This embryonic development follows precise stages that are remarkably similar between animal species and could date back to a period well before the appearance of animals. However, the transition from ...
At times in my life, an embryo has represented so much more than just a fertilized egg ... It was the equivalent of a welcomed, albeit heavy, period. I am not a walking incubator with a default ...
A fossilised prehistoric organism discovered in 2017 has led scientists to conclude that eggs emerged long before the first animals evolved, implying that they came before chicken. Chromosphaera ...