Life Sciences Commons^™

Dicliny In Bouteloua (Poaceae: Chloridoideae): Implications For The Evolution Of Dioecy, Michael S. Kinney, J. Travis Columbus, Elizabeth A. Friar

Aliso: A Journal of Systematic and Floristic Botany

The New World grass genus Bouteloua (Chloridoideae: Cynodonteae) comprises 57 species, 13 of which produce unisexual spikelets and hence are diclinous. Andromonoecy, gynodioecy, monoecy, trimonoecy, and dioecy all occur in the genus, and ten species are known to express more than one of these breeding systems. Employing a phylogenetic estimate based on parsimony analysis of DNA sequences from the ITS (nrDNA) and trnL–F (cpDNA) regions representing 35 species of Bouteloua, including ten of 13 diclinous species, we used parsimony character state reconstructions to investigate the evolution of unisexual spikelets and breeding systems. Our specific goals were to estimate …

The Emergence Of Sex, Ursula Goodenough

Biology Faculty Publications & Presentations

Biological traits, the foci of natural selection, are by definition emergent from the genes, proteins, and other “nothing-buts” that constitute them. Moreover, and with the exception of recently emergent “spandrels,” each can be accorded a teleological dimension—each is “for” some purpose conducive to an organism's continuation. Sex, which is “for” the generation of recombinant genomes, may be one of the most ancient and ubiquitous traits in biology. In the course of its evolution, many additional traits, such as gender and nurture, have emerged. Patterns of sexual exchange are the basis for patterns of biological evolution and are central to the …

Editor's Note, Padraig O'Malley

New England Journal of Public Policy

This issue of the New England Journal of Public Policy that deals with issues of climate change, oil, and water and the interconnection of the three with the future of the planet.

Initially our topic was conceived as “Oil & Water” only. We planned to present the proceedings of an Institute for Global Leadership symposium held at Tufts University in 2005. There was then still a debate about global warming, although the Kyoto Treaty was in place. But without the world’s preeminent manufacturer of greenhouse gas (GHG) emissions, the United States (20 percent of the total emissions with 5 percent …

Does Increasing Biology Teacher Knowledge Of Evolution And The Nature Of Science Lead To Greater Advocacy For The Teaching Of Evolution In Schools?, Ross Nehm, Irvin Sam Schonfeld

Publications and Research

This study investigated whether or not an increase in secondary science teacher knowledge about evolution and the nature of science gained from completing a graduate-level evolution course was associated with greater preference for the teaching of evolution in schools. Forty-four precertified secondary biology teachers participated in a 14-week intervention designed to address documented misconceptions identified by a precourse instrument. The course produced statistically significant gains in teacher knowledge of evolution and the nature of science and a significant decrease in misconceptions about evolution and natural selection. Nevertheless, teachers' postcourse preference positions remained unchanged; the majority of science teachers still preferred …

Evolution, Jonathan Eisen

Jonathan A. Eisen Ph.D.

No abstract provided.

Runx2 Is Essential For Larval Hyobranchial Cartilage Formation In Xenopus Laevis, Ryan Kerney, Joshua Gross, James Hanken

Ryan Kerney

The vertebrate transcription factor protein Runx2 is regarded as a “master regulator” of bone formation due to the dramatic loss of the osseous skeleton in the mouse homozygous knockout. However, Runx2 mRNA also is expressed in the pre-hypertrophic cartilaginous skeleton of the mouse and chicken, where its developmental function is largely unknown. Several tiers of Runx2 regulation exist in the mouse, any of which may account for its seeming biological inactivity during early stages of skeletogenesis. Unlike mouse and chicken, zebrafish require Runx2 function in early cartilage differentiation. The present study reveals that the earlier functional role of Runx2 in …