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In a 228-197 vote, Democrat lawmakers opposed a Republican resolution condemning voting by illegal aliens.

The growing population has become “a real problem,” especially over the last 10 years, he says. During the summer and fall, families enjoying outdoor activities must be on the look-out for bears. Many locals invite along other hunters for protection. Last year, in Pelly Bay, all the bears that were captured were caught in town, Nirlungayuk says. “You now have polar bears coming into towns, getting into cabins, breaking property and just creating havoc for people up here,” he says.

NASA-supported researchers have discovered the first known microorganism on Earth able to thrive and reproduce using the toxic chemical arsenic. The microorganism, which lives in California's Mono Lake, substitutes arsenic for phosphorus in the backbone of its DNA and other cellular components. More...

She's being called the world's first "bionic woman." Claudia Mitchell, who lost her left arm in a motorcycle accident, can move her replacement robotic arm just by thinking. "I can flex my elbow and open and close my hand with the mere thought of doing it," she said. ...

As Darwin would have loved to have known, genes made of DNA are the basic unit of inheritance. But in recent years, researchers have shown that differences not related to DNA sequence can also be passed down, a phenomenon called epigenetic inheritance. Some studies have implicated chemical groups that bind to genes. A new study in mice, however, suggests other possibilities--some of which could dramatically alter our notions of inheritance. Epigenetic inheritance has long been known in plants and yeast. In the mustard plant Arabidopsis, for example, epigenetic alterations in leaf and flower shape can be passed on to offspring....

Darwinian evolution follows very few of the available mutational pathways to attain fitter proteins, researchers at Harvard University have found in a study of a gene whose mutant form increases bacterial resistance to a widely prescribed antibiotic by a factor of roughly 100,000. Their work indicates that of 120 harrowing, five-step mutational paths that theoretically could grant antibiotic resistance, only about 10 actually endow bacteria with a meaningful evolutionary advantage. The research is described this week in the journal Science. "Just as there are many alternate routes one might follow in driving from Boston to New York, one intrinsic property...

What determines a gene's evolutionary rate? In particular, does it depend solely on functional constraints imposed on the structure of the encoded protein or are there higher-level factors related to the selection at the organismal level? These questions seem to be among the most fundamental ones in biology because comprehensive answers will reveal the nature of the links between genome evolution and the phenotypes of organisms. A recent study by Wall et al (2005) proves more convincingly than ever before that systemic determinants of gene evolution rate do exist, and an intriguing paper by Fraser (2005) sheds light on some...

Explaining the evolution of complexity has been a challenge to darwinian theory since its conception. At the molecular level, biological complexity involves networks of ligand-protein, protein-protein and protein-nucleic acid interactions in metabolism, signal transduction, gene regulation, protein synthesis and so on. As organismal complexity increases, it has been observed that more control is required for the positive and negative regulation of genes such that complexity correlates with an increase in both the ratio and absolute number of transcription factors. Both theoretical studies and genome analyses (Wagner, 1994, 2003; Mendoza & Alvarez-Buylla, 1998) have been used to examine the evolution of...

Convergent evolution occurs on all levels of biological organization, from organ systems to proteins. For instance, eyes and wings have evolved independently multiple times, and many aquatic vertebrates share a streamlined shape, despite their independent evolutionary origins. On the smaller scale of proteins, lysozymes have been recruited independently for foregut fermentation in bovids, colubine monkeys and a bird. Antifreeze glycoproteins in antarctic notothenioids and northern cod (living at opposite ends of the globe) have independently evolved similar amino acid sequences. Recent studies have identified abundant genetic circuit motifs in transcriptional regulation networks of the yeast S. cerevisiae and the bacterium...