Scientists Try To Figure Out Where Giraffes Got Their Long Necks

Have you ever wondered how giraffes got their long necks? For the first time ever, these animal's genomes, as well as those of its closest living relatives - the reclusive okapi in the African rainforests - have been sequenced, and it revealed the first clues about the genetic changes that led to the evolution of their exceptionally long neck.

The research, which was published in the scientific journal Nature Communications said that the giraffe's stature is an extraordinary feat of evolution, inspiring awe and wonder for the last 8,000 years. The changes required to build the animal's imposing structure and to equip it with the necessary modifications that have been a source of mystery since the 1800s, when Charles Darwin himself puzzled over its evolutionary origins.

The giraffe's heart, for instance must pump blood up to two meters up in order for it to supply ample blood supply to the brain. However, as noted by Phys.org, this has become possible because the giraffe's heart has evolved and it now has an unusually large left ventricle - making their blood pressure twice as high as it is with other animals.

To identify genetic changes that is responsible for the unique characteristics of giraffes, scientists compared gene-coding sequences of the giraffe and okapi to other mammals, including the cow, sheep, goat, camel, and even humans. The link between the okapi and the giraffe was similar because they have diverged from a common ancestor relatively recently on the evolution timescale.

What made the giraffe unusual is that it has the same number of bones as the neck and legs of humans. Douglas Cavener of the Penn State University stated, "To achieve their extraordinary length, giraffe cervical vertebrae and leg bones have evolved to be greatly extended. At least two genes are required - one gene to specify the region of the skeleton to grow more and another gene to stimulate increased growth."