زمین شناس

                                            تکامل زیستی در استراکدها

                                   Evolutionary Biology of Ostracoda   

                                  (Developments in Palaeontology & Stratigraphy)

                                by: Tetsuro Hanai, Noriyki Ikeya, Kunihiro Ishizaki 

                                                        size: 31.8 MB   

At the general meeting of the Houston symposium, when we proposed to invite the next symposium

to Shizuoka, Japan, someone asked us about the theme of the upcoming symposium. We

replied that we intended to focus attention on the evolutionary biology of Ostracoda, its fundamentals

and applications. On second thought, however, we felt that this theme would be inappropriate

because evolutionary biology is a nomothetic science, whereas the study of Ostracoda adopts

a more or less idiographic approach. Thus it was realized that our intention comprised two general

approaches.

One fundamental approach is expressed in the words “evolutionary biology” and is especially

intended to extend evolutionary biology into the geological past utilising Ostracoda. Taking advantage

of their ideal characteristics for evolutionary research, it is possible to determine palaeobiologically

significant events and develop theories. Recent progress in evolutionary biology seems

to have been mainly based on studies of experimental organisms suitable for genetic research,

with hardly any fossil evidence. Furthermore, theoretical syntheses in the field of evolutionary

biology have recently advanced rather rapidly without sufficient palaeontological evidence. We

believe that Ostracoda are one of the most useful organisms for studies intended to overcome

difficulties originating from these circumstances. Understanding evolutionary process can doubtless

be achieved through the cooperation of biologists and palaeontologists. This ostracod research

group, which has been assembling every two or three years since 1963, is in a good position to

conduct such studies.

Another traditional approach may be expressed by the two words, “of Ostracoda”. In spite of the

complaints about idiographically oriented methodology, which employs a little classification and

generalizes on the descriptive level, if we trace the history of this methodology back into the time

of Linnaeus and consider that our knowledge of Ostracoda was virtually nil at that time, our

present knowledge is unexpectedly vast in both space and time; it also includes aspects from

many fields of biology and other related sciences, as anyone who has studied Ostracoda knows.

This knowledge of Ostracoda has been strengthened by generalizations on the descriptive level

in the same manner as generalities have known as ‘laws’ in evolutionary biology. Even if we

defer to the criticism of a strongly idiographic approach, the addition of the words “of Ostracoda”

will, at least, still prevent studies from becoming mere intellectual exercises in the nomothetic

and evolutionary disciplines.

Our other aim is to learn of fundamental studies which can be of vital importance, especially for

biostratigraphy and palaeobiogeography, and therefore in the exploration for petroleum resources.

Studies made by petroleum palaeontologists may even be able to relate evolutionary changes in

ostracod fauna to the temporal influx of sea water flowing into the continents and to the movement

of the plates.

        As this was the first time this symposium was held outside of America or Europe, its results will                     

aid and influence future ostracod studies in the Asian area. We wish to thank all our contributors

and discussion participants for helping to promote a productive and well attended symposium.

Chinese ostracodologists kindly agreed to receive an excursion to visit fossil localities in China.

For advice, assistance, and help in surmounting the language barrier, we are grateful to many

of our colleagues. Professor John W. Neale and Dr. Heinz Malz prolonged their stays in Japan

and gave us invaluable advice, assistance and support. Dr. J. F. Babinot, Dr. P. Carbonel, Dr.

Thomas M. Cronin, Dr. P. 0. Ducasse, Professor Gerhard F. Hartmann, Professor Joseph E.

Hazel, Dr. Yasuaki Ishiwada, Professor Roger L. Kaesler, Dr. Takahiro Kamiya, Dr. R. E. L.

Schallreuter, Dr. I. Gregory Sohn, and Dr. Robin C. Whatley also gave us valuable advice and

helped us in innumerable ways. We are deeply indebted to all of these people for their unstinting

help and encouragement both during the symposium and in the editing of these proceedings.

Tetsuro HANAI

Noriyuki IKEYA  and

  Kunihiro  ISHIZAKI