Tracing Patterns of Evolution through the Tree of Life： Introduction

One and half centuries ago, Charles Darwin (1859) presented overwhelming evidence and argued that all life on the earth shared common descent, and "from so simple a beginning endless forms most beautiful and most wonderful have been, and are being evolved". Ernst Haeckel (1886)

One and half centuries ago, Charles Darwin （1859） presented overwhelming evidence and argued that all life on the earth shared common descent, and ＂from so simple a beginning endless forms most beautiful and most wonderful have been, and are being evolved＂. Ernst Haeckel （1886） and several of his contemporaries attempted to trace the pattern of descent among all extant andextinct forms in what Darwin referred to as ＂the great Tree of Life＂.