The Howard Hughes Medical Institute They had this video that was called the tuskless elephants at Goran gosse And I was like oh what's this Goran gossip That's a national park in Mozambique Some elephant populations seem to be missing their tusks Is he while most African elephants have tusks some female African elephants are born without them and never grow them But the number of tuskless elephants was multiplying in Mozambique during and after the country's decades long Civil War which ended in 1992 Large tusked elephants in gorongosa were killed for their ivory which was sold to buy arms and ammunition Around 90% of the elephants there were killed but many female elephants without tusks survived and thrived Campbell's stayton had heard all of this before But then I realized that there wasn't actually a lot of empirical data about what the response was from what the genetic basis of the trait was Was it genetically inherited at all So he made some calls and assembled to team I saw that video in November and by June I was in a helicopter over Mozambique Campbell's stayton and his team worked with local researchers who had tracked elephants for decades They found that the tuskless trait was genetic found in the X chromosome and it was deadly in males So if a tuskless mom had babies she has a 50% chance of passing the trade on to her offspring So 50% of her daughters will be test 50% will be tuskless 50% of her sons will be tusked but that other 50% would die The upshot which they published this week in the journal science is that females without tusks are pretty likely to have tuskless babies which is why the trade was becoming so prevalent It's one of the most detailed examples of how human activity can influence the genes of a population That's fanny peli a wildlife biologist in Canada who wasn't involved in the work The reason why that's important is because if you stop the killing right now you know the time it would take for the population to restore that traits would be much longer now that there's been a change in the genes and then if it wasn't Those changes can ripple through ecosystems Campbell state and points out that other species in gorongosa rely on elephants having tusks to dig up holes for water and strip bark from trees You know people during the Mozambique and Civil War were not thinking about the evolution of elephants I imagined in the slightest You know yet those actions during that 15 year period had all these cascading consequences all the way up from a single gene to an entire ecosystem health Consequences that are still continuing nearly 30 years after the war Just one third of Americans who are pregnant are vaccinated The CDC wants that number to go up saying the benefits outweigh any known or potential risks Hear more tomorrow on morning on weekend edition rather This is.