How old are most species of North American birds? A longstanding debate centers on whether Pleistocene events caused substantial avian diversification. Two new syntheses of speciation times by Johnson and Cicero, and Weir and Schluter provide compelling evidence of recent Pleistocene speciation, whereas diversification rate analyses by Zink et al. suggest that most speciation events occurred ea...

B. L. Zink,1,* R. Islam,2 David J. Smith,2 and F. Hellman3 1Department of Physics and Astronomy, University of Denver, Denver, Colorado 80208, USA 2Center for Solid State Science and Department of Physics and Astronomy, Arizona State University, Tempe, Arizona 85287, USA 3Department of Physics, University of California, Berkeley, California 94720-7300, USA Received 20 March 2006; revised manusc...

Abstract We investigate qualitative properties of the underlying scheme Rapoport–Zink formal moduli spaces p -divisible groups (resp., shtukas). single out those cases where dimension this is zero maximal possible). The model case for first alternative Lubin–Tate space, and second Drinfeld space. exhibit a complete list in both cases.

Penelitian ini bertujuan untuk mengetahui titer antibodi ND dan AI pada pemberian kombinasi Vitamin E, Zink, Selenium ayam kampung betina. dilaksanakan Januari--Maret 2022 di Kandang Laboratorium Lapang Terpadu Fakultas Pertanian, Universitas Lampung. terdiri dari 4 perlakuan 3 ulangan yaitu P0 : air minum tanpa sediaan Selenium, Zink (kontrol); P1 dengan 0,015 g/kg BB/hari (sediaan vitamin E 0...

The timing of origin of modern North American bird species in relation to Pleistocene glaciations has long been the topic of significant discussion and disagreement. Recently, Klicka and Zink (1997) and Avise and Walker (1998) enlivened this debate by using calibrated molecular distance values to estimate timing of speciations. Here we use new molecular studies to test their conclusions. Molecu...