Letters.To tree or not to tree? "Should we junk Linneaus?" (SN: 10/23/99, p. 268) failed to note a fundamental division among systematists. "True Tree-ers" believe that viewing a phylogenetic tree phylogenetic tree Diagram showing the evolutionary interrelations of a group of organisms that usually originated from a shared ancestral form. The ancestor is in the tree trunk; organisms that have arisen from it are placed at the ends of tree branches. is tantamount to viewing evolution. "Practicing Cladists" believe that cladograms are hypotheses to be tested with further data and rejected if a better hypothesis is found. Basing a nomenclature on unknowable un·know·a·ble adj. Impossible to know, especially being beyond the range of human experience or understanding: the unknowable mysteries of life. characters for hypothetical ancestors, as engendered by the uninomial nomenclature of True Tree-ers, accepts ignorance as the final answer. Continual improvement Continual Improvement (also called incremental improvement or staircase improvement) is a process or productivity improvement tool intended to have a stable and consistent growth and improvement of all the segments of a process or processes. of phylogenetic phy·lo·ge·net·ic adj. 1. Of or relating to phylogeny or phylogenetics. 2. Relating to or based on evolutionary development or history. hypotheses and associated improvements in nomenclature to reflect that increased knowledge is advocated by Practicing Cladists. Which seems like the scientific method? James K. Liebherr Ithaca, N. Y There may be a valid evolutionary basis to the current taxonomy system. Today's taxonomists, when they were toddlers, undoubtedly had the same drive to name and categorize as all the rest of us. "Bird!" they would shout enthusiastically. "Yes," Mom would reply fondly, "bird, chicken," or "No, not bird, butterfly." This behavior suggests that Linneaus did not invent systems of nomenclature, he tried to formalize kinds of nomenclature already present as unique names grouped in hierarchies. Shouting encouraging jargon to each other, guided by the narrow-beam flashlight of pure reason, modern taxonomists who feel that the names and hierarchies given to organisms don't reflect reality are eagerly and bravely leading the way into total obscurity. Mark Deyrup Archbold Biological Station The Archbold Biological Station is a research institute with a surrounding 2,000 ha estate near Lake Placid, Florida, USA. It includes an extensive area of Florida Scrub, a scientifically interesting and highly threatened ecosystem. Lake Placid, Fla. I agree that the current Linnaean hierarchy may have its shortcomings A shortcoming is a character flaw. Shortcomings may also be:
Aaron Wendt College Station, Texas College Station is a city in Brazos County, Texas, situated in Central Texas. It is located in the heart of the Brazos Valley. The city is located within the most populated region of Texas, near to three of the 10 largest cities in the United States - Houston, Dallas, and San Tale end? Perhaps there is a simple solution to the controversy between paleontologists and molecular biologists over whether whales are descended from mesonychians or artiodactyls ("The whales tale," SN: 11/6/99, p. 296). Primitive whales may not be ancestral to more modern ones. Both sides in the controversy would thus be vindicated: Ambulocetus, Pakicetus, and their more fully marine descendants in the extinct whale suborder suborder /sub·or·der/ (sub´or-der) a taxonomic category between an order and a family. sub·or·der n. A taxonomic category ranking between an order and a family. Archaeoceti would in fact be descended from mesonychians, while the two extant whale suborders would share a common ancestor (probably more recently) with hippopotamoid artiodactyls. If this is the case, then the key transitional forms leading to true whales have not been discovered yet. Clark Welder Fenton, Mich. Dumb or numb with fear? "When monkeys play dumb" (SN: 11/6/99, p. 299) suggests that subordinate monkeys play dumb when in the presence of dominate males to avoid attracting retaliation from the dominant animals. An alternate explanation is in "Grown-up grown-up adj. 1. Of, characteristic of, or intended for adults: grown-up movies; a grown-up discussion. 2. monkey brains get growing" (SN: 3/21/98, p. 180). This article indicates that hippocampal hip·po·cam·pus n. pl. hip·po·cam·pi A ridge in the floor of each lateral ventricle of the brain that consists mainly of gray matter and has a central role in memory processes. memory formation and learning of information may be disrupted by a stress reaction to an aggressive animal. Perhaps the mere presence of the dominant males was a stress to the subordinate males, causing the poor performance. Cynthia Swacina Rockton, Ill. Do monkeys who play dumb produce fewer new neurons than monkeys who don't? Or does playing dumb reduce stress enough to leave neuron generation unaffected? These questions remain unanswered. --B. Bower |
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