1.9 Cases of Leukemia per 10,000 CT Scans in Children

In the breakdown of results, the study authors from Group Health Research Institute and University of California, Davis note that the risk of developing leukemia was highest from head scans for kids under age 5 with a rate of 1.9 cases per 10,000 CT scans. Younger children and girls seemed more susceptible to solid cancers than older kids and boys. Every 300 to 390 scans of a girl’s abdomen or pelvis was associated with the development of one solid cancer. The study estimates that 4,870 fut...

 Australopithecus afarensis' Hip Bone Indicates She Could ...

When Lucy’s hundreds of fragments were assembled, she turned out to be a female of a new species, Australopithecus afarensis, dating back 3.2 million years. She was between 20 and 30 years old, 3.5feet tall, weighing a scant 60 pounds, and possibly afflicted with arthritis. But most important, she walked on two legs. How can we tell? From the way that the femur (thighbone) connects to the pelvis at one end and to the knee at its other. In a bipedally walking primate like ourselves, the fem...

 Effect of Human Brain Size on Labor and Bipedalism

The real obstetrical dilemma came long after Lucy and her colleagues became extinct, when there was a sudden upsurge in brain expansion. About 1.5 million years ago, die adult hominid brain went from the Australopithecine size of 400 cubic centimeters to 750 cubic centimeters in a species called Homo habilis, the first member of our genus. In other words, the brain just about doubled in size. A mere million years later. the hominid brain doubled once again until it reached its present average...