“Cultural mimicry”: a caterpillar that decorates itself with flowers

April 5, 2012 • 10:38 am

Alert reader Michael called my attention to a post on fauna that highlighted a moth with a cryptic caterpillar.  The moth is the wavy emerald moth (Synchlora aerata), and the adult looks like this:

(photo from Bug Guide)

The interesting thing about this beast is that the caterpillar practices what I call “cultural mimicry”: it bedecks itself with plant material from its surroundings to hide itself from predators.  Now undoubtedly this behavior is genetically hard-wired in the caterpillar; I call it “cultural mimicry” simply because the caterpillar takes things from its environment to hide itself.  This is equivalent to what an octopus does: changing its color to match its temporary surroundings; but it’s probably easier to evolve “bedecking” behavior than the complex system of chromatophores and environmental assessment required in the octopuses.  The genes coding for this behavior can simply be those coding for the behavior: “occasionally cover yourself with plant material plucked from around you”.

As fauna notes:

The Caterpillar of the Wavy Emerald Moth (Synchlora aerata), family Geometridae, a species found throughout much of North America. The larvae feed on many plants in the family Asteraceae (like Liatris spp. and Rudbeckia spp.) as well as a variety of other flowering plants. They are known to pluck the petals from the flowers of their host plants and affix them to their backs using silk. Once the petals begin to wilt and discolor, the caterpillar discards the old petals and picks new petals, which camouflage the animal.

Here’s one on a Liatrus:

From Bug Guide (link above)

The caterpillar on a prairie coneflower, having taken part of the central disc to cover itself (this photo and following one by Jim McCormac from Ohio Birds and Biodiversity, used with permission):

and on wingstem, (Verbesina alternifolia):

And one on Achillea millefolium, from Friends’ Central School of Lepidoptera Research (I’ve added the circle to highlight the larva):


If you don’t like my neologism of “cultural mimicry,” how about “The Chatterley Phenomenon”?  As literate readers will recall, in one of the salacious part of Lady Chatterley’s Lover Mellors the gamekeeper bedecks Lady Chatterley’s nether locks with campions and forget-me-nots (link here).

A Jurassic LOLcat

April 5, 2012 • 9:42 am

I appreciate all the readers who wrote in saying they like the biology posts.  Now, I don’t plan to change the mix on this website (and those of you who asked for more atheism, fewer cats, and so on might be disappointed), but I’m glad people get some benefit from the science.  At any rate, those miscreants who wrote that they ignore the cat posts can stop reading this one.

Re today’s post on feathered theropods, here’s how a Jurassic moggie would dine (it also happens to be the best LOLcat ever):


Tennessee governor set to sign anti-evolution bill; new monkey trial in the offing!

April 5, 2012 • 8:04 am

Two weeks ago I posted on Tennessee’s “teach-the-controversy” bill, which had passed the state House and Senate.  Here’s a summary again (my emphasis):

This bill prohibits the state board of education and any public elementary or secondary school governing authority, director of schools, school system administrator, or principal or administrator from prohibiting any teacher in a public school system of this state from helping students understand, analyze, critique, and review in an objective manner the scientific strengths and scientific weaknesses of existing scientific theories covered in the course being taught, such as evolution and global warming. This bill also requires such persons and entities to endeavor to:
(1) Create an environment within public elementary and secondary schools that encourages students to explore scientific questions, learn about scientific evidence, develop critical thinking skills, and respond appropriately and respectfully to differences of opinion about controversial issues; and
(2) Assist teachers to find effective ways to present the science curriculum as it addresses scientific controversies.

The bill has been opposed by every member of the National Academies of Science who lives in Tennessee, by the American Association for the Advancement of Science, by the Tennessee Education Association, and by the Tennessee branch of the American Civil Liberties Union—i.e., every organ of rationality in the state.

Despite this, Tennessee governor Bill Haslam is about to sign the bill into law. According to the Vanderbilt University student newspaper:

Haslam said the State Board of Education has told him the measure won’t affect the state’s current scientific curriculum for primary, middle or high school students. Louisiana enacted a similar law in 2008.

“I think the one thing about that bill is this: Nothing about the curriculum of the state of Tennessee will change, and the scientific standards won’t change,” he said. “So I think some of the discussion about its impact has probably been overblown.”

