Orchids mimic simians

May 28, 2012 • 5:10 am

Unless small monkeys try to copulate with orchids, this isn’t an evolved mimicry, but the resemblance is remarkable. Here is Dracula simia from the cloud forests of Ecuador, often called the “monkey orchid” for obvious reasons.  But, as I note below, another orchid species is the one that’s most commonly given that name.

Another photo, this one taken by Eric Hunt:

The genus Dracula is quite diverse, with many beautiful species. You can see many of them here. I expect Lou Jost will have a few words about these.

Here’s what is most often meant when someone says “monkey orchid.” It’s the European Orchis simia, which gets its name because the flowers look like groups of dancing monkeys, complete with head, four limbs, and a small tail (e.g., this photo from Wikipedia). It’s said to be “a favorite with children.”

UPDATE:  Lou, as expected, has weighed in on the species (see comments), and kindly provided two more pictures of Dracula that he took himself. Here are his comments (flowers in order):

Here are a couple more Dracula pics if you like. The Dracula fuligifera is actually a scan of the flower. It is endemic to my study area near Banos, Ecuador. The other one is also a form endemic to my area near Banos, most like D. exasperata from Colombia but without its hairs. Both occur in EcoMinga’s Rio Zunac Reserve.

Dracula fuligifera
Dracula exasperata (perhaps)

 

Tortoise has sex with a shoe—narrated by Attenborough!

May 27, 2012 • 3:23 pm

Via Matthew Cobb by way of Scicurious originally from Laughing Squid, we have a video of a lonely tortoise trying to mate with a shoe (Crocs actually look like the hybrid offspring of a turtle and a sneaker).  The enamored reptile periodically emits heartbreaking squeaks.

What animal video could be funnier than that? When the same video is narrated by Sir David Attenborough, as he did on BBC One’s Graham Norton show:

Attenborough could read the phone book and I’d listen in rapture.

Python luring behavior

May 27, 2012 • 8:12 am

(Addendum below.) This appears to be a green tree python (Morelia viridis, SE Asia and Australia); notice how it remains absolutely motionless but waves its brightly-colored tail, a behavior called “caudal luring.” As this paper in Herpetologica notes:

Caudal luring by ambush-foraging snakes can increase their encounter rates with prey (Neill, 1960). The wiggling of a brightly colored tail presumably mimics the movements made by insect larvae, which are prey items of frogs and lizards (Greene and Campbell, 1972). Frogs and lizards are attracted to the lure and become prey themselves when they move within striking distance of the snake (Greene and Campbell, 1972). The use of this behavior as a foraging strategy has been well documented in viperids, but previous studies did not test whether this behavior varies among age classes or sexes.

Another paper on caudal luring in the green python reports the behavior in young snakes when rodents and lizards (Anolis) were offered.  But luring diminished with age, corresponding to a change in the color of the tail tip from bright yellow to the green “ground color” of the adult body.  The authors suggest that the lure could be used to attract insectivorous marsupials, birds, and other reptiles. I’m not sure why the behavior and tail color diminish with age—presumably the snakes use other methods of hunting when they’re older.

h/t: Matthew Cobb via Ed Yong (Twitter) via (I think) the snake’s owner.

Addendum by Greg Mayer: I posted on caudal luring in Mexican moccasins a little while back:

http://whyevolutionistrue.com/2012/01/14/cantilurday-viperid-mexican-mocassin/

The video above is great! I’d never seen that kind of movement, and it clearly seems to be predatory in intent. Just last week, I was giving a demo of a green tree python at the Racine Zoo; I don’t recall if the one we have at the Zoo has a differently colored tail. The species is famous for being yellow or red as juveniles, and turning green when they get bigger. The color change is accompanied by an ecological change from ground-dwelling, lizard-eating juveniles, to canopy-dwelling, bird-eating adults. David Wilson, Robert Heinsohn, and John Endler have shown that the color change makes them less conspicuous in their respective habitats. Jerry’s remark about changing habits as they age is absolutely right– they change color, where they live, and what they eat.

There’s a nearly identically patterned species in South America, the emerald tree boa (Corallus caninus), which has the same ontogenetic color change, and sits on branches the same funny way; I don’t know if they caudal lure or not (the tail is prehensile in both). It’s a remarkable case of convergence, as the species are in different families or subfamilies (depending on if you’re a lumper or splitter).

Caudal movement (which occurs in lizards too) has also been considered a protective behavior, distracting predators from the vital head. There’s some discussion of this in the moccasin post comments. In the tree python, it seems undoubtedly predatory, rather than protective.

For more on snake natural history, with lots on eating and avoiding being eaten see Snakes, by my friend and colleague Harry Greene, one of whose papers is cited above.

______________________________________________________________

Wilson, D., R. Heinsohn, and J.A. Endler. 2007. The adaptive significance of ontogenetic colour change in a tropical python. Biology Letters 3:40-43. pdf

Weekend malaise: part 2b

May 27, 2012 • 4:35 am

While we’re on the topic of growing vertebrates, here’s the update on the litter of kittens I described on Monday, putting up this picture of a one-day-old brood taken by reader pyers:

They’re now 5 weeks old, and pyers sent me some recent photos of the same kittens, with this caption: “Well here they are at 5 weeks ! Adorable yes!  Easy to photograph? No!  Every time the little darlings were posed they buggered off!!”


