The first phylogeny 30 Sep 202030 Sep 2020 The only diagram in the Origin is famously the hypothetical series of species forming a tree structure, but it isn’t an actual classification based on his principles. I have previously noted the rise of cladograms towards the end of the 19th century, but in a talk by Ian Hesketh, I was drawn to the following cladogram by Fritz Müller in his Für Darwin, in 1864, a mere 5 years after the Origin was published. And it even uses a distinction between homologous ancestral characters in distinction to what we now call conversantly evolved characters. Here it is in the English translation paid for by Darwin himself in 1869. The organisms being discussed here are amphipods of the genus Melita, of which there are around 80 species known today. Müller points out that genera are often created using characters like the secondary flagella of the antenna, which is variable, while the asymmetric clasping structure is shared by five species. So he classifies the relationships between the species using the clasp rather than the antennae. This is, to the best of my knowledge, the first classification using common descent as the principle, making a distinction between what we now call apomorphies and plesiomorphies, after Hennig. Darwin sketched a few, but did not publish them, and anyway his methodology was not so clear as Müller’s. By contrast with Muller, Haeckel’s grandiose trees in the Generelle Mophologie in 1866 showed no evidence of understanding clearly what Müller had done. So is this the earliest cladogram? Can anyone point to another? Thanks Evolution Natural Classification Systematics
Evolution What is special about humans? 23 Nov 201827 Feb 2019 As soon as somebody asks the question “what is a ____?” we get into trouble. Not because we do not know about the thing in the blank, but because we tend to have the wrong idea about how to answer that question. Since the Greeks, the general feeling is that… Read More
Evolution When do species begin? 11 Jun 200922 Jun 2018 Last night I attended a talk by Alexander Bird of Bristol on the metaphysics of natural kinds. I confess that a lot of it struck me as largely irrelevant to the actuality of the science as the level of metaphysics here, involving possible worlds and necessity, not to mention semantic… Read More
Biology Downward Causation 9 Aug 201122 Jun 2018 The final claim for there being an ontological sense to emergence is “downward causation“, a phrase coined by the evolutionary epistemologist Donald Campbell in the 1970s. The idea here is that emergence is real because higher-level (or bigger, composite) entities cause changes in the properties and dynamics of their parts…. Read More
A year on, 1865, Mivart made a decent stab at it, covered in detail here: http://www.isita-org.com/jass/Contents/2011vol89/e-pub/21368345.pdf and Craw wrote about Muller’s work, Craw, RC (1992). “Margins of cladistics: Identity, differences and place in the emergence of phylogenetic systematics”. In Griffiths, PE (ed.). Trees of life: Essays in the philosophy of biology. Dordrecht: Kluwer Academic. pp. 65–107. Another year, 1866, and there is Albert Gaudry (Tassy writes about him: https://doi.org/10.1016/j.annpal.2005.09.003) And in a new book: https://materiologiques.com/en/histoire-des-sciences-et-des-techniques/301-levolution-au-museum-albert-gaudry-9782373612264.html But this does all really rather depend on what a cladogram is, or means. To contrast Muller (1864), Mivart (1865) and Gaudry (1866) might be a worthwhile exercise. But method to one side, if anything branches, isn’t it a cladogram? We did not do that contrast but a peek in this might add to the tale (or confusion): https://www.cambridge.org/core/books/cladistics/D3C3FC2E69F52FB3BDBDBA219157E625