Category: Science

Photobiology

| May 30, 2015 | Reply

I’m enjoying photography, especially portraits. The final products are fun to create, but what is it that I’m looking for in a portrait? I’m convinced that photographers can benefit from some of the findings on what it means to be attractive by those who study biology, and specifically, evolution.

The above-linked Wikipedia article has lots of information on this topic of physical attractiveness as explored scientifically. Here’s an excerpt pertaining to women:

Research has attempted to determine which facial features communicate attractiveness. Facial symmetry has been shown to be considered attractive in women, and men have been found to prefer full lips, high forehead, broad face, small chin, small nose, short and narrow jaw, high cheekbones, clear and smooth skin, and wide-set eyes. The shape of the face in terms of “how everything hangs together” is an important determinant of beauty. A University of Toronto study found correlations between facial measurements and attractiveness; researchers varied the distance between eyes, and between eyes and mouth, in different drawings of the same female face, and had the drawings evaluated; they found there were ideal proportions perceived as attractive. These proportions (46% and 36%) were close to the average of all female profiles. Women with thick, dark limbal rings in their eyes have also been found to be more attractive. The explanation given is that because the ring tends to fade with age and medical problems, a prominent limbal ring gives an honest indicator of youth.

In a cross-cultural study, more neotenized (i.e., youthful looking) female faces were found to be most attractive to men while less neotenized female faces were found to be less attractive to men, regardless of the females’ actual age. One of these desired traits was a small jaw. In a study of Italian women who have won beauty competitions, it was found that their faces had more “babyish” (pedomorphic) traits than those of the “normal” women used as a reference.

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The Beauty of the Sun – Spectacular Nasa Visuals

| May 26, 2015 | 3 Replies

Published on Feb 11, 2015
February 11, 2015 marks five years in space for NASA’s Solar Dynamics Observatory, which provides incredibly detailed images of the whole sun 24 hours a day. Capturing an image more than once per second, SDO has provided an unprecedentedly clear picture of how massive explosions on the sun grow and erupt ever since its launch on Feb. 11, 2010. The imagery is also captivating, allowing one to watch the constant ballet of solar material through the sun’s atmosphere, the corona.

In honor of SDO’s fifth anniversary, NASA has released a video showcasing highlights from the last five years of sun watching. Watch the movie to see giant clouds of solar material hurled out into space, the dance of giant loops hovering in the corona, and huge sunspots growing and shrinking on the sun’s surface.

The imagery is an example of the kind of data that SDO provides to scientists. By watching the sun in different wavelengths – and therefore different temperatures – scientists can watch how material courses through the corona, which holds clues to what causes eruptions on the sun, what heats the sun’s atmosphere up to 1,000 times hotter than its surface, and why the sun’s magnetic fields are constantly on the move.

Five years into its mission, SDO continues to send back tantalizing imagery to incite scientists’ curiosity. For example, in late 2014, SDO captured imagery of the largest sun spots seen since 1995 as well as a torrent of intense solar flares. Solar flares are bursts of light, energy and X-rays. They can occur by themselves or can be accompanied by what’s called a coronal mass ejection, or CME, in which a giant cloud of solar material erupts off the sun, achieves escape velocity and heads off into space. In this case, the sun produced only flares and no CMEs, which, while not unheard of, is somewhat unusual for flares of that size. Scientists are looking at that data now to see if they can determine what circumstances might have led to flares eruptions alone.

Goddard built, operates and manages the SDO spacecraft for NASA’s Science Mission Directorate in Washington, D.C. SDO is the first mission of NASA’s Living with a Star Program. The program’s goal is to develop the scientific understanding necessary to address those aspects of the sun-Earth system that directly affect our lives and society.

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How Europeans evolved into tall white-skinned milk-drinkers

| April 10, 2015 | Reply

Fascinating research shows that the traits of light colored skin and the ability to digest lactose (found in milk) as adults evolved recently:

First, the scientists confirmed an earlier report that the hunter-gatherers in Europe could not digest the sugars in milk 8000 years ago, according to a poster. They also noted an interesting twist: The first farmers also couldn’t digest milk. The farmers who came from the Near East about 7800 years ago and the Yamnaya pastoralists who came from the steppes 4800 years ago lacked the version of the LCT gene that allows adults to digest sugars in milk. It wasn’t until about 4300 years ago that lactose tolerance swept through Europe.

