[SciShow intro plays]   Olivia: You might have seen ivory heirlooms before – old sculptures or piano keys made out of elephant tusks, or sometimes tusks from other animals. Nowadays, ivory trading is banned in most of the world, and was declared almost completely illegal in the United States earlier this year. But sadly, poaching still claims the lives of tens of thousands of elephants every year.

A new study from the University of Utah let researchers figure out how old a tusk is using carbon dating, adding to genetic data about which elephant groups the tusks came from. This way wildlife protection officials can pinpoint the source of illegal tusks, and boost anti-poaching efforts.

Tusks are just giant teeth kind of like ours, mostly made of a bunch of carbon and inorganic minerals that form a hard tissue called dentin. And, like us, the inside has a pulpy part with some cells that produce dentin. By sampling an elephant tusk from a point close to the skull, where the dentin layer is thin, the researchers were able to use carbon dating to measure how long ago the animal died.

See, atomic testing in the mid-20th century dumped a lot of a mildly radioactive form of carbon, called carbon-14, into our atmosphere. That carbon-14 got incorporated into plants, and then into things that eat the plants, like elephants and humans. And by measuring carbon-14 levels, researchers have a handy method to figure out the age of recent biological stuff. The result of this study was sort of a good-news, bad-news scenario.
Almost all of the illegal ivory that was tested was new, from within the last three years. On the one hand, this means older, government-secured stockpiles of ivory aren’t being stolen. And on the other hand, it means a lot of elephants have been poached very recently.

The scientists also combined their findings with data from another study that genetically tested the same tusks – comparing DNA in the ivory tissue to the DNA of wild elephants. They laser-targeted East Africa as the worst place to be an elephant right now, and the most important place to stop poachers. With any luck, this research will help us fight against elephant population decline, and even be used to help out other endangered species that are being poached for their body parts.

In less unfortunate animal news, do you know anyone who’s farsighted? Presbyopia, or farsightedness, is a common thing that happens with age. As our eyes get older, the biochemistry changes and our muscles weaken, so the lenses get stiffer and can’t change shape to focus as effectively. Basically, it becomes harder to focus on things when they’re close up, and easier when they’re farther away. That’s why you might see someone in a restaurant waving the menu away from them like they’re playing trombone.   And according to new research published in the journal Current Biology, this condition isn’t unique to humans. Just ask some of our close primate relatives – bonobos. Like most primates, bonobos groom each other, picking off pests and debris. They keep each other clean, and strengthen social bonds too. All that junk should be easiest to see up close, but researchers had noticed that older bonobos would sit farther and farther away when grooming each other. Nobody really followed up with a detailed study, until now.   These scientists tracked a group of 14 bonobos in the wild for several months, with apes as old as 45, which is pretty old for them. The researchers made careful measurements of their grooming distance, using videos and photographs. And they found that the 5 bonobos that were over 40 years old sat significantly farther back than their younger pals. One particular bonobo had even been captured on video grooming in 2009. Since then, she had scooched farther back to groom.
Even though presbyopia seems like it would make survival way harder, bonobos are really socially collaborative, and it’s possible that they take care of their elders when their eyesight starts to go. The researchers also observed that bonobo eyesight seems to decline like human eyesight does. In other words, the farsightedness and aging pattern was similar, without the researchers correcting for the fact that we live longer than bonobos, or that our eyes have different focusing powers -- which they have to do when comparing humans to more distantly-related primates.

Basically, this means that farsightedness can’t be blamed on any particular element of our modern lifestyle, like sitting in dark rooms staring at computer screens. Instead, it’s an inherent part of getting older. It happens to us, it happens in some of our closest primate relatives, which means that it could’ve been happening before humans were even a thing. So studying aging in apes can help us learn how the way our bodies change when we get old has been shaped by evolution.   Thanks for watching this episode of SciShow News, brought to you by our patrons on Patreon. If you want to help support this show, go to Patreon.com/SciShow, and don’t forget to go to YouTube.com/SciShow and subscribe!