Written by Dina Fine Maron for National Geographic.
[Excerpt]
“Their goal is to uncover more information about how these animals move, eat, and what their genomes look like. Long hopes to detail how elephants without the benefit of tusks as tools may alter their behavior to get access to nutrients. Rob Pringle, at Princeton University, plans to look at dung samples for insights about both diet and the army of microbes and parasites that live inside each elephant’s gut. Another collaborator, Shane Campbell-Staton, an evolutionary biologist at the University of California Los Angeles, will study blood, searching for answers about how genetics influences the phenomenon of tusklessness.
Exactly how this trait is inherited is “puzzling,” Campbell-Staton says. Tusklessness does seem to occur disproportionately among females. It makes sense that tuskless males wouldn’t be able to compete for breeding access to female elephants, he says. But if this trait was traditionally X-linked—passed down along the X chromosome, which helps determine sex and carries genes for various inherited traits—we would think that because males always get their X chromosome from their mothers that you’d have a really large population of males that are tuskless. “But we don’t see that. Tuskless males are extremely rare in African elephants,” he says.”