University of Pittsburgh

Submitted for Bachelor’s Thesis in the History and Philosophy of Science

Destructive Interference: The Evolution of "Lamarckism"

Francis Cartieri

Table of Contents

I. Introduction ... 3

II. Historical Overview ... 5

III. Strict Lamarckism: The Influence of Circumstances and the four Evolutional Laws ... 8

IV. The Evolution of “Lamarckism” ... 12

V. Modern Lamarckian Claims in Perspective ... 15

VI. Conclusion ... 20

Bibliography ... 22

“ Nature, in producing successively all the species of animals, beginning with the most imperfect or most simple in order to end her work with the most perfect, has gradually made their organization more complex; and with these animals spreading generally throughout all the habitable regions of the globe, each species received from the influence of the circumstances in which it is found the habits now recognized in it and the modifications of its parts that observation shows to us…”
-Lamarck, Philosophie Zoologique, 1809

I. Introduction

Most biologists resist positive claims about Lamarckian modes of inheritance, as they perceive such claims as threatening the hegemony of the Darwinian paradigm in which they operate. However, this hesitance may be misguided and unconstructive, should it arise from misconceptions about the relationship between contemporary ‘Lamarckian’ discoveries and the views which Lamarck himself actually held. Given the recent revitalization of interest in Lamarckian evolutionary perspectives (Cairns et al. 1988, Hall 1991, Ewer 1996, 2004; Steele 1979, 1998; Jablonka and Lamb 2007), and the lingering ambiguity concerning what constitutes Lamarckian theses, it would be prudent to evaluate the relationship between contemporary Lamarckian theses and traditional Lamarckian positions.
Scientists working in evolutionary fields tend to label as ‘Lamarckian’ any claims that imply the inheritance of somatic mutations; adaptations derived through interaction between the organism and environment, and subsequently passed to offspring (the most famous example being the giraffe stretching its legs and neck to reach higher leaves). However, the relationship connecting contemporary ‘Neo-Lamarckian’ ideas and traditional Lamarckian ideas is dubious at best, and conceptually misleading at worst, both for working scientists and casual laymen. For example, traditional Lamarckian inheritance acts through the whole organism or its parts, while modern Lamarckian inheritance tends to act on individual cells or even whole populations. The invocation of the label “Lamarckian” carries historical and conceptual baggage that I would like to disambiguate from recent, supposedly ‘Lamarckian’ modes of inheritance. To accomplish this, I will reveal and clarify the evolutionary claims that Lamarck himself published, most notably in Jean-Batiste Lamarck’s Philosophie Zoologique, and evaluate the relationship between his traditional claims, and more recent claims labeled as “Lamarckian” by contemporary scientists. This paper will provide an analysis of the conceptual interplay occurring between modern Lamarckian claims, and what Lamarck actually believed and published, via an investigation of the evolution of the term Lamarckian/Lamarckism from 1809 to the present; my conclusion, then, should be a fair appraisal of the relationship existing between Lamarck’s actual claims and contemporary Neo-Lamarckian claims.

II. Historical Overview

By 1815, Jean-Baptiste Lamarck had articulated what he believed to be “a truly general theory, linked everywhere in its parts, always consistent in its principles, and applicable to all the known data.” This truly general theory was nothing less than the union of a wealth of empirical observations of the natural world and a guiding philosophy of life that accounted for “the source of existence, the manner of being, the faculties, the variations, and the phenomena of organization of the different animals.” (ZP 184) Though Lamarck had established himself as a master systematist rivaling Linnaeus among his own contemporaries, he considered his work in nascent biology and evolution (incidentally, Lamarck actually coined the term ‘biology’) to be his most difficult, ambitious, and ultimately, his most important contribution to human understanding (Lamarck 1809). However, Lamarck’s general theory was almost universally ignored (Corsi 207); at best, he faced polite indifference, and at worst, outright slander and ridicule (Madaule 13). From the very outset of its publication, Lamarck’s Zoological Philosophy was repeatedly misinterpreted, his ideas misquoted, and his name misappropriated. Unfortunately, the distortion of his ideas did not cease upon Lamarck’s death; even his academic eulogy, tragically written by his adversary Georges Cuvier, served to confuse and malign Lamarck’s ideas on the evolution and organization of nature (Cannon 1959). In the following sections I will provide the historical context from which Lamarck’s general theory of biology arose, with special attention paid to the ways in which the scientific environment distorted his ideas. These observations will be informative when I review the ‘evolution’ of Lamarckism in the history of science and attempt to make sense of the connection between historical Lamarckism and modern Lamarckian claims.

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