Note the emphasis on “evolution and global warming.” If that’s not religious motivation—and a legitimate reason for contesting the constitutionality of the bill—I don’t know what is.

And here’s some lovely doublespeak:

House sponsor Bill Dunn, a Knoxville Republican, said the proposal states that it is “not … construed to promote religion.”

“What the bill says is that as long as you stick to objective scientific facts, then you can bring that into play,” the Knoxville Republican said. “So if students start asking questions or if there’s debate on it, it’s not a one-sided debate. But it is a fair debate, in that it’s objective scientific facts that are brought forward.”

If that’s the case, why do they single out evolution and global warming? Why not quantum mechanics and the Krebs cycle? After all, there’s just as much valid scientific opposition to quantum mechanics and the Krebs cycle as there is to evolution.

People of Tennessee, your state is about to look really stupid.

h/t: Chris

A huge feathered dinosaur

April 5, 2012 • 5:34 am

Fortuitously, I have a couple of biology posts lined up today. The first one, which comes Via Ed Yong, describes a huge new species of dinosaur that was covered with feathers. A new paper in Nature by Xu et al. describes the discovery in China of three nearly complete skeletons of Yutyrannus huali, a very large theropod dinosaur that was covered with filamentous feathers. (“Yu” is Mandarin Chinese for “feathers,” “tyrannus” is Latin for “king,” and “huali” means “beautiful” in Mandarin.)  The species is related to T. rex, also a theropod.

The beautiful feathered king was found in Liaoning Province, China, and here’s a slab preserving two of the specimens.  The line drawing tells you what you’re seeing.  These were very large individuals: the giggest weighed about 1414 kg, and the smaller ones, probably juveniles, about 600 and 400 kg respectively.  Those are big dinos: 1414 kg is 3,117 pounds, exactly the weight of a 1990 Volvo GLE.

Figure 1 | Yutyrannus huali (ZCDM V5000 and ZCDM V5001).
a, Photograph of the slab preserving ZCDM V5000 and ZCDMV5001. b, Line
drawing of the slab. Abbreviations: cav, caudal vertebra; cev, cervical vertebra;
dr, dorsal rib; dv, dorsal vertebra; ga, gastralia; lfe, left femur; lfi, left fibula; lh,
left humerus; lil, left ilium; lis, left ischium; lm, left manus; lp left pes; lr, left
radius; ls, left scapula; lt, left tibiotarsus; lu, left ulna;ma, mandible; pu, pubis; rc,
right coracoid; rfe, right femur; rh, right humerus; ril, right ilium; rm, right
manus; rp, right pes; rr, right radius; rs, right scapula; rt, right tibiotarsus; ru,
right ulna; sk, skull; sy, synsacrum.

According to the authors, the dino’s most striking feature is its “highly pneumatic midline crest resembling that of Guanlong and the carcharadontosaurian Concavenator. . “.  Here’s a reconstruction of the smaller Guanlong‘s cranial crest from Dinopedia (the beast was about 3 m long).  We don’t know what these crests were for: the color below implies one hypothesis, which was display. In other dinosaurs they might have been used to exaggerate sound production, but I’m not sure whether they’re hollow in  Y. huali.

Below is Figure 2 from the new paper, showing the skull and mandible of Y. huali. The crest is visible at the top of the skull, but it’s not as elaborate as that of Guanlong (see the reconstruction below).

The important feature here are the filamentous “feathers” that you can see in sections c-h of the photographs (click to enlarge):

According to the authors, the feathers (described as “filamentous integumentary structures,” are seen in all three specimens, are very long (15 cm, about 6 inches), and are found on the back and neck, on the forearms, and near the pelvis.  This implies that the whole damn beast was covered with filamentous feathers, and that’s seen in this artistic reconstruction from Ed Yong’s site:

Reconstruction of Y. huali by Brian Choo

What were the feathers for? Certainly not for flight, since these things are too big to either jump in the air (“ground up” theory) or glide down from trees (“trees down” theory), and at any rate the feathers are too thin to provide any lift. The authors suppose that they might represent “an adaptation to an unusually cold environment,”  since the species lived during a period of weather that was unusually cold during the Cretaecous. And although dinos were supposedly “cold blooded” (ectothermic), there’s some evidence that they were really “warm-blooded”; this is based on morphological evidence and the fact that these dinos might have been fast-moving rather than sluggish, which would require a high metabolism.

