The reason why giraffes have long necks is one of the issues that has been discussed for years. According to the standard story, giraffes’ ancestors with longer necks than others were able to reach more nutritious leaves at the top of trees and were therefore more likely to survive and reproduce. Their offspring inherited this trait, which resulted in their long necks.
However, according to Darwin, sexual selection also plays an important role in such situations. Other, more complex influences have been noticed since his time. Some zoologists have theorized that the fight for mates may contribute to giraffes’ strong necks, and new evidence presented in the journal Science supports this.
Normally, it is quite difficult to find out the cause of a trait that evolved millions of years ago. But Professor Deng Tao of the Chinese Academy of Sciences, co-author of the study, found an impressive 16.9 million-year-old fossil in the Junggar Basin in Xinjiang. The researchers named the newly identified species Discokeryx xiezhi. Discokeryx is among the earliest known members of the giraffe superfamily.
The head bone structure of this species appears to have evolved for blows, and the authors say it resembles the skull structure of more modern animals, such as musk oxen, which use their heads to protect themselves and show their strength.
The authors also note that giraffes used head beating as a tool to gain mates long before they had a long neck. Although modern giraffes began their evolution five million years ago, the use of their heads and necks as weapons has a much longer history. Males were able to gain more strength by having a longer neck, and reaching leaves that other animals could not reach was probably a secondary advantage. Their long necks allowed these animals to create much more power with their solid heads.
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