Your Inner Fish, Neil Shubin

The paleontologist author is an expert on fish fossils and he uses this specialty to help us discover the evolutionary shift from water to land animals – from fish to humans.  It is a good story and well told. 375,000,000 years ago a primitive fish not only developed lungs, but also the bony structure that leads from species to species to the arms and legs of future reptiles, amphibians, birds, and mammals. Quite a journey.

This book is a study of human anatomy and the way that it connects us to the rest of the natural world.  It is important to recognize how we have found genes in everything from the single cell to our closest species partners that have helped us to understand the cures to diseases, have helped us find ways to benefit future generations and to look for new ways to research medicine and future treatments.  It is a compelling look at the natural world and it reminds me of what we would miss if we allow the loud mouths who deny evolution to set back science with their primitive views.

Below are some key graphics and stories from the book.

 

“Unlike fish and amphibians, our knees and elbows face in opposite directions.  This feature is critical: think of trying to walk with your kneedcap facing backward.  A very differeent situation exists in fish like Eusthenopteron where the equivalents of our knees and elbow face largely in the same direction.  We start development with little limbs oriented much like those in Eusthenopteron, with elbows and knees facing in the same direction.  As we grow in the womb, our knees and elbows rotate to give us athe state of affairs we see in humans today.

“Our bipedal pattern of walking uses the movements of our hips, knees, ankles, and foot bones to propel us forward in an upright stance unlike spawled posture of creatures like Tiktaalik.  One big difference is the position of our hips.  Our legs do not project sideways like those of a crocodile, amphibian or fish; rather, they project underneath our bodies.  This change in posture came about by changes to the hip joint, pelvis, and upper leg: our pelvis became bowl shaped, our hip socket became deep, our femur gained its distinctive neck, the feature that enables it to project under the body rather than to the side.”

The development of the fetus is really intriguing as the gill structure (arches) are consistent with the shark (and many other animals).  They become gills in the shark, but develop other important organs (natural biological genetic engineering) in the human.

The mapping of these elements is amazing and this book continues to relate fossils to present as well as moving across species from single cells through mammals.