THE ISSUE OF SALTATIONS IN BIOLOGICAL EVO LUTION

In this article the concepts of giant mutation and evolutionary saltat ion are considered. After a description of these processes there is a reminder that during the last few years paleontologists have given ver y fine descriptions of anageneses and zoologists have established that hybridism between closely allied species is far more frequent than wa s believed only twenty years previously. Precopulation and postcopulat ion isolation appears to take place progressively. There is also a rem inder of the theoretical reasons why saltations creating high taxons s hould he also statistically impossible. However, particular situations are analysed in which rapid evolutions can produce images of saltatio ns and these are discussed. It is concluded that speciation as the pas sage from one high taxon to another is made up of continuous phenomena .