Fair and Unbalanced

Hey, look . . . just to show how open-minded I am, I’m going to add a tag for “Evolution,” in which I’ll discuss evolutionary topics from a neutral perspective. The “Darwinism” tag will still be for examples of mindless social conformity to evolutionary dogma, along with attempts to assign miraculous powers to Darwin or his ideas. “Superstitions” is for unsupported claims regarding abstract ideas and unobserved phenomena.

I’ll start out here with a list of Darwin’s theories, taken from Ernst Mayr’s One Long Argument: Charles Darwin and the Genesis of Modern Evolutionary Thought (1991), pp. 36–37.

1.  Evolution as such. This is the theory that the world is not constant nor recently created nor perpetually cycling but rather is steadily changing and that organisms are transformed in time.

2.  Common descent. This is the theory that every group of organisms descended from a common ancestor and that all groups of organisms, including animals, plants, and microorganisms, ultimately go back to a single origin of life on earth.

3.  Multiplication of species. This theory explains the origin of the enormous organic diversity. It postulates that species multiply, either by splitting into daughter species or by “budding,” that is, by the establishment of geographically isolated founder populations that evolve into new species.

4.  Gradualism. According to this theory, evolutionary change takes place through the gradual change of populations and not by the sudden (saltational) production of new individuals that represent a new type.

5.  Natural selection. According to this theory, evolutionary change comes about through the abundant production of genetic variation in every generation. The relatively few individuals who survive, owing to a particularly well-adapted combination of inheritable characters, give rise to the next generation.

Mayr states that Darwin considered these theories to comprise a single, unified theory. However, he then notes that although evolution as such was well accepted immediately after the publication of The Origin of Species, most evolutionists disagreed on one or more of Darwin’s other theories. Mayr presents a chart (One Long Argument, p. 37) showing how Darwin’s contemporaries disagreed:

Common descent

Multiplication of species

Gradualism

Natural selection

Lamarck

No

No

Yes

No

Darwin

Yes

Yes

Yes

Yes

Haeckel

Yes

?

Yes

In part

Neo-Lamarckians

Yes

Yes

Yes

No

T. H. Huxley

Yes

No

No

(No)*

de Vries

Yes

No

No

No

T. H. Morgan

Yes

No

(No)*

Unimportant

*Parentheses indicate ambivalence or contradiction.

In fact, Mayr states that the “opposition to natural selection continued unabated for some eighty years after the publication of the Origin. Except for a few naturalists, there was hardly a single biologist, and certainly not a single experimental biologist, who adopted natural selection as the exclusive cause of adaptation” (One Long Argument, p. 132).

Literary theorist Joseph Carroll supports Mayr’s account of the development of evolutionary theory in the introduction to the 2003 Broadview edition of The Origin of Species:

Mayr is correct in affirming that the Darwinian paradigm shift took several decades to complete. For the theory of natural selection, there was never any sudden gestalt switch. As Mayr describes it, giving the inside view of a major contributor to the process, there was instead a gradually accumulating body of theoretical genetic work that slowly converged with the work of naturalists (ecologists and systematists) and paleontologists. The combined weight of these different fields eventually convinced the majority of scientists qualified to judge in the case. Ridley confirms Mayrs account, and he concurs with Mayr in locating the consolidation of the Modern Synthesis in the late forties. He observes that by the mid-forties the modern synthesis had penetrated all areas of biology. The 30 members of a committee on common problems of genetics, systematics, and paleontology who met (with some other experts) at Princeton in 1947 represented all areas of biology. But they shared a common viewpoint, the viewpoint of Mendelism and neo-Darwinism. A similar unanimity of 30 leading figures in genetics, morphology, systematics, and paleontology would have been difficult to achieve before that date (Evolution, 18).

However, Carroll disagrees with Mayr about the unity of Darwin’s theories; Carroll argues that Darwin saw the logical necessity for all of the parts of evolutionary theory to fit together, including the parts that Darwin didn’t actually understand at all, such as genetic inheritance of traits. I am not going to critique Carroll’s argument here, but I will note that “logical necessity” exists only for mathematical abstractions, not for historical narratives or empirically derived theories. If your scientific theory has any component included out of logical necessity, then you have strayed from naturalistic observation into idealistic speculation.

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2 thoughts on “Fair and Unbalanced

  1. The quoted text is hard to read. Plus, with no sidebar, your links are at the bottom, and most people won’t scroll to the bottom to check out your links. May I suggest one of the other 60 or so wordpress.com templates that all leave you wanting for something, in hopes that you’ll pay money to be able to get something you want.

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