Palaeo After Dark

The gang discuss two papers that look at community structure in fossil and modern biota. The first paper looks at the size distribution of dinosaur communities and finds an interesting lack of mid-sized predators. The second paper looks at a modern kelp forest community to determine if fishing refugia results in ecological cascades in this system. Meanwhile, James is a magician, Amanda would rather be playing D&D, and Curt remembers Dino Riders.

 

Up-Goer Five (Curt Edition):

Our friends look at two papers that look at how animals live together in a place. The first looks at some very old and angry animals. When people look at how big these old angry animals are, they find something weird. If we look at all the angry things, we have a lot of big things, some small things, but not that much in the middle. When we look at that only eat things that get their food from the sun and see how they are different from the things that eat other animals, they find that this missing middle is because there are no middle animals in the things that eat other animals. One thought for why this could be is that some of the real big animals that eat other animals might have kids that fill the middle when they start to grow up.

The second paper looks at these places in the water that you can't drink where there are things that move through the water, things that move on the ground and have big hard things on them that come to points, and things that make food from the sun which are big and green. In a lot of places like this, if there are not some animals that eat a lot, the things with the points can eat all of the big green things. This place doesn't have one of those animals that eats a lot, but it was a place where people can not go in and grab some of the animals that move in the water. Since there are still big green things here, the people who wrote this paper wanted to see if the animals in the water were good at eating the animals with points. It seems that, while the animals in the water are doing better, so are the animals with points. This means that other things must be going on to let the big green things still be there.

 

References:

Malakhoff, Katrina D., and Robert J. Miller. "After 15 years, no evidence for trophic cascades in marine protected areas." Proceedings of the Royal Society B 288.1945 (2021): 20203061.

Schroeder, Katlin, S. Kathleen Lyons,  and Felisa A. Smith. "The influence of juvenile dinosaurs on community  structure and diversity." Science 371.6532 (2021): 941-944.

Direct download: Podcast_208_-_Stable_States.mp3
Category:general -- posted at: 3:00am EDT

The gang discusses two papers that look at snake evolution and ecology. The first paper looks at the evolutionary steps required for venom spitting behavior in cobras, and the second paper looks at how snake populations in the tropics are being impacted by mass amphibian die offs. Meanwhile, James likes the Resident Evil Lady, Curt meets big Bowser, and Amanda has a BIIIIG beer.

 

Up-Goer Fiver (Curt Edition):

Our friends talk about long animals with no legs. Some of these long animals have bad stuff that they can put into your body. The long animals that can make the bad stuff and also make their neck really wide are a group of long animals that have some animals that can push the bad stuff out of their body a great way away from their body. The first paper our friends talk about is trying to find out how these long animals that can push bad stuff a far way out of their body were able to do this. Did they get it from their moms and dads a long long time ago. The paper looks at what the bad stuff is made of, and finds that the things that are close family with the long things that can push bad stuff far away have bad stuff that looks the same. But there is one part of the bad stuff that there is more of in the things that push bad stuff far away that isn't in all of the long animals. The cool thing is, the moms and dads of these animals had this other bad stuff even though they do not push bad stuff far away from their bodies. This means that the other bad stuff changed first, and then the long animals started pushing bad stuff far away from their bodies.

The second paper looks at how long animals are hurt when their food goes away. Another group of animals that breathe through their skin has been having a real hard time because they keep getting sick. This paper looks at how the sick animals that breathe through the skin are causing some of the long animals to die because they can no longer get as much food (from the animals that breathe through their skin). Some long animals are doing really well, but most of the long animals are not doing well. This means that something that hurts one group of animals can and will hurt a lot of other animals over time.

 

References:

Zipkin, Elise F., et al. "Tropical snake diversity collapses after widespread amphibian loss." Science 367.6479 (2020): 814-816.

Kazandjian, Taline D., et al. "Convergent evolution of pain-inducing defensive venom components in spitting cobras." Science 371.6527 (2021): 386-390.

Direct download: Podcast_207_-_Sneks_and_the_Toad_Wars.mp3
Category:general -- posted at: 4:00am EDT

1