Caturday felids: Official Kittehs

January 29, 2011 • 6:23 am

As reported by the Milwaukee-Wisconsin Journal Sentinal, the mayor of Sharon, Wisconsin, is a CAT, a wandering tubby beast named Freddy.

. . . the cat known as the mayor of Sharon, or Freddy, lives at the Village Hall, greeting folks who come to pay water or property tax bills. He meows to go out twice a day to make his rounds in the small downtown, visiting the post office, the back doors of restaurants and at least one tavern, as well as stopping to catch mice in a wooded area across from the Village Hall.

He’s not averse to a little recreational drug use, which turns him into the Charlie Sheen of cats:

Even though he has the Village Hall to himself on weekends and evenings, he’s only gotten into trouble once – when someone accidentally left some catnip on a desk. When Kunkel and Redenius came in the following day, they found papers strewed about on the desk and the catnip scattered. Other than that, he leaves everything alone.

Aside from a great personality and boatloads of charm, apparently the mayor has an acute sense of time.

“It’s really funny. We’ll let him out in the afternoon and we’ll say ‘Freddy, you need to be back by 4:15 when we’re closing,’ ” said Redenius. “And he usually is. If he isn’t, he’s usually somewhere else and we have to start calling and knocking on doors.”

Here’s a video of hizzonor:

And from across the Pacific comes another kitteh official: Tama.  As reported by The Guardian, this female calico (all calicos are female, of course, and if you don’t know why, read about it here) is official stationmaster of the Kishi station in Japan.  The station was underused until they appointed Tama stationmaster (and equipped her with a tiny hat); traffic then rose sharply.  Hundreds of tourists visit Kishi to see Tama, who’s famous in Japan.

Here’s Tama wearing her official uniform:

Our Japanese correspondent Yokohamamama reports that Tama’s tag says “Station Master TAMA, and, in smaller letters at the bottom, Kishi Eki (Kishi Station).”

According to the LOLzy Wikipedia article, Tama doesn’t work alone:

Her staff consisted of two feline assistant stationmasters, Chibi (ちび?, born May 12, 2000) and an orange tabby cat named Miiko (ミーコ?, October 3, 1998 – July 20, 2009). Now only Chibi remains. Tama appeared in a documentary about cats titled La Voie du chat in French and Katzenlektionen in German by Italian filmmaker Myriam Tonelotto, broadcast on European TV channel ARTE in April 2009.

Kishigawa Line announced that it was releasing a new “Tama Densha” (たま電車, Tama railcar/train?) train that was customized with cartoon depictions of Tama. It began running in spring 2009.

And here’s a video. Sadly, it’s in Japanese, but you get the idea:

Cats bring joy to nearly everyone, and dull the pain of life.  This cartoon shows why they should be allowed to enter another profession: MEDICINE:

h/t:  Sigmund

Annals of airline security: Part II

January 28, 2011 • 5:21 pm

I was sensitized to airline security after I was forced in Boston to be scanned by the See-You-Naked Machine, and then groped on the buttocks.  Here’s the latest outrage: a 59 year old Canadian woman was bringing her husband a toy soldier from England, but the soldier’s three-inch plastic gun was confiscated by officials at Gatwick Airport. The officials branded the tiny weapon a “firearm.”

The woman, Julie Lloyd, was forced to leave the security line and mail the “gun” back home to Canada.

Here’s the gun that was deemed too dangerous to fly:

It doesn’t even have a trigger!

And here’s the toy soldier who brandished it:

At least it’s not American tax dollars at work.

Cup-pake!

January 28, 2011 • 11:04 am

The fellow who posts over at Three Ninjas read the post on my famous pake, a cake into which three pies had been baked.   He must have liked the concept, because for his birthday one of his coworkers baked him a pake—actually, cup-pakes, smaller versions that, as he put it, “facilitate workplace sharing”.  Cup-pakes must be even harder to make since one first has to make the mini-pies instead of using regular store-bought pies.

Here’s a cross section of the natal cup-pake, with celebratory birthday cetaceans in the background.

Three Ninjas reports that it was delicious.

