生物迁移思想的起源与发展

THE ORIGIN AND DEVELOPMENT OF THOUGHT OF BIOMIGRATION

生物迁移命题是由达尔文（１８５９）提出来的。他在《物种起源）一书中认为，一个物种只能有一个起源中心；在条件允许的前提下，它会从这个中心迁移到力所能及的地区。然而，当布克曼（１９２２）的“迁移炮弹”理论问世之后，迁移研究几乎陷于停顿状态差不多５０年。李四光是在“迁移炮弹”阴影下，依然坚持迁移观点的少数科学家之一。越来越多的事实证明了达尔文迁移思想的强大生命力。屡见不鲜的化石“穿时”现象和时代差异，大量的生物地理新资料，使人们从不可知论的桎梏中逐渐解脱出来。特别是８０年代以来，由于地壳运动理论研究的新需求，以及大陆漂移和海水进退规程研究的新进展，掀起了重新认识迁移的高潮。作者依据自己的积累和前人的研究成果认为，迁移的研究方法可概括为：最低层位的地理追索方法、演化程序的地理追索方法和相应环境的追索方法。迁移如同演化，在达尔文力的全弥漫作用（Ａｌｌｐｅｒ－ｖａｄｉｎｓａｃｔｉｏｎ）下时刻在进行着。迁移与其说是生物自身的一种能力，倒不如说是环境给予的一种机会。迁移造就并维系着丰富多彩的自然生态系统。迁移研究必将发展而形成一门新的学科─—古生物迁移学（Ｐａｌａｅｏｂｉｏｍｉｇｒａｔｏｌｏｇｙ）。生物迁移思想是与地质力学?

he idea of biomigration was first proposed by Darwin(1859).He considered that any one species of organisms had only a single center of creation.So far as the environment allows it would migrate from the center to areas as far as possible. Adams' concept of center o f dispersal (1902),Matthew's theory of new center-old margin (1915 ),Willis' age-area hypothesis(1922) represented discussions on the idea of biomigration in those days. But after Buckman's plane of migration came out (1922),the point of view that migration was unknowable cast a shadow on the field of science. From then on the study of biomigration had been almost at a standstill for nearly fifty years. During the date shrouded in Buckman's mist,J.S. Lee(1927, 1928) was one of few men who still held Darwin's idea of migration. More and more facts showed the vitality of Darwin's idea. Frequent occurrences of fossil diachronism and a wealth of new biogeographical materials made people throw gradually off the shackle of the unknowabilitism of biomigration. Especially since the eighties a new upsurge of investigation into biomigration has been started owing to new requirements of the studies of the crustal movement,continental drift,marine transgression and regression theories.The feasible ways to explore biomigration can be provided by ① geographical tracing of the lowest horizons;② geographical tracing of the evolutionary sequences;③tracing of the corresponding habitats.Migration, as evolution,keeps going at all times under all pervading action of the Darwin's constraint.It is better to look upon migration as a kind of chance given by habitat than as a kind of ability of biota itself. Migration has created and is maintaining natural ecosystem.The studies of migration will grow into .a new branch of palaeobiogeograplly-biomigratology. Geomechanics has emerged and gone on all along with the thought of bioa migration.Its founder J. S. Lee (1927, 1928)had noted the migration of biota following the regular movement of the seawater toward and away from the equator.There must be some connection between the biota migration and the seawater movement,and this was hinted as changes of climate by J. S. Lee (1962). They may originate from a common cause-change of the rate of the earth's rotation.