Gould S J
Museum of Comparative Zoology, Harvard University, Cambridge, MA 02138.
Proc Natl Acad Sci U S A. 1994 Jul 19;91(15):6764-71. doi: 10.1073/pnas.91.15.6764.
Among the several central meanings of Darwinism, his version of Lyellian uniformitarianism--the extrapolationist commitment to viewing causes of small-scale, observable change in modern populations as the complete source, by smooth extension through geological time, of all magnitudes and sequences in evolution--has most contributed to the causal hegemony of microevolution and the assumption that paleontology can document the contingent history of life but cannot act as a domain of novel evolutionary theory. G. G. Simpson tried to combat this view of paleontology as theoretically inert in his classic work, Tempo and Mode in Evolution (1944), with a brilliant argument that the two subjects of his title fall into a unique paleontological domain and that modes (processes and causes) can be inferred from the quantitative study of tempos (pattern). Nonetheless, Simpson did not cash out his insight to paleontology's theoretical benefit because he followed the strict doctrine of the Modern Synthesis. He studied his domain of potential theory and concluded that no actual theory could be found--and that a full account of causes could therefore be located in the microevolutionary realm after all. I argue that Simpson was unduly pessimistic and that modernism's belief in reductionistic unification (the conventional view of Western intellectuals from the 1920s to the 1950s) needs to be supplanted by a postmodernist commitment to pluralism and multiple levels of causation. Macro- and microevolution should not be viewed as opposed, but as truly complementary. I describe the two major domains where a helpful macroevolutionary theory may be sought--unsmooth causal boundaries between levels (as illustrated by punctuated equilibrium and mass extinction) and hierarchical expansion of the theory of natural selection to levels both below (gene and cell-line) and above organisms (demes, species, and clades). Problems remain in operationally defining selection at non-organismic levels (emergent traits vs. emergent fitness approaches, for example) and in specifying the nature and basis of levels, but this subject should be the central focus in formulating a more ample and satisfactory general theory of evolution on extended Darwinian principles.
在达尔文主义的几个核心意义中，他对莱尔式均变论的阐释——将现代种群小规模、可观察到的变化原因视为通过地质时间的平稳延伸，构成进化中所有规模和序列的完整源头的外推主义观点——对微观进化的因果霸权以及古生物学只能记录生命偶然历史而不能成为新进化理论领域这一假设的形成，起到了最大的推动作用。G. G. 辛普森在其经典著作《进化的节奏与模式》（1944年）中，试图反驳古生物学在理论上无活力这一观点，他提出了一个精妙的论点，即他书名中的两个主题属于一个独特的古生物学领域，而且模式（过程和原因）可以从对节奏（模式）的定量研究中推断出来。然而，辛普森并未将他的见解转化为对古生物学理论有益的成果，因为他遵循了现代综合理论的严格教义。他研究了他潜在理论的领域，得出找不到实际理论的结论——因此，对原因的完整解释终究可以在微观进化领域找到。我认为辛普森过于悲观，现代主义对还原主义统一的信仰（20世纪20年代至50年代西方知识分子中的传统观点）需要被后现代主义对多元主义和多层次因果关系的承诺所取代。宏观进化和微观进化不应被视为相互对立，而应被视为真正互补的。我描述了两个可能寻求有益宏观进化理论的主要领域——不同层次间不平稳的因果边界（如间断平衡和大规模灭绝所示）以及自然选择理论向低于生物体（基因和细胞系）和高于生物体（种群、物种和进化枝）的层次的层级扩展。在非生物体层次上操作定义选择（例如，新兴特征与新兴适应性方法）以及明确层次的性质和基础方面仍然存在问题，但在基于扩展的达尔文主义原则制定更充分、更令人满意的进化通论时，这个主题应该是核心关注点。
