Eye color and hair color play a role in human partner choice but visual stimuli can also determine mating preferences in the animal kingdom.

In many species, the male’s fortunes in the mating stakes are decided by a conspicuous breeding dress. A study of brightly coloured fish has now demonstrated that this has less to do with aesthetics than with the sensitivity of female eyes, which varies as a result of adaptation to the environment. Females more attuned to blue will choose a metallic blue mate, while those better able to see red will prefer a bright red male.

These mating preferences can be strong enough to drive the formation of new species – provided that habitat diversity is not reduced by human activities.

A team of Yale scientists has found that certain countries and some U.S. states stand to benefit from the use of compact fluorescent lighting more than others in the fight against global warming. Some places may even produce more mercury emissions by switching from incandescent light bulbs to compact fluorescent lighting.

Estonia, which relies heavily on coal-powered energy generation, tops the list as the country that would see the greatest reduction in mercury emissions for every incandescent bulb it replaces with a compact fluorescent light bulb (CFL). However, given its similar reliance on coal-fired plants, coupled with its huge population, China stands to reduce its mercury emissions by the greatest overall amount. Other countries near the top of the list include Romania, Bulgaria and Greece; within the U.S., North Dakota, New Mexico and West Virginia have the greatest potential to reduce their mercury emissions.

But much of South America, Africa, the Middle East and parts of Europe, along with Alaska, California, Oregon, Idaho and several New England states, would actually increase their mercury emissions by making the switch from incandescent to fluorescent lighting. The results depend on a complex relationship between a number of factors, including how dependent a region is on coal-powered energy generation, the chemical makeup of the coal used in those plants, and existing recycling programs for CFLs.

Small stretches of DNA with unknown utility harbor a big
secret, say researchers at the Stanford University School of Medicine, but they don't know what it is.

Those secrets are always the biggest. Individual laboratory animals appear to live happily when these genetic ciphers are
deleted so why these snippets have been highly conserved throughout evolution is the real mystery.

Small stretches of seemingly useless DNA harbor a big secret, say researchers at the Stanford University School of Medicine. There's one problem: We don't know what it is. Although individual laboratory animals appear to live happily when these genetic ciphers are deleted, these snippets have been highly conserved throughout evolution.

MicroRNAs, the tiny molecules that fine-tune gene expression, were first discovered in 1993, but it turns out they've been around for a billion years. Evidence published in Nature by scientists in the lab of Whitehead Institute for Biomedical Research Member and Howard Hughes Medical Institute investigator David Bartel provides a window into the early evolution of these key regulators, placing their origin within the earliest of animal lineages.

The research also suggests that microRNAs present early on have undergone extensive changes, which likely have altered their functions across various lineages.

The effect of media violence on behavior is not as straightforward as you might think. Although many studies have been conducted examining the link between violence on TV and aggressive behavior, most of these studies have overlooked several other potentially significant factors, including the dramatic context of the violence and the type of violence depicted as well as the race and ethnicity of the viewers.

In a new study appearing in the September issue of Perspectives on Psychological Science, psychologists Seymour Feshbach from the University of California, Los Angeles and June Tangney from George Mason University investigated the effect that exposure to violent TV programs has on negative behavior in children from different ethnic backgrounds.

When a cell's chromosomes lose their ends, the cell usually kills itself to stem the genetic damage - University of Utah biologists say their discovery about how those cells evade suicide and start down the path to cancer may lead to new treatments.

A new study of fruit flies is the first to show in animals that losing just one telomere, the end of a chromosome, can lead to many abnormalities in a cell's chromosomes, which are strands of DNA that carry genes.

"The essential point is that loss of a single telomere may be a primary event that puts a cell on the road to cancer," says Kent Golic, a professor of biology at the University of Utah and senior author of the study, published in the journal Genetics.