Fetal circulation demonstrates an engineering complexity that requires advanced planning. Astonishingly, the fetus survives in a fluid-filled environment (the amnion) and is busy developing a respiratory system designed for breathing air! Therefore, there must be a temporary mechanism or system that converts a non-air-breather into an air-breather at birth. This temporary, “in between,” system functions in the presence of: 1) three shunts, 2) unique fetal hemoglobin and 3) a blood supply that travels to and from a proxy lung—the placenta.
At the moment of conception, DNA contains not only the information required in the form of Watson’s blueprint, but also; 1) the capability to obtain the physical elements, 2) that manufacture the nanotechnology, 3) which produces the molecules, 4) that create the structures, 5) which interact with other structures in a rapidly changing physical environment.
The engineering of fetal circulation must anticipate a high-pressure, non-functioning pulmonary system that will change in one instant to a low-pressure and now instantly functioning respiratory system. Furthermore, the maternal-fetal system must include a mechanism to expel the now unnecessary placenta, because a retained placenta causes maternal death. Fetal circulation is not compatible with adult life, and adult circulation is not compatible with fetal life.
In fetal development, the heart is being formed to function as an adult. However, we know that the fetal and adult circulation systems are incompatible with each other, therefore, this incompatibility must be taken into account. The system engineered to overcome this incompatibility includes three shunts and specific physiologic changes. But how does this all come about by Darwin’s required “numerous, successive, slight modifications?”
No Darwinist can explain how nature purports to select mutations that possess immediate beneficial effects, which also provide intricately engineered physiologic mechanisms that are required for future developing and interacting organ systems within incompatible physiologic environments.