The history of biological systematics documents a continuing tension between classifications in terms of nested hierarchies congruent with branching diagrams (the ‘Tree of Life’) versus reticulated relations. The recognition of conflicting character distribution led to the dissolution of the scala naturae into reticulated systems, which were then transformed into phylogenetic trees by the addition of a vertical axis. The cladistic revolution in systematics resulted in a representation of phylogeny as a strictly bifurcating pattern (cladogram). Due to the ubiquity of character (...) conflict—at the genetic or morphological level, or at any level in between—some characters will necessarily have to be discarded ( qua noise) in favor of others in support of a strictly bifurcating phylogenetic tree. Pattern analysts will seek maximal congruence in the distribution of characters (ultimately of any kind) relative to a branching tree-topology; process explainers will call such tree-topologies into question by reference to incompatible evolutionary processes. Pattern analysts will argue that process explanations must not be brought to bear on pattern reconstruction; process explainers will insist that the reconstructed pattern requires a process explanation to become scientifically relevant, i.e., relevant to evolutionary theory. The core question driving the current debate about the adequacy of the ‘Tree of Life’ metaphor seems to be whether the systematic dichotomization of the living world is an adequate representation of the complex evolutionary history of global biodiversity. In ‘Questioning the Tree of Life’, it seems beneficial to draw at least four conceptual distinctions: pattern reconstruction versus process explanation as different epistemological approaches to the study of phylogeny; open versus closed systems as expressions of different kinds of population (species) structures; phylogenetic trees versus cladograms as representations of evolutionary processes versus patterns of relationships; and genes versus species as expressions of different levels of causal integration and evolutionary transformation. (shrink)

From the revolutionary discoveries of Galileo and Newton to the mind-bending theories of Einstein and Heisenberg, from plate tectonics to particle physics, from the origin of life to universal entropy, and from biology to cosmology, here is a sweeping, readable, and dynamic account of the whole of Western science. In the approachable manner and method of Stephen Jay Gould and Carl Sagan, the late Brian L. Silver translates our most important, and often most obscure, scientific developments into a vernacular that (...) is not only accessible and illuminating but also enjoyable. Silver makes his comprehensive case with much clarity and insight; his book aptly locates science as the apex of human reason, and reason as our best path to the truth. For all readers curious about--or else perhaps intimidated by--what Silver calls "the scientific campaign up to now" in his Preface, The Ascent of Science will be fresh, vivid, and fascinating reading. (shrink)

The Iranian prophet and reformer Zarathustra (Greek: Zoroaster) founded his religion in the 6th Century BC. In a series of visions he was taken up to Heaven and Ahura Mazda - creator of all that is good - charged him with enlisting Humanity in the fight against Aura Mainyu - the principle of chaos and destruction - offering Mankind a free choice between Good and Evil. It is hard to overstate the importance of Zoroastrianism. According to Professor of Iranian Studies (...) Dr Mary Boyce: "It was the first to teach the doctrines of an individual judgment, Heaven and Hell, the future resurrection of the body, the general Last Judgment, and life everlasting for the reunited soul and body." 'The Teachings of Zoroaster' is an excellent introduction to this little-known and often misunderstood religion, giving Zoroastrianism its rightful place as the precursor of many Christian, Judaic and Islamic beliefs. (shrink)

Defining Species: A Sourcebook from Antiquity to Today provides excerpts and commentary on the definition of «species from source material ranging from the ...