“Species”

On the thread entitled “Species Kinds”, commenter phoodoo asks:

What’s the definition of a species?

A simple question but hard to answer. Talking of populations of interbreeding individuals immediately creates problems when looking at asexual organisms, especially the prokaryotes: bacteria and archaea. How to delineate a species temporally is also problematic. Allan Miller links to an excellent basic resource on defining a species and the Wikipedia entry does not shy away from the difficulties.

In case phoodoo thought his question was being ignored, I thought I’d open this thread to allow discussion without derailing the thread on “kinds”.

1,428 thoughts on ““Species”

  1. John Harshman: You are either incapable of or uninterested in clarity. This makes it painful to attempt any sort of discussion with you. Do you care?

    I have absolutely no idea what you are getting at.
    Perhaps by clear you mean agreeing with you?

    If you think I’m being unclear ask clarifying questions and I will be happy to answer them but don’t expect my answers to correspond to your preconceived notions of what I aught to say.

    They won’t, I’m not you.

    On the other hand why not turn over a new leaf and stick to the topic instead of being so concerned about my thoughts about God all the time?

    peace

  2. fifthmonarchyman: Can you give a couple examples of “hybrid species” that contains the accepted 50/50 split you speak of?

    It’s comparatively common in plants for species to originate by allopolyploidy, in which case exactly half the genome comes from one parent species and half from the other. Red wolf, if it’s a species, would seem to be an example in animals.

  3. fifthmonarchyman: I have absolutely no idea what you are getting at.
    Perhaps by clear you mean agreeing with you?

    I’m just asking for straight answers to simple questions. You don’t have to agree with me. You just have to be comprehensible. I’m sure you think the incomprehension is all on me, but take a look at the few questions you have tried to answer. Would anyone other than you understand those answers? I doubt it. You can’t even answer “do you care?”

  4. fifthmonarchyman: I think you mean that a few times in the course of a millions of years interbreeding resulted in known lateral gene transfer that became established in the wider population . I’d say given the limited population size and non-overlapping habitats of these animals that is a heck of a lot.

    You are correct about what I meant. Whether you would say that’s a heck of a lot doesn’t seem relevant.

    according to the article I linked the criteria of genetic isolation they are probably already a species

    Really? They’re genetically isolated from both coyotes and wolves? Interesting. Where does it say that, and what would cause that to happen?

    Again a introgression event is not the same thing as interbreeding. The 5% means that not only was interbreeding happening but the offspring of such unions were not evolutionary dead-ends but provided advantage of some kind over their more prudish and darwinianly “pure” neighbors.

    Stripped of the weird moral opprobrium, you are correct. But if there were selection favoring introgression, it wouldn’t take more than a few interbreedings, perhaps as little as one, to account for the introgression.

  5. John Harshman: It’s comparatively common in plants for species to originate by allopolyploidy, in which case exactly half the genome comes from one parent species and half from the other. Red wolf, if it’s a species, would seem to be an example in animals.

    I’m sorry but you are just incorrect. The question is do you care?

    https://motherboard.vice.com/en_us/article/jpgddd/the-red-wolf-is-mostly-coyote-conservation-endangered

    quote;

    By conducting whole-genome sequence analysis on 28 canids—including gray wolves, red wolves, eastern wolves, coyotes, and even domestic dogs—the team found that the red wolf is about 25 percent gray wolf and 75 percent coyote, while the eastern wolf is about 50 to 75 percent gray wolf, and roughly one quarter coyote.

    end quote:

    wanna try again

    Do you have any actual examples of “hybrid species” that have the golden 50/50 ratio you speak of?

    peace

  6. John Harshman: You can’t even answer “do you care?”

    Do I care about what?
    Do I care if I am clear? of course I do.
    Do I care that you claim to be unable to understand me? Not so much

    The problem with your claim is that any specific questions you do ask are almost always about my thoughts about God and not about the topic at hand so I know you are not striving for actual understanding but to muddy the waters.

    You do ask over and over what the point is but even then you admit that your reason for doing so is because you are concerned it’s really about Jesus.

    Do you have any specific questions about the implications of the science presented in the article?

    peace

  7. fifthmonarchyman: Do you have any actual examples of “hybrid species” that have the golden 50/50 ratio you speak of?

    Yes, any allopolyploid. Sorry about the red wolf; I misremembered.

    Why do you end every post with “peace” when what comes before is so combative, not to say dickish?

    I’ve asked a lot of specific questions. I don’t care to repeat them right now. Just please entertain for a moment the idea that part of our communication failure is yours.

  8. John Harshman: Really? They’re genetically isolated from both coyotes and wolves? Interesting. Where does it say that, and what would cause that to happen?

    do I really have to spoon feed this stuff to you?

    from the article I linked

    quote:
    Despite the mixed-species background that created it, there is no ongoing hybridization in most of this creature’s range, which centers around New England—and that means we have a new species in our midst
    end quote:

    peace

  9. John Harshman: Just please entertain for a moment the idea that part of our communication failure is yours.

    I’m certainly no angel but I try to be 😉

    John Harshman: Why do you end every post with “peace” when what comes before is so combative, not to say dickish?

    It helps to remind me that despite the way that I am responded to my aim should always in the end be—–peace

    I’m sorry if I come off as little combative at times but it is no fun wading through the crap shower that is constantly flung at any one here who is willing to admit to theism.

