A misguided science story just appeared in the Washington Post. Read on.
I will claim some expertise in this critique because my field of study is speciation. Indeed, I literally wrote the book on speciation in collaboration with Allen Orr. But regardless of my “science cred”, Theresa Vargas, a local reporter for the Post, apparently has very little. She has a degree in sociology from Stanford and another from the Columbia University School of Journalism. That doesn’t automatically disqualify her for writing science-based journalism. But the article below does, for, as they say, “It’s not even wrong.” (Click on screenshot; if it’s paywalled judicious inquiry might yield a transcript.) The errors, glaring to a biologist, could have been avoided had Vargas simply picked up the phone and called an ornithologist or someone who studies speciation. You would never see Carl Zimmer, for instance, writing a story so full of errors.
First, a didactic digression by yours truly:
What is a “species”? Some (but not all) biologists use the “Biological Species Concept” (BSC), which conceptualizes a species as a group of interbreeding individuals who are reproductively isolated from members of other such interbreeding groups when they co-occur in nature. That is, members of different species cannot exchange genes in the wild, so that a gene in one species, while it can spread to all other members of its own species, cannot get into another species—barring rare events like “horizontal gene exchange” mediated by parasites or viruses.
The barriers that prevent reproduction between co-occurring species are many, and can involve preference for different microhabitats, lack of sexual attraction so that individuals don’t mate even if their hybrids could be fertile, the use of different pollinators (in plants), different mating periods (“temporal isolation”) and sterility or inviability of any hybrids that do form. All of these factors—collectively called “reproductive isolating barriers” (we summarize them in two chapters of our book—keep different species distinct. Three caveats here:
1.) Sometimes there are intermediate cases in which speciation is not an all-or-none phenomenon. During the evolution of reproductive barriers, there is a long time period when the barriers aren’t yet complete, and gene exchange between incipient species is possible. Or, there may be rare cases in which two fairly distinct groups form occasional hybrids in the wild (ducks are one group that does this). However, if those hybrids are sterile, or can’t find mates, then the hybridizing species are indeed true species. In our book we call these forms “species-like”, and emphasize that speciation is a process that eventually leads to the complete cessation of gene flow in most cases. In such cases delimiting species is a rather arbitrary task. But many species in nature—probably most—cannot form fertile and viable hybrids with others (think human and chimp or pigeon and starling), and there’s no subjectivity in delimiting species.
2.) Sometimes species that are distinct in the wild can hybridize in confinement, as in zoos or farms, and even form fertile hybrids. This does not mean that they are members of the same species, for jailing animals can break down reproductive barriers—like habitat preference or distaste for cross-mating—that would keep species separate in the wild. For example, tigers and lions once had overlapping ranges in India, but hybrids were never found. But in zoos they occasionally hybridize, forming “ligers” or “tiglons”; and some of the female hybrids are fertile. But lions and tigers are not the same species merely because you can force the production of fertile hybrids in zoos. What is important is what happens in the wild when species co-exist. (If they don’t live in the same area, it’s sometimes difficult to tell. You can crossbreed these in the zoo or lab, and if the hybrids are sterile or inviable, that tells you that they would be separate species even if they lived in the same place. But this is a one-way test: zoo hybrids infertile or dead = different species; zoo hybrids viable and fertile = can’t tell.)
3.) The reproductive criterion of the BSC is accepted by nearly all evolutionary biologists, though some miscreants, mainly systematists, have other criteria. Allen and I explain in Chapter 1 and the Appendix of our book why we don’t think these criteria are good, and why they aren’t useful in explaining the Big Question of Speciation: why is nature “lumpy”, with distinct and usually easily identifiable groups, rather than forming a continuum? That is the true question of the origin of species, and one Darwin didn’t answer in his famous book. (He had no notion of species as reproductive units.)
Those caveats aside, let’s briefly look at Vargas’s story.
In the TC Feathers Aviary in Chantilly, Virginia (where my sister and her husband reside) live two parrots. Kirby is a male harlequin macaw, and Suzie is a female military macaw. They were of very different size and appearance, as you can see below:
They roamed free in the store, and eventually mated. They produced an egg, and it hatched into what Vargas calls a “new species”. It was dubbed “Kuzie” (a hybrid name), and grew up into a bird with intermediate traits. Here’s Kuzie as a chick:
And as an adult:
The hook in this story, which apparently entranced many readers (see the comments), was the romance between members of two supposedly different species, and the production of a cute chick born before the eyes of the customers. (The birds are not for sale.) The attraction and production of a chick between two very different birds seems to be good news in these troubled times, and that’s the way the article was written. (Perhaps they are seen as members of different bird “ethnicities”.)
