Darwinian gradualism and its limits: The development of Darwin's views on the rate and pattern of evolutionary change

✍ Scribed by Frank H. T. Rhodes

• Publisher: Springer Netherlands
• Year: 1987
• Tongue: English
• Weight: 988 KB
• Volume: 20
• Category: Article
• ISSN: 0022-5010
• DOI: 10.1007/bf00138435

✦ Synopsis

One aspect of the continuing debate concerning the evolutionary process has been the nature of Darwin's views in comparison with those of most exponents of the contemporary theory of punctuated equilibrium. Some writers have claimed a fundamental difference between Darwin's "pure gradualism," with its "even and slow" transformation, and the episodic and relatively rapid change postulated by punctuated equilibrium. ] Others have argued that there was essentially no difference between Darwin's views and those of contemporary advocates of punctuated equilibrium, z Detailed review of the text of the six editions of The Origin of Species shows that Darwin's thoughts on the "tempo and mode" of evolution were not limited to the "pure gradualism" that some recent writers have suggested? Darwin recognized the importance of the development and isolation of local varieties in the rise of new species, their subsequent migration to other areas, the "breaks" in local fossil sequences that this produced, and the fact that many species remain unaltered for along periods. His views thus included the principal tenets of what we now describe as "punctuated equilibrium." Darwin's estimates of the time involved in the rise of new species were not significantly different from those of recent writers.

These views, expressed in the first edition of the Origin (1859), were elaborated and extended in subsequent editions (1860--1872). Nevertheless, the Origin, in all editions, remained "an abstract," as Darwin called it, and thus it includes few detailed