Palaeo After Dark

The gang discuss two papers that discuss the methods we use to determine how different things are from each (i.e. disparity). In particular, do variations in parts of an animal give us a good sample of the morphological variability of the total animal? Meanwhile, Amanda wants a whale, James has strong opinions about vertebrae, and Curt tries to narrow in on what Amanda views as "cute".

 

Up-Goer Five (James Edition):

The group looks at two studies that want to see if we can say how different animals are. There are many ways that we can try to see how animals are different from each other. The first paper looks at two ways of seeing if animals are different, one by looking at how points on the animals change between them and another by looking at what parts the animals have. The paper shows that the both types of study give the same answer, which is good news.

The second paper wants to see if we get the same answer for how animals are different from each other when we look at only one part of the animal instead of looking at the whole animal. This study also shows that when you look at part of an animal, you get the same answer as when you look at the whole animal. This is also good news! There's lots of good news, let's have a party.

 

References:

Hetherington, Alexander J., et al. "Do cladistic and morphometric data capture common patterns of morphological disparity?." Palaeontology 58.3 (2015): 393-399. 

 Hopkins, Melanie J. "How well does a part represent the whole? A comparison of cranidial shape evolution with exoskeletal character evolution in the trilobite family Pterocephaliidae." Palaeontology 60.3 (2017): 309-318. 

Direct download: Podcast_115_-_Amanda_Now_Wants_Tiny_Whales_to_be_a_Thing.mp3
Category:general -- posted at: 3:00am EDT

The gang discuss two papers that describe the life strategies of trilobites, a diverse and charismatic group of extinct arthropods. Specifically, they look at two papers that look at enrollment and movement of trilobites. Meanwhile, Amanda educates James on the nature of pain, James envisions Curt's inevitable end, and Curt invents a hockey/extinct arthropod family film.

 

Up-Goer Five (James Edition):

The group looks at two papers that look at old animals with many legs that live in the bad drink water place and are made out of rock. These animals are all over the place and are good to study much like small animals with hair and big ears are used today. One paper makes pictures of the old animal with many legs on the computer to see how they turn into a ball. This paper is very easy to understand and shows that these animals can turn into a ball in a number of different ways and that they started doing these different ways a number of different times. However, once they have made this change they seem to stick with it. The second paper is not very easy to understand. It looks at where these old animals with many legs form lines and tries to work out whether they are forming lines so it is easier for them to walk. A lot of numbers are used to work out how easy it is for them to walk, but it is not clear what the numbers say. They suggest the lines these animals with many legs make are the same as ones people that ride things with two round moving things instead of legs make, but this just makes things more confusing.

 

References: 

Trenchard, Hugh, Carlton E. Brett, and Matjaž Perc. "Trilobite ‘pelotons’: possible hydrodynamic drag effects between leading and following trilobites in trilobite queues." Palaeontology (2017). 

 Esteve, Jorge, et al. "Modelling enrolment in Cambrian trilobites." Palaeontology 60.3 (2017): 423-432. 

Direct download: Podcast_114_-_Trilobites_Mice_of_the_Paleozoic.mp3
Category:general -- posted at: 3:00am EDT

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