Category: Science

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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NYT features the story of the skepticism of James (The Amazing) Randi

| November 8, 2014 | Reply

The NYT has recently featured the story of the skepticism of James (The Amazing) Randi. Excellent detail on the battle between Randi and con man Uri Geller.

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Why there are not any civilizations without temples – Video featuring Jonathan Haidt

| October 31, 2014 | 1 Reply

Jonathan Haidt explains why there are not any civilizations without temples, starting at minute 14 of this video. This is the 2013 Boyarsky Lecture at Duke University. About 10,000 years we went from an almost instantaneous transition from hunter-gathers to Babylon. A huge part of our evolutionary development is this newly learned ability of humans to circling around sacred objects (religious and political objects are two dominant examples) in order to form teams. As we circle around, we generate a social energy that knits the social fabric, but also encourages Manichean thinking–us versus them, blinding us to our own faults and faulty thinking. No shades of gray are allowed when we are intensely groupish. This kind of groupish thinking is radically incompatible with scientific thinking. Science is squeezed out, replaced by sacred objects, groupishness and authoritarian obeisance.

At min 24, Haidt gets to the crux of his talk. Those of us who focus on the “care” (empathy) foundation of morality, often circle about it bonding with others like us, rejecting and denigrating the impulses and ideas that tend to drive those who are politically conservative.

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