Is the evolutionary tree a fractal structure?

We analyse the time sequences of major evolutionary leaps at various scales , from the scale of the global tree of life, to the scales of orders and fa milies such as sauropod dinosaurs, North American fossil Equidae, rodents, and primates including the Hominidae. In each case we find that these data are consistent with a log-periodic law to a high level of statistical signi ficance. Such a law is characterized by a critical epoch of convergence T-c specific to the lineage under consideration and that can be interpreted as the end of that lineage's capacity to evolve. ((C) Academic des sciences/E lsevier, Paris.).