Seals give birth only when conditions are right. After mating, a female seal can delay implantation of the embryo in the ...

Two to three weeks after conception, an embryo faces a critical point in its development. In the stage known as gastrulation, the transformation of embryonic cells into specialized cells begins. This ...

The earliest days after fertilization, once a sperm cell meets an egg, are shrouded in scientific mystery. The process of how a humble single cell becomes an organism fascinates scientists across ...