Why Evolution is True is a blog written by Jerry Coyne, centered on evolution and biology but also dealing with diverse topics like politics, culture, and cats.
I think the Archie comics are a purely American phenomenon, but they’ve been around forever—certainly when I was a kid in the Pleistocene. And I read it faithfully, as, I suspect did most of our older readers here. You would remember Archie, Jughead, Riverdale High, and the two attractive women, Veronica and Betty, between which one had to choose as a favorite.
I didn’t realize Archie had been around longer than I, but it’s true: the comic has been going for 73 years.
Until today.
As The Associated Press reports, in today’s issue of the comic Archie finally meets his demise, looking at least four decades younger than he is! And he dies in an unusual way:
Archie Andrews fans already know that their beloved, red-haired comic book icon is going to die while trying to save a friend’s life. Now ArchieComics publisher and co-CEO Jon Goldwater has offered more specifics about the character’s sacrifice: Archie will perish after intervening in an assassination attempt on the series’ first openly gay character, Kevin Keller, The Associated Press reports.
The heroic act will take place in the 36th issue of Life With Archie (out Wednesday, July 16th), while the following installment will move forward one year and feature the Riverdale crew honoring the life and legacy of their fallen friend. The image to the left shows Archie right before his death. [JAC: first image below]
“The way in which Archie dies is everything that you would expect of Archie,” Goldwater said in a statement. “He dies heroically. He dies selflessly. He dies in the manner that epitomizes not only the best of Riverdale, but the best of all of us. It’s what Archie has come to represent over the past almost 75 years.”
From the AP: This image provided by Archie Comics shows Archie in his final moments of life in the comic book, “Life with Archie,” issue 37. Archie Andrews will die taking a bullet for his gay best friend.
I didn’t realize that Archie had become so politically correct over the years:
While the original comic book series starring Archie began as an innocent look at a group of pals at Riverdale High School, Archie Comics has in recent years strived to appeal to modern sensibilities with “Life with Archie,” a more socially relevant spin-off aimed at longtime adult Archie fans. Over the past four years, “Life with Archie” plots have involved Kevin’s marriage, the death of longtime teacher Ms. Grundy and Archie’s love interest, Cheryl Blossom, tackling breast cancer and affordable health care.
Lord, that’s about every issue there is except for immigration reform and legal weed! Well, farewell, Arch! Here he is—gone but not forgotten.
Sana Hamelin contacted me on behalf of her partners in the Denver Cat Company, a cat cafe which is poised to open in the Mile High City. Sana was a corporate attorney who gave it all up for cats; here she is with one of her business partners, Keven Murphy (the other partner is Stella Min.) These people are serious about moggies:
The Cat cafe has received the go-ahead from the authorities, and is supposed to open in the fall. It will be the first cat cafe in the US (Oakland has one in the works, but it will probably open later if it opens at all)—indeed, there is no other cat cafe in North America. That’s just wrong! Japan has them, Europe has them, but not our continent?
The Denver Cat Company has an impressive website with an updated blog, an FAQ, a “Why fund us?” page and a mission statement, so go look at it. Everything seems to have been planned to the smallest detail. All they need is support.
I wrote Sana about where they would get the cats, and she answered:
We plan on getting our cats from Dumb Friends League and any other shelter that cannot sustain a no-kill model, so as to save them from being euthanized. There will be about a dozen cats at the cafe at any given time (with some available for adoption). One of our newest team members is passionate about special needs cats and we are trying to figure out if we could build our adoption model specifically with a focus on disabled cats.
They need $50,000 to open, and so far have only $150. I know we have some readers in the Denver area, so if you want to help, throw in a few bucks (you can donate as little as $5, and for that you get a pass). They’re going to open regardless of how much they raise, and they’ll charge only $5 per hour with the kitties. Plus you can adopt some of the cats!
It’s a worthy cause: you get the company of cats with your coffee, the cats get fusses, and some of them get adopted. How can you lose? You can donate here (I’ve done so, and there are rewards for donating; be sure not to put spaces in your credit card number), and vote for the cafe here at the bottom of the page (I don’t know what that accomplishes, but they need only 42 more votes to get to 420 and surely you guys can do that!). I mean, if the potato salad guy can get 60 grand for nothing, doesn’t this deserve at least that much?
