منابع مشابه
How the horned lizard got its horns.
Many descriptions of evolutionary adaptations are criticized as “just-so stories” (1) that are based more on intuition than on direct tests of adaptive hypotheses. The elaborate crowns of horns possessed by many species of horned lizards (genus Phrynosoma) are classic examples of intuitively adaptive features that lack direct tests of function. The bony horns that give horned lizards their name...
متن کاملSpatial Patterns in the Abundance of the Coastal Horned Lizard
Coastal horned lizards ( Phrynosoma coronatum ) have undergone severe declines in southern California and are a candidate species for state and federal listing under the Endangered Species Act. Quantitative data on their habitat use, abundance, and distribution are lacking, however. We investigated the determinants of abundance for coastal horned lizards at multiple spatial scales throughout so...
متن کاملترجمه و نقد کتاب the justification of science and the rationality of religious belife
چکیده ندارد.
15 صفحه اولComment on "How the horned lizard got its horns".
Recently, Young et al. (1) purported to identify the mechanism behind the origin and maintenance of horns in horned lizards (Phrynosomatidae: Phrynosoma) by demonstrating directional selection for increasing horn length in one population of Phrynosoma mcalli from the southwestern United States. In drawing their conclusions, Young et al. asserted rather than demonstrated the current function of ...
متن کاملHow did the horned lizard get its horns?
IN THEIR BREVIA “HOW THE HORNED LIZARD got its horns,” K. V. Young et al. present an important example of natural selection in the wild, suggesting that loggerhead shrike predation drove the evolution of elongated horns in the flat-tailed horned lizard (2 Apr., p. 65). Although the authors acknowledge that selective forces other than shrike predation may also be involved, they make no mention o...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: The Iowa Review
سال: 1981
ISSN: 0021-065X,2330-0361
DOI: 10.17077/0021-065x.2835