There is on the blogs a lot of debate as to when the idea of common descent and the tree of life originated – “genetic futureâ€, as usual, gets it correct, “Panda’s Thumb†gets it correct, and “genetic inferenceâ€and “evolving thoughts†as always, get it politically correct.
From any political post of “genetic inference†and “evolving thoughts†you can deduce that they will lie about Darwin, and conversely from the fact that they are lying about Darwin, you can deduce their position on every question of political significance.
People attribute common descent to Darwin primarily because they hate Darwin and Darwinism, for Darwin and Darwinism is natural selection, a doctrine whose implications are disturbingly brutal, and when applied to humans, horrifyingly politically incorrect. So they pick up something else, almost at random – typically common descent and the tree of life – and call it Darwinism.
It is perfectly clear, and not an all controversial, that Lamarck and earlier thinkers proposed the tree of life – that animal species were related through common ancestors, and that the seeming gaps were the result of extinctions.
Here is an image of page 463 of Lamark’s Philosophie zoologique, a table titled “Origins of the Various Animalsâ€. This table is used on page 458 in a discussion of common descent:
If he proposed multiple parallel origins, he would not have needed to explain the gaps. That he explained gaps as due to extinctions makes it clear his tree is intended as prehistory, as development over time from a single root, as well as a scheme of classification.
Darwin’s contribution, as he makes perfectly clear, was natural selection. If you read Darwin, he does not treat common descent as a big new idea, but as something that is widely suspected, something that has long been in the air.
Darwin first starts talking of the Tree of Life in Chapter 11 of “the origin of species†– and clearly believes it to be an existing concept, widely accepted among his audience, and already seen by them.
If the number of the species included within a genus, or the number of the genera within a family, be represented by a vertical line of varying thickness, ascending through the successive geological formations, in which the species are found, the line will sometimes falsely appear to begin at its lower end, not in a sharp point, but abruptly; it then gradually thickens upwards, often keeping of equal thickness for a space, and ultimately thins out in the upper beds, marking the decrease and final extinction of the species. This gradual increase in number of the species of a group is strictly conformable with the theory, for the species of the same genus, and the genera of the same family, can increase only slowly and progressively; the process of modification and the production of a number of allied forms necessarily being a slow and gradual process,- one species first giving rise to two or three varieties, these being slowly converted into species, which in their turn produce by equally slow steps other varieties and species, and so on, like the branching of a great tree from a single stem, till the group becomes large.
Which implies that people were drawing trees embodying both descent and classification before Darwin, and Darwin expected his audience to have seen those trees
Darwin’s big new idea was natural selection, and all of the important and violently controversial ideas that follow from natural selection, such as sexual selection resulting in sex roles and sexually specific behavior, sociobiology resulting in an innate sense of property and intuitions about rights, races as the precursor of speciation, and so on and so forth. From genocide to rape, you can read all about it in “The Origin of Species†and “The Descent of Man†– not to mention property rights, which some are apt to put in the same league as genocide and rape.
If a idea about biology can get you beaten up and denied tenure, it is Darwinism. If it cannot, it is not. Common descent will not get you into trouble, therefore is not Darwinism, but speciation gets hazardous. If you stick to speciation in three spined sticklebacks you may be OK, proposing clinal speciation for wolves and coyotes will get you in deep trouble – the cline between wolves and coyotes was exterminated for being politically incorrect, and no one dares mention clinal speciation in the context of primates. Thus speciation, the origin of species, is Darwinism. You can tell by the application of baseball bats as a method of debate. Common descent is not Darwinism. You can tell by the absence of baseball bats as a method of debate.
[In the comments, Constantinople draws my attention to the evidence that it is Buffon, Lamark’s teacher, that first proposed the tree of life as prehistorical, and not merely classificatory, and also argues that anyone who depicts the tree of life should be presumed to depicting a prehistoric lineage, not merely a classification scheme, unless he explicitly says otherwise, which would put priority to way back before Buffon. I however, am not so much interested in who had priority, but in present day madness and evil. There is nothing particularly evil about attributing priority to Darwin, but it is definitely mad, and tightly correlated with evil political beliefs. If it was possible to figure out who had priority for the tree of life, Darwin would have told us who had priority.]
The key question seems to be whether Lamarck believed that individuals of different species did, or could, literally have common ancestors. Looking this up, I do not find a lot of people claiming that Lamarck did, but I do find a lot of people claiming that Buffon did. Lamarck was a student of Buffon, so the default assumption (unless he clearly specified otherwise) should be that Lamarck shared this view.