This is Sana’s dream, and you can help it come true by helping open North America’s first cat cafe. I’ll add one more thing: if you donate $175, and become a “mega-sponsor”, I’ll send you an autographed copy of WEIT (with a thank you drawing of a cat) on top of the regular rewards for that level of donation:
The mega-sponsor reward package* + four additional 1-hour passes guaranteeing two reservations within the first six weeks after the Grand Opening (80 available).
~All mega-sponsor reward packages include (1) two Pre-Opening exclusive passes; (2) access to the entire family of cats, including kittens, for up to three hours; (3) free refreshments; and (4) your choice of a merch item*
Just send me a screenshot of the receipt.
Well, I’ve said my piece except for this: I know two Colorado cats (Firpo and Butter), and I’m sure they’d support this endeavor.
A while back, when I said in the comments of an evolution post that there were no good “ring species,” a few readers asked me what I meant by that. “What about the salamander Ensatina eschscholtzii? Or seagulls in the genus Larus? Aren’t those good ring species?” My answer was that those had been shown not to be ring species in the classic sense, but there was still one species that might be a candidate: the greenish warbler Phylloscopus trochiloides around the Tibetan Plateau.
But now that one, too, has been struck off the list of ring species, leaving no good cases. Its removal from the class is documented in a new paper by Miguel Alcaide et al. in Nature (reference and link below), in a group headed by Darren Irwin, a professor at the University of British Columbia and including my next-door Chicago colleague Trevor Price.
But first, what is a ring species? Ring species constitute one big and supposedly continuous population in which the attainment of biological speciation (to people like me, that means the evolution of two populations to the point that they cannot produce fertile hybrids were they to live in the same place in nature) does not require full geographic isolation of those populations. Rather, speciation in that continuous population occurs through a gradual spread of the range of the animals, coupled with selection in different places that causes their genetic divergence.
It was long thought by many that for a single species to become two species—to undergo “speciation”—the populations had to be completely separated geographically, so they could evolve along divergent paths without the pollution of genetic interchange that would reduce their divergence. We now know that that isn’t true, and speciation can result even though the populations becoming new species exchange some genes while diverging. Allen Orr and I discussed all this in our 2004 book Speciation, the book that I still consider my proudest accomplishment (see chapters 3 and 4 for the discussion of speciation with gene flow; “ring species” are discussed in chapter 3, pp 102-105).
So a ring species is one case of speciation that is supposed to occur without any geographical isolation.
It works like this: a species expands its range and encounters a roughly round geographic barrier like a valley, the Arctic ice cap, or an uninhabitable plateau. It divides and spreads around the edges of the barrier, so that its range becomes circular as it expands. And as the range begins to form a circle, the populations within it begin to become genetically different as they respond to local selection pressures. But the circle is never interrupted, so while each part of the expanding species becomes genetically different, it still exchanges genes with adjacent populations.
What this causes is a group of populations in which adjacent areas are genetically similar, but become less similar as they become more distant. That’s because the more-distant populations supposedly experience more-different environments, and gene flow between distant populations is attenuated because genes have to flow through all the intervening populations.
At the end, the populations have expanded so far that the ring has “closed”: the species has completely encircled the barrier and the two most genetically diverged populations contact each other. If they are so genetically diverged that they cannot form fertile hybrids, they then appear to be two biological species.
This is a bit of a conundrum because the two “good” species are connected by a chain of populations around the circle, and each population can exchange genes with the adjacent one. This holds all the way around, so, in theory, every population in the ring really belongs to the same species. It’s like breeds of dogs: the Chihuahua can exchange genes with a slightly bigger dog, and that one with a slightly bigger dog, and so on up to the Great Dane. Given this, are Chihuahuas the same species as Great Danes? If you put both species in a kennel together, they couldn’t form hybrids, so you might think “yes, they are different species.” But if you put all breeds of dogs in a kennel, they’d eventually, by mating with dogs of similar size, form a hybrid swarm of mongrels in which Chihuahua and Great Dane genes are found in the “hybrid swarm”.
So even though the populations at the end of the ring behave as two different species when they meet, they’re connected all around the ring by gene flow.
Such species are known as “ring species.” They’re interesting for two reasons. First, they show that you can get the evolution of complete reproductive isolation without geographic isolation. Second it’s a judgment call whether you call them one or two species. If you call them two species, where do you draw the line between the two, given that any adjacent pair of populations around the ring are clearly members of the same species?
