Promiscuous Teens Earn Barely Lower Grades

It's all in how you present a subject. A recent study currently making its way through reportage shows a slight negative correlation between number of sex partners and GPA in high school. The headlines depend on who you read. Some headlines (linked to the articles) for example: Survey: Sex affects grades and Teen sex doesn't cause bad grades and Teen Sex Not Always Bad for Grades all cite the same study presented to the American Sociological Association in Atlanta yesterday. The American Family Council declared that the study confirms the negative link between teenage sexuality and academic performance. It really doesn't. There was no academic difference between abstinent kids and those who have committed relationships including sex. But girls in the promiscuous hook-up crowd earned GPA's of 0.16 points less than virgins. That's about 1/3 of the way between an A and an A-. Horrors. But everyone knows that the adolescent emotional problems that lead to promiscuity also tend to lead to bad grades. But that's just folk wisdom; common sense. Now there is an Actual Study to confirm the correlation. It's a pity that none of the coverage I've found links to the study itself.

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Skin color as evidence of natural selection

In this TED talk, author Nina Jablonski (Skin: A Natural History) suggests that whenever someone demands proof of evolution by natural selection, you should roll up your sleeve and show them your skin color. You carry this evidence around with you every day. You should point out that skin color changes depending on where one's ancestors lived. Check out the dramatic world map image at about 4:20 of the video. Darker skin colors can be found near the equator and lighter skin colors abound in higher latitudes. There is a fundamental and undeniable relation between skin color and latitude. But that is just the beginning of her story. We all have melanin: nature's sunscreen. It protected equatorial people from harmful UVB rays, but nonetheless allowed their skin to produce vitamin D, which is now recognized as essential for proper skin, bones and immune system function. When humans moved to higher latitudes, their skin tones lighted up to allow better production of Vitamin D. Jablonski warns, however, that the angle at which sunlight hits the earth at higher latitudes blocks most UVB rays, allowing only UBA rays which cannot produce Vitamin D. Hence, those of us living in the northern latitudes, no matter what our skin color but especially those of us who work indoors, are at risk for lack of vitamin D. She urges doctors to do a better job warning patients in higher latitudes about the potential damage to skin, bones and immune system caused by their lack of vitamin D.

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Putting our close genetic relationship to chimpanzees into perspective

Genomics Professor Katherine Pollard explored the genetic basis for being human in a video presentation titled "What Makes Us Human. Here a rather dramatic announcement from her talk:

Mouse and rat actually have a common ancestor longer ago than human and chimp, and some people will be surprised by that. They will say, "We are so much more different than a chimp . . . mouse and rat must be pretty similar." Actually mouse and rat on average are much more different from each other than we are from a chimp, and that's sort of a humbling fact to keep in mind.
We're not exactly like chimpanzees, of course, but there are quite a few overlaps (as well as differences), which Pollard explores beginning at the 4-minute mark. Surprisingly, young chimpanzees have a better competency in counting and numbers than young humans. At the 11-minute mark, you can see that the human genome is 95% similar to that of a chimp (or 99%, depending on how you define similarity), and that it is 28% similar (or 89%, depending on definition of similarity) to the genome of a mouse. [More . . . ]

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Richard Dawkins discusses the Greatest Show on Earth

In this Fora.TV video of a talk he gave at U.C. Berkeley, Richard Dawkins discusses his most recent book, The Greatest Show on Earth. In the early minutes of the talk, he explains why fossils are "icing on the cake" and he illustrates the "problem" with gaps by use of a humorous story. At minute 43:00, Dawkins explore the anthropic principle. At minute 49:00, Dawkins comments on the use of the word "why," as part of his comment on the question "Why are we here?" He explains: It's no more deserving of an answer than the question: "Why are unicorns hollow?" Dawkins also comments on the mechanism the creates conscious pain at minute 52:00, before declaring his own attempt to explain it to be incoherent. On the likelihood of a random mutation improving an organism, Dawkins points out that it is highly unlikely: "There are many more ways of being dead than alive." This video offers lots more engaging back and forth in the comments portion, following the main presentation. [More . . . ]

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