This book is the first of its kind, providing in-depth analysis of the retrograde evolution occurring during major extinction periods. The text offers a non-strictly adaptative explanation of repetition of phyla after the major extinctions, utilizing a study of seven phylogenetically distinct groups. This opens a new experimental field in evolutionary biology with the possibility of reconstructing ancestral forms in lab by applying artificial stresses.
"This book is about fossils, and, thus, the images of various creatures of the Past dominate the book's pages. The readers will praise the author for his care of them: the informative abstract, the clear conclusion, the lengthy list of references, and the detailed index of fossil names facilitate understanding of GUEX'S ideas and simplify reading of his marvelous book. GUEX'S book is must read to all modern palaeontologists and stratigraphers. Many biologists and geologists will also find it useful" (Dmitry a. ruban, Zentralblatt für Geologie und Paläontologie, iss. 5 - 6, 2016)