Weekend malaise: part 2a

May 27, 2012 • 4:25 am

The world seems ugly and sad today, and the Squidly One is dissing cats at his website with a video so dire that I can’t even link to it.

What do we need to combat this misery? BABY ANIMALS!  Here are a passel of ducklings that I filmed this morning on Botany Pond, right outside my office.  Note that they’re the same brood that I filmed earlier.  All seven are still alive, and their down is being replaced by feathers. With Ceiling Cat’s will, they might actually fledge this year.

Weekend malaise

May 26, 2012 • 11:33 am

Do not expect deep thoughts or even controversy today; I’ve been working since 5:15 a.m. and just was interviewed by Neil Denny for the Little Atoms podcast (check the link for a passel of wonderful interviews), so I’m worn out.  Neil is taking a four-week road trip from California to New York, interviewing scientists along the way (see his ongoing itinerary, with interviews, here). He’s just come from the Creation Museum, and has had chats with Genie Scott and Francisco Ayala in California; he’ll be writing a piece for the Guardian this weekend on the Creation Museum. He’s then headed to North Carolina, New York (where he’ll talk to participants at the World Science Festival), Boston, and Ithaca.  What a great job: he gets paid to drive across America and chat with scientists!

The interview was almost completely about evolution and its evidence. Neil asked good questions and was a delightful chap. I’ll link to his evolution pieces in the Guardian and the interview when they appear.

At any rate, I feel like I should post something this afternoon, so here’s a U.S. News and World Report interview with Richard Leakey (via Matthew Cobb and Roger Highfield’s Twitter), in which the renowned anthropologist makes one palpably false and one dubious statement about the acceptance of evolution.

The palpably false statement is this:

Richard Leakey predicts skepticism over evolution will soon be history.

Not that the avowed atheist has any doubts himself.

Sometime in the next 15 to 30 years, the Kenyan-born paleoanthropologist expects scientific discoveries will have accelerated to the point that “even the skeptics can accept it.”

“If you get to the stage where you can persuade people on the evidence, that it’s solid, that we are all African, that color is superficial, that stages of development of culture are all interactive,” Leakey says, “then I think we have a chance of a world that will respond better to global challenges.”

Well, things haven’t moved much in 60 years in the U.S., so I’m not nearly so optimistic.  And he’s even more wrong if he thinks the change in acceptance of evolution will come about because people will finally grasp the evidence. That evidence has been around for a gazillion years. No, the change will come when people aren’t resistant to evolution because of their faith.  And that will take a few more decades than Leakey predicts.

I suspect Leakey doesn’t realize the full import of belief as an obstruction to accepting evolution; at least that’s what’s implied by a his further statements:

Leakey insists he has no animosity toward religion.

“If you tell me, well, people really need a faith … I understand that,” he said.

“I see no reason why you shouldn’t go through your life thinking if you’re a good citizen, you’ll get a better future in the afterlife ….”

Maybe he’d have a bit more animosity if he realized that religion—not lack of appreciation of the evidence—is the major impediment to what he sees as a life-or-death need for the world to accept evolution.  And about that “seeing no reason why you shouldn’t think you’ll have a nice afterlife”, well, Dr. Leakey, what about the evidence?  The evidence you have for human evolution in Africa isn’t there for an afterlife.

Leakey thinks that accepting evolution is the linchpin to a better world. Much as I’d like to believe that, I can’t share his sentiments:

Any hope for mankind’s future, he insists, rests on accepting existing scientific evidence of its past.

“If we’re spreading out across the world from centers like Europe and America that evolution is nonsense and science is nonsense, how do you combat new pathogens, how do you combat new strains of disease that are evolving in the environment?” he asked.

“If you don’t like the word evolution, I don’t care what you call it, but life has changed. You can lay out all the fossils that have been collected and establish lineages that even a fool could work up. So the question is why, how does this happen? It’s not covered by Genesis. There’s no explanation for this change going back 500 million years in any book I’ve read from the lips of any God.”

The people who are designing new antibiotics and pathogens already appreciate evolution; licking those problems doesn’t absolutely require that everyone else share that appreciation. I would love it if that happened, but I have no illusions that our world will suddenly change for the better if everyone accepted evolution. If a genie gave me a choice between two wishes: 1) everyone in the world suddenly accepts evolution in the way we scientists understand it; or 2) all religious belief would suddenly vanish from our planet, I know which one I’d pick.  Choice number 2 would eliminate far more harm than #1, and has the added benefit that it will automatically produce acceptance of evolution as a byproduct.

I do love my job, and want to inspire people to understand why evolution is so marvelous—the true story of our origins, with fantastic organismal “design” the result of a blind, mindless process of gene competition—but I’m under no illusion that the battle to get it accepted will make a huge difference to our planet.  What will make a bigger difference is to inculcate general habits of skepticism, rationality, and respect for truth—and a  general disdain for superstition. Those, of course, are the habits of science.

Dennett on atheism denial

May 26, 2012 • 8:31 am

Here’s a really nice, well-delivered talk by Everyone’s Atheist Grandfather, Dr. Daniel Dennett. It stems from his work with Linda LaScola on preachers who are secret nonbelievers, and the topic is “You might be an atheist.” He gave it at the recent Global Atheist Convention in Melbourne, and the YouTube caption says that there were 4,000 people in the audience!

I love his relaxed style of elocution and roguish humor (see the witticism/truism that starts at about 15:00).