Evolution quotes 6 May 2010 But is it not possible to apply a test whereby a true species may be known from a mere variety? Is there no criterion of species? Great authorities affirm that there is—that the unions of members of the same species are always fertile, while those of distinct species are either sterile, or their offspring, called hybrids, are so. It is affirmed not only that this is an experimental fact, but that it is a provision for the preservation of the purity of species. Such a criterion as this would be invaluable; but, unfortunately, not only is it not obvious how to apply it in the great majority of cases in which its aid is needed, but its general validity is stoutly denied. The Hon. and Rev. Mr. Herbert, a most trustworthy authority, not only asserts as the result of his own observations and experiments that many hybrids are quite as fertile as the parent species, but he goes so far as to assert that the particular plant Crinum capense is much more fertile when crossed by a distinct species than when fertilised by its proper pollen! On the other hand, the famous Gaertner, though he took the greatest pains to cross the Primrose and the Cowslip, succeeded only once or twice in several years; and yet it is a well-established fact that the Primrose and the Cowslip are only varieties of the same kind of plant. Again, such cases as the following are well established. The female of species A, if crossed with the male of species B, is fertile; but, if the female of B is crossed with the male of A, she remains barren. Facts of this kind destroy the value of the supposed criterion. [Thomas Henry Huxley, Darwiniana, 1893] Evolution History Quotes Species and systematics Species concept EvolutionHistoryQuotes
Evolution Tautology 6: A resolution 3 Sep 200922 Jun 2018 If, as Byerly and Michod think, along with many others such as Brandon (1990), there are two kinds of “fitness”; actual and expected, and only with actual fitness is there any possibility of a tautology, we need to work out what expected fitness is. Brandon calls it “adaptedness” proper; a… Read More
Creationism and Intelligent Design Genes – the language of God 5: God and genes 15 Jul 201410 Aug 2014 Genes – the language of God 0: Preface Genes – the language of God 1: Genes as Language Genes – the language of God 2: Other popular gene myths and metaphors Genes – the language of God 3: Why genes aren’t information Genes – the language of God 4: Why… Read More
Epistemology Pattern cladism and the myth of theory dependence of observation 4 Mar 2011 A new paper has been published in the History and Philosophy of the Life Sciences, entitled “Pattern Cladism, Homology, and Theory-Neutrality” by Christopher Pearson. Either the journal has done something horrible to the text, or the author doesn’t know the difference between Willi Hennig and William Hennig, or between Gareth… Read More