But everything in the article about the birds themselves, save the fact that they reproduced, is wrong.
1.) The parents are not members of separate species. While the military macaw (Ara militaris) is indeed a real species, the father, a harlequin macaw, is himself not a member of a recognized species but a hybrid. As The Spruce Pets notes:
Harlequin macaws are only produced in captivity. This bird is known as a first-generation hybrid because it is bred from two “true” species of macaw, the blue and gold macaw [JAC: Ara ararauna, the “blue and yellow macaw”] as well as the greenwing macaw [JAC: Ara chloropteris, usually called the “red-and-green macaw“] . The result is a bird with the coloring and characteristics of both parent birds.
But Vargas calls the parents members of different species, not even mentioning that Kirby is a hybrid bird.
There are love stories, and then there is the love story of Suzie and Kirby. Theirs is a rare pairing, one that both defies nature and resulted from it. The two are species of parrots that don’t normally mate. Kirby is a harlequin macaw, and Suzie is a military macaw.
Nope. Even though Kirby was a fertile hybrid, he wasn’t a member of a species different from Suzie’s. Kirby was a “hybrid,” pure and simple.
2.) The chick is not a “new species.” So the hybrid male mated with a pure-species female, producing a male chick that had genes from three species (A. ararauna, A. chloropteris, and A. militaris). That’s truly a mule of a bird. It is a triple hybrid, but what it is not is a member of a new species. But Vargas calls it that in the headline and implies it in the text:
Kuzie, they realized, wasn’t just the product of an unusual love story. He was the product of an unusual love story that might have created a one-of-a-kind species.
Later Kirby and Suzie produced another chick, this time a female called Millie. So there are now two hybrid individuals (they don’t necessarily have the same species’ gene complement because the hybrid father produces sperm having different genes from its own two parental species).
Are the hybrids fertile? Could Millie and Kuzie produce their own chicks? Who knows! But even if they could, that says nothing about them becoming members of a new species. They are, like Kirby, hybrids. (Occasionally a new species of plant or butterfly can form in nature after hybridization, but that’s in nature, and, while common in plants, is exceedingly rare in animals.)
So what we have is a cute human interest story that is dead wrong from a biology point of view. But who cares—except for a petulant biologist like me?
In fact, I made a “get off my lawn” comment after the story (screenshot below), which, says Matthew, was like cracking a walnut with a hammer. (I’d add that it was a bad walnut). I wrote it in the heat of science passion, so it’s not especially well written and is also a wee bit intemperate!
One more point. Vargas’s story is almost like a religious tale in the sense that the truth is irrelevant because the story makes people feel good. That’s evident in the 200 readers’ comments after the story. Here’s just one:
Of course I will inform the Post, as I’m a curmudgeon, and most likely they will ignore me and not correct the story. So it goes. Cute stories drive out true stories (Coyne’s Law of Science Journalism.)
h/t: Carl
Interesting article. And importantly, completely clear to me, even with my layman’s understanding of biology.
How is the popular version of Speciation going Jerry?
At a very, very glacial pace. In other words, not at all.
Most glaciers nowadays are moving in reverse at an accelerating pace. 😎
No. Glaciers are continuing to travel forwards, like they always have. What is moving backwards is the snout of (many) glaciers, where the rate of melting increases to the point that the forward motion of the glacier can no longer sustain the presence of ice at or beyond the previous snout position.
And that’s before the seemingly paradoxical situation of glaciers where an increased temperature, particularly basally, can lead to an increase in flow rate of the glacier and advance of the snout.
That’s what I said. One step forward, two steps back. 😎
Did you pitch the popular version to the publisher?
I’m trying to think of a better simile. Paint drying is similarly variable. I dread to think of the current state of the art in sheep numerology.
This story illustrates what seems to be a common phenomenon: the hubris of people feeling that they can write accurately about subject areas they have had little or no training in. I see this often in writings about historical subjects by people who think anyone can do it. It is incumbent on people who actually know the subject area to correct blatant errors.
The Dunning-Kruger effect spreads wide and deep and shows no sign of retreat. What is remarkable is that learning a few necessary facts before pen goes to paper is just a few clicks away.
“She has a degree in sociology from Stanford and another from the Columbia University School of Journalism.” [PCC]
Seems that should qualify her for a NY Times op-ed column holding forth on most anything.
“…the truth is irrelevant because it makes people feel good.”
So do addictive drugs. And alcohol. And sexual predation makes some people feel good, too.
Sheesh.
L
Alcohol is in a class which does not include addictive drugs? How?
