The gang discusses two papers about jawless fishes. The first paper looks at some soft tissue preservation of early vertebrates which include preserving evidence of an ancient heart, while the second paper investigates how the fossil record of hagfish can inform the order in which characteristics evolved within the group. Meanwhile, James "solves" his problems with machines, Amanda keeps making new friends whether they like it or not, Curt claims no responsibility, and everyone loves these kawaii line drawings.

Up-Goer Five (James Edition):

This week the group look at two papers that are about different animals that have no legs and live in water. The first paper is about a very strange animal that lived a very long time ago that people have thought might be an early part of the group that is made up of things with hard parts inside. The paper looks at things inside the animal and show that they are made of old blood showing the parts of the animal that carried the blood and the parts that clean it. These parts suggest that the animal is in fact an early part of the group that eventually get hard parts inside. The second paper looks at three animals that are part of the group of animals that make thick wet stuff and have a mouth that does not move. They also have small eyes under the skin and live in deep places and it has been thought they show what all animals with hard parts inside used to be like. These three old animals show how the eyes have changed over time and that these animals used to have normal eyes. One of the animals is starting to get small eyes and this shows that the eyes did not get small because they lived in the dark because this one is from water that is not deep.

References:

Tian, Qingyi, et al. "Evidence for aorta and other blood vessels in fossil yunnanozoans from the Cambrian period." Royal Society Open Science 13.6 (2026): 260043.

McCoy, Victoria E., et al. "Stepwise loss of complexity in hagfish eyes prior to deep sea colonization." Biology Letters 22.5 (2026): 20260127.