The Sound of Science - "Fruits and Frugivores"

Nov 23, 2018

Kate: This is the Sound of Science on WNIJ. I’m Kate Powers from NIU STEM Outreach. I’m joined in the studio by Sam Watt. Sam, I want to share some cutting-edge research I just read about.

Sam: Oh, is it about machine learning or gene editing?

Kate: No Sam, it’s about fruit.

Sam: How is fruit cutting-edge? We’ve been studying it since forever. What could possibly be new about fruit?

Kate: Well, you heard about how flowers attract pollinators with beautiful petals, right?

SAM: Sure, flowers attract pollinators so the flowers can reproduce. Where’s the new here?

KATE: Here it is: Researchers from Duke University and their partners recently discovered just how closely fruit and their symbiotic partners evolve. The researchers studied frugivores in two geographically separate jungles.

SAM: A frugivore?

NIU STEM Outreach

KATE: That’s an animal that eats fruit! In this case they studied apes and lemurs. Both primates are physically similar and have similar diets of tree fruit. But the apes live in the Ugandan forest and the lemurs live in the jungle of Madagascar. The interesting difference in this study is that apes have full color vision, like people, and lemurs can only see in the blue-yellow spectrum. It was found that fruit in the Ugandan forest was most likely to be bright red against a green background, a color combination that would pop for the apes that live there. The fruit in the Madagascar forest was more frequently yellow or blue, a color that the lemurs can see better. Some fruit, which is blue to the human eye, emits UV light which is visible only to the aye-aye lemur!

SAM: So, the fruit would be more attractive in a color that the primates can see among the green leaves!

KATE: Exactly, but it goes even further than that. The scientists bagged fruit from both forests and let the fruit ripen in the bag, eventually collecting the gases the fruit gave off. Those gases were analyzed, and it was determined that the fruits eaten solely by lemurs gave off a larger assortment of compounds. Those fruits were sending lemurs the message “Hey! I’m over here, come eat me!”

SAM: And the fruit would want the lemur to eat it because then the lemur would digest it and, er, “disperse” the seeds through the rest of the forest? Thanks for sharing that, Kate. Remember if you have any burning science questions please send them our way at stemoutreach@niu.edu. This has been the Sound of Science on WNIJ.

KATE: Where you learn something new every day.