animals. This paper finds the head and it helps to show us a lot of cool things about not just these animals in the past, but also how these animals have changed over time. This helps us understand why the groups we have today are the way that they are.

References:

Lhéritier, Mickaël, et al. "Head anatomy and phylogenomics show the Carboniferous giant Arthropleura belonged to a millipede-centipede group." Science Advances 10.41 (2024): eadp6362.

Hou, Jin‐bo, and Melanie J. Hopkins. "New evidence for five cephalic appendages in trilobites and implications for segmentation of the trilobite head." Palaeontology 67.5 (2024): e12723.