Embryonic development: early human life

This literature reviewResearchers Polina A. Loseva and Vadim N. Gladyshev from Harvard Medical School are trying to provide some answers to the controversial question:

But when does their biological life begin?

Science can already provide “a range of answers,” these researchers write.

Critical stage for separating the soma from the germ line: The researchers point out that if science does not allow us to determine the zero point of human life, significant progress has been made in understanding early embryonic development of mammals.

• It has become clear that the 14-day phase actually has characteristics that make it a key moment for human evolution: this phase marks the separation of the soma from the germ line and represents, in biology, the boundary between rejuvenation and aging. At this stage, germ cells and somatic cells develop specific morphological characteristics.

This review thus proposes a new “critical” meaning for the 14-day phase of an organism's life, based on recent mechanistic advances and knowledge from the latest studies on aging.

It can be read in the Journal of Aging.