The gang discusses two papers that look at the morphology and ecology of early fishes. The first paper investigates a hypothesis for how the pectoral girdle could have evolved, and the second paper looks at the functional morphology of a Paleozoic jawless fish. Meanwhile, Amanda missed some context, James throws some shade, and Curt is annoyed by AI.

Up-Goer Five (Curt Edition):

The friends talk about two papers that look at animals from a long time ago that live in water. The first paper looks at how part of the shoulder in people may have first started as a part of another part of the animal in these animals that lived in water a long long time ago. They find these parts of this animals from a long long time ago that they can use to see how the parts around the head grew. They use this to say that the shoulder parts may have started as a part of the thing these animals use to breath.

The second paper looks at the mouth of a type of animal that lived in water a long long time ago that did not have a hard part in the mouth to move up and down and eat food. They use an animal they found with a lot of parts to see how these animals may have lived and what they could have eaten. They find that this animal could have been picking up food from ground at the bottom of the water or they could have been of taking food out of the water. This shows that even animals without a hard part to move up and down to eat food were finding ways to eat a lot of different things.

References:

Brazeau, Martin D., et al. "Fossil evidence for a pharyngeal origin of the vertebrate pectoral girdle." Nature 623.7987 (2023): 550-554.

Dearden, Richard P., et al. "The three-dimensionally articulated oral apparatus of a Devonian heterostracan sheds light on feeding in Palaeozoic jawless fishes." Proceedings of the Royal Society B 291.2019 (2024): 20232258.

The gang discusses two papers that look at the correlation between climate change and extinction risk in the fossil record. The first paper uses climate modeling to simulate extinction risk during past periods of climate change, and the second paper uses new radiometric age dates to infer diachronous extinction between marine and terrestrial environments during the Permian mass extinction. Meanwhile, James orders food, Curt stirs the pot, and Amanda lives with her choices.

Up-Goer Five (Curt Edition):

The friends look at two papers that look at times when a lot of things died. The first paper uses computers and numbers to see how things could die during times when things get real hot or real cold. They look at real times in the past when lots of things die during these cold and hot times, and then they use their computers and numbers to make those things happen in the world of a computer to see if they can find out what may or may not make that happen. They find that lots of things can cause animals to die during these times when things get hot or cold, but how big the space animals live in and how many different types of places these animals can live in are big for knowing if they will or will not die.

The second paper looks at a time in the past when almost everything died. This is a time when it got real hot. Things die on the land and in the water. A lot of what we study is in the water because those things are able to get covered in ground faster than the things that live on the land. But this paper finds some rocks from the land and does some work with the matter that makes up these rocks to see how old the rocks are. These rocks have animals in them that would die because of this big bad time when everything died. But the time that they found was after when everything in the water died. So this could mean that animals may have died first in the water and then died after on the land. This could be because the way the world changes when things get hot is going to be different in the water and on land.

References:

Malanoski, Cooper M., et al. "Climate change is an important predictor of extinction risk on macroevolutionary timescales." Science 383.6687 (2024): 1130-1134.

Wu, Qiong, et al. "The terrestrial end-Permian mass extinction in the paleotropics postdates the marine extinction." Science Advances 10.5 (2024): eadi7284.