Palaeo After Dark

The gang discusses two papers that investigate the impact that the geographic occupation of a species has on its evolution, both in the distant past and in modern systems. Also, James pops some pills, Amanda takes a deep dive into Deviant Art, and Curt acts as a passive enabler.

 

Up-Goer Five (Amanda Edition):

This week our friends talk about how many animals there are in the whole world. They also talk about where animals live all over the world. The first paper does a good job talking about both where animals live and how many animals there are. It talks about many, many times when there were lots of new kinds of animals showing up, and also times when there were not many animals showing up. They also talk about times when it looks like many animals died but maybe they didn't. There are different ways to talk about how many animals there are in the whole world. Whether there are all kinds of different animals but they are the same all over, whether there are all kinds of different animals and they are all different all over, and whether there are some animals that are only found only in little places. The other paper talks about how when new kinds of animals show up that it is important to look at where the new animals are from, and whether they can talk to other animals that are like their brothers and sisters. If they can talk to other animals that are like their brothers and sisters, then they are not new kinds of animals. But if they can't talk to the animals that are like their brothers and sisters, then they are a new kind of animal. This paper thought that maybe it would be a kind of important piece of the animal that would make it new and not able to talk to its brother and sister animals. But it turns out that where the animal is from is very important, and it seems like if the animal lives far away and can't talk to its brother and sister animals for even a short time, it will become a new kind of animal. So we know that where animals are from is important, and if where they are from means they can't talk to brother and sister animals, that is really big for making new kinds of animals.

 

References:

 Worsham, McLean LD, et al. "Geographic isolation facilitates the evolution of reproductive isolation and morphological divergence." Ecology and Evolution

 Stigall, Alycia L., et al. "Biotic immigration events, speciation, and the accumulation of biodiversity in the fossil record." Global and Planetary Change 148 (2017): 242-257. 

Direct download: Podcast_125_-_Feeling_Isolated_Biogeography_and_Evolution.mp3
Category:general -- posted at: 3:00am EST

The gang discusses two papers that complicate our understanding of some important fossils. Specifically, we focus on abiotic "stromatolites" and cryptic tool marks on bones. Also, Curt comes up with a book title, James discusses his workout regiment, and Amanda gets very excited about all things Michigan. 

 

Up-Goer Five (Curt Edition):

The friends talk about things that look like something but are actually maybe something else. First, they look at things that layer on top of each other. These things that layer on top of each other were found in rocks from a long long time ago and were thought to be made from living things that eat light. However, we can also make these things that layer on top of each other with a paint can. This means that we need to watch out when we find these things that layer on top of each other a long long time ago because they may not always be made by these living things that eat light.

Second, the friends look at marks on the hard parts in animals that hold them up. Some people thought the marks on the hard parts in animals that hold them up were made by people cutting those animals to pieces. However, other people say the marks on the hard parts in animals that hold them up could be made by animals with long noses who lie in water and you should never smile at. These animals that you should never smile at who jump out of the water can cut marks on the hard parts of animals that look very very much the same as the ones that come from people cutting animals to pieces. This means we need to watch out when seeing these marks because they may or may not show that people were there.

 

References:

Sahle, Yonatan, Sireen El Zaatari, and Tim D. White. "Hominid butchers and biting crocodiles in the African Plio–Pleistocene." Proceedings of the National Academy of Sciences (2017): 201716317. 

 McLoughlin, N., L. A. Wilson, and M. D. Brasier. "Growth of synthetic stromatolites and wrinkle structures in the absence of microbes–implications for the early fossil record." Geobiology 6.2 (2008): 95-105. 

 

Direct download: Podcast_124_-_A_Second_Opinion.mp3
Category:general -- posted at: 3:00am EST

The gang discusses two papers with differing opinions about whether or not extinction events in the fossil record follow a periodic pattern. Also, James is dealing with very reputable people, Curt forces people to talk about things they don't care about, and Amanda becomes VERY interested in energy conservation.

 

Up-Goer Five (James Edition): 

This week the group looks at two papers seeing if really bad times when lots of things died happen on a time table or if really bad times when lots of things died do not run on time and came come any time they want. The first paper says the death train does not run on time and that we do note see a time table that it sticks to. They state that past papers that have tried to see the when the death train comes have made time tables out of chance visits and that we can not use these time tables because we may be waiting for the death train a long time and then find that two death trains show up at once. The other papers in the past said that this time table is caused by the stars and that things coming from space are making the death train run on time. The new paper says that this is not true because there is no time table and the stars can't control a time table that is not there.

