Genesis 1:25 “God made the beast of the earth according to its kind.”

Adult giraffes are the tallest land animals at 18 feet. They can run 34 miles per hour. They sleep only 30 minutes a day and can go weeks without water. But the most startling feature of giraffes is their neck.

Why are their necks so long? Evolutionists answer with a combination of two factors: 1) The need to eat to survive (good ole survival of the fittest) and 2) the need to breed (apparently, long necks are sexy).

The theory goes that an early giraffe ancestor, “Canthumeryx,” started reaching for leaves up in tree branches. Over millions of years, as certain of these “Canthumeryx” were more successful over their kin, their “successful” genes were passed on until we ended up with today’s long neck.

What about breeding? Once these necks started elongating, female giraffes were partial to males who, when pounding their necks against each other during contests, developed the strongest necks.

So, the theory is: 1) stretching for leaves over millions of years, combined with 2) beating each other with their elongated necks, resulted in the most fit males to be “naturally selected” to pass on their genes.

To validate this theory, evolutionists turn to fossil evidence. But there are no clear transitional forms – just a guess at lining up fossilized bones in an ancestral chain to show common ancestry by anatomy.

But as usual, the devil is in the details. To understand common ancestry, we must go to the cellular level – the foundation for anatomy. It was here we discovered the giraffe’s blood circulatory system.

You see, a giraffe’s brain is about 8 feet higher than its heart. To get blood from its heart up to its brain, a giraffe must have an enormous heart that can pump blood extremely hard against gravity. What’s more, it must maintain such blood pressure if the giraffe’s neck is vertically in the air.

To pump blood up 8 feet against gravity, giraffes have a 2.5 foot-long, 25-pound heart. Although their heart is huge, in proportion to its size a giraffe’s heart is comparable to other animals. Their heart’s power comes from a very strong beat due to the incredibly thick walls of the left ventricle that allow more volume of blood to be pumped in one stroke. At the same time, its circulatory and renal systems must be able to manage the extremely high 280/180 blood pressure with heartbeat rate of 170 times per minute.

But what happens when a giraffe lowers its head below its heart to get a drink of water? What happens to all the blood that the heart normally pumps so powerfully against gravity to the brain? What prevents the 25-pounf heart muscle from pumping so much blood down to the brain that it ruptures?

On the flip side, when the giraffe raises its head, shouldn’t it black out from reduced blood pressure?

The answer to all these questions was discovered by in two special features of the giraffe’s cellular makeup for blood circulation: 1) a complex system of control valves in the jugular veins, and 2) a special network of blood vessels in its head, known as the rete mirabile caroticum.

So, the giraffe is specially equipped with: 1) a huge heart powerful enough to send an adequate amount of blood eight feet upwards against gravity, 2) a complex pressure-regulation system, 3) unique “control valves” that prevent overpressure when it lowers its head, 4) a network of blood vessels that helps stabilize blood pressure as the giraffe moves its neck up and down, 5) arteries in the lower part of its body much thicker than other animals, to withstand the high blood pressure,

Now, back to evolutionary explanations. Rather than guesswork with fossils, there are at least two obvious questions that come out of examining the giraffe’s unique blood circulatory system:

1) As the giraffe’s neck grew over millions of years and small incremental genetic changes via the power of natural selection, how did the giraffe’s elongated neck, specialized heart, circulatory valves, and renal system all evolve together, at the same time, over millions of years? Its heart had to grow in unison with its neck elongating, or it couldn’t pump blood up to its brain. How did the neck and heart grow together?

2) How do scientists explain the origin and development of the control valves and the rete mirabile caroticum in an evolving giraffe? All the valves and blood vessels had to be there at the same time to correctly regulate the blood pressure, or the giraffe dies. It is an irreducibly complex system. But how?

There is a second, better explanation that is grounded in what we know about system design: the blood circulatory system is the result of Intelligent Design.
The Evidence of Faith’s Substance _ Article #564