For example, Wikipedia states, “Buffon considered the similarities between humans and apes, and the possibility of a common ancestry.”
The alternative genetic inference et al. offer of Lamarck should not be the default interpretation of his words insofar as they have been presented here and in the other blog entries, assuming that the material I have found about Buffon is correct. If someone wants to interpret Lamarck in some way other than the default, they need to provide evidence if they expect someone to believe them. This they have not provided in the entries linked to. They merely assert that it is so.
Let me add to this. We should by default (i.e., unless there is clear evidence otherwise) take Lamarck to believe in actual branching of species (i.e., common ancestry) for the following reasons:
1) It is our own most natural interpretation of the comments and illustrations so far shared. Really, we should start with our own natural interpretation of a text, and be moved off it reluctantly. The alternative is for the world’s texts to be opaque (e.g., “he said, ‘it is raining'”, but I have no idea what he said, never mind that my natural interpretation of “it is raining” is that it is raining).
2) It is the natural default interpretation of any diagram that the items in the diagram be one to one with concrete things. Granted, not all diagrams are necessarily like this but it is the place to start. Consider it a kind of Occam’s Razor for the interpretation of diagrams: don’t multiply represented entities beyond necessity.
3) It is apparently what Lamarck’s own mentor Buffon believed, as I described previously. Lamarck should be presumed (a) to know what Buffon believed, and (b) to have shared Buffon’s views unless otherwise specified. This is surely the default interpretation of anyone’s views – that if they are the student of a person and they do not clearly repudiate the teacher’s views, then the assumption ought to be that they share those views.
4) The idea of family trees (of human families) was – I presume – common at the time. Any structurally similar notion concerning life should, by default, unless it is clearly proven otherwise, assume to have occurred to Lamarck, and if Lamarck did not agree with the analogy he should have added a disclaimer.
5) It is true. The truth does have a way of letting itself be known, and if someone makes a statement which might be interpreted one way, and might be interpreted another way, it is common practice (and correct practice) to interpret the the statement one way. In fact, this is how English works. A lot of sentences stated in English are intrinsically ambiguous. They could, by themselves, mean many things. They are interpreted in one way based on context and based largely on what would make them true. This, by the way, applies even to statements which are false. People regularly misspeak, and are automatically corrected in the minds of their listeners, and this should be the case.
6) Even those who argue against it seem to admit it to some degree. See for example the comments of Ray Martinez in Panda’s Thumb blog. He is forced to admit:
“Lamarck’s view was predominantly ladder and not branching. You are misapplying the exception to be the norm.”
He initially argued that “Lamarck postulated a ladder concept, quite different from branching tree.” He backed away from this and said that the branching that Lamarck did indeed accept was “the exception” rather than “the norm”. Well, even if we are to take Martinez at his (second) word (and we now have reason to distrust him) that is perfectly compatible with common ancestry. A scientist might believe that the vast majority of evolution takes place without branching but that nevertheless the tree does very occasionally branch and that the entire tree is a single tree.
7) The evidence so far supplied against the interpretation of Lamarck as postulating an actual tree (as opposed to, as the critics argue, a mere formal tree) ranges from nonexistent (mere assertion) to ambiguous.
I misstated (4). To restate:
4) The idea of family trees (of human families) was – I presume – common at the time. Any structurally similar notion concerning life should, by default, be taken to have been understood and intended to be understood on the model of a genealogical family tree by both Lamarck and his audience, unless it is clearly proven otherwise. The analogy ought at any rate to have occurred to him and if Lamarck did not agree with the analogy he should have added a disclaimer.
The most compelling evidence that Darwin did not originate the idea of common descent and the tree of life is that Darwin did not claim to originate the idea of common descent and the tree of life. He is always clear as to what he is claiming priority for. It simply is not what “The origin of species” is about. Rather, in Chapter 11 he asserts that groups of species are well known to form trees over geological time, and that natural selection explains this observation – implying that other people had published trees as actual prehistorical trees, implying a pre-existing debate over the reality of the tree of life with existing evidence, published before the “origin of species” favoring an actual prehistorical tree.
The question appears to me to be so completely open and shut, so flatly black and white, that the interesting and important question is the psychological and emotional motive for attributing the tree of life to Darwin. We need to ask why the delusion, not whether the evidence is reasonable. The political content of the blogs that attribute the tree of life to Darwin, provide evidence of a motive.
It is probably impossible to say who had priority. If Darwin knew, he would have told us.
What I examine is not who had scientific priority in proposing common descent and the tree of life, but present day madness and evil.