Project 1:
Chapter 1: The front page of the magazine relates to the book because on the front cover is a picture of a fish with a flat head. In the book, Neil Shubin talks about how in the Arctic he first saw the skeleton of a fish with a flat head, this led him to believe it would explain the early stages of the human skull, neck and potentially the limbs. This flat headed fish called the Tiktaalik was an important find because it showcased the transition between fish and land animals (specifically tetrapods). On the cover of the magazine it also says “When Fins Became Limbs”. In chapter one it explains how the Tiktaalik has fins but inside the fins there are bones that resemble bones typically found in the upper arm, forearm and parts of the wrist. The Tiktaalik also has joints while still having scales and webbing typically found …show more content…
This gene is basically like the human ZPA gene whose function is to make one part of the body different from another. The hedgehog gene functions the same way. This gene was also found in chickens and was then named the sonic hedgehog gene. It was concluded that every living thing with a limb had this gene in some form. The sonic hedgehog gene is found in the tissue of the ZPA and if not active during the right time it could cause extra fingers or fingers looking the same.
Randy Dahn was looking for more answers so he decided to do experiments on sharks and skates. He found their sonic hedgehog gene relatively quickly and then discovered it became active at the same time in sharks as it would in a chicken. He confirmed that it made identical copies of the DNA on the opposite side of the shark’s limb if injected there. His final experiment was to inject the skate fin with a mouse sonic hedgehog protein to see if it would have an effect. The mouse protein did have an effect and the skate rods (inside the fin) came out with a new shape from their normal