Smith, Hobart M. (1956, June). Schistic evolution. Evolution, 10 (2), 228-229. Retrieved March 28 from http://links.jstor.org/.
Keywords: horizontal evolution, speciation, splitting, schistic evolution, differentiation, synchrony
Because all patterns of evolution involve some kind of speciation, this term should not appear, as it has until recently, among the three recognized evolutionary patterns: “splitting,” phyletic, and quantum. “Splitting,” a recent substitute for speciation, has a dual meaning of its own, and can also refer to the initial step in phyletic evolution. The overlap of the two terms causes confusion and controversy, and has fueled a new search for an unambiguous term. Simpson in his recent paper proposed schistic as a hierarchical equivalent to, without ambiguity with, phyletic and quantum, and Smith analyzes the term, finding it satisfactory.
Dodelson, S. (2007, May). Seeing the red limit. Astronomy, 35 (5), 40-43.
Keywords: redshift, cosmic distances, intrinsic luminosity, Hubble’s Law, spectral absorption lines
Scientists measure the vast distances between galaxies by analyzing properties of the energy that their stars radiate. Atoms absorb some energy, creating absorption lines in energy spectra. Lab experiments correlate positions of absorption lines with specific elements. The “shifting” of these lines toward the blue or red area of the spectrum indicates distance, speed, and direction with respect to the observer. Hubble’s Law states that greater distance reveals greater velocity. Because space is expanding, light speed and the universe’s scale factor cannot help scientists measure extremely distant objects. Intrinsic luminosity reveals the speed of universal expansion, which is mysteriously accelerating.