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 ...

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

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 ...