Your Inner Fish

In class 9/20/13, we discussed the chapters we read for homework the night before, in Your Inner Fish. The chapters we read were about how Neil Shubin and his colleagues process of finding Tiktaalik. An important topic discussed in these chapters was where to find fossils. The way to find a good fossil is to look at rocks of the right age (time period), right type of rock (sedimentary rocks), and exposure (fossils towards the surface). Also, the chapters discussed layers of rocks, upper layers are younger and contain more complex and younger fossils, and lower layers contain more simple and primitive fossils. Fossils are formed through a slow process of layer and compacting of sediment.

The discovery of Tiktaalik in Greenland by Neil Shubin and his colleagues gives evidence of evolution. Tiktaalik has a neck which was used for a similar function as humans use necks today; structures which are used for similar functions and have similar structures are known as homologous structures, which further proves that humans and Tiktaalik have the same common ancestor. Tiktaalik is also the missing link between amphibians and fish because it has limbs and can breathe on land and in water.