FOUR SIMPLE RULES EXPLAIN THE FIRST 5 DAYS OF HUMAN LIFE

Five days elapse from the time a sperm fertilizes an egg until it is implanted in the secure environment of the uterus. During this time, the egg develops from one cell into a cell cluster surrounded by a layer of cells that specialize in penetrating the uterine membrane. Researchers from the University of Copenhagen have now cracked the code that explains how life can develop during these first 5 days without any intervention or support from the mother