Sun, 26 November 2017
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.
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.
Sun, 12 November 2017
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.
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.