When eagles mate

January 28, 2011 • 9:48 am

I’m sure everyone is wondering, in light of the EagleCam, how eagles actually DO IT.  They’re going to be producing eggs in a month or so, and we’ll all be watching, but before that a certain act must ensue.  How, exactly, do eagles copulate?  Do their sharp talons hurt each other? How long does it take?

Never fear, YouTube has the answer.  They have everything, so if you just search for “eagle sex” you’ll find a pair of bald eagles filmed in flagrante delicto:

As in most birds, the act takes only a few seconds (seven by my count), and is preceded by a lot of mutual singing.  If you watch carefully at the end, you’ll see the female light a cigarette while the male flies off to brag to his buddies.

h/t: Yokohamamama

How many species of humans were there?

January 28, 2011 • 7:42 am

I must say that while Science’s reporting about evolution and ecology is pretty dire—they’re mostly puff pieces with little critical thought—the work of Ann Gibbons is an exception.   When presenting a new theory or discovery, she always seeks out any significant dissent in the scientific community, and weighs in critically herself.  Gibbons was, for example, one of the first print journalists to note the problems with Darwinius (“Ida”), the putative missing link that turned out to be not so link-y.

The latest issue of Science contains a short but comprehensive piece by Gibbons (free, I believe) on the latest findings in human evolution, including the second discovery of hybridization between archaic humans and “modern” Homo sapiens.  (This is the Denisova fossil that I wrote about recently.)

Do read Gibbons’s piece, as it’s a good way to get up to speed in 20 minutes or so.  She discusses the controversy about whether modern H. sapiens evolved “multiregionally,” transforming itself in many different places, or via replacement from a band that left Africa less than 100,000 years ago.  The hybridization data—Gibbons notes that up to 10%  of some modern human genomes came from mating with “archaic” ancestors—makes it impossible to clearly demarcate the two theories.  Gibbons ends her article by describing a wary rapprochement between the two main advocates of those competing theories:

As for Stringer and Wolpoff, both now in their 60s, their battle has mellowed. Their views, while still distinct, have converged somewhat, and they shared a beer at a Neandertal meeting last year. “The reason we get on well now,” says Stringer, “is we both think we’ve been proved right.”

But I want to discuss briefly a shorter second piece by Gibbons in the same issue of Science, “The species problem.”  Here she brings up the controversy about whether modern humans, Neandertals, and Denisovans were members of different species or the same species.   This question is far more important in dealing with humans than, say, with fruit flies, simply because there were far fewer types of hominins, and anthropologists’ careers depend on whether or not they name a new species.  That’s why there are so many species names in the hominin family tree—names that turn on characters as tiny as a few millimeters in the measurement of a tooth.  It’s likely that, several million years ago, three or four species of hominin did exist at the same time—and maybe at the same place—giving rise to fanciful scenarios about war and (especially) inter-group mating.  There’s nothing more salacious, in an evolutionary sense, than imagining a burly, hairy, and robust hominin male copulating with a female from a more modern-looking species.

But that was more than a million years ago.  What about the more modern groups of Homo, like Neandertals?  According to Ernst Mayr’s biological species concept, which Gibbons describes, individuals are members of the same species if they can mate with each other when they encounter each other in nature, and, critically, produce fertile, viable hybrids.  If they can’t, then there must exist genetic barriers to mixing of genes, the so-called “reproductive isolating barriers” that maintain the integrity of species.

But there is some slack in how biologists use the definition, for hybridization of this type can range from being very rare (e.g., the medium and small Darwin’s ground finches, which hybridize at a rate of about 2%) to more pervasive (e.g., the black duck and mallard form hybrid swarms when they meet).   If there’s only a small amount of hybridization, and the species’ gene pools stay pretty separate, most biologists consider the case to involve different species (this is the situation in the Darwin’s finches I just mentioned).

