Ecology Evolution extinction

Butterfly “extinction” that wasn’t

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Edith’s checkerspot butterfly (Euphydryas editha)/Michael C. Singer, University of Plymouth

From ScienceDaily:

The evolution of wild species, adapting them to human management practices, can cause localised extinctions when those practices rapidly change. And in a new study published in Nature, Professors Michael C. Singer and Camille Parmesan have used more than 30 years of research to fully document an example of this process.

A large, isolated population of a North American butterfly evolved complete dependence on an introduced European weed to the point where the continued existence of the butterfly depended on the plant’s availability. The insects then became locally extinct when humans effectively eliminated that availability, confirming a prediction made by the same authors in a 1993 Nature paper.

Thus the advent of cattle ranching more than 100 years ago set an eco-evolutionary trap that the insects obligingly fell into, and the trap was sprung when humans suddenly removed the cattle, withdrawing their ‘gift’, and driving the butterflies to extinction.

As soon as the butterflies encountered the plantain, their caterpillars survived better on it than on their traditional host, Blue-Eyed Mary (Collinsia parviflora), causing the adults to evolve preference for laying eggs on the plantain. By the mid-2000s, they were 100% reliant on the plantain and the Collinsia had been abandoned.

However, within three years of the ranch’s cattle being removed due to financial pressures, the butterflies became locally extinct as the grasses around their favoured new host were no longer grazed, and the plantains became embedded in those grasses, cooling the micro-environment. The Collinsia was unaffected by removal of cattle, so if the butterflies had not evolved so rapidly in response to the introduction of the plantain, they would most likely have survived.

Around five years after the extinction, Edith’s checkerspots recolonized the meadow. Since they were all found feeding on Collinsia, the original host plant, scientists believe these colonists to be a new population, and that the lineage which had called the ranch home for several decades no longer exists. Paper. (paywall) – Michael C. Singer, Camille Parmesan. Lethal trap created by adaptive evolutionary response to an exotic resource. Nature, 2018; 557 (7704): 238 DOI: 10.1038/s41586-018-0074-6 More.

“Extinction” is put in scare quotes above, though not in the ScienceDaily release, because this event is correctly termed an “extirpation” from a region. The extirpation did not stop checkerspots from other regions from moving into the area five years later. This sort of thing may well be common in nature. “Extinction” should properly mean dead and gone, like the trilobite and the tyrannosaur.

A question arises: Given that butterflies often hybridize, some extinctions may not mean quite what we think.

Also, a surprising number of life forms we believe to be extinct turn out not to be (lazarus species).

The study authors suggest that similar events may be happening in Europe. We’d best e clear about what those events are, exactly.

See also: Sixth mass extinction, but no news on defining “species”?

Extinction (or maybe not): New Scientist offers five “Lazarus species”

Lazarus species: animals listed as extinct that turned up again.

In a meadow in America a group of butterflies have been drawn into a lethal evolutionary trap. This trap, set by humans, was abruptly sprung when people left the area, leading to a local extinction. Nature Video uses painted hands to tell the story of the Edith’s checkerspot butterfly. More.

43 Replies to “Butterfly “extinction” that wasn’t

  1. 1
    Bob O'H says:

    “Extinction” should properly mean dead and gone, like the trilobite and the tyrannosaur.

    And indeed the population that had become adapted to P. lanceolata had gone the way of the dodo.

  2. 2
    PaV says:

    If we’re going to talk about butterflies, then mention should be made of Goldsmidt’s “Material Basis of Evolution,” in which he identifies a different soil as the cause of a supposed speciation event at the ‘end’ of an adaptive ring.

    Not a change in “allele frequency,” but a change in soil type.

    And Bob, I noticed you wrote “population,” and not “species.” Very telling.

  3. 3
    PaV says:

    From Science Daily:

    Around five years after the extinction, Edith’s checkerspots recolonized the meadow. Since they were all found feeding on Collinsia, the original host plant, scientists believe these colonists to be a new population, and that the lineage which had called the ranch home for several decades no longer exists.

    Are scientists supposed to “believe” or to “know”?

    They don’t appear to know ‘up’ from ‘down.’ Supposition substitutes for science.

  4. 4
    Bob O'H says:

    PaV – this work is nothing to do with speciation, so I guess it is telling that I don’t refer to species.