The second paper responds to the first paper and says that the time table is there and the way the first paper checked the time table was too mean. The second paper points out that the death train can be early or late and still be running on a time table. They look at the same numbers as the first paper and say that the death train is just early or late quite a bit but still runs on its time table.

 

References: 

Erlykin, Anatoly D., et al. "Mass extinctions over the last 500 myr: an astronomical cause?." Palaeontology 60.2 (2017): 159-167.

Melott, Adrian L., and Richard K. Bambach. "Comments on: Periodicity in the extinction rate and possible astronomical causes–comment on mass extinctions over the last 500 myr: an astronomical cause?(Erlykin et al.)." Palaeontology 60.6 (2017): 911-920.

Direct download: Podcast_123_-_Periodicity_of_Extinction.mp3
Category:general -- posted at: 3:00am EST

James and Curt are joined by friends of the show Brendan and Carlie to discuss the talks presented at the Geological Society of American annual meeting in Seattle, WA. Day 2 starts at 1:12:43. Day 3 starts at 3:05:06. Day 4 starts at 3:59:34. Videos of each day are available on youtube under the channel Palaeo After Dark

 

Additional music: "Puzzle Pieces 2 (I Don't Believe in Ghosts)" by The Mixtapes and distributed by Paper + Plastic:

http://paperplastick.limitedrun.com/products/551888-mixtapes-these-are-us

Direct download: Podcast_122_-_GSA_2017_We_Have_a_Fridge.mp3
Category:general -- posted at: 3:00am EST

The gang discusses two papers that use fossil evidence to determine the past ecology and niche-space of past organisms, specifically dodos and hyenas. How can we use information from bones to interpret diet, life cycle, and behaviors of long dead animals? Also, James decides to start Skynet on the grounds that they will let him become a weather controlling tiger-bot, while Amanda and Curt draw hard lines in the sand about Don Bluth cartoons. 

 

Up-Goer Five (James Edition):

The group looks at two papers that are interested in seeing how things lived. The first is cutting into the inside hard parts of animals with that should fly but could not fly and are in the same family as animals that can fly and live with people in cities. These animals died when people came to their rock in the big water that you can not drink with lots of bad friends. The people that came to the home of these animals did not care about them much, and so the words we have from them are not very good and often do not agree. The study looks at the hard parts and the words of the people to see how these animals lived. They show that the animals grew quickly and changed their clothes a lot over the year which is why different people thought they looked different, and that they laid their round baby boxes during the part of the year when there was not bad sky stuff.

The next study looks at the teeth of cats that want to be dogs that are today only found in the big place where the rains are down but in the past were found in many places that people lived. They want to see if these cats that want to be dogs eat the same thing at different points in time. They show that the cats that want to be dogs eat different things today than they used to, and that maybe this is because there are very big cats that are definitely cats in the big place where the rains are down that stop them getting other food.

 

References:

 DeSantis, Larisa RG, et al. "Assessing niche conservatism using a multiproxy approach: dietary ecology of extinct and extant spotted hyenas." Paleobiology 43.2 (2017): 286-303. 

 Angst, D., et al. "Bone histology sheds new light on the ecology of the dodo (Raphus cucullatus, Aves, Columbiformes)." Scientific Reports 7 (2017). 

Direct download: Podcast_121_-_Reconstructing_the_Niche.mp3
Category:general -- posted at: 3:00am EST

The gang discusses two papers that deal with different examples of convergence. The first discusses how brood parasite female cuckoos mimic birds of prey, and the second paper discusses convergent morphological evolution in early tetrapodomorph fishes. What do these two papers have in common. you may ask? Both discussions have Amanda cheerfully yelling the word "Convergence!"

Meanwhile, Amanda narrowly avoids drunk Amazon shopping, James demands truth in advertising, Curt doesn't believe that these papers are remotely related in any way, and everybody gets very easily distracted by the prospect of fire-belching furnaces and knife-wielding murderbots. <EDITOR'S NOTE: The group start talking about science about 10 minutes in>

 

Up-Goer Five (Curt Edition): 

The group looks at two papers where the same things keep happening to many different animals. The first paper looks at an animal that can fly and is a bad mom that leaves the kids with some other flying mom so she does not have to raise them. This flying bad mom can pretend to be something else and kind of looks like something else that is big and angry. When the flying bad mom drops the kids at the home of the other flying mom, she pretends to be a very big and angry flying thing by screaming as she leaves the home of the other flying mom. People showed that the sound of the bad mom screaming sounds just like the big angry thing she is pretending to be, which makes the other flying moms scared so they do not know that the kids have been left at their home. The kids then eat the other flying moms out of house and home.