A couple of other points:

  • Mating between different groups is not enough to deem them conspecific: those matings have to produce viable and fertile hybrids.  And “viable and fertile” means not only that the hybrids can have offspring, but that they do have offspring in the wild.  Some interspecific hybrids in birds, for example, are viable and fertile, but are not recognized as proper mates by members of either parental species because those hybrids look weird or have strange mating behaviors.  That is a form of reproductive isolation, too: it’s analogous to sterility, but sterility on the grounds of not being attractive as a mate.
  • Therefore, if one just sees hybrids in the wild, that’s not enough to claim that the parental groups must be members of the same species. Those hybrids have to constitute a genetic bridge between the parental groups; that is, they have to be fertile and mate with the parental species.  Often we simply don’t know this.  I believe Peter Grant once had a paper in Science noting that about 10% of bird species are known to form hybrids with closely-related species.  That’s been used to claim that hybridization is pervasive in birds, and that bird species might not be so “real” after all.  But that’s a wrong conclusion.  We simply don’t know anything about the fertility and viability (and sexual attractiveness!) of most of those hybrids.  And the hybrids have to occur in nature, not in zoos or other artificial enclosures that might break down reproductive barriers that exist in nature.

Gibbons reports an opinion by Jean-Jacques Hublin, who works on human evolution:

In the real world, [Hublin] says, Mayr’s concept doesn’t hold up: “There are about 330 closely related species of mammals that interbreed, and at least a third of them can produce fertile hybrids.”

Not so fast!  That 330 number means nothing, since most of these produce sterile or inviable hybrids.  Too, how much of that “interbreeding” was observed in the wild versus zoos? (I don’t know the answer).  And only the cases seen in nature count. Lions and tigers hybridize in zoos, producing fertile “ligers” and “tiglons”, but they didn’t hybridize when they once co-occurred in India. Zoos break down reproductive barriers: animals hybridize because they’re bored, horny, and there’s simply nothing else to mate with.

Finally, if we assume that 110 mammal species produce fertile and viable hybrids that interbreed with the parents in nature (that’s a generous estimate), this constitutes only 2.4% of all mammal species (there are about 4500).  It’s misleading to claim that the biological species concept “doesn’t hold up” because it’s ambiguous at best 2.4% of the time. Think of all the other 97.6% of species where it’s not ambiguous.  That’s the problem with using rare exceptions to invalidate a concept that works nearly all the time.  Beware of these “anecdotal horror stories,” as one biologist called them.

So I don’t agree with Svante Pääbo, who is quoted by Gibbons as saying “I think discussion of what is a species and what is a subspecies is a sterile academic endeavor.”  This may be true when arguing about human fossils in the past, or in a single lineage, but is not generally true in sexually-reproducing plants and animals.  As I’ve noted before, species are real, objectively delineated entities in nature, and discussing why they are distinct, and how to diagnose them, is hardly a sterile exercise.  Species are not arbitrary divisions of an organic continuum.  In sexually reproducing taxa they form distinct groups, well separated in “morphospace” and “genospace.”  We need to understand why that is.

  • Finally, it’s dubious to define species based on the degree of morphological difference between them.  As Gibbons notes, “There’s also no agreed-upon yardstick for how much morphologic or genetic difference separates species.”  She’s absolutely right—to settle on such a yardstick is to make an arbitrary decision.  The black duck and mallard, for example, look pretty different, but are probably members of the same species.  If two species of geographically isolated birds were as different in appearance from each other as, say, Asians and Sudanese humans, they’d be called different species. Yet we don’t think of human “races” as different species because, despite their different appearances, they crossbreed easily and form mixed populations when they encounter each other.  Morphological (and genetic) differences are often a poor key to species status, particularly when we’re so attuned to small differences, as is the case in human fossils.

So what about “modern” H. sapiens, Neandertals, and Denisovans?  Clearly they hybridized, and some of the hybrids were fertile, for traces of Denisovan and Neandertal genes remain in our genomes.  On this basis, anthropologist John Hawks deems Neandertals, modern humans, and Denisovans members of the same species; Gibbons quotes him as saying “They mated with each other.  We’ll call them the same species.”  (I hope by “mating” he means “mated and produced fertile offspring”.)

But a little bit of gene flow isn’t enough to convince most of us that these groups were conspecific. On that basis, the Darwin’s finches would be deemed conspecific, but nobody does that.  The question is whether that gene flow reflected lack of opportunity for mating (in which case they might be the same species), or pervasive hybridization (between, say, modern humans and Neandertals) but only weak viability or fertility of the “hybrids” (in which case they’d be different species).   We will probably never know the answer to this.

