Chapter 2:: GETTING A GRIP

Q. What did further examination of Tiktaalik’s fins reveal about the creature and its lifestyle?



- In the second chapter Shubin mentions the similarity between the basic skeletal structure of all organisms, with emphasis on the hand. Shubin believes that studying the variations in limbs that have evolved over the years will help constitute our map of evolution. Now when comparing the human torso with that of a pig, we notice that their resemblance is comparable. However when evaluating the limbs in the hands of these two orgainisms, we realize that not only are their structures different, but the human hand shows skeletons representing the thumb, which is a signature human structure.

- Sir Richard O Wen, in 1822 began investigating the evolution of the thumb. Bats, horses, gorillas, humans even dinosaurs all had exactly the same limb structure; one bone, two bones, bunch of little bones. Sir Owen recognized the coinciding features in all of these organisms while examing their skulls as well as the backbones.Thus he concluded that there is a fundamental design in all vertebrates.

- This theory also helped discover how and where Tiktaalic was habitauted. The wrist bone in its fin, was due to the fact that it either lived on the ocean floor, or in shallow streams. Thus it  should have been able to lift its body off the floor in order  to maneuver its way around. This was an important discovery in this chapter of the book, as it provides us with further evidence that humans are related to fish like Tiktaalik.