pp. 267 in Intractable Neurological Disorders, Human Genome Research and Society. Proceedings of the Third International Bioethics Seminar in Fukui, 19-21 November, 1993.

Editors: Norio Fujiki, M.D. & Darryl R.J. Macer, Ph.D.


Copyright 1994, Eubios Ethics Institute All commercial rights reserved. This publication may be reproduced for limited educational or academic use, however please enquire with Eubios Ethics Institute.

Flexibility in living organisms: A story in regeneration

Tokindo S. Okada
Director, Biohistory Research Hall, Takatsuki, Osaka, JAPAN


Developing organisms are provided with an enormous flexibility in morphogenesis, as demonstrated classically by the production of twin embryos from each half of a separated early embryo. In fully grown forms, the flexible nature of living organisms can be recognised in the regeneration of lost parts. Although the ability to regenerate differs between species, it is distributed generally. There is little doubt that regeneration is one of the key, and basic mechanisms, for maintaining life, as has been clearly stated by the American biologist J. Goss. "If there were no regeneration, there would be no life. If everything is regenerated, there would be no death". Thus, studies on regeneration are part of the essential scientific basis to discussion of that most important philosophical problem of "life and death".

Regeneration studies are one of the most fascinating areas of Developmental Biology and probably of the whole of Natural History. In spite of the recent great revival of Developmental Biology, not much research attention has been paid to research on the flexible nature of morphogenesis, nor to regeneration studies.

This lecture was to introduce the essential importance of regeneration for life and a number of exciting facts showing how flexible living organisms are, to the general public, including an intellectual lay audience. My talk consisted of four main parts:
1) An historical background to the discovery of regeneration
2) Rules governing the replication of lost parts

3) Cell changes supporting regeneration
4) A short discussion of "biological death" based on regeneration studies


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