history of db

1. INTRODUCTION TO DEVELOPMENTAL
BIOLOGY
BY
VENNILA.J

2.  WHAT IS DEVELOPMENT?

3. HISTORY OF DB
• DESCRIPITIVE AND COMPARATIVE EMBRYOLOGY
• EXPERIMENTAL EMBRYOLOGY
• ANALYTICAL EMBRYOLOGY MORGAN T.H. -1919

4. HISTORICAL REVIEW
• CELL THEORY

5. FIRST WESTERN PHILOSOPHER
• ANAXIMANDER -600B.C.

6. GREEK PHILOSOPHER
• EMPEDOCLES

7. FATHER OF ZOOLOGY
• ARISTOTLE (384-322B.C.)
• THE TREATISE ON EMBRYOLOGY -book

8. William Harvey and Marcello Malpighi

9. PREFORMATION THEORIES
• DUTCH SCIENTIST-SWAMMERDAM
• HOMUNCULUS
HARTSOEKER

10. EPIGENETIC THEORY
• CASPER FRIEDRICH WOLF –SIMPLER FORM TO MORE COMPLEX
ORGANISATION.
• JOHAN FRIEDRICH HAECKEL SUPPORTED

11. BAER’S LAW
• FATHER OF MODERN EMBRYOLOGY
• STATES more general features
common develop earlier
than special features
which distinguish various
members of the group.

12. RECAPITULATION THEORY
• MULLER AND HAECKEL BAER’S TO RECAPITULATION
• ONTOGENY RECAPITULATION PHYLOGENY
BIOGENETIC LAW
• MODERN VERSION OF RECAPITULATION

13. WEISMANN’S THEORY OF GERMPLASM
GERMPLASM THEORY
LANDMARK OF DB

14. MOSAIC THEORY
• WILHELUM ROUX
• ONTOGENIC DEVELOP –DIFF CELL FROM A >/< UNDIFF EGGTO
GREATER DIFF AND SPECIALISA OF CELL.

15.  REGULATIVE THEORY
• HANS DRIESCH OPPOSED MOSAIC THEORY
GRADIENT THEORY
• BOVERI
SPEMANN’S THEORY OF ORGANISERS
• SPEMANN