Do we grow old because of natural cellular mechanisms or because of gradually accumulated environmental toxins, like lead?

Growing old in the age of lead

Good news for Lindsay Lohan and Amy Winehouse:

Sedentary lifestyles could make you old before your time.

Live slow die young

The sunscreen that you dutifully slather on before a swim on the beach may be protecting your body—but a new study finds that the chemicals are also killing coral reefs worldwide.

Swimmers' Sunscreen Killing Off Coral

Here is the Discovery Institute trying to make hay out of a recent symposium hosted by John "Edge" Brockman:

In the end, Robert Shapiro’s statements said it all: We don’t know how the ribosome and its required proteins evolved, but we know that “Both are obviously products of long evolution of preexisting life through the process of trial and error.” This is a prime example of “evolution-of-the-gaps,” and it demonstrates that intelligent design could go a long way towards solving problems in 21st century biology. This also demonstrates that intelligent design proponents have worthwhile contributions to make and deserve a place at the table in these kinds of discussions.

After all, 21st century biology is synthetic, right?

Leading Biologists Marvel at the “Irreducible Complexity” of the Ribosome, but Prefer Evolution-of-the-Gaps

The human brain responds to recognizable signals for sex and for rewarding drugs of abuse by activation of limbic reward circuitry. Does the brain respond in similar way to such reward signals even when they are “unseen”, i.e., presented in a way that prevents their conscious recognition? Can the brain response to “unseen” reward cues predict the future affective response to recognizable versions of such cues, revealing a link between affective/motivational processes inside and outside awareness?

We exploited the fast temporal resolution of event-related functional magnetic resonance imaging (fMRI) to test the brain response to “unseen” (backward-masked) cocaine, sexual, aversive and neutral cues of 33 milliseconds duration in male cocaine patients (n = 22). Two days after scanning, the affective valence for visible versions of each cue type was determined using an affective bias (priming) task. We demonstrate, for the first time, limbic brain activation by “unseen” drug and sexual cues of only 33 msec duration. Importantly, increased activity in an large interconnected ventral pallidum/amygdala cluster to the “unseen” cocaine cues strongly predicted future positive affect to visible versions of the same cues in subsequent off-magnet testing, pointing both to the functional significance of the rapid brain response, and to shared brain substrates for appetitive motivation within and outside awareness.

These findings represent the first evidence that brain reward circuitry responds to drug and sexual cues presented outside awareness. The results underscore the sensitivity of the brain to “unseen” reward signals and may represent the brain's primordial signature for desire. The limbic brain response to reward cues outside awareness may represent a potential vulnerability in disorders (e.g., the addictions) for whom poorly-controlled appetitive motivation is a central feature.

See also:

Using a brain imaging technology called functional magnetic resonance imaging (fMRI), scientists have discovered that cocaine-related images trigger the emotional centers of the brains of patients addicted to drugs — even when the subjects are unaware they've seen anything. The study, published Jan. 30 in the journal PLoS One, was funded by the National Institute on Drug Abuse (NIDA), part of the National Institutes of Health (NIH).

A team of researchers at the University of Pennsylvania, led by Dr. Anna Rose Childress and Dr. Charles O'Brien, showed cocaine patients photos of drug-related cues like crack pipes and chunks of cocaine. The images flashed by in just 33 milliseconds — so quickly that the patients were not consciously aware of seeing them. Nonetheless, the unseen images stimulated activity in the limbic system, a brain network involved in emotion and reward, which has been implicated in drug-seeking and craving.

"This is the first evidence that cues outside one's awareness can trigger rapid activation of the circuits driving drug-seeking behavior," said NIDA director Dr. Nora Volkow. "Patients often can't pinpoint when or why they start craving drugs. Understanding how the brain initiates that overwhelming desire for drugs is essential to treating addiction."

Prelude to Passion: Limbic Activation by “Unseen” Drug and Sexual Cues

Blue-eyed? Thank a genetic switch that turns off your body's ability to make brown pigment in your peepers. Researchers have finally located the mutation that causes blue eyes, and the findings suggest that all blue-eyed humans share a single common ancestor born 6000 to 10,000 years ago.

