The following letter by palaeontologist Beverly Halstead appeared in Nature in 1980 when cladistics were unfamiliar to most biologists. It provoked one of the most noted controversies in the journal's history, and letters to the editor flew thick and fast. The letter itself appears to reflect a tendency to confuse cladistics with punctuated equilibrium as well as palaeontologists' historical preference for anagenesis. A good review of the incident is Anatomy of a Controversy, Halstead vs the British Museum (Natural History), by Steven Schafersman, pp 186-219 in What Darwin Began by Laurie Godfrey, Allyn and Bacon, 1985.
Museum of Errors
Nature 288, 208 (1980)
SIR - Two years ago (Nature 275, 683, 1978), I questioned the wisdom of what is happening at the Natural History Museum in South Kensington. If a national museum is concerned with aspects of social engineering by promoting concepts that happen to be current in the present climate of opinion, are there not sinister implications? I was especially alarmed by the museum's new exhibition scheme, and asked that sufficient pressure should be brought to bear to "curb the activities of the Public Services Department and to ensure the survivial of the museum's reputation for scholarship in its public galleries".
Since then, time has passsed. It is no longer a question of raising the alarm, but simply of reporting what has already happened.
Two areas of the museum's work have already succumbed: dinosaurs in 1979 and fossil man in 1980. Both the new exhibits are simply vehicles for the promotion of a system of working out relationships known as cladistics. The accompnaying booklets Dinosaurs and their living relatives (1979) and Man's place in evolution (1980) explain with startling clarity the essence of cladistics. In both books the fundamental assumptions are spelt out unequivocally. "First we assume that new species arise when one species splits into two. This assumption allows allows us to test the relationships we suggest, because it means that every species must have a closest relative. Second we assume that none of the species we are considering is the ancestor of any of the others." It is axiomatic, therefore that no species in the fossil record can be considered ancestral to any other nor can one species evolve directly into another.
With regard to both dinosaurs and fossil man, it is evident that the application of cladistics is quite inappropriate. The well attested sequence of human fossils representing samples of succeeding populations has until the Natural History Museum's latest exercise, been taken as a classic example of the gradual evolution of a single gene pool. Certainly there is not any serious doubt about Homo erectus being direcly encestral to Homo sapiens.
Yet the concept of one species being direclty ancestral to another is contrary to the rules of cladistics. So we read in the section on Home erectus (under the heading "The Homo erectus people were not quite like us ... the Homo erectus skull has several charactereistics that the modern skull does not share. Because of these special characteristics, we think that the Homo erectus people were not our direct ancestors"
But then on the opposite page is a photograph of the Petralona skull, from Greece, which the author considers an example of Homo sapiens or Homo erectus because of its mixture of features. This particular skull makes nonsense of the entire methodology being promoted in the books and exhibition. According to the stated assumptions of cladistics none of the fossil species can be ancestral by definition. This presents the public for the first time with the notion that there are no actual fossils directly ancestral to man. What the creationists have insisted on for years is now being openly advertised by the Natural History Museum.
The scientists on the museum staff, be they experts on dinosaurs or on fossil man, have had their scientic judgement over-ridden by the Department of Public Services. What exactly is the cladistic framework to which the Public Servies Department is so fervently dedicated? Why is there such a fanatical insistence that data should be presented within such a framework?
And why should there be a deliberate policy tht involves the removal from the public gaze of important and scholarly exhibits in the museum such as the Insect Gallery and the Fossil Mammal Gallery? Is it because they povide to dramatic a contrast with the propaganda of the new style exhibits?
The questions that should arise in everyone's mind are what is this all about, what actually is going on and what is behind it all? The answers can be found by reading the literature of cladistics. The tenor of this is seen in the abuse of E. Mayr and G.G. Simpson, and indeed of Charles Darwin himself, because of their firm adherence to the consept of gradualism and to the idea that the processes that can be observed at the present day, when extrapolated into the past, are sufficient to explain changes observed in the fossil record. The synthesis of population genetics and palaeontology presented by Simpson in his two seminal works Tempo and mode in evolution (1944) and The major features of evolution (1953) is anathema to cladists.
The next question is why should the notion of gradualism arouse passions of such intensity? The answer to this is to be found in the political arena. There are basically two contrasting views with regard to human society and the process of change through time: one the gradualist reformist and the other is the revolutionary approach. The key tenet of dialectial materialism, the world outlook of the Marxist-Leninist party according to J.V. Stalin, is in the recognition of "a development in which the qualitative changes occur not gradually but rapidly and abruptly, taking the form of a leap from one state to another" (Engels). This is the recipe for revolution. If this is the observed rule in the history of life, when translated into human history and political action it would serve as the scientific justification for accentuating the inherent contradictions in society, so that the situation can be hurried towards its appropriate "nodal point" and a qualitative leap supervenes.
With regard to evolution and the fossil record, neither Engels nor Lenin, both of whom discussed the subject at length - to their great credit - insisted upon a pattern of such qualitative leaps, they were merely content to see in evolution and the fossil record evidence of change, albeit gradual.
This has always been a matter of some disquiet for Marxist theorists. If it could be established that the pattern of evolution was a saltatory one after all, then at long last the Marxists would indeed be able to claim that the theoretical basis of their approach was supported by scientific evidence. Just as there are "scientific" creationists seeking to falsify the concept of gradual change through time in favour of catastrophism, so too there are the Marxists who for different motives are equally concerned to discredit gradualism.
What is going on at the Natural History Museum needs to be seen in this overall context. If the cladistic approach becomes established as the received wisdom, then a fundamentally Marxist view of the history of life will have been incorporated into a key element of the educational system of this country. Marxism will be able to call upon the scientific laws of history in its support, with a confidence that it has previously enjoyed.
This is the course of action to which the authorities of the Natural History Museum seem to have committed themselves either unwittingly or willingly.
Department of Zoology and Geology
University of Reading, UK