WASHINGTON — Oregon scientists used human skin cells to create fertilizable eggs, a step in the quest to develop lab-grown eggs or sperm to one day help people conceive.

A remarkably well-preserved dinosaur embryo, unearthed from a fossilized egg in southern China, is offering scientists an extraordinary window into the evolutionary origins of bird-like behavior.

“In addition to offering hope for millions of people with infertility due to lack of eggs or sperm, this method would allow for the possibility of same-sex couples to have a child genetically related ...