  5. 5
    Allan Keith says:

    PaV,

    And Bob, I noticed you wrote “population,” and not “species.” Very telling.

    How is this very telling? The word “extinction” is not limited to an entire species. In fact, when talking about modern ecosystems as opposed to the fossil record, the word extinction is used far more frequently to describe populations. For example, the eastern cougar is considered extinct.

  6. 6
    ET says:

    So if a population moves from one area to another they become “extinct” in that first area/? Really?

    Seems like a very poor choice of the word.

  7. 7
    Allan Keith says:

    ET,

    So if a population moves from one area to another they become “extinct” in that first area/? Really?

    Seems like a very poor choice of the word.

    Take it up with the dictionary.

    Extinction: a situation in which something no longer exists.

  8. 8
    Bob O'H says:

    ET – I’m not aware of anyone suggesting that that is what happened.

  9. 9
    Eric Anderson says:

    AK @7:

    LOL!

    He quotes a dictionary definition that does not support his statement about a move from one area to another. “Existing” is certainly not limited to occupying a particular geographical region.

    Either something exists or it doesn’t.

  10. 10
    Allan Keith says:

    Eric,

    He quotes a dictionary definition that does not support his statement about a move from one area to another.

    That wasn’t my statement.

    “Existing” is certainly not limited to occupying a particular geographical region.

    Nobody said that it was. I was just saying that modern eciology more often uses the word “extinction” to describe the loss of a population (usually in a specific area) than to describe the loss of a species. For example, the eastern cougar is extinct. But Puma concolor, the species that the eastern cougar belonged to, still exists and is plentiful.

    But if you want to be precise, the correct term to use for situations like this is “extirpated”.

  11. 11
    News says:

    Eastern cougar? Report sightings here. The bumf from the government at the page is a masterpiece of evasion but never mind. If you see a cougar in southern Ontario (where the vast majority of the human population lives), do let the government know. They have a relocation program that does not involve the fur trade.

    Cougars are famously elusive but occasionally one is captured, this one in Cobourg on Lake Ontario, in Toronto’s exurbs.

  12. 12
    asauber says:

    “localised extinctions”

    This is like “global warming”… lets play loose with the terms to perpetuate the narrative we like. Forget about precision in language. We need marketing, not science.

    Andrew

  13. 13
    ET says:

    Bob O’H:

    I’m not aware of anyone suggesting that that is what happened.

    There isn’t anything to indicate that it didn’t happen.

  14. 14
    ET says:

    Allan quotes a dictionary:

    Extinction: a situation in which something no longer exists.

    Look up the word “exists”- if the species is still alive it still exists.

  15. 15
    bb says:

    The Kroger grocery chain was the primary supplier to residents in the mid-western area known as Smithville. Then Wal-Mart moved in, setting an evolutionary trap. Lower prices for the most desired staples, wider selection, and longer hours of operation caused those accustomed to shopping at Kroger to spend more time at Wal-Mart. The Smithville Kroger population dwindled, then……..was extinct, like the local Kroger branch.

    “It is a remarkable demonstration of evolution. When shoppers adapt their ways to opt for a more economic supplier.” Said David Robinson, a noted anthropologist. “What would happen to the new Wal-Mart population, if the store closes, and Kroger reopens to fill the niche?”

    It would be fun to see if a paper based on the unremarkable bit above could be published in a journal.

  16. 16
    Allan Keith says:

    ET,

    Look up the word “exists”- if the species is still alive it still exists.

    Then you should petition all the biologists and ecologists and tell them to stop using a term that they have always used.

    From the OP,

    The evolution of wild species, adapting them to human management practices, can cause localised extinctions when those practices rapidly change.

    Are you suggesting that we shouldn’t be worried about localized extinctions? Or are you just arguing for argument sake?

  17. 17
    ET says:

    Allan:

    Then you should petition all the biologists and ecologists and tell them to stop using a term that they have always used.

    You’re the clown who provided the definition that doesn’t fit what they are talking about.

    Are you suggesting that we shouldn’t be worried about localized extinctions?

    Yes, why worry when the population could have just moved on? There aren’t any Amazon tribes near where I live does that meant they are locally extinct? Really?

  18. 18
    ET says:

    bb @ 15- Excellent- nicely done

  19. 19
    Allan Keith says:

    AK,

    Or are you just arguing for argument sake?

