For a long time now, I have had troubles with the use of the word “Darwinism”. Not just by creationists and antiscience advocates like IDevotees, but by scientists themselves. You routinely see press releases and book titles that declare the death or some fatal illness of Darwinism, which, in every case, their own theoretical or experimental contributions points up. It is time, I think, to lose the word entirely.
The term has a history that is itself confusing and contradictory. Let’s consider some of the things it has been used to denote:
1. Transmutation of species
2. Natural selection
2.1 As a cause of adaptation
2.2 As a cause of speciation
2.3 As a cause of species stability
3. Competition and struggle
3.1 Between members of the same species
3.2 Between different species
3.3 For existence
3.4 By an act of sheer will
4. Common descent (phylogeny)
4.1 Common descent of related species
4.2 Common descent of all life
5.1 Genetic selection
5.2 Individual selection
5.3 Selfish genes
5.4 Hamiltonian inclusive fitness
5.5 Weismannian Barrier
5.6 Central Dogma of Molecular Biology
6. Opposition to religion
6.2 Chance and accident
6.3 Rejection of Creationism
7. Social and moral nihilism
7.1 Social Darwinism
7.8 Unwarranted egalitarianism
8. Philosophical Darwinism
8.1 Population thinking
8.2 Universal Darwinism
9. Anything Darwin believed in contrast to the current writer/speaker
9.1 Inheritance of used, and disinheritance of unused, traits
9.2 Speciation by natural selection
9.4 Sexual Selection
Basically, when a term has no definition, or has too many definitions, it cannot be a term capable of being defined. But there is another way the term might have some reference – as a name. That is, as the name of a historical sequence of events. And this sense has a lot more going for it, despite Gould’s and others’ denial. If something has a definition, then it has an essence, but we can see that from actual usage, “Darwinism” has no essence, but instead has a cluster of sometimes contradictory meanings, depending on the speaker and context (for example, “Darwinian” meant historical phylogenies in the context of the transformed cladism debates). But if something is a name, then it can grow, change or even lose meanings and descriptive properties over time.
As a name, “Darwinism” means basically any idea that can be said to have derived by descent, as it were, or transmission as the modern style has it, from Darwin. This enables us to include Huxley (opposed gradualism and selection as the cause of speciation), Wallace (opposed sexual selection), Weismann (opposed inheritance of characters based on parental life history), but at the same time exclude Spencer’s social theories (as they were in place largely before Darwin published) and the notion that all is basically random (since that is a view falsely ascribed to Epicurus by the theists, and is in any case not true of Darwin).
But this sense of the term means that the only meaningful way to talk about Darwinism is as a historical sequence or object, and hence it can not be defined exclusively and uniquely. For example, Haeckel’s Darwinismus was a mystical philosophy of deism, Goethe, Lamarck and Darwin all rolled into one, and the sense in which a good many critics of “Darwinism” today mean it is Haeckel’s anticlericalism against Catholicism. The claim that “Darwinism” is a historical entity is due to David Hull, and I fully agree with him, with some caveats.
Historical entities like any other evolutionary entity retain some aspects of their past. Physics uses the term “mass” today because Newton and others used it in the 17th century. We talk about “selection” because Darwin terms his process “Natural selection” 150 years ago. These are primitive notions embedded in the modern descendants, but they are not definitive sine qua nons. One can be a “Darwinian” in some sense without accepting very much of what Darwin uniquely believed, in virtue of being at the tail end of a long sequence of historical development. As a corollary, anyone who came up with the same idea, in, say, Imperial China, without knowledge of Darwin nor contributing to his ideas, is not Darwinian no matter how exactly his ideas match Darwin’s or ours.
Many scientists like to assert that they are “non-Darwinian” or “post-Darwinian” or “trans-Darwinian” in order to establish the novelty of their own views. Sometimes this occurs by asserting the truth of some view that is opposed to Darwin’s, notably Lamarck. The neo-Lamarckians of the 1880s through to the 1910s saw themselves as completing Darwin by adding into the mix a novel mechanism he rejected. But in fact the view that adult experience affected inheritance was not Lamarck’s alone, and was partially shared by Darwin, and in most other respects they were Darwinians. More recently, the work of people like Eva Jablonka on the existence and evolutionary importance of epigenetic (non-nucleotidal or nuclear) inheritance has been unfortunately termed “The Lamarckian Dimension”. Similar claims are made against neo-Darwinian ideas by developmentalists and ecologists, by cytologists and so on.
If we want a simple notion that can be given the term “Darwinian” uniquely and unambiguously, it can only mean the process of selection (natural, sexual, social, individual, group, genetic, epigenetic, whatever): the three conditions proposed by Lewontin and since elaborated for any process of selection, whether it causes stability, direction change, disruptive change or whatever. They are:
1. Phenotypic variation (that is, the traits of the entity vary from individual to individual)
2. Fitness variation for different phenotypes
3. Hereditability of fitness
As Lewontin himself said, “These three principles embody the principle of evolution by natural selection. While they hold, a population will undergo evolutionary change.” But this is not quite right, either, because selection can be, and often is, a process that causes no change, so “Darwinian” evolution has to include stasis.
When people say that, as they sometimes do, selection equals evolution, they are equivocating on both terms. R. A. Fisher knew this very well, and so he began his classic book in 1930, The Genetical Theory of Natural Selection, with the sentence “Evolution is not Natural Selection”. And as the subsequent debates between Fisher and Wright indicated, some evolution is not caused by natural selection, and some selection does not cause evolution.
So given these caveats, “Darwinian” can only mean “natural selection”, which is historically problematic because Darwin’s real originality lay not in that notion, but in the recognition that life diversified in a historical tree, which we call Common Descent” or “Phylogeny”. Others had proposed selection-like mechanisms (usually of stability, but a couple had said it caused change), but only Darwin recognised that the Linnaean system of classifying “groups within groups” was more than a convenience or logical structure, but a historical outcome.
So let’s retire the term altogether. Replacement terms are easy to come by – phylogeny, selection, drift, mutation, germline inheritance, social biology (sociobiology) and so on. And hence when a critic has trouble with one notion, this will impede the rapid slide to rejection of it all.