Trail of tears, damaged skulls
Evicted from their Southeastern homeland by the federal government in the 1830s, Native Americans were sent on forced marches to eastern Oklahoma that became known as the Trail of Tears, an ordeal of disease, starvation and death. Now a study of Cherokee remains suggests that the stress interfered with the normal growth of their skulls.
"It is a sign that something was going on in the environment that was hindering growth," said Ann H. Ross, an anthropologist at North Carolina State University and an author of the study, which appears in Annals of Human Biology.
Previous studies have shown that stress affects cranial length. The authors looked at the skull measurements of adult Cherokees born between 1783 and 1874. The skulls of those born later in the period were significantly shorter than those born earlier.
Some Cherokees were able to avoid the forced march by hiding in the Smoky Mountains; skull measurements from that group indicated that their cranial lengths also shrank, but not as much.
Big bang a big question
While scientists believe the universe began with a Big Bang, most Americans put a big question mark on the concept, an Associated Press-GfK poll found.
The survey asked people to rate their confidence in statements about science and medicine. When considering concepts scientists consider truths, Americans have more skepticism in those that are farther away in scope and time: global warming, the age of the Earth and evolution and the Big Bang theory.
Just 4 percent doubt smoking causes cancer, 6 percent question whether mental illness is a medical condition that affects the brain and 8 percent are skeptical there's a genetic code inside our cells. More — 15 percent — have doubts about childhood vaccine safety.
About 4 in 10 say they are not too confident or outright disbelieve that the Earth is warming, mostly from man-made heat-trapping gases, that the Earth is 4.5 billion years old or that life on Earth evolved through natural selection, though most were at least somewhat confident in each of those concepts. But 51 percent question the Big Bang theory.
anatomically incorrect bugs
A Brazilian cave insect has done a most unusual sex-role reversal, a new study finds: Females have penises, and males have vaginas.
All four known species of the genus neotrogla in Brazil have this anatomy, which has not been seen in any other animal, said Rodrigo Ferreira, a cave biologist at the Federal University of Lavras in Brazil and an author of the study, in the journal Current Biology.
"We were completely shocked," he said.
The female's penislike organ, called the gynosome, is erectable and inflates inside of the male's vagina. Copulation lasts 40 to 70 hours and sperm is transferred from the male to the female. The researchers believe the reversal may have evolved because of the dark, nutrient-poor environment in the caves. To produce eggs, females may need to seek sperm for nourishment.
But many of the caves where the insects are found are in danger from mining and development, Ferreira said. "We have the risk of losing these species even before we have the chance to know them," he said.