Science News Roundup: Ancient Avocados, Warrior Princesses, and Global Birdsong Patterns

So the first is a discovery about ancient avocados that could help keep guacamole on your list of snacks.

So the next one looks at the mummified remains of Egyptian princesses and upends some of our assumptions about how they lived.

And the last study takes a global look at birdsong. And trust me, Ailsa, it's going to be trilling. See what I did there?

All right. So let's start with these ancient avocados - never knew that they were ancient or could have been. Is my avocado toast in danger here?

Well, not yet. So when you pick up avocados at the grocery store, or when you get guac in your burrito, chances are that it's from a single type of avocado. It's called the Hass avocado.

And Ailsa, this type of avocado makes up more than 80% of commercial avocado production.

Which is, you know, kind of convenient because it means that our avocados tend to be, like, consistent in their size, shape, flavor-wise. But because they're all genetically identical, they're all susceptible to diseases in the exact same way.

Oh. Like farmers are putting all their eggs - ha-ha, or avocados, shall we say - in one basket here? So are there other varieties of avocados that we could grow so there's sort of, like, genetic variation?

Yeah. There are. And a lot of them look very different.

They're bigger. They're wider. They're glossier, and on the inside, they tend to be less fatty.

Well, that's not as tasty.

Well, but they're more genetically diverse. So this is archaeobotanist Kevin Wann. He's a fellow at the Smithsonian Museum of Natural History and a PhD candidate at Texas A&M doing avocado research.

But what Kevin wanted to know was how much genetic diversity he was dealing with. So he collected DNA samples from a bunch of different avocado varieties in Mexico and Central America, mostly from local farmers or home gardens.

Yeah. And he sequenced the genomes of these avocados to compare them to each other and also to an existing archive of avocado varieties. Kind of like a 23andMe or Ancestry.com test but for avocados.

That's kind of cute. OK. So what did they find?

So he found a lot of genetic diversity and a few varieties of Nicaraguan avocados that were super genetically similar to those in South America, which suggests they were brought there by ancient farmers and then hybridized with native species. Kevin published a paper on these findings this past week in the scientific journal Plants, People, Planet.

Then I talked to anthropologist Amber VanDerwarker. She's at UC Santa Barbara, and she wasn't involved with the study. But she said Kevin's research really reveals this genetic diversity that has been preserved over the past thousands of years by these intrepid, ancient farmers. And she told me it's important for us to keep this diversity alive - right? - so avocados stay sustainable into the future.

OK. So let's move on to Egyptian princesses. Tell me more.

Yeah. So maybe what I love most about this story is that it came from an effort to unclutter a basement.

Yeah. So that's what The Egyptian Museum in Cairo was doing when they rediscovered this box with the mummified remains of six members of an ancient Egyptian royal family that had been excavated and stashed more than a hundred years ago.

Yeah. Totally normal thing to find in one's basement.

Of course.

So who was this family?

It was five princesses and a king who lived thousands of years ago, around 1800 B.C.

Wow. A girl dad.

Yeah. Exactly.

Yeah. But one of the things that confused the archaeologists when they found these remains was that the women were all buried with weapons, like daggers and maces and bows and arrows, which archaeologists typically associate with men.

Of course.

So the assumption was the princesses were buried with these weapons for symbolic reasons.

Symbolic? Wait. Hello. Have these people not ever heard of "Xena: Warrior Princess"?

Because women do carry weapons sometimes, OK?

Exactly. And that's what the person who helped find these remains wanted to figure out.

Yeah. Her name is Zeinab Hashesh. She's a bioarchaeologist at Beni-Suef University in Egypt. And she says, you know, we all have this assumption that princesses are like Disney characters.

That they are fluffy. They are wearing beautiful dresses and very beautiful jewelry.

When Zeinab looked at these bones, she noticed that these skeletons had really strong muscle attachments.

These women were buff.

Exactly. And she did a deeper analysis of the bones, and she found these women were, yeah, buff. They were really strong.

Yeah. They were really buff. They had strong forearms, strong shoulders, and, like, some of them had curvatures in their hand bones which are likely from the repeated use of a bow and arrow.

Wow. Wait. So these women literally were warrior princesses?

Well, Zeinab says it's unclear if these findings, which are published in the journal Frontiers in Environmental Archaeology, proved that they were actually, like, warriors in the sense that they fought. That's also what I heard from another Egyptologist who wasn't involved in the study. But he says it does show that their lives weren't as relaxed as we might have thought, that they did real work.

They were shooting bows and arrows. All right. Our final topic is birdsong. What are you going to tell me about singing birds?

Yeah. So this study analyzed more than 116,000 birdsongs from perching birds, which include, you know, robins and thrushes, warblers and crows, and on and on.

Cool. OK. So what were the scientists looking for specifically in all of these birdsongs?

Yeah. So they were listening for how the pitch of songs were changing over time to try to find patterns. Acoustic motifs is the technical term.

And they found that for all the variety there is in these birds worldwide, they're all trying to communicate basically one of two messages, either attracting mates or claiming territory, and they use these eight basic motifs.

OK. So what are the eight different motifs?

So there are three different types of trills. There's a slow trill, sung here by a northern cardinal recorded outside of Minneapolis.

And an ultrafast trill.

Whoa.

Was that the ultrafast I just heard?

Ultrafast.

Yeah. And that one's sung by a Bohemian waxwing in the Canadian province of Newfoundland and Labrador.

That's amazing. It was almost like - I don't know - like a drill.

The most appropriate use of the word ultra you can imagine.

Yeah. And it's worth noting that all these recordings were collected from a public database where birders uploaded songs.

And we don't have time to cover all eight of them, but another pattern that's maybe worth knowing is the flat whistle.

That's sung by a three-wattled bellbird in Costa Rica. And the reason it's worth knowing that call is the researchers on this new study found that in the dense, loud tropical forests all over the world, birds have independently evolved this type of call.

Here's the lead author of this study, Quentin Bacquele. He's a PhD candidate studying bioacoustics in Paris.

So that's really impressive to see that nature found the same solutions for the same constraints but across different parts of the world.

So in other words, Ailsa, birds separated by oceans and continents all landed independently on the same types of acoustic patterns to communicate.

All right. That was Nate Rott and Hannah Chinn from NPR's science podcast Short Wave. As always, thank you to both of you so much.

Yeah, thank you.

Thanks for having us.