Neil Shubin Your Inner Fish Summary

Your Inner Fish - Book Report The book “Your Inner Fish” written by Neil Shubin takes us through his search and knowledge of fossils as a paleontologist. The main idea is well, finding your inner fish or in scientific terms tracing back the evolution from fish to land living animals such as mammals. Neil shares his experience looking for important fossils that reveal our evolution into humans. The fossil finding process is long and hard, it can take years before something life changing is discovered. Neil Shubin knows all about this as it took him and his team years of searching to find one of the most important fossils that tell about evolution, the Tiktaalik. Early on in the book Neil asks us “How can we visualize events that happened millions

The sequences of DNA that make us what we are and any other living things what they are. Neil tells us that his lab is divided into two parts. One to study fossils and one to study DNA and embryonic development. So, while Shubin was in the Arctic, another researcher in his lab was busy injected a form of Vitamin A into shark and skate embryos. They wanted to see how the limbs would know how to develop. In the 1950s and 1960s Edgar Zwilling and John Saunder did experiments on chicken eggs to uncover how the skeleton is formed. They discovered that two patches of tissue essentially control the development of limbs. Neil explains to us that the patch of tissue that makes the pinky side different from the thumb side is called the zone of polarizing activity or ZPA. Later, geneticists working with flies discovered a gene they called hedgehog. This gene controlled which end of the fly was which. When they found the chicken version of the gene they named sonic hedgehog. The gene is only active in the cells that are involved in limb development. The form of Vitamin A that was being used by Niels lab causes Sonic hedgehog to activate. Every limbed creature has the sonic hedgehog gene. It was proven that the gene works the same in all animals when they took a mouse gene and injected into a shark embryo and it worked the same way as Vitamin

In fact, they are the reason we even know some organisms existed. Neil goes on to describe his days as a first time fossil hunter. He says you have to look for something that doesn’t look like rock. Teeth can tell us about the diet of an animal for example our teeth show that we are all purpose eaters. We have incisors for cutting, canines for holding and molars for grinding. The entire order of carnivores is defined by four teeth called carnassials. If you have those kind of teeth, you are a member of the carnivore family, if you don’t have those teeth, you can’t be in that family. The earliest teeth in the fossil record come from Conodonts. There is evidence that teeth were the first hard part ever. Niels next topic is about heads. Our skulls are made up of 3 parts : plate, blocks and rods. Human heads can be similar to other animals. Some nerves can be simple other complicated. Human development stages are similar to sharks first a jaw and some parts of the ear. Heads are formed by linking two vertebrae together.There is a pattern for all animals like all the other things we talked about such as