Progress Daily

Eric Lander, calculates that the cost of DNA sequencing has fallen to a hundred-thousandth of what it was a decade ago. The genome sequenced by the International Human Genome Sequencing Consortium took 13 years and cost $3 billion. Now, using sequencers from Illumina, a human genome can be read in eight days at a cost of about $10,000. Pacific Biosciences has a technology that can read genomes from single DNA molecules, and thinks that in three years’ time this will be able to map a human genome in 15 minutes for less than $1,000.

“Biology 2.0,” by Geoffrey Carr

Viewing curvaceous women has an effect on straight men’s brains similar to that of alcohol and other drugs.

Steven Platek’s researchers asked 14 men (average age of 25) to rate women’s attractiveness before and after plastic surgery that moved fat from their waist to buttocks, changing their waist-to-hip-ratio (WHR).

FMRI showed activation in the subjects’ brain reward centers in response to naked female bodies when surgically altered to express an optimal (~0.7) WHR with redistributed body fat, but relatively little activation when body mass index (BMI) was altered.

“Optimal Waist-to-Hip Ratios in Women Activate Neural Reward Centers in Men”

“Watching curvaceous women feels like drugs to men: study, goodnews

In a way analogous to Gordon Moore’s famous law about the improvement of computers, both the price of sequencing DNA and the price of making it have plummeted over the past decade. The former means that the world’s databases are filling up with genes from every part of the tree of life. The latter means those genes can be cut and pasted together with greater and greater ease.

“Genesis redux,” The Economist

Sexual selected traits come in two main forms: weapons, which are used to fight off competitors; and ornaments, which are used to advertise genetic fitness to the opposite sex.

According to David Puts, human masculine traits — big muscles, facial hair, square jaws, deep voices and a propensity to violence — evolved for their usefulness in fighting with or indimidating other men (”Beauty and the beast: mechanisms of sexual selection in humans“).

In species whose males do not fight for access to females, males are generally the same size as, or smaller than, females. Human males have 40% more fat-free mass than women, which to the difference in gorillas, a species in which males unquestionably compete with other males for exclusive sexual access to females.

“To get the girl,” The Economist

In the past year, nearly 4,800 women participated in an experiment at Faceresearch.org. They were young women, mostly in their early- to mid-twenties, and all identified their ethnicity as white.

The female subjects were presented with two male faces & asked to choose the face they considered more attractive and indicate how much they preferred it to the other one.

The faces were actually two copies of the same photo, each manipulated by software that masculinizes or feminizes a person’s features.

In countries where poor health is particularly a threat to survival, women leaned toward “manlier” men — those with shorter, broader faces and stronger eyebrows, cheekbones and jaw lines.

Women with the weakest masculinity preferences tended to live in some of the healthiest countries: Sweden, Finland, Denmark and Austria and (number one) Belgium. Other countries in the study with low masculinity preferences are Romania, Greece and New Zealand.

Women with the strongest masculinity preferences tended to hail from the countries with higher disease and mortality rates and some of the poorest scores on the health-care index: Mexico, Brazil, Bulgaria and Argentina. (The researcher included only white subjects; Asian and African nations were not included.)

The US had the 5th highest masculinity preference out of the 30 countries, and was 20th in healthiness.

“Why Women Don’t Want Macho Men,” by Jena Pincott

Since 1948 three generations of residents in Framingham have participated in regular medical examinations. A new study (”Alone in the crowd: The structure and spread of loneliness in a large social network”; .pdf file here) by John Cacioppo that uses Framingham to analyse loneliness has found that it spreads very much like a communicable disease.

Participants in the study were routinely asked to list people who would probably know their whereabouts in the next 2 to 4 years, & were asked to describe their relationship with each person as friend, spouse, sibling, neighbour or colleague. Between 1983 and 2001 participants were regularly asked to state how many days a week they felt certain feelings, such as loneliness.

Analyzing this data, the researchers found that loneliness formed in clusters of people, and that once one person in a social network started expressing feelings of loneliness, others within the same network would start to feel the same way. Those who had immediate contact with lonely people were around 50% more likely than average to feel lonely themselves. In people who knew people who had direct contact with lonely people, the figure was 25%. Those with three degrees of separation showed roughly a 10% increase.

The effects were more noticeable among friends than family, and stronger among women than men.

“Alone in the crowd,” The Economist

The fertility rate of half the world is now 2.1 or less — “the replacement rate of fertility” (the number that is consistent with a stable population). If current trends continue, sometime between 2020 and 2050 the world’s fertility rate will fall below the global replacement rate.

Mothers in developing countries today can expect to have three children. Their mothers had six.

“Falling fertility,” The Economist

Richard Tol collected data on climate and conflict in Europe over the past thousand years (”Climate Change and Violent Conflict in Europe over the Last Millennium“).

Until the mid-18th century, the correlation between the number of conflicts and the average temperature is continuously and significantly negative — lower temperatures mean more wars. The line remains close to the 95% confidence level, suggesting there is only one chance in 20 that it is an accidental, random effect. Then, suddenly, the negative correlation vanishes. (The line goes into positive territory, but not enough to be statistically meaningful.)

The researchers suggest that in the more remote past the effects of cold weather on harvests led to supply shortages, and that these increased the likelihood of people fighting over food and the land needed to produce it. They argue that the reason the relationship between warfare and cold vanishes in the mid-18th century is that this is the moment when the industrial revolution began. The food supply increased and improvements in transportationallowed food to be more easily shipped to areas of scarcity.

Farmers could more often produce reasonable yields during colder weather — and long-distance trade provided a buffer against crop failure.

“Cool heads or heated conflicts?,” The Economist

According to Andrew Smithers‘ two favourite stock market valuation measures, the q ratio (which compares share prices with the replacement cost of net assets) and the cyclically adjusted price/earnings ratio (which averages profits over ten years), the US market is still overvalued. According to these measures, Wall Street fell to merely average, not low, valuations in the recent crash.

“The end is nigh (again),” The Economist

Research by Emma Cohen (”Rowers’ high: behavioural synchrony is correlated with elevated pain thresholds“), suggests that training in a synchronised group may heighten tolerance for pain, & allow people to train longer.

The researchers got 12 members of Oxford’s heavyweight squad to row on machines in four 45-minute sessions over two weeks. In two sessions they rowed in complete isolation and in the others in groups of six, perfectly synchronised. Immediately following each session they deduced pain tolerance by gradually tightening a cuff around each rower’s arm. When he said “now” they stopped squeezing and noted the pressure.

The rowers’ pain thresholds were significantly higher following the group sessions. This was despite nearly identical power outputs in all four tests and efforts to control for possible confounding variables, such as the time of day.

“Fitter with friends,” The Economist