All animal, vegetable + mineral stories

Popular causes not necessarily best

jake — Mon, 22 Oct 2007 13:48:00 -0400

Conservation policies favoring keystone animal species are insufficient to conserve the world’s biodiversity because many of these target animals don’t live in the world’s most biodiverse spots: lowland tropical forests under pressure from agriculture, logging, and other human activities.

‘Speed limit’ found on rate of evolution

jake — Mon, 22 Oct 2007 13:10:24 -0400

Harvard University scientists have identified a virtual “speed limit” on the rate of molecular evolution in organisms, and the magic number appears to be six mutations per genome per generation — a rate of change beyond which species run the strong risk of extinction as their genomes lose stability.

By modeling the stability of proteins required for an organism’s survival, Eugene Shakhnovich and his colleagues have discovered this essential thermodynamic limit on a species’ rate of evolution. Their discovery, published this week in the Proceedings of the National Academy of Sciences, draws a crucial connection between the physical properties of genetic material and the survival fitness of an entire organism.

Leading scientists announce creation of Encyclopedia of Life

50443248 — Tue, 02 Oct 2007 12:00:45 -0400

Realizing a dream articulated in 2003 by renowned biologist E.O. Wilson, Harvard and four partner institutions have launched an ambitious effort to create an Encyclopedia of Life (EOL), an unprecedented project to document online every one of Earth's 1.8 million known species. For the first time in history, the EOL would grant scientists, students, and others multimedia access to all known living species, even those just discovered.

The effort, announced today (May 9), will be supported by a new $10 million grant from the John D. and Catherine T. MacArthur Foundation and $2.5 million from the Alfred P. Sloan Foundation.

Losos’ lizards give evolutionary clues in island experiments

50443248 — Mon, 01 Oct 2007 15:41:16 -0400

Tiny islets in the Bahamas have proven useful laboratories to illustrate natural selection’s effects on island lizards, which saw their legs lengthen, then shorten as ground-dwelling predators drove them into the trees.

The experiments capped years of research into a type of lizard called an anole on the Caribbean islands. The research, conducted by Jonathan Losos, the Monique and Philip Lehner Professor of the Study of Latin America, examined the relationships between lizards that shared similar habitats and characteristics but lived on different islands.

Losos described his research Tuesday (Sept. 18) during the kickoff talk in this year’s lecture series sponsored by the Harvard Museum of Natural History (HMNH).

Primates expect others to act rationally

50443248 — Mon, 01 Oct 2007 16:11:22 -0400

When trying to understand someone’s intentions, nonhuman primates expect others to act rationally by performing the most appropriate action allowed by the environment, according to a new study by researchers at Harvard University.

The findings appear in the Sept. 7 issue of the journal Science. The work was led by Justin Wood, a graduate student in the Department of Psychology in the Faculty of Arts and Sciences (FAS), with David Glynn, a research assistant, and Marc Hauser, professor of psychology at Harvard, along with Brenda Phillips of Boston University.

Scientists have something to chew on

50443248 — Mon, 01 Oct 2007 16:20:15 -0400

In a groundbreaking study, two Harvard scientists have for the first time extracted human DNA from ancient artifacts. The work potentially opens up a new universe of sources for ancient genetic material, which is used to map human migrations in prehistoric times.

Before this, archaeologists could only get ancient DNA from relics of the human body itself, including prehistoric teeth, bones, fossilized feces, or — rarely — preserved flesh. Such sources of DNA are hard to find, poorly preserved, or unavailable because of cultural and legal barriers.

By contrast, the genetic material used in the Harvard study came from two types of artifacts — 800 to 2,400 years old — that are found by the hundreds at archaeological sites in the American Southwest.

First orchid fossil puts showy blooms at some 80 million years old

50443248 — Mon, 01 Oct 2007 16:27:21 -0400

Biologists at Harvard University have identified the ancient fossilized remains of a pollen-bearing bee as the first hint of orchids in the fossil record, a find they say suggests orchids are old enough to have coexisted with dinosaurs.

Their analysis, published this week (Aug. 29) in the journal Nature, indicates orchids arose some 76 to 84 million years ago, much longer ago than many scientists had estimated. The extinct bee they studied, preserved in amber with a mass of orchid pollen on its back, represents some of the only direct evidence of pollination in the fossil record.

New science provides compelling framework for early childhood investment

50443248 — Mon, 01 Oct 2007 17:10:00 -0400

A remarkable convergence of new knowledge about the developing brain, the human genome, and the extent to which early childhood experiences influence later learning, behavior, and health now offers policymakers an exceptional opportunity to change the life prospects of vulnerable young children, says a new report from the Center on the Developing Child at Harvard University.

