Fish

It's one week before the birth of my baby and I have many ultrasound photos capturing her adventure from the earliest embryo inside the womb. It is hard not to feel awestruck watching her growth from a humble-looking yolk sac to a lovely one with brain, heart, nose and legs.

Having a wife as an obstetrician means abundant opportunity for me to watch and adore my yet-to-be-born baby's face. Sure, the photos of her face invite lots of oohs and aahs from our enthusiastic friends and families. "Amazing! The nose looks like mum's and her mouth resembles dad's…"

In no ways is her face to be confused with others. No one will be surprised that we're obsessed with the question how different and unique our baby is to be. I really believe it's so.

After my recent bedtime reading of Neil Shubin's Your Inner Fish, however, I start to look at our body in another way.

It turns out that we all look incredibly alike, instead of being unique in oneself. In his entertaining book, the distinguished paleontologist showed me all the exciting similarity between our anatomy and that of mammals, reptiles, and even fish. The chapter on the twelve pair of cranial nerves is the funniest. Most medical students, writes Shubin, should have had lost their ways amidst the maze of these twelve nerves, branching to take bizarre twists and turns inside the skull. Complicated as they are – believe it or not – cranial nerves inside our head shared a remarkable and elegant blueprint with every skull on earth. This applies, alas, to that of a shark, a bony fish, a salamander, or a human. Quite contrary to my imagination, virtually all of our cranial nerves are present in sharks, for instance. The parallels go deeper than having the equivalent trigeminial nerves, facial nerves, glossopharyngeal nerves, vagus nerves: these equivalent nerves in humans and our aquatic cousins supply similar structures, and they even exit the brain in the same order.

The message from Neil Shubin is clear: we're profoundly similar to each other. We are.