Scientists have analyzed many cervical vertebrae from 71 specimens of giraffes in order to determine how this species acquired longer necks throughout historical periods.
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The age-old question of how the giraffe got its long neck may now be at least partly answered: Long necks were present in giraffe ancestors that lived at least 16 million years ago, a new study finds.
The first ever study to compare the necks of giraffes with those of their relatives and ancestors showed the evolution in giraffe family with passage of time.
Nikos Solounias, a Prof. of anatomy at the New York Institute of Technology (NYIT) College of Osteopathic Medicine, said that though the ancestors of giraffe were having short necks so it was a mystery that how giraffes evolved long necks. “First, only the front portion of the C3 vertebra lengthened in one group of species”.
The second stage was characterized by an elongation on the back or caudal portion around one million years ago. In fact, the modern species (Giraffa camelopardalis) is the only one that underwent both stages of growth: head and tail.
The study, which includes a computational tracking model of the evolutionary elongation, is published in Royal Society Open Science.
After that, 1 million years ago, another species stretched the back of their spinal bones that contributed to the neck size of modern day giraffe.
However, the researchers also found the neck of another member of the giraffe family was shortening at the same time as the modern giraffe’s neck was getting longer.
She said: ‘We found that the most primitive giraffe already started off with a slightly elongated neck.
For future study, researchers want to examine the evolution of giraffe’s long leg bones.
In addition, giraffes are not the only animals to have evolved long necks.
“That’s when we saw the stages playing out”, said Danowitz. A new study suggests that giraffe’s iconic neck occurred in several stages around 16 million years ago.
Male giraffes also use their long necks to battle each other in violent fights over females. The okapi, with its short neck, is on this side of the family tree.
Scientists have compared the recent findings with the evolution of other long-necked species and they have discovered that giraffes are not the only animals to feature this physical trait.
A second stage of elongation occurred around one million years ago. Giraffes, like humans, have seven cervical vertebrae, but the giraffe’s vertebrae are large, measuring up to 10 inches (25.4 centimeters) long.
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The first stage of transformation began around 7 million years ago when cranial end of the vertebra of the species known as Samotherium stretched.
