Your Inner Fish
by Neil Shubin.
by Neil Shubin.
I got this book like 2 weeks ago but I haven't finished it yet because I'm slacking wayyy too much. Eeek.
In case, you didn't know: Neil Shubin and his team discovered the fossils of Tiktaalik in 2006. Tiktaalik represents an important transition from fish to the early tetrapods. To learn more about Tiktaalik, check out Wikipedia for some general information.
In the first chapter, Neil describes how the expedition was planned and how it went. Using the theory of evolution amongst other evidence that were previously unearthed, the team predicted the location, age and type of the rocks where the transitional forms from fish to tetrapod could be found.
Chapter 1: Finding your inner fish (pg.10)
...there is strong geological evidence that the period between 380 million to 365 million years ago is the critical time. The younger rocks in that range, those about 360 milion years old, include diverse kinds of fossiled animals that we would all recognize as amphibians or reptiles...... [amphibians] with their necks, their ears, and their four legs, they do not look like fish. But in the rocks that are about 385 million years old, we find whole fish that look like, well, fish. They have fins, conical heads and scales; and they have no necks. Given this, it is probably no great surprise that we should find evidence of the transition between fish and land-living animals.
And then they discussed where to find such rocks...
Chapter 1: Finding your inner fish (pg.15)
...three areas with Devonian freshwater rocks, each with a river delta system. First there is the east coast of Greenland. This is home to the Jenny Clack's fossil, a very early creature with limbs and one of the earliest know tetrapods. Then there is eastern North America, where we had already worked, home to Hynerpeton. And there is a third area, large and running east-west across the Canadian Artic.
It took four expeditions to Ellesmere Island spanning 6 years and they finally found Tiktaalik. A transitional form that have both features of fish and tetrapods.
Chapter 1: Finding your inner fish (pg.23)
Our new creature broke down the distinction between these two kinds of animals [fish and tetrapods]. But like early land-living animals, it has a flat head and a neck. And, when we look inside the fin, we see bones that correspond to the upper arm, the forearm, even parts of the wrist. The joints are there, too: this is a fish with shoulder, elbow, and wrist joints. All inside a fin with webbing.
And what else does Neil has to say about Tiktaalik?
Chapter 1: Finding your inner fish (pg.26)
How can I be so sure that this fossil says something about my own body? Consider the neck of Tiktaalik. All fish prior to Tiktaalik have a set of bones that attach the skul to the shoulder, so everytime the animal bent its body, it also bent its head. Tiktaalik is different. The head is completely free of the shoulder. This arrangement is shared with amphibians, reptiles, birds and mammals, including us. The entire shift can be traced to the loss of a few small bones in a fish like Tiktaalik.
The wonder of transitional forms.
The rest of the books describes the numerous evidence for evolution from fossils to cells and from genes to embryology. It's wonderful. I'd say it's a must read for those who enjoys an intellectual booster from various evidence neatly explained in the book (even for laymen readers).
