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The novel Your Inner Fish: A Journey into the 3.5-billion-Year History of the Human Body by Neil Shubin explores the origins of humanity. Shubin makes it clear from the start of the novel that humans have changed over time through evolution, and the fossil record has secrets of our past hidden inside of it. Even though only a miniscule fraction of organisms are fossilized, fossils can be used to glimpse into the past and study our ancestors. Shubin focuses on how similar humans are to other animals, both morphologically and genetically. For example he highlights that all animals have heads, even fish, a trait that can be adequately explained through common descent. It is by far more likely that having a head is a shared trait, than it is that it independently arose in numerous recent lineages. This is one of the main themes of the book, highlighting similarities humans share with other animals. Darwin used the same method in On the Origin of Species, but here Shubin can built off of Darwin’s foundation by using modern discoveries.

In Your Inner Fish, An entire chapter is devoted to teeth. Teeth are incredibly useful when studying fossils because they are hard features that easily fossilize. In fact teeth are sometimes the only hard parts of animals to fossilize. Shubin includes personal anecdotes regarding his search for fossils, including finding some of the earliest known specialized teeth. Shubin does not only talk of his incredible fossil discoveries, but also the entire history of life. There are numerous reasons as to why it took so long for multicellular life to proliferate. Firstly, the conditions must be right, the environment must be suitable for life and contain enough oxygen to meet energy demands. Multicellular life takes significantly more energy than unicellular life.

Shubin is credited with having discovered what is often referred to as a missing link in evolution. He discovered Tiktaalik, a species that represents the transition from water to land. Tiktaalik is of special interest because it has features of both tetrapods and fish. Shubin states that “Tiktaalik’s message is so straightforward even preschoolers can see it. For our purposes, there is an even more profound take on Tiktaalik. This fish doesn’t just tell us about fish; it also contains a piece of us” This fish was the first one discovered that has its head free from the shoulder, as in humans. This trait can be explained by the loss of several small bones in a fish similar to Tiktaalik. Furthermore, Tiktaalik has tetrapod featured like a flat head and neck but also fish features such as scales and fins. It is clearly a transitional fossil that shows when fish started to venture out onto land.

The novel Your Inner Fish by Neil Shubin explores the origins of humanity. Shubin makes it clear from the start of the novel that humans have changed over time through evolution and the fossil record has secrets of our past hidden inside of it. Even though only a miniscule fraction of organisms are fossilized fossils can be used to glimpse into the past and study our ancestors. Shubin focuses on how similar humans are to other animals, both morphologically and genetically. For example he highlights that all animals have heads, even fish, a trait that can be adequately explained through common descent. It is by far more likely that having a head is a shared trait, than it is that it independently arose in numerous recent lineages. The main theme of the book, highlighting similarities humans share with other animals. Darwin used the same method in On the Origin of Species, but here Shubin can built off of Darwin’s foundation by using modern discoveries.

The object is a fly larvae. It has a body length of 1.3cm, a tail length of 1.5cm and a total length of 2.8cm. The larvae has translucent skin and organs are visible internally. It has a dark colored head and tail. The tail seems to continue into the body and the very end of the tail is uncovered by the translucent tissue. The larvae often stops moving when touched or agitated. It cannot travel long distances in a straight line, and generally rolls over or abruptly changes direction. However, it seems to prefer being in motion to staying still. The larvae exhibits bilateral symmetry and the body contracts and expands to aid in movement.

• Larvae

• Relatively small body a couple cm, slightly longer tail

• Long tail, longer than body length

• Tail has dark line in it

• Dark head

• Translucent skin

• Moves inside of its skin

• Has sets of small feet to help move and grip

• Pieces of wood chips visible inside, has been eaten

• Often plays dead when disturbed

• Black hair like structure extrudes out of skin at end of tail

• Black dots visible internally

• Body length 1.3cm

• Tail length 1.5cm

• Total length 2.8cm

• Width of body 4mm

• Width of tail 0.5mm

• Cannot move straight for long periods of time, often rolls over

• Body lengthens and shortens to move

• Bilateral symmetrical with paired organs