Science News in Brief

Elephants Avoid Costly Mountaineering:

"Using global-positioning system data corresponding to the movements of elephants across the African savannah, researchers have found that elephants exhibit strong tendencies to avoid significantly sloped terrain, and that such land features likely represent a key influence on elephant movements and land use. On the basis of calculations of energy use associated with traversing sloped terrain by such large animals, the researchers found that this behavior is likely related to the fact that even minor hills represent a considerable energy barrier for elephants because of the added calorie consumption required for such movements."

Velvet Worm Brains Reveal Secret Sisterhood With Spiders:

Velvet worms, living fossils that look like a child's rendition of caterpillars, are more closely related to spiders and scorpions than to butterflies, according to new research.
Known to scientists as onychophorans, velvet worms have been thought to be similar to the ancestors of modern arthropods, the jointed-legged creatures that includes insects.
Fossils that look very much like today's onychophorans can be found in rocks 540 million years old.
"When I looked at their brains, I was shocked because I didn't expect to see what I saw," said Nicholas J. Strausfeld of The University of Arizona in Tucson. "I just felt from their organization that these looked like spider brains, that they had more in common with spider brains than with other arthropod brains."

Read the rest of the article as it is, like, totally kewl and fascinating!

Why Are Uniforms Uniform? Because Color Helps Us Track Objects:

"We report the rather surprising result that people can focus on more than three items at a time if those items share a common color," he said. "Our research suggests that the common color allows people to overcome the usual limit, because the 'color coding' enables them to perceive the separate individuals as a single set."

Ah, this brings back memories....my co-advisor insisted that we mark all the quail with aluminum wingbands and provide the technicians the list of numbers so, if a bird gets lose in the room, they'll now in which cage to put it back. I insisted that we color-code the birds with wingbands in 10 or so different colors, each category of bird marked with a different color and each cage marked with the appropriate color, arguing that animal technicians do not have time or care much about checking the list for numbers (something I could prove by showing the log of misplaced birds over time), but a monkey can be trained to sort by color. In the end, I just bought 10 colors of bands, banded the birds myself, and never had a problem of misplaced birds again. The log proved me right, so I won that argument. The linked study explains why.

Effects Of Nutrition On Learning:

Poor nutrition early in life can impair neural development, leading to lower IQ in humans and flawed song learning in birds. Recent evidence indicates that many organisms can offset some of the changes associated with early poor nutrition by modifying their physical development. For example, poorly nourished children can undergo a period of accelerated growth once their diet improves, ultimately appearing normal as an adult. But such compensatory measures may come at a price, with cognitive or other developmental disabilities emerging later in life.

Surprisingly, this paper is not by Steve Nowicki. I'd like to know his take on it.

High Estrogen Levels Associated With Dementia In Older Men; No Association Observed With Testosterone:

A prospective population-based study has found that higher estrogen levels in older men are associated with an increased risk of dementia. By contrast, levels of testosterone were not associated with cognitive decline.
----------snip-----------
The researchers hypothesize that the estradiol association could be explained by increased aromatase activity in the brain which may be associated with a neurodegenerative process. It is then possible that the high levels of estradiol are a consequence or early marker of Alzheimer's disease rather than a cause.

Link Between Income And Happiness Is Mainly An Illusion:

While most people believe that having more income would make them happier, Princeton University researchers have found that the link is greatly exaggerated and mostly an illusion.
People surveyed about their own happiness and that of others with varying incomes tended to overstate the impact of income on well-being, according to a new study. Although income is widely assumed to be a good measure of well-being, the researchers found that its role is less significant than predicted and that people with higher incomes do not necessarily spend more time in more enjoyable ways.

Direct Link Established Between Tropical Tree And Insect Diversity:

It may be obvious that forests with greater numbers of tree species should support a wider variety of leaf-eating insects than do less diverse forests, but no one had ever done the experiment to rule out the major alternative explanation: that insect species in the tropics eat the leaves of a smaller number of host trees (are more host specific), which would also result in more insect species in a given area. This study presents the best experimental evidence to date to account for the latitudinal gradient in herbivorous insect biodiversity.

Pine Plantations May Be One Culprit In Increasing Carbon Dioxide Levels:

The researchers estimate that some 10 million acres - roughly the size of New Hampshire and Vermont - of mainly hardwood and natural pine forests will be chopped down to make way for pine plantations by 2030 in just three Southern states. That translates into roughly 700,000 tons more carbon dioxide released into the atmosphere annually, or 21 million tons over the 30-year period.

It's All In The Genes: Landmark Research Shows Genetic Link To Community Makeup And Ecosystem Evolution:

It's common knowledge that genes control traits such as eye and hair color. But a large group of scientists from two continents has found that the genes of one organism not only control the characteristics of that individual but also dictate the behavior of thousands of other organisms in a community.
They say these genes, in fact, influence the evolution of an entire ecosystem.

No, no, no. Wrong concept! Organisms interact with each other, not genes. Genes are invisible to selection. Interactions between organisms (not genes), indirectly, by sorting among phenotypes (which are not bean-bag-genetics straighforwardly determined by particular genetic sequences), drives the evolution of genes within those organisms. The selection works from outside in, not the other way round.