Thanks for your explanation, and your comment there didn’t come off too petulant 🙂
I don’t understand where the idea that there is love or a romance comes from. They didn’t really seem to have much choice of partner.
I don’t think that love or romance require large pools from which to select mates.
What about music and moonlight?
As Robinson said to Friday. Or the other way around.
The Post should be ashamed of itself. How can they expect, as journalist, to have the credibility they think they deserve by putting out such a error filled story. Have they cross pollinated with the Inquirer to get this crap. Have they joined up with Trump land?
I JUST finished reading that story and was staring out of the window, thinking “this isn’t right.” I look forward to the correction.
I bet you five bucks they don’t issue a correction (I already tweeted at them)!
I will take that bet — and propose that if it’s issued under a lame “clarification” heading, the bet’s off.
Well, I tweeted it to the Post. Do I have to do more than that, like find the science editor and email him/her/hir?
No, no. That should be sufficient notice. I would think there would be other people pointing out the error, as well.
One would like to think that their in-house science journalist(s) have already splattered their keyboards with coffee, then their (sub-) editor with objecting emails. But I would be moderately surprised if they had any staff journalists in the science (or “features”?) department as opposed to a filing cabinet full of freelancer’s CVs and examples.
I forwarded it to the Post’s science and health editor anyway, just to be sure that they don’t miss it!
Reminds me that, when I was in law school, we used to refer to hook-ups between law students as “mating in captivity.” 🙂
Doesn’t sound very comfortable, a couple living in an aviary. Hell, I once had a three-story walk-up loft apartment and that was plenty incommodious enough for anyone. 🙂
To me, this seems to illustrate the problems with the concept of a species. I’m not saying that species are not real, but there is no clear way to define them, particularly when you look at changes over time. Humans evolved from apes, but there was no moment when an ape mother gave birth to the first human.
Jerry says that a hybrid is not a member of any species. That means that when a Neanderthal mated with a Homo Sapiens, that hybrid was not a Sapiens. That hybrid then mated with other Sapiens. At what point do the hybrid children or grandchildren, etc rejoin the species?
Species are defined contemporaneously; no serious biologist would try to name species in a single lineage of descent (except in humans). So the “problem” you single out is a non-problem.
If there’s substantial introgression, as in Neanderthals and “modern” H. sapiens, it’s more or less arbitrary when the descendants are considered members of one species or another. But I consider Neanderthals and “modern” humans members of the same species, so I don’t have that problem.
Well, it still sounds like a problem to me. What you say means that there is no continuity of species over time: the species bison bison today is not the same as bison bison yesterday.
You add the caveat ‘except in humans’ – why should humans be different when it comes to defining species? And you then admit that it’s more or less arbitrary when the descendants are considered members of one species or another.
It seems to me that it is the same problem as defining ‘river’ or ‘stream’: the categories are obviously useful to us, but they are arbitrary, helpful for our poor brains to try to make sense of the world, but not reflecting real hard distinctions in the world, which flows on irrespective of our categories.
Jon:
That is true, but how could it be otherwise? The flow of the many genes [& their alleles] up through time within a species can branch & branch & branch & converge etc & when we compare two randomly chosen individuals at a particular snapshot of a future moment there WILL be many differences in the alleles these two randomly chosen individuals happen to carry. It is certainly true that in all the history of Bison bison there will be an allele that’s disappeared entirely from the species & maybe new alleles have appeared that were not present 10,000 years ago. But it’s still Bison bison even though we can’t magic an ancient Bison bison into modern times to see if it will mate & produce viable, reproductive young with the species now.
We use the species concept because of its descriptive utility – it is simply a fact of nature that extant organisms are not smeared across a spectrum of appearance, behaviour & ‘mate-ability’ – the extant organisms are organised in ‘streams’ & ‘rivers’ with huge gaps of empty ‘design space’ in the gene flow landscape.
So I repeat my question to you Jon [top of this comment] – how could it be otherwise?
Thanks for that, I can now make sense of Jon’s comment.
That’s kind of you to say Iain – I aimed for 85% accuracy & bugger any errors.
I struggled to formulate the words, not being an R. Dawkins nor a J. A. Coyne – I contemplated mentioned there’s two sub-species of Bison bison [to further my case], but decided not to do so as I’m at my complexity limit – currently refuelling on Armagnac V.S.O.P. & the brain cells aren’t firing quite in tune. Which is nice [Fast Show].
Lol… just a heads up and of no consequential input to the argument. Laingholm is the name of a little corner of the planet where I live. I need not ask if you’re enjoying your evening. CHEERS.
