Researchers say they have discovered how to transform human embryonic stem cells into germ cells, the embryonic cells that ultimately give rise to sperm and eggs, an advance that will allow researchers to observe previously inaccessible human germ cells in laboratory dishes.

"This achievement opens a new window into what was only recently a hidden stage of human development," said Susan B. Shurin, M.D., acting director of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), the NIH Institute that provided funding for the study. "Laboratory observation of human germ cells has the potential to yield important clues to the origins of unexplained infertility and to the genesis of many birth defects and chromosomal disorders."

A recent article addressed the issue of children being frightened of costumed characters and some of the other fears they might experience.  In some cases, this fear escalated into a phobia.

However, comments like "fears likely helped our ancestors survive" generate more alarm than comfort to me. Besides being pretty obvious, it raises the question of why fear should be considered such a bad thing, especially for children.

I can certainly understand that an unreasonable fear that has escalated all of out proportion and become debilitating can be problematic. I suspect that the vast majority of fears and phobias don't actually fall into that category.