The other paper looks at animals that are in the water but could sometimes come out on the land from a long time ago. As time went on, more of these animals spent more time out on land than on the water, and they also changed how they looked. This made us think that the things spending more time on land changed in ways for them to spend more time on the land. But this new animal shows that those changes happened in things that didn't spend as much time on land, so maybe the changes aren't just because things were on the land so much.

 

References:

York, J. E., & Davies, N. B. (2017). Female cuckoo calls misdirect host defences towards the wrong enemy. Nature https://doi.org/10.1038/s41559-017-0279-3

Zhu, Min, et al. "A Devonian tetrapod-like fish reveals substantial parallelism in stem tetrapod evolution." Nature Ecology & Evolution (2017): 1.

Direct download: Podcast_120_-_Something_Something_Convergence.mp3
Category:general -- posted at: 3:00am EST

The gang discusses two papers that look at the complex issues surrounding the identification of sexual dimorphism in archosaurs (e.g. birds, dinosaurs, and alligators/crocodiles). Meanwhile, James has very strong opinions about Fat Tire beer, Amanda becomes lost in independent research, and Curt accidentally tears the podcast apart.

 

Up-Goer Five (James Edition):

The group looks at two papers that want to see whether animals that lived a long time ago are boys or girls. The first paper is looking at lots of small animals that could fly and had hard mouths. We find them in small, not so small, and big, and it has been suggested that the big ones were boys, the not so small ones were girls, and the small ones were young. Some of them have big back ends, and it was thought that maybe those that had big back ends were boys and those that did not have big back ends were girls. The paper thinks that maybe both boys and girls had big back ends, because they find big back ends on the young ones. The group however have seen another paper that thinks that boys did have big back ends and girls did not have big back ends and the small ones were actually a different type of flying animal with hard mouths.

The second paper is looking at trying to tell if big angry animals without hair were boys or girls. To do this they look at big angry animals that are around today and animals with hard mouths that are too big to fly that are around today. They show that big angry animals and animals with hard mouths that can sometimes fly grow different, and if you did not know which ones were boys or girls it is very different to tell which of the big angry animals are boys and girls. They show that most big angry animals without hair from a long time ago grow like big angry animals today, and so we should wait for a lot of facts before deciding if they are boys or girls, and that when we have thought we have found different things between boys and girls in the past we may have been looking at grown ups and babies.

 

References: 

 Hone, David WE, and Jordan C. Mallon. "Protracted growth impedes the detection of sexual dimorphism in non‐avian dinosaurs." Palaeontology 60.4 (2017): 535-545. 

 Peters, Winfried S., and Dieter Stefan Peters. "Life history, sexual dimorphism and ‘ornamental’feathers in the Mesozoic bird Confuciusornis sanctus." Biology letters (2009): rsbl20090574. 

Direct download: Podcast_119_-_Dimorphic_Dinosaurs.mp3
Category:general -- posted at: 3:00am EST

The gang discuss two papers that attempt to resolve the taxonomic placement of animals with complex or confusing morphologies. Also, they somehow go off on a tangent about careers in academia, publish or perish, and the various lengths people can go to try and maximize their research output. Meanwhile, Amanda has some issues with her light sockets, James tries to pass off "facts"about rats, Curt makes references to 90's cartoons, and everyone greets our new guest, the "Pony".

 

Up-Goer Five (James Edition): 

The group looks at two studies where animals that were thought to be one thing were shown to be another. The first paper looks at a very old animal known from three parts. One part was thought to be a soft animal that moved in the water and had the same thing for a mouth and a bottom, another part was thought to be an animal that hid in a hard house and grabbed food as it passed, and another was thought to be something that has a soft thing in it for sending news from end to end. The new study shows that these are all the same thing, and that is part of a big group of animals that can move in water or stick to rocks and attack things with small arms.
The other study is looking at big angry animals with no hair, especially one big angry animal that it is not known where it should go. The big angry animal is not that big and not that angry, and seems to be like both big angry animals with no hair that ate other animals and big angry animals with no hair that ate green things that do not move. The new study shows that it is part of one of the groups of big angry animals with no hair that eats green things that do not move, but the ones that have big heads and short necks. Parts of it look like big angry animals with no hair that eat other animals because it is an early part of the big angry animals with no hair that eat green things that do not move that have big heads and short necks even though we find it after we find some of its friends.