Does this make the species status of these three groups purely arbitrary?  I don’t think so. What we can do is get a “yardstick” by seeing whether other species of primates that were separated for as long as Neandertals, Denisovans, and modern humans—roughly half a million years—have evolved into reproductively isolated groups.  I’m not sure what the answer is (it’s probably sitting there somewhere in the literature), but I’d guess that they wouldn’t be separate species, especially because humans have much longer generation times than other primates and so would speciate even more slowly.  If it were my call, I’d agree with Hawks (but for somewhat different reasons), calling Neandertals, Denisovans, and modern humans all members of Homo sapiens.

But as for the hobbits, H. floresiensis, I’d stick with calling them a different species.  They diverged from modern H. sapiens much further in the past, although they may have been contemporaneous with us.

EAGLES!

January 27, 2011 • 7:32 am

There’s an eagle in the nest on the the live Eaglecam. If you’re awake, go look!  I’ll keep the site visible on my spare laptop much of today and post here with the time (EST) when I see eagles.  Check back from time to time.

6:52 AM EST: EAGLES: two of them! What magnificent birds!  One of them is bringing sticks to the nest, which is obviously still being built.  Eggs and chicks to come!

7:54 AM EST: Both eagles still there; they’re building the nest.

9:00 AM EST: Eagles out hunting or looking for sticks.

(Oops!  Sorry; I accidentally trashed the comments along with the earlier post, since I wanted to keep the eagles at the top.  Do repost if you had a comment that’s germane.  I’ll keep this post and comments up.)

11:00 AM EST: The pair back in the nest, engaged in more twig-fiddling.  Many of us are starting to realize how hard it is to build a good nest!

You can find information about bald eagle nests here.  Among the tidbits:

Of all birds in the world, Bald Eagles hold the record for the biggest nest ever built. One nest in Florida was 6.1 meters deep, 2.9 meters wide, and weighed 2,722 kg (almost 3 tons). Could a Bald Eagle nest this size fit in your classroom?

How can a pair of Bald Eagles possibly build that huge nest and still have time to lay eggs, incubate them, and raise the babies in a single breeding season?

The answer is, they don’t! Throughout the season, and sometimes even during fall and winter, eagles keep adding sticks to the nest, and they reuse nests, continuing to build on to them, for many years. That huge record-breaking nest in Florida was the largest nest ever found, and it was very old. The average eagle nest is only 1.5-1.8 meters in diameter and 0.7-1.2 meters tall, and the first year a nest is built, it may be much smaller than that.

In most regions, a pair of eagles starts working on their nest from 1 to 3 months before the female lays the first egg. However, in the northern regions they can’t delay this long. For example, according to Birds of North America, “In Saskatchewan, adults build or repair nests in September prior to migration and build or repair nests in April upon return from wintering grounds.”

3:00 PM EST:  One eagle in the nest, just chillin’.

3:05 PM EST:  HEY!  No more eagles until you read your biology!

4:34 PM EST:    Il n’y a aucun aigle

5:00 PM EST:    One eagle recumbent. 

Nabokov was right all along

January 27, 2011 • 7:31 am

This is a really cool result: a paper published 66 years ago, speculating about the evolutionary history of a group of butterflies, has just been vindicated by a combination of new molecular and ecological work.

But what is even cooler is that the author of the earlier paper was Vladimir Nabokov.

You know Nabokov (1899-1977) as a famous writer, author of, among other books, Lolita, Pnin, Pale Fire, and Speak, Memory.  He also taught literature at Cornell from 1948 to 1959; his classroom lectures have been published and they are absolutely superb.

But what you probably didn’t know was that he was also a world-class lepidopterist, specializing in the “alpha taxonomy” (description and publication of new species) of butterflies.  From 1945-1948 he was Curator of Lepidoptera at Harvard’s Museum of Comparative Zoology (MCZ), the institution where I got my Ph.D.  If you read his novels, you’ll often find a mention of butterflies.

