The Giraffe's Amazing Neck

The amazing giraffe’s neck: proof of a great designer!

By Andrew Miiller

Stop for a moment and think about your heart beating in your chest. Every time it beats, two to three ounces of blood are pumped into your arteries.
Now, imagine what would happen if your heart started pumping 6 to 9 ounces at each beat. Your blood pressure would triple. The increased pressure on your arterial walls would first cause you to feel dizzy and nauseated. Soon your vision would blur, and you would develop a splitting headache. A spike in blood pressure this high would likely rupture the capillaries surrounding your brain, causing immediate death. Whoa!

Thankfully, our hearts are not strong enough to maintain a blood pressure that high.
Giraffes, on the other hand, have a blood pressure two to three times yours. Their blood pressure has to be this high in order to move enough blood from their hearts up their 8-foot necks and into their heads. That’s why a giraffe’s heart measures 2 feet long, weighs 24 pounds, and pumps 16 gallons of blood every minute.

A problem arises, however, when the giraffe lowers its 96-inch neck to take a drink. As the giraffe’s heart works with gravity instead of against it, a tsunami of blood rushes down the giraffe’s neck straight into its head, causing the capillaries surrounding its brain to literally explode under pressure—or at least, that’s what would happen, were it not for five blood pressure regulation systems installed in the head and neck of giraffes, all working in perfect harmony to keep the giraffe alive.
Trying to describe how these systems came to exist via natural selection poses a major headache for evolutionists.

Before we can explore the awesome internal workings of the giraffe’s neck, however, we need some background on the theory of giraffe evolution.

Charles Darwin proposed the hypothesis for giraffe evolution most commonly believed, which goes something like this:

Millions of year ago, the world was populated by giraffes with short necks like those of a cow or a deer. Among this population of short-necked giraffes, there were some with necks a few inches longer. Since these giraffes could reach the leaves of the trees they browsed upon more easily, they became healthier than the other giraffes and thus produced more offspring.

Random mutations then continued to favor giraffes with ever-longer necks. Natural selection occurred again and again, favoring the longer-necked giraffes.

This cycle supposedly repeated itself over and over until, after millions of years, giraffes evolved with the extended necks we see today! (It is interesting that male giraffes always have a neck about 2 feet longer than female giraffes, but they still do not seem to be any more adept at finding food. If two inches made a difference in the natural selection process, would not female giraffes have died out eons ago?)

The design of the giraffe’s neck could not have evolved. When you really put pressure on the evolutionists’ theory—that it happened from millions of chance mutations—that theory, well, explodes.

Drinking Without Dying
Back, now, to our drinking giraffe. A giraffe’s head does not explode from a blood pressure spike when it lowers its neck thanks to an elaborate hydraulics system that regulates the amount of blood moving through the neck at any given time.

As soon as a giraffe begins to lower its neck, nerve endings in neck arteries detect the increase in blood pressure. These nerve endings then send an electrical signal to the brain to activate two blood-flow reduction systems. The first system causes the artery walls to contract, and the second system causes a series of arterial valves to close. Both of these reactions reduce the amount of blood flowing through the neck to the point where the blood pressure in the giraffe’s head is low enough not to cause any harm at all.

Remember, the theory of evolution is supposed to be completely undirected, with no end goal—no design—in mind. Natural selection favors the random mutations that are the most beneficial. So, the neck-lengthening process, the artery contraction process, and the arterial valve regulation process all had to evolve independently and simultaneously for the giraffe to survive. If all three systems did not develop simultaneously, the longer-necked giraffe would have had its head blown off the first time it went to take a drink. And just like that—2 million years of evolution go down the drain.

Rise Up, Pass Out
These are not the only systems that had to evolve simultaneously. Even if the giraffe was able to evolve both of the above regulatory systems simultaneously with the lengthening of its neck, it would pass out as soon as it raised its head from drinking. Why? Because now, the blood pressure in its head would be too low.

But wait, there’s another carefully engineered system that keeps it conscious—and alive.
Our giraffes has a sponge-like network of capillaries surrounding its brain. This “sponge” holds blood in the head as it rises up. These capillaries are aided by two additional systems. First, valves in the veins heading down the giraffe’s neck constrict blood flow, preventing blood from leaving the head too fast. Second, the heart does a double-pump whenever the giraffe raises its neck in order to get enough blood back to the head. No problem!

Except for evolution, that is.

Five Separate Systems
All together, there are five separate system that all would have had to develop together as the giraffe’s neck lengthened in order for the evolutionary theory to work.

Each system would require millions of mutations in the giraffe’s genome. Three changes in the genome in one generation are generally fatal, so you can see how long this would actually take. When you consider that only a miniscule fraction of mutations are beneficial and that only a miniscule fraction of those beneficial mutations have anything to do with the blueprints for a sponge in your head, you see just how improbable the evolution of even one of these regulatory systems is. And when you consider that all five regulatory systems had to have evolved simultaneously, you see the odds against evolution are longer than a giraffe’s neck—exponentially longer.

The truth is, there is no logical explanation for the ability of a giraffe to stay alive—unless it was created by an intelligent creator. The giraffe’s neck is a great proof of our Creator God!

Illustrations by Sarah Stewart