There used to be several examples of “ring species” that were staples of evolution textbooks, the most famous being the salamander Ensatina eschscholtzii in California. This species was first worked on by Robert Stebbins but later and most intensively by David Wake of the University of California at Berkeley and his colleagues. It was a classic example supposedly demonstrating all the principles I described above.
An ancestral population of salamanders from what is now Northern California or Oregon was supposed to have spread southward, and then split, with one group expanding its range down the Coast Range, and the other moving east and then expanding southward down along the foothills of the Sierra Nevada. The intervening “center” of the ring was the Central Valley of California, which is grassy, dry, and uninhabitable by these plethodontid salamanders, which need moist habitat. The species thus formed a classic ring, differentiating genetically as both branches moved south. In fact, they became different in color and morphology, and were classified into seven subspecies, as shown in the diagram below.
The ring closed when the ranges encountered each other in southern California, where the subspecies E. eschsholtzii eschscholtzii encountered the long-diverged subspecies E. e. klauberii. These two did not interbreed in nature, and so behaved as different species. Genetic studies demonstrated a long divergence between these, attesting to the “move around the ring” scenario, but also to a lesser divergence between adjacent populations. The ring is shown in the following diagram, along with the distribution of subspecies:
This complex, then, was long regarded as the paradigm of ring species, and was (and is still in places) taught as an example of this form of speciation with gene flow.
Except it’s wrong. That is, it’s not a ring species in the classical sense. Why not? Because genetic studies, done by both Dick Highton at Maryland and then by Wake and his colleagues themselves (references below) also showed that in places around the ring there were sharp genetic breaks, suggesting not a process of continuous gene flow over the 5-10 million years it took to close the ring, but sporadic geographic breaks in the ring, so that the salamanders could differentiate without pesky gene flow from adjacent populations. Some adjacent populations showed very sharp genetic differentiation, implying geographic isolation in the past (Continuous gene flow would not produce such “breaks”.) Finally, geologic work has shown that it is very unlikely that there were two unbroken forest corridors for those millions of years required to produce a ring.
Based on these results, everyone has now concluded that the formation of this “ring” involved sporadic and important episodes of geographic isolation between populations, so it’s not the classic “continuous gene flow” scenario involved in making a ring species. As Wake himself said in his 1997 paper (reference below), “The history of this complex has probably featured substantial [geographic] isolation, differentiation, and multiple recontacts.” (You can read about the Ensatina story in greater detail at “Understanding evolution,” a great site produced by U.C. Berkeley.)
Well, that’s a bummer, but it still shows how geographic isolation by distance can promote reproductive isolation and speciation. Other putative cases of ring species, including gulls in the genus Larus encircling the Arctic, also fell victim to genetic studies, showing that it was very unlikely that they were ever a continuous ring that was geographically uninterrupted.
That left the greenish warbler, which we touted in our book as perhaps the one good case of a true ring species. This species was similar, in that ancestral populations south of the Tibetan plateau were said to have expanded around that uninhabitable plateau (these birds need forests!), meeting north of the plateau in Siberia. Here’s a diagram of the ring with its six present “subspecies” (in different colors), along with the sonograms of each population’s song. The place where the ring was supposed to have joined, and where the populations act as different species, is the crosshatched red/blue area at the top:
Here’s a greenish warbler from Sikkim:
Phylloscopus trochiloides
The original scenario, published by Irwin et al. (2001; reference below) and discussed in our book, suggested that as the species encircled the Tibetan Plateau from the south, the populations diversified in both color and song, with the songs becoming more complex—but in different ways—as the two branches headed north. The evolutionary impetus for song differentiation is not known, but probably involved sexual selection, possibly based on food availability.
By the time the populations met in the north, the male songs were so different that the two populations didn’t recognize each other as members of the same species (i.e., females of one population didn’t respond to the song of males of the other), and so there was no interbreeding, even though there was supposedly interbreeding all along the continuous ring. (The geographic “break” in China is probably due to recent deforestation.)