References:

Ou, Qiang, et al. "Three Cambrian fossils assembled into an extinct body plan of cnidarian affinity." Proceedings of the National Academy of Sciences(2017): 201701650. 

Baron, Matthew G. and Barrett, Paul M. "A dinosaur missing-link? Chilesaurus and the early evolution of ornithischian dinosaurs" Biology Letters(2017): https://dx.doi.org/10.6084/m9.

Direct download: Podcast_118_-_Dealing_with_Problematica.mp3
Category:general -- posted at: 3:00am EST

The gang discuss two papers that study how the geographic ranges of turtles and frogs changed through time, and how these changes affected their ecology and evolution. Also, James drinks what he presumes is ground horse, Curt goes full Ian Malcolm, Amanda shares life lessons about furniture, and everyone imagines what turtle they are. [Editor's note: The actual science starts about 13 minutes in, I just didn't have the heart to cut it down.]

 

Up-Goer Five (Amanda and James Edition):

Today our friends talk about animals with hard backs and no hair, and also animals that jump and have little skin. The group looks at two studies that look to see whether where animals are and have been is important. We talk about how animals with hard backs and no hair used to live in many, many places. Today they live in less places. Maybe some day they will live in more places again if it gets warm because of people. But maybe not because some animals with hard backs and no hair do need it to be wet. And if it is not wet when it gets warm again then they will not be able to live in more places again. We don't know. Being wet does seem to matter a lot, though. With animals that jump and have little skin, maybe they changed in place or maybe they went all over the place and changed as they went. We read that people think that they did not change as they went, but rather changed in one place and then went to other places. 

 

References:

Waterson, Amy M., et al. "Modelling the climatic niche of turtles: a deep-time perspective." Proc. R. Soc. B. Vol. 283. No. 1839. The Royal Society, 2016. 

Chan, Kin Onn, and Rafe M. Brown. "Did true frogs ‘dispersify’?." Biology Letters 13.8 (2017): 20170299. 

Direct download: Podcast_117_-_Hero_Terrapins_and_Fighting_Frogs.mp3
Category:general -- posted at: 3:00am EST

The gang discuss two papers that offer new evidence which re-contextualizes our understanding of the evolutionary history of two important Mesozoic groups, dinosaurs and marsupials. Meanwhile, Amanda comes up with a terrible/great new idea for liquor consumption, Curt consistently offers bad advice to his friends, and James cracks open a bottle of sangria and then everything gets a bit fuzzy. Can you guess that this was the fourth podcast recorded in a single week? Can you hear the life drain from James? (Editor's Note: The "science" starts 13 minutes in. Apologies, we will be better in the future. [Editor's Editor's Note: Probably not.])

 

Up-Goer Five (Amanda Edition): 

Today our friends talk about very large animals with no hair that everyone loves but our friends don't care about, and also funny animals with hair that are not like us because they do not have big babies. It turns out the very large animals with no hair that everyone loves are all brothers and sisters in a very funny way, not like we used to think at all. The very large animals with no hair that everyone loves have three kinds: long necks that eat leaves, ones that eat other animals, and ones that eat leaves but do not have long necks. We thought that the ones that had long necks and the ones that eat other animals were close brothers and sisters. But it turns out they might not be. The ones with long necks might be the oldest brothers and sisters, then the ones that ate leaves but did not have long necks, and then the ones that ate other animals. With the funny animals with hair that are not like us because they have small babies, they were thought to have started in places other than where our friends live. But it turns out that maybe they actually started where our friends live, and not where other people live across the big waters. 

 

References:

 Baron, Matthew G., David B. Norman, and Paul M. Barrett. "A new hypothesis of dinosaur relationships and early dinosaur evolution." Nature 543.7646 (2017): 501-506. 

 Wilson, Gregory P., et al. "A large carnivorous mammal from the Late Cretaceous and the North American origin of marsupials." Nature Communications 7 (2016). 

Direct download: Podcast_116_-_Changing_Relationships_Dinosaurs_and_Marsupials.mp3
Category:general -- posted at: 3:00am EST