What came first, the Chicken or the Ape?

I recently read the book "Why is a Fly Not a Horse?" by Giuseppe Sermonti. I really enjoyed it. It gets you thinking about genetics and evolution. He has a wealth of knowledge from a lifetime of work in molecular biology. He said as a student he was a great believer in evolutionary theory and the idea that with the proper environmental pressures new species could be created from old ones. However later in life he has come to look skeptically at the "Theory of Evolution." That species can and do change themselves in response to environmental pressures is a well documented fact, but the idea that all species diverged from a single organism, or even that any single species has diverged into two distinct species is still simply an idea with no hard proof.

I enjoyed the approach he gave in that he looked into what actually distinguishes one species from another. Of course we have had it drilled into our heads that it is all about DNA. However, there is more to life and the development of an organism than its DNA. There are other factors that determine how an organism will develop that the DNA cannot control. Without going into too much detail I will mention prion diseases (DNA determines the order of amino acids, but not the shape of the protein), bee and ant colonies (many distinct classes, but all have the same DNA), butterflies (it used to be a caterpillar?), other animals which have distinctive changes upon maturation but which can still survive and reproduce in conditions that prohibit maturity, and twins (definitely the same DNA, but not the same fingerprints).

Many other interesting facts and thoughts are explored in the work, and I would recommend it to anyone who has any interest in the realm of genetics and biology. I will also add that it is a translation from Italian and it is a little difficult to read.