It was a classic example of ring species, though there was one worry. Mitochondrial DNA (mtDNA) studies in the southwestern part of the ring showed a sharp genetic break between two populations in Kashmir, suggesting that perhaps there was some ancient geographic isolation before the ring began moving. But that differentiation in what is, in effect one gene (the mitochondrial genes are all linked), could have other explanations.
Now, however, genetic analysis of 95 birds and more than 2,000 sites throughout the genome (not just in the mitochondrion), has revealed four genetic clusters around the ring with a sharp intergradation between them (there’s another cluster in the Caucasus, not around the ring). For those of you who know about Bayesian cluster analysis, here’s what the clusters look like around the ring. (Smaller clusters are in the supplementary information.)
Note especially the big break in the southwest, between the yellow and blue populations, and the plot showing the abrupt genetic break between them (lower left), indicating a hybrid zone between populations that were previously isolated geographically. This is in fact in the same place as the worrisome break in mtDNA reported earlier. There are also smaller breaks between Pakistan and Kyrgyzstan, and between Nepal and China (not shown above), but it’s not as clear that those reflect previous geographic isolation rather than simply sampling error or selection with some gene flow.
The authors also found, contrary to previous information, that there are indeed some hybrids (fertile ones, since they backcross) produced where the ring closes at the top, so they aren’t really acting like full biological species.
At any rate, the authors conclude that this case doesn’t correspond to the classical notion of a “ring species,” for that requires no geographic isolation while in this case there almost certainly was some. As the authors note:
Our results indicate that allopatric divergence played a strong role in shaping patterns of genomic divergence during the formation of the greenish warbler ring. Previous findings nonetheless support the idea that geographical isolation has not been the sole driver for the establishment of reproductive isolation; natural and sexual selection also appear to play major roles.
Well, yes, but geographic isolation is never the sole drive of any evolutionary divergence, for something has to make the populations diverge: either selection (natural, sexual, or both) or genetic drift. But it’s good of them to pursue their initial finding more intensively, even if that effaced the cool result of a “ring species” that they reported earlier. But nature is nature, and what happened is what happened. In the end, the authors conclude what I concluded before I saw their first paper: there are no good examples of ring species in nature:
Finally, this study provides meaningful information concerning the interpretation of ring species as prominent illustrations of speciation in the face of gene flow. Earlier analyses of AFLP markers supported the greenish warbler as the last known example in birds of an ideal ring species in which the terminal forms became reproductively isolated despite being connected by gene flow during their whole history of divergence. . It is possible that speciation-by-distance ring species could exist, but their extreme rarity may be explained by the rapidity of Earth’s climatic shifts compared to the time that reproductive isolation takes to occur; over these great spans of time, and as exemplified by the present study, populations are very likely to be temporarily divided.
In other words, perhaps it’s too much to hope for a “true” ring species, for that requires a species’ range to remain unbroken for millions of years—and yet climate and habitat change all the time.
Nevertheless, the results do show a “ring species” of a sort: isolation of two “end” populations of a ring that makes them look like two species, even though all through the ring you don’t see reproductive isolation of adjacent areas. And it shows that speciation can occur despite there having been some gene flow at some times. In nature, populations that form new species must often sometimes exchange genes if they’re not completely isolated by geography (i.e. the finch species that colonized the Galápago), so the dichotomy between “no gene flow” and “pervasive gene flow” may be artificial.
Oh, and there are no good ring species, so don’t go around saying that there are! Mayr concluded the same thing in his great 1963 book Animal Species and Evolution (this book was largely responsible for making me an evolutionary biologist), but he didn’t have genetic data, and he didn’t consider the greenish-warbler case. It’s no great loss, though, that we lack good examples, for ring species didn’t really demonstrate any new evolutionary principles. They showed something we already knew—that reproductive isolation is promoted by anything that reduces gene flow between populations. But they showed it in a cool and novel way.
I am informed by the diligent attorneys at the Freedom from Religion Foundation (FFRF) in Madison, Wisconsin that the Lebanon, Missouri school board has not answered the FFRF’s second letter to the Superintendent of Schools about Principal Kevin Lowery’s prayer at a public school. That letter, shown below, was sent three weeks ago, on June 24. I didn’t publish it at the FFRF’s request, so that the folks in Lebanon would have time to respond without pressure. (I doubt that my publishing it would constitute “pressure,” though.)
