Quote: Sweeping out the cruft for cladistics in human origins

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Eric Delson, Niles Eldredge, and Ian Tattersall in 1977 published on one of the first cladistic analyses of humans and our close relatives: “Reconstruction of Homlnid Phylogeny: A Testable Framework Based on Cladlstic Analysis”.

I was reading through this paper the other day, and found the introductory paragraph provocative, and certainly worth a re-reading.

The controversy that has raged to this date in hominid phylogenetics will continue to bedevil us, if we persist in approactfing the problem in the usual fashion. As things stand, neither new data, nor new techniques for their manipulation, will now alter the level of controversy one way or the other---only the number of people active in the field will determine how many different opinions are held. This situation stems from the form in which hypotheses are conventionally proposed---and statements of phylogenetic relationship are very much hypotheses. The simple truth is that the sundry hominid "phylogenies" available in the literature are scenarios amalgams of statements of ancestor-descendant relationship thoroughly admixed with, and largely (although not always consciously) based on, a priori models of the evolutionary process, on interpretations of the significance of the stratigraphic and geographic occurrence of fossils, and reconstructions of the palaeoenvironment and functional anatomy--hence adaptations, of these creatures. Statements as complex as these, as far removed from the data base as they frequently are, are difficult to test rigorously and leave us only with a vague feeling that one perhaps seems more "sensible" or more plausible probabilistically than another. We may celebrate the controversy as healthy, but it is a bit disconcerting to realize that phylogenies stated in these terms are by their very nature incapable of rigorous comparison, testing and rejection.

This has a markedly ironic tone today, in the best Alanis Morissette sense. The passage introduces a paper that argues that the “scientific” approach of cladistics should clear up the confusion of hominid systematics. It didn’t turn out that way.

The advent of cladistic methodology in human evolution studies only brought new forms of disagreement. As a younger generation of scientists applied cladistic approaches, they introduced a much broader diversity of views about hominin relationships than had existed in the 1960s and 1970s.

Many of the players writing about hominin relationships were aggressive in their papers and at scientific conferences. They irritated many others by acting like they were the “real” scientists, using “objective” methods.

Some other paleoanthropologists established themselves as the anti-cladists, publishing about how cladistic approaches “atomize” traits that should really be considered as part of integrated functional or developmental packages. The cladists would often assert that such hypotheses are untested, and therefore should not be considered in phylogenetic analysis.

This would be a great area for a historian of science to examine. It was a transition in methods, a generational turnover, and many of today’s active paleoanthropologists built their careers by publishing in this area.