A reasonable theory, then, is that many theropod dinosaurs developed feathers for insulation, and these were later co-opted for flight.  This is supported by the finding of this new large beast with rudimentary feathers. (An alternative theory is that they were used for sexual or species-specific displays.) Since feathers supposedly evolved only once (I can’t disgorge the evidence for this, but that’s my recollection), then their use in flight would represent what Steve Gould called an “exaptation”: the evolution of a new function for a trait that originally evolved for a different one (penguins’ use of their flippers for underwater “flying” is another example).

Here’s where Yutryannus fits into the phylogenetic tree of tyrannosaurs.  The ones known to be feathered are shown as feathered, but it’s also possible that even T. rex itself was, as I suggested in WEIT, covered with fluff.  That would detract a bit from its fearsome reputation!

Figure 3 | A simplified cladogram showing the systematic position of
Y. huali among the Tyrannosauroidea. Silhouettes indicate body size and
possible extent of plumage. Different tyrannosauroids seem to have attained
gigantic body size independently in the Early and Late Cretaceous, but only in
the Early Cretaceous is there direct evidence of a gigantic form with an
extensively feathered integument. This may reflect the relatively cold climate of
the middle Early Cretaceous. See also Supplementary Information.

_____

Xu, X., K. Wang, K. Zhang, Q. Ma, X. Xing, C. Sullivan, D. Hu, S. Cheng, and S. Want. 2012.  A gigantic feathered dinosaur from the Lower Creataeous of China. Nature online: doi:10.1038/nature10906

A movie on thylacines?

April 5, 2012 • 3:47 am

Last September I posted on the 75th anniversary of the passing of the thylacine. In case you missed it, I provide a paragraph and the movie from the original post:

Today is the 75th anniversary of the death of the last thylacine (Thylacinus cynocephalus, also known as the “Tasmanian wolf”), a marsupial that once inhabited New Guinea, Australia, and Tasmania.  “Benjamin,” a captive individual on display in the zoo at Hobart, Tasmania, died on September 7, 1936.  Below I’ve put a 42-second video clip of Benjamin in his cage (despite his name, this individual may have been female). You can see additional clips here.

Alert reader Philip, from Canada, has called my attention to the appearance of a new advernture movie about the search for the thylacine, “The Hunter,” starring the scary Willem Dafoe. Here’s the trailer:

(Notice the use of the old thylacine clips. I wonder if they’ll have a bogus beast in the film.).

The official movie site is here, and Rotten Tomatoes (which, suprisingly, rates it a high 75%!) reprises the plot, which sounds like a marsupial Jurassic Park:

The Hunter is the story of Martin, a skilled and ruthless mercenary sent into the Tasmanian wilderness on a hunt for a tiger believed to be extinct. Hired by an anonymous company that wants the tiger’s genetic material, Martin arrives in Tasmania posing as a scientist. He proceeds to set up base camp at a broken-down farmhouse, where he stays with a family whose father has gone missing. Usually a loner, Martin becomes increasingly close to the family; however, as his attachment to the family grows, Martin is led down a path of unforeseen dangers, complicating his deadly mission.

The movie came out last September, but appears to have vanished rapidly. Perhaps the last statement of the above trailer applies: “It’s probably better off extinct.”

Has anyone seen this?

Note to readers

April 4, 2012 • 12:13 pm

I must say that it discomfits me a bit that biology posts are overlooked in favor of ones on atheism and religion—nay, even ones on cats!  Now it takes about five times longer to write a biology post than one on, say, a HuffPo piece on Bart Ehrman, because I have to read the science paper twice, look up ancillary references, and try to explain it as best I can in non-technical language.  Despite that, posts on Jesus, atheism, and the like garner the lion’s share of attention.

Well, I’m judging that by comments alone.  My working theory, which I use to console myself, is that people still pay attention to the biology but most, not being experts, have little to say to contribute to the discussion, while everyone has an opinion on Jesus and atheism.  At any rate, biology is still my first love (next to cats), and I intend to continue posting about it. Although I write about what interests me regardless of the expected traffic, I’d like to know whether anyone pays attention to the science.

