LETHAIA REVIEWS

Lethaia, Vol. 14, p. 190. Oslo, 1991 04 15

Travel through animal life

JAN BERGSTROM

Krause, Gerhard 1990: Biogenetische Interphanotypen: Weg- weiser durch die Stammeslinien der Tiere. 197 pp., 41 figures, 25 colour plates. Paul Parey. Berlin. Hamburg. ISBN 3-489- 64834-X. DM 29.- hardbound.

This is a different book. According to the text it is a discovery trip through animal ontogenies. It is not streamlined in time, but this is not said with any negative intention. When he had already reached his 80th birthday, the author was persuaded by friends to summarize his views on animal evolution in a book. The result is the essence of our knowledge on embryology and ontogeny and is a fascinating attempt to use this knowledge to trace evolutionary steps leading to most important groups of animals, with the exclusion of articulates and molluscs. Krause tries to identify specific larval features as the remains of adult features of old ancestors - this is the old idea of recapitulation. Being old, however, does not mean that it is incorrect, although we - and Krause - now know that it is not reliable in detail. In addition, he tries to find the origins of fully formed structures in ‘preformed’ rudiments of other animal groups. The stops in the discovery trip are a number of levels marked by ‘inventions’. In doing all this, the author takes care of an old tradition and tries to make the best of it. The book is living history, living in the sense that Krause has incorporated a wealth of new data in his model.

There is no reason to think that this is the ultimate word on animal evolution, but it is one way to study it. and a very important way which has unfortunately gone out of fashion. Krause certainly does not have all the answers, but who has? He realizes that spiral cleavage was typical of the ancestral bilaterians. As one result. the deuterostomes are seen as end

members of a branch in which the spiralian characters are weakened and ultimately lost. In very general terms, Krause’s model so far agrees with the result of cladistic analyses of molecular sequence data. In practice, his tree has two main branches leading from the flatworm level. One consists of ‘eu- spiralians’: nemerteans, sipunculids, molluscs, annelids and arthropods. This branch is not analysed. The other, the ‘dys- spiralians’, leads through aschelminths over tentaculates to deu- terostomes.

Personally, I believe that Krause has made an achievement with the aschelminths including the chaetognaths, whereas the tentaculates are probably grouped together by mistake due to parallel evolution which has not been detected. Still, the facts are relevant, and the approach has much more to give, par- ticularly in combination with other approaches.

There are 41 text figures and 25 plates. The illustrations are informative and easy to study. except perhaps Fig. 41, which takes some effort to understand. It is strange that the author illustrates other authors’ phylogenetic trees rather than his own; Fig. 35 over aschelminths and coelomates was produced by Gruner and differs from .the message of the text in important respects. The plates give a nice and valuable overview of the animal kingdom, including egg cleavage patterns and onto- genies, and most of them are coloured in a very pedagogic way.

I recommend this little book to those who master the German language and who need a truly biological overview of animal diversity and evolutionary plasticity on a high taxonomic level.

Jan Bergstrom, Department of Palaeozoology, Swedish Museum of Natural History, Box 50007, S-10405 Stockholm, Sweden; 28th January, 1991.