Michael:
You’re right, it could not be otherwise. The point I am making is that ‘species’ is not a natural category of nature, but is an idea that we try to impose on nature, for our own convenience in thinking about the world. And the idea works when we think about the differences between cats and horses. But it does not fit well with reality when we think about changes over time, and hybridisation and species diverging and merging. Not to mention ring species.
So arguments over whether a particular animal is a member of a particular species or not are sterile: ‘species’ is not and never can be tightly defined.
It’s like arguments over whether Pluto is or is not a planet. There’s no natural right or wrong answer. You can choose a definition of planet that includes or excludes Pluto. Nature just carries on in its own infinitely variable way. We shouldn’t get tied up in the idea that we are arguing about reality when we are in fact arguing about the categories we choose.
Europeans average about four per cent Neanderthal DNA. Are we still hybrids?
Have they ever left the species? As per the definition of “species” that Jerry gives up-thread, the undisputed Homo sapiens, undisputed Homo neanderthalensis, and the “hybrid” offspring (whose status is under dispute here), are all part of a mutually-fertile interbreeding population. Therefore, they are all members of the same species, including, explicitly, the “Homo neanderthalensis” in the group. “Homo sapiens” is the senior taxon (first-defined) in this group, so after showing the two names are synonymous, the ICZN rules mean that you retain the senior synonym.
The same argument applies to the Denisovans.
The argument gets considerably harder for palaeontologists, who do not (generally) have access to any genetic data, and most soft-tissue or behaviorial information. The recognition that we are actually dealing with morphological species and assuming that they equate to biological species is something that a number of my classmates in Palaeontology 2nd, 3rd and 4th year classes struggled with.
By coincidence, earlier today I was watching a “TED talk” by Jack Horner (of a Bozeman Montana museum, IIRC) where he spent some time showing why his team were arguing for the synonymy of Triceratops(*) with Torosaurus and of Pachycephalosaurus(*) with Stygimoloch and Dracorex, as being members of two distinct growth series of morphological speciers, not five distinct biological species. (Senior, retained, synonyms asterisked *.)
“Species” is not as simple as undergraduate education says. This is a problem with education, not “species”.
When I was studying biology at the University of Zurich in the early 1980s, Neandertals were considered by the our anthropology professor as being a subspecies of H. sapiens: Homo sapiens neanderthalensis.
It’s another of those “ask three anthropologists ; get four opinions” questions.
Reblogged this on The Logical Place.
Hey, at least WaPo‘ll know who to turn to next time it needs to demystify one of those heartwarming Horatio Alger-style feature stories in its “Inspired Life” section.
I like the walnut -cracking analogy. I’ve cracked thousands of walnuts with dozens of hammers. What works best? It depends on the condition of the walnut and it’s shell. (Sometimes, when I run into a batch of good-looking yet had interior walnuts, sometimes I just smack them with a sledge hammer so they compost faster.)
“Good-looking yet had interior” should be: “good-looking-yet-bad-interior” —(WordPress…Guhhhh!).
There is a whole section of the paper devoted to the metaphysics of “There was an Old Woman who Swallowed a Fly / I don’t know why etc etc ad nauseam” ?
‘…ad nauseam’
Hers or yours? 😉
This hybrid is indeed not a new species. Parrot hybrids are quite common in captivity. I have a nice series of pictures of hybrid parrots on my blog Avian Hybrids: https://avianhybrids.wordpress.com/2018/07/24/readers-hybrids-a-lot-of-hybrid-parrots/
That link pretty much nails it. There is nothing newsworthy in the WaPo article.
I overlooked the words saying “First, a didactic digression.” So as I read the first two paragraphs of the post, I mistakenly thought they were the first paragraphs of the Washington Post article. And I thought to myself, “Wow, this actually seems pretty accurate and impressively concise and precise. I wonder why Jerry is so riled up.” Then I realized that it was JAC’s words I was reading! 🙂 Oops.
Yes, articles like this are a huge disappointment and set back the efforts of those of us teaching biology to non-scientists. I weep with you.
Like a mule?
cr
Cute stories drive out true stories (Coyne’s Law of Science Journalism.)
My meme supreme of 2020
On Sun, Jan 5, 2020 at 4:46 PM Why Evolution Is True wrote:
> whyevolutionistrue posted: “A misguided science story just appeared in the > Washington Post. Read on. I will claim some expertise in this critique > because my field of study is speciation. Indeed, I literally wrote the book > on speciation in collaboration with Allen Orr. But regardl” >
This is the same inscrutable ignorance I find with religious people contemplating biological questions. Why would you consult a holy book and not consult a biologist if you have a question concerning biology.