    ET,

    Yes, why worry when the population could have just moved on? There aren’t any Amazon tribes near where I live does that meant they are locally extinct? Really?

    I will take that as a yes.

  20. 20
    PaV says:

    How is this very telling? The word “extinction” is not limited to an entire species. In fact, when talking about modern ecosystems as opposed to the fossil record, the word extinction is used far more frequently to describe populations. For example, the eastern cougar is considered extinct.

    In the hands of evolutionists, words are drained of their meaning. You know, as in: “That depends on the what the meaning of is is.”

    So, now, a ‘species’ is a ‘species,’ unless its a population. Well, but how do you know its a ‘species’? Well, because ‘species’ don’t interbreed; they’re ‘populations’ that don’t breed. But, of course this is so even when ‘species’ do, in fact, interbreed.

    What a bunch of mush. To cover up failed theories and thought, as well as outright ignorance, words end up being mangled. This isn’t science; it’s ideology.

  21. 21
    PaV says:

    Bob O’H:

    Please dicpher this:

    A large, isolated population of a North American butterfly evolved complete dependence on an introduced European weed

    .

    Here there is not distance whatever between ‘adaptation’ and ‘evolution.’ Again, words are mangled; they become as malleable as ‘mush.’

    Try building something on mush.

  22. 22
    ET says:

    Earth to Allan Keith- I was not arguing. I was just pointing out the obvious- that the definition you provided doesn’t fit in the context of the discussion.

    Eric pointed it out earlier and instead of acknowledging it you spewed out an attempted distraction. And then you tried to change the subject.

    That is unethical and dishonest. 😉

  23. 23
    Allan Keith says:

    PaV,

    In the hands of evolutionists, words are drained of their meaning. You know, as in: “That depends on the what the meaning of is is.”…

    What a bunch of mush. To cover up failed theories and thought, as well as outright ignorance, words end up being mangled. This isn’t science; it’s ideology.

    Extirpation: Extirpation (also known as ‘local extinction’) describes the situation in which a species or population no longer exists within a certain geographical location.

    How is the way that biologists and ecologists use the word “extinction” an attempt to cover up a failed theory and thought? It is merely a descriptive term. The eastern cougar which used to be found all throughout north eastern North America is now extinct within this range. Walruses are now extinct in the gulf of St. Lawrence. The grey wolf is extinct in two thirds of its original range. None of these species is actually extinct.

    I feel like I am in the middle of the Monty Python dead parrot sketch with you and ET claiming that it isn’t dead, it is just pining for the fjords.

  24. 24
    bb says:

    AK’s position is an obvious game, as PaV points out the language distortion used to support the lame assertion. Researchers most-likely have no idea whether the population died out, or simply moved on, which would probably be impossible to tell. What is the difference between the group that spawned on the European weed, and those on the Blue-Eyed Mary? There probably isn’t one. ==It is probably the same population, like the Kroger shoppers that left for Wal-Mart.

    I have seen environmentalists label a well-planned, suburban, real estate development as “urban sprawl”, when that term refers to an unplanned collection of houses on the fringe of a city. I once confronted a lawyer over his use of the label and he offered his relativistic definition in defense. This is all that AK is doing, rather than admit he is wrong.

    It’s the same game that has hurt Californian farmers for the sake of the invented species “Delta Smelt”, which is just a term for smelt that are no different than the vast population in the ocean, but just happen to live in the San Francisco delta.

  25. 25
    ET says:

    And Amazonian tribes are extinct in the northeast too. Chinese peasant farmers have been extinct from the region since humans started taking notice. 😎

    The eastern cougar which used to be found all throughout north eastern North America no longer lives in great numbers within this range.

    Walruses have now moved from and no longer occupy the gulf of St. Lawrence.

    The grey wolf no longer occupies two thirds of its original range.

  26. 26
    Allan Keith says:

    ET,

    And Amazonian tribes are extinct in the northeast too.

    Translation: “That parrot’s not dead, it’s just pining for the fjords.

  27. 27
    ET says:

    Allan Keith- Your selective quoting of my posts betrays you. Clearly all you want to do is to argue for the sake of arguing. You are clearly a hypocrite.

    Or maybe thoughts have gone extinct from your brain. The not so great brain-drain thought extinction event.

