Answer:
Fibrinogen
Explanation:
Fibrinogen is one of the proteins present in the blood plasma. It makes 7% of the plasma proteins. During the process of blood clotting, the active thrombin enzyme serves to convert soluble fibrinogen into insoluble fibrin. These insoluble threads of fibrin form the clot. Both thrombin and fibrinogen are produced in the liver. If fibrinogen is less than 4%, the process of blood clotting will be disturbed due to the production of insufficient threads of fibrin.
Genetic drift occurs when there is no random mating across a population. This causes a change in allelic frequency due to a random sampling of the population.
As the aboriginal population explored the earth, a small part of the population became geographically isolated either due to continental drift and climate changes. As the isolated population grew bigger, they established their own gene pool. This resulted a change in genotypic frequencies from that of the aboriginal population.