As you may recall, Principal Lowery prayed at the Lebanon High School graduation—a blatant violation of the U.S. Constitution’s First Amendment—and the FFRF complained, as did as several past and present students. The school board and school superintendent ignored the FFRF’s first letter sent on June 2. If you don’t remember that fracas, some of the posts are at this search. I personally complained to the school board, and got no response save a snarky response from member Kim Light.
The school officials in the Lebanon School District have not responded to either letter. In other words, they’re stonewalling, hoping this will go away.
It won’t.
The next step, I suspect, is that they’ll find an attorney willing to participate in suing the Lebanon School Board, as well as a complainant with the standing to sue. I suspect that there will be no problem getting a complainant, though I don’t know for sure. I’ve also heard that the American Civil Liberties Union is preparing a lawsuit, but again, that’s hearsay: something I can’t substantiate.
You can see the second letter below, which will give you an idea of how the FFRF tries to resolve matters before they file a formal lawsuit. Nobody wants a lawsuit, for it’s expensive, time-consuming, and onerous. But believe me, if the FFRF doesn’t get a response, and the conditions above are satisfied, a lawsuit will be filed.
And when it is, Lebanon will be well advised to settle promptly. Actually, they should settle now, providing the written affirmation that the FFRF requests. Based on existing case law, Lebanon will lose that lawsuit on First Amendment grounds, and in the process will bankrupt their school district. For if they lose, they’ll have to pay court costs and the prosecuting attorney’s fees. In the Dover case, that was around one million dollars.
Really, Lebanon, are you so wedded to your “right” to pray in public that you will risk your children’s education, and the funding of their schools, for that? That’s a bad decision. You can always pray to yourself in schools, and anywhere else where you’re not a representative of the government. What is it about you that you insist on foisting your prayers on everyone, whether they want them or not, and in public schools? Do you not respect people who don’t share your beliefs? I wouldn’t foist atheism on public-school students, and you shouldn’t foist Christianity on them. That’s the way a secular society is supposed to work.
If a lawsuit goes forward, the Lebanon school board, school superintendent, and Principal Lowery will get what they deserve: a trouncing.
We have a roundup of bird species today from four different readers:
Reader Phil from Oz sends this:
An Australian bird for you. Little corella(Cacatua sanguinea). This was taken at Ocean Shores, near Byron Bay in northern New South Wales, Australia’s most easterly point.
I’m a biology student in Ecuador; last weekend I went to the beach and took this pictures, I hope you enjoy it…
In the picture you see a Sula nebouxii, (“Piquero de patas azules” in Spanish). I found this little one by the beach and it looks like he loved to have his picture taken!)
Reader John from Ethiopia sends a black predator and some notes on local worship:
Here is another fine bird, a Bateleur Eagle [Terathopius ecaudatus;the only species in its genus], spotted in the South Omo Region of Ethiopia.
You would like it here where I am at this moment (not): the Muslim call to prayer, blasting out from a gigantic loudspeaker about a quarter mile away, is facing stiff competition from chanting Ethiopian Orthodox Christian priests, broadcasting through their own gigantic speakers also about a quarter mile away. To be fair, the call to prayer lasts only about 10 minutes, five times a day, while the Ethiopian Orthodox (a very large and pious majority here in the north of the country) often chant all through the night.
Reader Tony Eales, also from Oz:
I have two shots of the Tawny Frogmouth (Podargus strigoides) a relative of the WEIT favourite nightjars. They’re experts at camouflage during the day as in the one in the photo pretending to be a stick, but can put on an arresting display as in the one I discovered being attacked by a pair of Brown Falcons. Also a spot the owlet nightjar (Aegotheles cristatus). It was the best shot I could get, he/she was expert at keeping a few leaves and branches between myself and it.
First the owlet nightjar; can you spot it?
Then the tawny frogmouths, this one being attacked by brown falcons:
It’s an expert at pretending to be a broken branch:
Yes, the perennial question is why on earth women would want to be bishops? But as long as men want to, and can, then women should too.
p.s. Don’t forget to contribute to the artist’s coffers if you can spare as little as $1 per month. Surely it’s worth $12 per year to keep the sarcasm (and humor) flowing. You can contribute here. He’s up to $800 per month, but that’s nothing compared to the Potato Salad Guy or Social Justice Warriors who make a lot more for contributing nothing.
The comic’s website is here.