Researchers have implicated the OCA2 gene in several eye colors. The gene is involved in the production of melanin, a pigment that gives hair and skin their hues. It also codes for brown eyes and can lead to green or hazel eyes when mutated. Despite years of searching, however, scientists have not found a mutation for blue eyes on the gene.

It turns out they were looking in the wrong place. Trying to narrow the site of the mutation, gene mapper Hans Eiberg of the University of Copenhagen and colleagues examined members of a large Danish family, an approach that allowed them to follow DNA as it passed from one generation to another. Then, by comparing people with brown or blue eyes, including people from Jordan and Turkey, the researchers were able to pinpoint the exact mutation. It wasn't on the OCA gene but rather on a nearby gene called HERC2.

Don't It Make Your Brown Eyes Blue?

From microorganisms to whales, from single cells to complex organisms, from plants to animals to fungi, from body plans to behavior, the diversity of life is amazing. Living organisms have a profound impact on our physical world of ocean, landscape, and climate; around us is a multitude of diverse ecosystems that provide a livable environment and many valuable resources. The study of life—biology—is a multifaceted endeavor that uses observation, exploration, and experiments to gather information and test hypotheses about topics ranging from climate change to stem cells. The field of biology is so diverse that it can sometimes be hard for one individual to keep its breadth in mind while contemplating a particular question.

This study was initiated at the request of, and with the sponsorship of, the National Science Foundation. It was conceived as a new approach to a question that has been asked before: What is the future of biology? In 1989 the National Research Council released a report on this topic entitled Opportunities in Biology. Over 400 pages long and four years in the making, the report provided a detailed snapshot of the state of biology at that time. Eleven different panels detailed the opportunities awaiting the rapidly diversifying field of biology. Reading the report today, the excitement of that time is palpable. Section after section describes new technologies and promises new discoveries. Each section focuses on a different subdiscipline of biology.

The Role of Theory in Advancing 21st Century Biology: Catalyzing Transformative Research

The world’s food supply is increasingly dependent on a small and narrowing list of highly engineered breeds: the Holstein, the Large White pig and the Rhode Island Red and Leghorn chickens. There’s a risk that future diseases could ravage these homogeneous animal populations. Poor countries, which possess much of the world’s vanishing biodiversity, may also be discarding breeds that possess undiscovered genetic advantages. But farmers say they can’t afford to wait for science. And so, on the African savanna, a competition for survival is underway.

A Dying Breed

Philip Ball for Nature, reporting on Researchers Take Step Toward Synthetic Life and Md. Scientists Create Full Chromosome of Synthetic DNA.

Scientists have succeeded in stitching together an entire bacterial genome, creating in the lab the full set of instructions needed to make a living thing. The stage is now set for the creation of the first artificial organism — and it could be achieved within the year.

From the archive:

Now, after three billion years, the Darwinian interlude is over.

Genome stitched together by hand

See also "Blink".

Ambady and colleague Nicholas Rule, both at Tufts University in Medford, Massachusetts, wondered about sexual orientation. They showed men and women photos of 90 faces belonging to homosexual men and heterosexual men for intervals ranging from 33 milliseconds to 10 seconds. When given 100 milliseconds or more to view a face, participants correctly identified sexual orientation nearly 70% of the time. Volunteers were less accurate at shorter durations, and their accuracy did not get better at durations beyond 100 milliseconds, the team reports in an upcoming issue of the Journal of Experimental Social Psychology. "What is most interesting is that increased exposure time did not improve the results," says Ambady.

Romantic attraction likely works just as fast, notes psychologist Paul Eastwick of Northwestern University in Evanston, Illinois. "If people make accurate judgments about sexually relevant aspects of a person this quickly," he says, "you have to stop and wonder how we size up one another's romantic potential in a matter of milliseconds."

An Eye for Sexual Orientation