Okay, here’s some cat stuffz.

Sigmund’s excellent eating adventure, with a Francis Collins chaser

April 4, 2012 • 9:53 am

Alert reader Sigmund (a contributor and also creator of Sneer Review), who lives in Europe, took his family to New York City this week.  He asked me for restaurant recommendations (I sent him to the Lower East Side, of course), and I also called upon food writer Josh Ozersky, a reader of this website.

Today, a bit heftier in the midsection, Sigmund sent me a report of his culinary peregrinations in NYC:

My favorite was the pastrami at Katz deli – although it filled me up so much I wasn’t able to manage a knish to go along with it!


The Texan barbeque at ‘Hill Country’ was good but a bit too carnivorous for my taste – we found a few great korean barbecues that were easier to manage (I like eating meat but the US barbeque style makes it feel like you are eating a whole cow at one sitting!)

The Korean restaurant was the New Wonjo, on West 32nd street, ‘Korea-Town’. We tried a couple of K-barbecues in that street and this was the best (there are plenty more to try in the vicinity, so there may be better options!) Apparently it’s open 24 hrs a day and was very busy when we were there. If you go, avoid the chicken (it’s just OK) and stick with the beef and pork barbecue.

I also found that Economy Candy shop you featured —and bought some WEIT themed candy: picture attached.

We managed to get to a couple of decent Chinese restaurants too – ‘Joe’s Shanghai’ for dumplings and Dim Sum Go-Go for (surprise) Dim Sum – although the latter was forced upon us, as our original choice, The Golden Unicorn, was being raided by the police when we turned up!

Speaking of cat butts, Sigmund had an unexpected encounter with a famous accommodationist:

PS We went to the Natural History Museum last week and the only downside was the sudden appearance of Francis Collins (in a video) in the Human Origins section – who proceeded to needlessly inject his own religion into things. There was absolutely no need for this in the exhibition – it is essentially a sectarian sermon in a museum devoted to science. I can understand the possible value of this in an evangelical church setting but not in a science museum.

In his looped video in the Spitzer Hall of Human Origins, Collins seems to be either promoting one type of religion (that which involves belief in a personal God) or, alternatively, extolling the value of cognitive dissonance:

“I’m a scientist who believes the tools of science are the way to understand the natural world and one needs to be rigorous about that. But I’m also a believer in a personal God. I find the scientific worldview and the spiritual worldview to be entirely complementary. And I find it quite wonderful to be able to have both of those worldviews existing in my life in a given day, because each illuminates the other.”

But belief in a personal God is not compatible with other religions, such as Hinduism, Buddhism or multiple other faiths. Why privilege evangelical Christianity above all others in this setting?

JAC:  This sort of thing really ticks me off: it’s not science but theology. Let people reconcile their faith with the truth on their own time. And I wouldn’t be surprised if some public money went toward creating this exhibit, which if true would violate the First Amendment.

More on Bart Ehrman’s new book about Jesus

April 4, 2012 • 6:34 am

This should anger up those readers who think that Jesus was largely mythological (i.e., not even based on a real person), or that the evidence supporting such a person was weak at best.  HuffPo has a piece on Bart Ehrman’s new book, Did Jesus Exist? called “In ‘Did Jesus Exist?’, Bart Ehrman’s portrayal of Jesus is surprisingly sympathetic.”  (See my earlier post on this book, which, much to my surprise, garnered >400 comments.)

At any rate, Ehrman seems to be taking a harder line than before on Jesus, though I believe he always suggested that Jesus was based on a real person: an early apocalyptic preacher. Ehrman’s never, so far as I know, given an iota of credence to the divinity of Jesus or any of the miracle stories.  Now, however, he’s pretty insistent that a “Jesus” was crucified by Pontius Pilate.

What do mythicists argue?

If Jesus really existed, mythicists ask why so few first-century writers mention him. These mythicists dismiss the Gospel accounts as biased and therefore non-historical. To many mythicists, the Jesus story is based on pagan myths about dying and rising gods.

What does Ehrman argue?