  28. 28
    Bob O'H says:

    PaV @ 21 – that sentence is clear enough to me. In the paper the authors point out that heritability for plant preference is high in the population, so this seems like evolution to me (i.e. a genetic change in the population).

    bb @ 24 – I don’t know of any evidence of a mass migration in checkerspot butterflies, and they have been studied for decades (indeed Mike Singer has studied them for decades). So why invoke some unseen (and unlikely: these butterflies don’t swarm) mechanism?

    What is the difference between the group that spawned on the European weed, and those on the Blue-Eyed Mary? There probably isn’t one.

    Actually there is. Host preference, for a start, and this is largely genetically determined.

  29. 29
    bb says:

    Bob O’H,

    I don’t know of any evidence of a mass migration in checkerspot butterflies

    But does that eliminate it from consideration? Was it ever considered? Did the preference change without mass migration?

    Host preference, for a start, and this is largely genetically determined.

    Was it genetically determined for the checkerspot butterfly to prefer the European weed initially, or was it free to choose before genetics changed to foster dependence? Has anyone challenged Singer’s conclusion, put it to the test, and reproduced his research?

  30. 30
    Bob O'H says:

    bb – I’m sure Mike and Camille didn’t consider alien intervention either. They’ve been studying this species for – literally – decades, and have no evidence for mass migration. These aren’t gregarious butterflies (at least not as adults), and they have studied its migration and generally it doesn’t migrate very far.

    Was it genetically determined for the checkerspot butterfly to prefer the European weed initially, or was it free to choose before genetics changed to foster dependence?

    No, before it would prefer the native host plant. Although preferences are strong, they are clearly not perfect (there’s a map of host preference in this report, for example).

  31. 31
    bb says:

    Bob O’H,

    Your reasoning is unconvincing.

    For at least the next four years, Edith’s checkerspot butterflies were completely absent from Schneider’s Meadow.

    …but the there was a population explosion Carter Springs. Absence isn’t extinction when the species can be found elsewhere. Whose to say the butterflies didn’t migrate for a time? Has anyone challenged Singer’s conclusion, put it to the test, and reproduced his research?

  32. 32
    PaV says:

    Allan Keith:

    The eastern cougar which used to be found all throughout north eastern North America is now extinct within this range.

    This is simply a glib statement you make, and you take it for granted that it means something; however, it is nonsensical. This is the problem with evolutionists: they make nonsensical statements and then think they have made some kind of point.

    It is madness to follow this stuff. I’ve basically stopped following evolution for about four years. It’s, as I said, “mush.” I’ve got better things to do.

    Now, as to the nonsensical nature of your comment: you say,
    “. . . is now extinct within this range.” “Extinct” in a range! Really!??

    This is what you should be saying: “The eastern cougar which used to be found all throughout north eastern North America is no longer FOUND within this range.”

    Here’s a hypothetical: a mountain lizard is cut-off from an entire portion of a mountain range by a water-carrying canal that makes crossing over completely impossible. Would we now say that this mountain lizard is "extinct" in this 'cut-off' portion of the range?

    This should be simple to see.

    What if an entire population, for a variety of reasons, perhaps induced by human populations, migrates to a completely different region? Are they now "extinct" in the region they moved out of?

    Enough.

  33. 33
    PaV says:

    Bob O’H:

    . . . so this seems like evolution to me (i.e. a genetic change in the population).

    But, of course, neutral molecular evolution is invisible. So, a “genetic change in the population” gets you nowhere.

  34. 34
    Eric Anderson says:

    AK:

    You make a fair point that we can certainly apply an adjective to a noun to limit the noun. I don’t have a problem with that, as long as people are clear what they are talking about. In addition to the less-than-clear terminology in the quoted parts of the OP, I think part of the skepticism you are hearing also stems from the popular and rather self-serving approach of researchers to phrase their research in terms that can provide more headlines and more funding. It is worth noting that claims of extinction from human activities are all the rage right now, so it grows tiresome. That is part of the concern with these kinds of claims. We would be quite naive if we didn’t recognize that a headline of “extinction” is much more attention-grabbing than a headline that human activities “impact” species.

    That said, I do grant that we can qualify a noun with an appropriate adjective.

    There are at least a few situations that come to mind. I’d be curious to know to which of these situations you think it would be appropriate to apply the label “extinction”, qualified by “local” or otherwise.

    1. Annual migration. Deer move to higher mountain meadows in the summer to graze and then when the snows fly move to lower elevations. Does that mean, come September or October, there is a “local extinction” of deer in the mountain meadows?