When it comes to skin color, the team found a patchwork of evolution in different places, and three separate genes that produce light skin, telling a complex story for how European’s skin evolved to be much lighter during the past 8000 years. The modern humans who came out of Africa to originally settle Europe about 40,000 years are presumed to have had dark skin, which is advantageous in sunny latitudes. And the new data confirm that about 8500 years ago, early hunter-gatherers in Spain, Luxembourg, and Hungary also had darker skin: They lacked versions of two genes—SLC24A5 and SLC45A2—that lead to depigmentation and, therefore, pale skin in Europeans today.

Further research shows that being tall or shorter can each have advantages in different environments:

[S]election strongly favored several gene variants for tallness in northern and central Europeans, starting 8000 years ago, with a boost coming from the Yamnaya migration, starting 4800 years ago. The Yamnaya have the greatest genetic potential for being tall of any of the populations, which is consistent with measurements of their ancient skeletons. In contrast, selection favored shorter people in Italy and Spain starting 8000 years ago, according to the paper now posted on the bioRxiv preprint server. Spaniards, in particular, shrank in stature 6000 years ago, perhaps as a result of adapting to colder temperatures and a poor diet.

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Falling through the center of the earth

| March 24, 2015 | 1 Reply

Fascinating thought experiment now has a more precise answer:

Suppose you dug a tunnel through the center of Earth, jumped in, and let gravity pull you through. How long would it take you to reach the other side of the planet? For decades, physics students have been asked to calculate that time and have been taught that the correct answer is 42 minutes. Now, a more realistic analysis has lopped 4 minutes off that estimate.

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Steven Pinker’s cognitive science quiz

| February 24, 2015 | Reply

How well can you answer these ten questions about cognitive science posed by Steven Pinker?

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The biggest difference between good science and religion

| February 10, 2015 | 1 Reply

The difference between good science and any religion. Good science is proudly self-critical. The Edge 2014 annual question, answered by almost 200 writers, is this: “Ideas change, and the times we live in change. Perhaps the biggest change today is the rate of change. What established scientific idea is ready to be moved aside so that science can advance?”

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Nation of skimmers rather than readers

| February 5, 2015 | 1 Reply

From the Washington Post, we learn that we are re-shaping our brains to accommodate the Internet.

Humans, they warn, seem to be developing digital brains with new circuits for skimming through the torrent of information online. This alternative way of reading is competing with traditional deep reading circuitry developed over several millennia.

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About blacks, whites and the other so-called races

| December 27, 2014 | Reply

In the NYT, Carl Zimmer writes about the so-called races, based on real evidence:

In 1924, the State of Virginia attempted to define what it means to be white.

The state’s Racial Integrity Act, which barred marriages between whites and people of other races, defined whites as people “whose blood is entirely white, having no known, demonstrable or ascertainable admixture of the blood of another race.”

There was just one problem. As originally written, the law would have classified many of Virginia’s most prominent families as not white, because they claimed to be descended from Pocahontas.

So the Virginia legislature revised the act, establishing what came to be known as the “Pocahontas exception.” Virginians could be up to one-sixteenth Native American and still be white in the eyes of the law.

People who were one-sixteenth black, on the other hand, were still black.’

On average, the scientists found, people who identified as African-American had genes that were only 73.2 percent African. European genes accounted for 24 percent of their DNA, while .8 percent came from Native Americans.

Latinos, on the other hand, had genes that were on average 65.1 percent European, 18 percent Native American, and 6.2 percent African. The researchers found that European-Americans had genomes that were on average 98.6 percent European, .19 percent African, and .18 Native American.

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Time to end the “war on drugs”

| November 12, 2014 | 1 Reply

What’s the drug war about? American psychosis, born of racism, but now one humongous wholly misguided attempt to put children into a protective bubble. But now there is some hope for change in the right direction, according to Ethan Nadelmann’s TED talk. He is Director of Drug Policy Alliance. Brilliant talk, concluding with a call to end the drug war.

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