Ehrman points out that only about 3 percent of Jews in Jesus’ time were literate, and Romans never kept detailed records. (Decades after Jesus’ crucifixion, three Roman writers mention Jesus in passing, as does the Jewish historian Josephus.) Though the Gospel accounts are biased, they cannot be discounted as non-historical. As for Jesus being a Jewish version of the pagan dying and rising god, Ehrman shows that there is no evidence the Jews of Jesus’ day worshipped pagan gods. If anything, Jesus was deeply rooted in Jewish, rather than Roman, traditions.

To me this sounds like pretty thin evidence for Jesus—more rationalization for the lack of evidence than any positive evidence—and gives nothing beyond what is in scripture. I’m not sure why there’s a new book if the evidence is just what it was before.  But I’m sure at least a few readers will get this book. If you’ve read it (and there are Amazon reviews), post your take below.

What is new is that Ehrman appears really peeved by the “mythicists,” and is really coming down on those who deny the existence of a historical person on which the Jesus myth is based:

As Christians prepare to celebrate the resurrection of Jesus, Ehrman, an agnostic, convincingly demonstrates in clear, forceful prose that there was a historical Jesus, a Jewish teacher of the first century who was crucified by Pontius Pilate. As for the so-called “mythicists” who argue otherwise, Ehrman has some choice words: “sensationalist,” “wrongheaded,” and “amateurish.”

“They’re driven by an ideological agenda, which is, they find organized religion to be dangerous and harmful and the chief organized religion in their environment is Christianity,” Ehrman said in an interview . . .

Yet Ehrman who said he spent a summer boning up on mythicist books, such as “The Greatest Story Ever Sold,” and “The Jesus Mysteries,” sees a growing embrace of the position that Jesus was a fictional figure.

Ehrman said he had long received occasional emails from atheists and others asking him if he thought Jesus actually lived. Then last year, he accepted an award at a meeting of the American Humanist Association in Cambridge, Mass. While there, he was dismayed to find many humanists, who describe themselves as “good without God,” adhered to widely discredited notions that Jesus never lived.

It eventually dawned on him that the Jesus deniers were the flip side of the Christian fundamentalists he had long ago foresworn. Both were using Jesus to justify their relationship to Christianity.

“I keep telling Christians, they don’t have to be afraid of the truth,” said Ehrman. “The same thing applies to atheists and humanists. It’s not going to kill them to think Jesus really existed.”

Of course, the words “Jesus really existed,” are deeply ambiguous, since they say nothing about the divine Jesus, and perhaps Ehrman should have added that immediately.  I’m hoping he isn’t being deliberately ambiguous to cater to believers.

The HuffPo piece is, however, surprisingly sympathetic to the non-divine-Jesus view:

The fact that Ehrman is siding with Christians on the historical truth of Jesus does not indicate a change of heart, much less a conversion. Instead, he said, it’s an attempt to say, “history matters.”

But for fellow nonbelievers, who cheered Ehrman’s previous books as proof that evangelicals are wrong about many biblical claims, the latest publication seems like the beginnings of family feud, if not an outright betrayal.

Some have already suggested Ehrman is painting atheists with too broad a brush.

“I don’t personally know a single atheist who would deny that Jesus existed,” said Louise Antony, professor of philosophy at the University of Massachusetts Amherst. [JAC: I think there are a few who post on this site!] “It would be really unfair to suggest that it’s part of being an atheist to deny the existence of Jesus as a historical person.”

. . . Largely missing from the quarrel is an acknowledgement of how far atheists and agnostics have come.

“They’re squabbling over the existence of a man, not a messiah or a god,” said Ryan Cragun, a sociologist at the University of Tampa. “No one is saying Jesus was God. If you step back it’s not that cataclysmic.”

I don’t really have a dog in this hunt, so I am not deeply invested in whether or not there was a historical person on whom Jesus is based.  It seems plausible, though I wouldn’t presume to pass judgment on the evidence, since I haven’t studied it.  But what is important, and all those Christians who buy the book should know this, is that both Ehrman and atheists see not a scintilla of evidence that Jesus was the son of God or divine in any way, was born of a virgin or resurrected, or is the way to salvation. That remains fiction to all thinking people.