    2. One-time migration. A population moves out of an area for good. Is this a “local extinction”? Would our answer change if the migration were for a slow lack of food source over time, due to predators, or due to changing climate?

    3. Abrupt change in food source. A population moves out of an area due to an abrupt change in food source. Is this a “local extinction” of the population? If so, it seems it would also be a “local extinction” of the food source?

    4. Dies out. A population actually dies out (rather than moving) in a particular isolated area, whether from lack of food, predation, or changing climate. Is this an “extinction”, local though it may be? Does it matter if other members of the species continue to live in other locations? If those members come back to this location, what do we call it?

    Thanks in advance for your thoughts,

  35. 35
    Allan Keith says:

    PaV,

    This is simply a glib statement you make, and you take it for granted that it means something; however, it is nonsensical. This is the problem with evolutionists: they make nonsensical statements and then think they have made some kind of point.

    All I have said is that biologists and ecologists do not limit the use of the word “extinct” to the loss of an entire species. It is not a judgement claim or an evolutionary claim. It is just a statement of fact. A quick Google search will demonstrate this.

  36. 36
    Eric Anderson says:

    Bob O’H @28:

    . . . so this seems like evolution to me (i.e. a genetic change in the population).

    Ah yes. Speaking of vague terminology!

    The last definitional refuge of the evolutionist is to claim that any change is “evolution”. That way evolution is super easy to prove!

    My kids represent a “genetic change” from the prior generation. Ta-da! Evolution!

  37. 37
    ET says:

    Allan:

    All I have said is that biologists and ecologists do not limit the use of the word “extinct” to the loss of an entire species.

    And we are pointing out they are playing fast and loose with words that have clear meanings.

  38. 38
    Allan Keith says:

    Erik, with regard to your questions:

    1) No. periodic migrations that are part of the normal life cycle should not be referred to as local extinctions.

    2) A one time permanent migration, regardless of the cause, could be called a local extinction.

    3) This could be a local extinction as well. Whether it is also a local extinction of the food source would depend on whether it is completely gone or just reduced.

    4) This would also be a local extinction.

    I understand that emotional baggage comes with calling it a local extinction, but this is not new terminology. Regardless of the cause, the local removal of a population from a defined area is defined as a local extinction or an extirpation.

    There are some local extinctions that are man made that we simply accept because their presence cause too much of a negative impact on us.

  39. 39
    Bob O'H says:

    bb @ 31 – if you really think that Edith’s checkerspot (or indeed any other checkerspot) undergoes mass migration, show us the evidence. This species (and checkerspots generally) are well studied, so I’m sure the evidence would be put there. Have you studied Edith’s checkerspot? Indeed have you even seen one? I’m happy to put my faith in people who have actually studied it.

    PaV @ 33 – who said anything about this being neutral? The argument is that the changes in host preference are driven by selection.

    Eric @ 36 – in this case there is a clear phenotypic change in the population in a trait that has a high heritability (i.e. there is an underlying genetic change). How is this not evolution?

    Folks – on the extinction thing, the terminology is clear. What is being talked about is a local extinction (i.e. the extinction of one population in a metapopulation). The terminology is standard (it goes all the way back to Levins in the late 60s), and I don’t think anyone would mis-understand what was actually meant.

  40. 40
    bb says:

    Bob O’H,

    I merely asked if they migrated. It’s a reasonable question, and conclusion, when the species is found in nearby regions. You said that you didn’t know of any evidence that they did. Is there any evidence that the population didn’t migrate? Like maybe they died off? That’s the implication of the word “extinction”, whether modified into a different definition by “localised” or not. Has anyone challenged Singer’s conclusion, put it to the test, and reproduced his research? You keep skirting this question.

  41. 41
    Eric Anderson says:

    AK, thanks.

    Re #4, what would we call the return of the species to the geographical area after a “local extinction”?

  42. 42
    ET says:

    I used to think that my neighbors moved to Maine but now I know that they just became locally extinct. 😎

  43. 43
    Bob O'H says:

    bb – what exactly are you asking for? There’s no evidence for migration of whole populations of this species. So it’s the natural assumption that the reason why there were some there one year and not the next is a local extinction. We know this happens a lot with butterflies (I first met Mike several years ago when he was working on a butterfly in Finland which does this a lot).

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