Thursday, November 5, 2009

Looking for adaptive benefits in all the wrong places

We are posting this Research Highlight from today's Nature magazine in total, because it's short and because, well, it deserves to be read in full. 

Research Highlights

Nature 462, 14 (5 November 2009) | doi:10.1038/462014b; Published online 4 November 2009

Animal behaviour: Fruit-bat fellatio

PLoS One 4, e7595 (2009)
Libiao Zhang of Guangdong Entomological Institute in China and his colleagues have documented what may be the first case of regular fellatio in adult animals other than humans.

They report that female short-nosed fruit bats (Cynopterus sphinx) licked their mate's penis during 14 of 20 observed copulations. Matings that involved licking lasted significantly longer than those that did not.

Possible functions for this behaviour include stimulation to prolong copulation and assist fertilization; mate guarding; antibacterial effects; and the detection of chemicals assisting in mate choice.

The authors say their observations could suggest a possible adaptive benefit for the activity in this species.

Two things: 1, if you go to the paper in PLoS One, you'll note that there are no pictures. 

And 2, adaptive benefit?  Why does there have to be an adaptive benefit??? Can't it just be fun?


25 comments:

Sam said...

So, the male bats don't return the favor? I guess the only thing to say about that is "typical".

Anne Buchanan said...

Thank you, Sam!

Ken Weiss said...

Well, there must be a selective reason for that, too! Maybe the female bats got a reputation for just faking it, and the males lost interest...or were too distracted by the favors being shown them.

This is yet another of the countless examples of the intense determination to find interpretable selection every where. Of course, maybe there is an advantage, but if so, to be an evolutionary product it must be due to specific genetic change, not just learning by experience (watching what other bats do and demanding the same).

Bats don't have drive-in theaters, but they do spend a lot of time in dark caves....

Anne Buchanan said...

So sorry, there is in fact a video at the end of the PLoS paper -- I happen to not be able to play it on my computer, but it is in fact on offer.

Holly Dunsworth said...
This comment has been removed by the author.
Holly Dunsworth said...

What I learned: I could have a PLoS ONE paper sitting right under my nose... right in my living room! (let's just say my dogs have a lot in common with bats)

Anne Buchanan said...

Ok, I am finally able to view the bat video. Let's just say, I bet the dog video would be better.

Holly Dunsworth said...

THE VIDEO HAS A PORN SOUNDTRACK!

Holly Dunsworth said...

errrr...I mean... the video has what I think a porn soundtrack might sound like...

Texbrit said...

On a serious note - I believe dolphins are another mammal that have been observed to sexually stimulate their partner in "alternative" ways; and perhaps bonobos do as well.

On a less serious note - Bats and airline pilots are now apparently the only mammals that are able to enjoy fellatio and still concentrate on flying (maybe).

On an even less serious note - Finally a story from the world of science to appeal to the masses!

On an even LESS serious - but highly coincidental (fate-driven even?) note - when I just now submitted this post the word string I was asked to type in for verification was "COXBLEW". I am not kidding. I had to come back to add this - it was too good to be true.

Ken Weiss said...

Of course, finally we get a lot of comments. Sex will do that!

Now, we need to learn how to put a sound track on this blog. There must be a way. Then we'll ask for volunteers to tape their own bat-like behavior (sound only, please, no video!).

The other thing we need to stress is that this blog is NOT a confessional site. So any comments about the comments or the original 'science' paper in (and typical of) Nature, have to be about science -- abstract, theoretical perhaps, but objective rather than subjective....

Otherwise, all readers of the blog will start imaginging things about all these posters and commenters....

Ellen said...

I think the problem is that the airline pilots couldn't concentrate on flying. So it's still bats: 1 pilots: 0 on this one.

Ken Weiss said...

Listen, pilots are highly skilled, but there are somethings that they simply would not do while in the air. The reason is not that it would make them feel like they were flying high, but because in the confines of a cockpit (er, flight deck) there simply isn't room (except for contortionists).

Now, I don't know whether that's true of the huge Airbus 380....

Anne Buchanan said...

TexBrit, I think they aren't counting bonobos because it's only the juveniles who do this.

Which means anything any of us did as teenagers doesn't count?

Texbrit said...

I am a pilot, I remind all.

Ken Weiss said...

Maybe there was more truth than one wants to believe, in the Northwest pilot's story. They said they were distracted by laptopping

Jennifer said...

that's why they have autopilot?

very interesting that this is the topic that got the most comments ever. And so early in the morning!!

Ken Weiss said...

'Autopilot' refers to a different kind of behavior, I think.

Texbrit said...

So, EcoDevoEvo Bloggers, you now know what you need to do henceforth. Let's have more sexy science posts! Had you only known... Well, maybe Volume II of The Mermaid's Tale can have an appropriately lowered tone! Searching the genome for the "adaptational" cause of human propensity towards dirty humour? "Certainly" it must be what has got us this far.

Texbrit said...

You can imagine the Airbus salesman making his pitch to the airline executives: "And the 380's navigation is controlled by the Navsoft Autotronic Navtroller Module D13C-ZZ4, providing state of the art..."

[Interruption by airline executive]:

"Sir, can you just move on to the "pilot comfort features" section of your presentation, please? We're in a hurry."

Ken Weiss said...

This is disgusting! This is a clean, serious site, that we hope is going to be read by university STUDENTS. They will have NO IDEA what this is all about (well, some graduate students might).

As to the gene-for dirty humor, that is a puzzler. Men will certainly all have that gene. Women often complain that men are, well, just too crude, so it must be sex-linked. On the other hand, if it really turns women off, how did it evolve.

Clearly, women have the hypocrite gene (also sex linked since men are always straightforward in what they say and do): women say they don't like crude behavior, but that's just to try to con other women into staying away while they get access to the crude men.

Something like this must have happened. Since deceptive dissembling requires language, it's a uniquely human sex-differenced trait.

As to bats, perhaps there's a lot that we can't understand from their ultrasound language.

Arjun said...

Ascribing to the fruit bats' behavior a particular 'adaptive benefit' implies a belief in a mechanistic basis for this behavior.

If them, why not us? In the same way, couldn't we construe our behaviors as the set of directed responses to physical and chemical stimuli?

Dead horses aren't exactly my beat, but it sounds like some researchers' predilection to believe in human exceptionalism has reared its head.

On a more serious note, as far as having enough head space in the cockpit, I think a dwarf would suffice as well.

Anne Buchanan said...

Arjun, yes, this is another case of assuming a trait was selected for for a reason or purpose, without consideration for the alternative explanation that it could exist for no adaptive reason at all.

And you're right, it's curious that this paper was considered publish-worthy given that, as has been pointed out in just this brief set of comments, animals other than humans and bats are already known to exhibit (though that might not be the correct word) this behavior. Maybe the video was what convinced the reviewers?

And finally, as for what can be done in cockpits, it sounds like our pilot commenter above would argue that no extraordinary measures are required at all.

Holly Dunsworth said...

It's settled. My next post will be about sex.

Ken Weiss said...

Well, you may be a regular on this blog, but keep it PG! No videos--at least, no _personal_ videos!