Page 170 - The Miracle of the Blood and Heart

THE MIRACLE OF THE
BLOOD AND HEART

... One of these duplicate genes was then mistargeted to the blood-
stream, where its protein product would have remained inactive
until exposed to an activating tissue protease—which would hap-
pen only when a blood vessel was broken. From that point on, each
and every refinement of this mechanism would be favored by natur-
al selection. Where does the many-layered complexity of the system
come from? Again, the answer is gene duplication. Once an extra
copy of one of the clotting protease genes becomes available, natur-
al selection will favor slight changes that might make it more likely
to activate the existing protease. An extra level of control is thereby
added, increasing the sensitivity of the cascade. 77
This account provides no information at all as to how the
system in question functions. A scientific response to it comes

When a blood vessel is damaged (bottom
right), certain blood cells begin secreting a
number of chemical substances (top right),
and cause a number of reactions to halt
blood flow. One of these reactions
forms the protein fibrin, which
forms a fibrous mesh to
impede the flow of blood
(top left).
Harun
Yahya

168