10.26.2012 – GOLLYGEE!

A study of honeybees has shown that a lack of sleep impairs their ability to recall recent events. From Scientific American:

After characterizing how honeybees find their way home when released in a new location, the scientists captured and then released bees in unfamiliar territory some 600 meters from their hive. In addition to tracking how long the bees needed to return home, the researchers monitored bee sleep. Bees take brief naps throughout the day in addition to longer periods of nocturnal sleep. (Snoozing bees are easy to spot because their antennae droop.) The scientists made their observations both by watching bees in person and by tracking their activity via radio-frequency devices that they glued onto some of the insects.

The researchers verified first that finding a new route home did not alter other foraging behaviors, although it did lead to an increase in sleeping time in the first part of the night. Curious as to whether this change might reflect some learning or memory process, the team decided to see what happens when bee slumber is disturbed by selectively placing the insects in a box that was gently agitated for about eight hours, making it difficult for them to relax and get a good night’s sleep.

The next day the researchers found that sleepless bees and well-rested ones performed no differently when left to find their way home from a novel location. In other words, lack of sleep apparently did not inhibit the bees’ learning processes. “This suggests that there are forms of learning that seem to be totally independent of sleep,” Menzel says.

The scientists observed, however, a significant and obvious difference when bees were brought to the new spot for a second day. This time, bees that had slept well found their way home faster and fewer got lost along the way than on the previous day. That observation indicates that the well-rested bees had learned from their experience the day before. Drowsy bees, however, took about as long to return home on the second day as on the first, and were just as likely to get lost.

The study appears in the Journal of Experimental Biology.

It turns out that cavemen might not have chomped away on gigantic bison burgers as we often think. It had been estimated that protein intake made up 60-80 percent of the caveman’s diet. A new study suggests that this is wrong as only about 45 percent of the modern diet consists of protein. And that is protein of any type, not just from meat. From Scientific American:

[M]any studies estimate that between 60 and 80 percent of the prehistoric human diet came from proteins, with most of that from animal sources.

That was surprising because no more than 45 percent of modern diets come from protein of any type.

…

That contradiction led O’Connell to wonder if the offset was wrong because it relied on animal estimates, not humans.

To find out, her team took human blood samples from a study where scientists meticulously re-created people’s usual diets, measured exactly how much they ate over a week, and took precise samples of each meal. By comparing the nitrogen isotope ratios in the food and human blood samples, they were able to estimate how much heavy nitrogen the human body stores. (They then extrapolated their estimate for blood samples to human hair and to bone.)

Previous estimates based on animal studies were too small and thus inflated how much animal protein our ancient ancestors ate, she said.

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“We are suggesting that animal proteins would be less important overall and that’s particularly true for interpretations of Neolithic farmers,” she said. “What that would mean is that they are having more of a balance of animal and plant proteins in their diet, suggestive of a mixed existence strategy.”d, the first farmers, who lived around 12,000 years ago, likely ate no more than 40 to 50 percent of their protein from animal sources. Those people ate a diet more similar to subsistence farmers in modern-day India or China, O’Connell said. Hunter-gatherers from the Paleolithic period also ate less meat, she added.

GOLLYGEE!

Date: 10.26.2012

lack of sleep can effect memory

how much meat did cavemen eat?