Bats, Flowers, Tongues and Why “Necessity Is the Mother of Evolution”
If my tongue was as long as the tube-lipped nectar bat, it would be over 9 feet long. It’s only 5 cm long, but has a 9 cm tongue! This uniquely-outfitted creature was only discovered in 2005, and its feeding captured here for the first time by National Geographic cameramen.
By the way, did you know that bats constitute the second largest order of mammals after rodents?! More than 1,200 separate species have been identified.
The tube-lipped nectar bat and its favorite flower food source, C. nigricans, are an amazing example of coevolution. Here’s how it likely worked:
If you’re a flowering plant, your whole goal is to get pollinated. So a nectar-producing flower wants to make its nectar hard enough to reach that a pollinator (like the bat) has to really try to get at their snack, maximizing the potential for rubbing up against the flower and getting a good dusting of pollen. But the flower can’t make it so difficult to reach that the bat goes elsewhere for food. So evolutionary pressure says you might make your nectar tube as long as the bat can reach.
If you’re a bat, your goal is to eat. That means that in addition to learning how to hover like a bird (which is a big deal in itself), you need to possess a tongue that’s long enough to reach down and get your food. Pollen? You don’t eat pollen. You don’t care about pollen. But you just happen to get some on your head while slurping up dinner, and maybe you drop it in the next flower you visit. Evolutionary pressure says that you will be driven to have a long enough tongue in order to reach down into the flower as well as a head that fits inside the flower opening.
That’s exactly what we see here!! Two species triggering change in the other species based on selective pressures. And it’s stunning to behold.
(via Why Evolution Is True)