The report, "A Science-Based Framework for Early Childhood Policy," integrates new research findings in neuroscience with extensive evaluations of early childhood programs, and provides a highly credible, comprehensive guide for evidence-based policymaking. It was released today (Aug. 6) in Boston at a press conference at the Annual Meeting of the National Conference of State Legislatures.

Sensory organ differentiates male/female behavior in some mammals

50443248 — Mon, 01 Oct 2007 16:50:40 -0400

For years, scientists have searched in vain for slivers of the brain that might drive the dramatic differences between male and female behavior. Now biologists at Harvard University say these efforts may have fallen flat because such differences may not arise in the brain at all.

Rather, they say, the epicenter of sex-specific behavior in many species may be a small sensory organ found in the noses of all terrestrial vertebrates except higher primates. Their work, appearing this week in the journal Nature, indicates that defects in this organ, known as the vomeronasal organ, lead female mice to adopt male behaviors such as mounting and pelvic thrusting while abandoning female behaviors such as nesting and nursing.

Teen diets can hurt their lungs

50443248 — Tue, 02 Oct 2007 09:27:34 -0400

For most teenagers in the United States and Canada, fish and fruit are not high on their delicious list. Also, many of them — about 20 percent of those under 18 — cough, wheeze, and suffer from asthma and bronchitis. Researchers at the Harvard School of Public Health (HSPH) have found a connection between these two situations.

A study of more than 2,100 high school seniors found that those who eat the least fruit and fish have the weakest lungs.

Trial Turns Over New Leaf for Traditional Herb

404132862 — Thu, 19 Jul 2007 13:58:08 -0400

If a painting’s worth were measured by the money it fetched, van Gogh’s famous rendering of his friend and physician Dr. Gachet would be among the most valuable in all of art. “Portrait of Dr. Gachet”—which depicts a languid man holding a purple foxglove, the plant from which the drug digitalis is derived—was sold in 1990 for an astounding 82 million dollars. The great and famously tortured artist had his own reasons for valuing the portrait. He suffered from severe epilepsy and depended heavily on Gachet’s prescription of digitalis to treat his debilitating seizures.

The ranks of epilepsy medications have expanded considerably in the past hundred years, due mostly to the addition of pharmaceutically derived compounds.

Sex differences in brains reflect disease risks

50443248 — Tue, 02 Oct 2007 09:32:42 -0400

Women’s brains are different from men’s. That’s not news. What is news is that the differences are smaller than most people believe. They are not big enough to say that one sex is smarter or better at math than the other.

What is also news is that the small differences can be significant when it comes to memory, arousal, reasoning, and risk of some diseases. The latter include depression, anxiety, schizophrenia, drug abuse, Alzheimer’s, diabetes, and heart disease.

“Brain differences, though small, help us to understand the nature of sex differences in disease, and thus will hopefully aid in devising sex-specific treatments and prevention strategies,” notes Jill Goldstein, a professor of psychiatry and medicine at Harvard Medical School (HMS).

Eggs, nests make colorful bedfellows at HMNH

50443248 — Tue, 02 Oct 2007 11:00:00 -0400

Large and small, plain and colored, splotched and dotted, eggs from the Harvard Museum of Comparative Zoology’s vast collection are on display at the Harvard Museum of Natural History in a new exhibition of eggs and nests.

The nests, like the eggs, come in all shapes and sizes. Unlike eggs, which have the same basic plan, nests vary greatly in complexity, from the simple dirt mounds of reptiles to the elaborate creations of Africa’s weaver birds to no nests at all.

Forty percent of world lacks clean water, solutions sought

50443248 — Tue, 02 Oct 2007 11:49:16 -0400

The pictures — of children with sunken eyes and shriveled skin; oxen being herded across a river where women clean their clothes and fill their pitchers; an African villager sipping water from a shallow puddle — made the point like no words could at the May 11 Center for International Development symposium “The Impact of the Global Water Crisis on Health and Human Development” at the Harvard School of Public Health (HSPH). Still, the statistics were almost equally startling: More than a billion people worldwide lack safe water sources, and 2.6 billion — 40 percent of the world’s population — have no basic sanitation. Nearly 2 million people a year, 90 percent of them children under 5, die from dehydration and associated malnutrition and microbial diseases.

Howard Gardner's 'quintet of minds'

50443248 — Tue, 02 Oct 2007 11:54:47 -0400

It’s been more than 20 years since Harvard psychologist Howard Gardner offered up a radical idea: that humans possess multiple forms of intelligence rather than just a single type that is easily tested by linguistic and logical-mathematical parameters.

His groundbreaking “Frames of Mind” (1983) changed traditional psychological views of intelligence, and helped educators question conventional teaching and testing.

In a new book this year, Gardner — the John H. and Elisabeth A. Hobbs Professor of Cognition and Education at the Harvard Graduate School of Education (HGSE) — goes beyond describing cognition. He ventures into prescription.