Here’s Nabokov at the MCZ in 1945, from the article on his butterfly work at the New York Public Library Site:

Nabokov’s speciality was the butterfly subfamily Polyommatinae (called “blues” because of their color) in the family Lycaenidae.

Lycaeides melissa, subspecies samuelis. A “blue” from the northeast U.S.  The species was first described by Nabokov.

In 1945 Nabokov published a formal description and revision of some lycaenid butterfies in Psyche, the journal of the Cambridge Entomological Club (I’m a member!).  Here’s the title of his paper:

The paper is long (62 pages), and largely devoted to describing species based on their genitalia, the character that seems to evolve most rapidly among insects—and many other groups, probably because of sexual selection (see William Eberhard’s excellent Sexual Selection and Animal Genitalia).  At the end of the paper he speculates, based on the morphology of the various species, that the “blues” arrived in the New World from Asia over the Bering Strait.  He further speculated that there were actually five successive invasions from Asia, each giving rise to a different New World group.  And the first invasion produced species that made it to Central and South America, with the North American representatives eventually becoming extinct.

A group of investigators from a bunch of places, led by my friend Naomi Pierce at Harvard, just tested Nabokov’s theory with the modern tools of molecular biology and systematics.  Their results, published in a paper in the Proceedings of the Royal Society (free access!) and described by Carl Zimmer in yesterday’s New York Times, show that Nabokov was right on all counts.

Here’s what the authors found:

  • Using six genes, they made a molecular phylogeny of 73 species of blues from all five “sections” described by Nabokov.  This analysis showed that, indeed, the five separate invasions posited by Nabokov each produced a monophyletic group (i.e., a group descended from a single ancestral species). The butterflies also descended, as Nabokov posited, from Asian ancestors, and certainly came to the New World by migration over the Bering Strait.
  • The oldest group was, as Nabokov suggested, the butterflies in the neotropics: Central and South America.  The other groups were younger, and in the precise age sequence that Nabokov posited had arrived from Asia (and then radiated in North America).
  • The branches of the phylogeny were dated using a “molecular clock.” They were found to have begun about 11 million years ago, and continued until about 1 million years ago.  During the earliest part of that period the Bering Strait was not continuous between Asia and North America, and so some of the ancestral blues must have crossed an expanse of ocean.
  • The authors then determined the temperature-tolerance ranges of each group based on the climate where its members are now living.  From that, they reconstructed the temperature tolerance of each group’s ancestors. (You can do this for any measurable trait, morphological or physiological, using a method called “ancestral character state reconstruction”.)  And they found that the temperatures tolerated by each successive invader declined over time.  The earliest invader tolerated higher temperatures than the next, and so on for all five invasions.
  • The spiffy result: the temperature tolerances posited for each ancestor matched very nicely the temperatures thought to have prevailed in “Beringia” (the region on either side of the Bering Strait) at the time of the invasions.  Here’s part of the authors’ Figure 1, showing the temperature tolerances of ancestors during each of the five invasions (vertical bars), and the temperatures posited to have existed in Beringia, all over the 11 million years from the first to the last invasion:


Note the good match between the actual temperatures in Beringia and the temperatures tolerated by the ancestral invader of each of the five groups. Clearly, the butterflies now in the neotropics tolerated high but not low temperatures, and so were likely driven to the south as the climate became colder.  This also implies that each group has pretty much retained the ancestral temperature tolerance of its ancestor, though the ancestral five groups did diverge from one another in tolerance.

What a lovely piece of work, and how nice that the modern work, using all the highfalutin tools of molecular biology, systematics, ancestral state reconstruction, and so on, managed to confirm the speculations of one itinerant zoologist/author equipped only with a microscope and a bunch of butterfly genitals!


h/t: Carl Zimmer for providing pdfs.

____________

R. Vila, C. D. Bell, R. Macniven, B. Goldman-Huertas, R. H. Ree, C. R. Marshall, Z. Bálint, K. Johnson, D. Benyamini, and N. E. Pierce.  2011.  Phylogeny and palaeoecology of Polyommatus blue butterflies show Beringia was a climate-regulated gateway to the New World.  Proc. R. Soc. B published online before print January 26, 2011, doi:10.1098/rspb.2010.2213