WASHINGTON (AP) — Scientists have pinpointed how years of civil war and poaching in Mozambique have led to a greater proportion of elephants that will never develop tusks.
The research was published Thursday in the journal Science. It examined the impacts of ivory poaching during the Mozambican Civil War (1977 to 1992) on the evolution of African savanna elephants in Gorongosa National Park.
Like eye color in humans, genes are responsible for whether elephants inherit tusks from their parents.
A hefty set of tusks is usually an advantage for elephants, allowing them to dig for water, strip bark for food and joust with other elephants. But during episodes of intense ivory poaching, those big incisors become a liability.
While tusklessness was once a rare trait in African savannah elephants, it’s become more common. That's because tuskless females are more likely to survive intense poaching and pass their genes to offspring.
Scientists have identified two genes that likely play a role in whether or not an elephant inherits tusks.
“Whole-genome scans implicated two candidate genes with known roles in mammalian tooth development (AMELX and MEP1a), including the formation of enamel, dentin, cementum, and the periodontium,” researchers wrote. “One of these loci (AMELX) is associated with an X-linked dominant, male-lethal syndrome in humans that diminishes the growth of maxillary lateral incisors (homologous to elephant tusks).”