    I not complaining mind you, I a big boy and I can handle it.

    peace by the way in the sense of shalom is not the absence of conflict it’s completeness, soundness, welfare,

    peace

  10. John Harshman: Just please entertain for a moment the idea that part of our communication failure is yours.

    Especially that word “peace” at the end of your posts. That appears to be a real barrier to communication with John. LoL!

  11. fifth,

    I’m sorry if I come off as little combative at times but it is no fun wading through the crap shower that is constantly flung at any one here who is willing to admit to theism.

    If you were actually making good arguments for theism, then you would earn some respect. (Why do you suppose that when the chips are down, God never reveals to you what you need to make your case? It’s almost as if he doesn’t exist.)

    Your thinking is very poor, fifth. Folks here can easily spot your errors, and we are trying to explain them to you. Your ego is getting in the way.

  12. Meanwhile, in an alternate universe, God brings Man in front of each of the animals to see what they will name it.

  13. fifth,

    For example, I explained why this statement of yours was wrong…

    I think “conventional” implies not real so I would not use that terminology either.

    If species are not real then Darwin was wasting his time trying to explain their origin.

    …by pointing out that:

    By Fifth Logic ™, New York City is not real.

    Time to trade in your logic, Fifth.

    Your error is obvious. The boundaries of a species, like the limits of a city, are a human convention. That doesn’t mean that what is enclosed within those boundaries or limits is unreal, or that the boundaries and limits themselves do not correspond to objective features of reality.

  14. I actually observed a sign: The City of New York ends here!

    Of course, cities don’t inter-breed, so keiths’s analogy fails.

  15. keiths: The boundaries of a species, like the limits of a city, are a human convention.

    Not usually. For the most part they’re pretty tight.

  16. Mung:
    Meanwhile, in an alternate universe, God brings Man in front of each of the animals to see what they will name it.

    In Latin

  17. John,

    How would tightness contradict the idea that the boundaries are a human convention? Human conventions can be loose and arbitrary, but that doesn’t mean that they have to be.

  18. fifthmonarchyman: such as? be specific please

    The first ones I came across in google are Tragopogon mirus and Tragopogon miscellus, but it’s been estimated that as much as 5% of all speciations in plants are by allopolyploidy. It’s said to be especially common in ferns.

    Now contrast that response with

    fifthmonarchyman: do I really have to spoon feed this stuff to you?

    Which is more reflective of Christian morality?

  19. keiths:
    John,

    How would tightness contradict the idea that the boundaries are a human convention?Human conventions can be loose and arbitrary, but that doesn’t mean that they have to be.

    Well, I would have said that the clear and objective nature of those boundaries (particularly if we’re using the biological species concept) argues against their being a human construct. The locations of those boundaries are discovered, not invented.

  20. John Harshman: Which is more reflective of Christian morality?

    Spoon feeding. I’ll keep that in mind if you ever take me off ignore, lol.

    John needs to be spoon fed.

  21. John,

    Well, I would have said that the clear and objective nature of those boundaries (particularly if we’re using the biological species concept) argues against their being a human construct. The locations of those boundaries are discovered, not invented.

    The choice of the biological species concept, as a way of establishing species boundaries, is itself a human convention. But again, that doesn’t make it loose or arbitrary. It is a genuine attempt to carve nature at some plausible and meaningful joints.

    Fifth’s statement is clearly incorrect:

    I think “conventional” implies not real so I would not use that terminology either.

  22. keiths: The choice of the biological species concept, as a way of establishing species boundaries, is itself a human convention. But again, that doesn’t make it loose or arbitrary. It is a genuine attempt to carve nature at some plausible and meaningful joints.

    But not entropy, right?

  23. keiths: Why would you say that?

    Because, iirc, I was arguing that entropy had an objective physical basis and you were arguing that it was strictly mental. Remember all that talk of “epistemic probability”?

  24. Mung,

    Because, iirc, I was arguing that entropy had an objective physical basis and you were arguing that it was strictly mental.

    I’m a physicalist, Mung. For me, the mental is physical. What else could it be?

    The entropy of system S as seen by observer A can be different from the entropy of the same system as seen by observer B. That’s because observer A and observer B can have different knowledge regarding the exact microstate of S.

    It’s still a physical difference, but the difference is in the observers’ states, not in the state of system S.

  25. Neil Rickert,

    Yeah, islands are a conventional thing, because we can arbitrarily say that the border between water and land is here or there or wherever. Good point.

  26. fifthmonarchyman:

    If God does not exist you and I and your love ones and all of humanity are not even an afterthought when it comes to “the universe” we are simply a infinitesimal puff of vapor belched from a tiny speck forgotten as as quickly as it arose. No meaning whatsoever.

    Your version of God may exist (personally, I very much doubt it) or some other version of God may pertain, or there’s another explanation for why there is a universe not involving Gods. Seems to me it’s a personal choice that both you and I are free to make as no evidence supports any worldview to the extent that it answers “why is there this universe?”. Frankly, I don’t find your poor analogies (not just yours, 🙂 ) at all persuasive.

    empty because it necessarily by definition contains no meaning whatsoever.
    sad because it’s so empty

    If God does not exist what you think or feel is nothing but the gurgling of a tiny insignificant chemical reaction that lasts for a fraction of an instant and is subsumed into the surrounding abyss.

    Perhaps this makes sense to you.

    If you think differently it only means you are the self deluded gurgling of a tiny chemical reaction that lasts for a fraction of an instant and is quickly subsumed into the surrounding abyss.

    I find the thought of utter oblivion at my physical death reassuring. I don’t need the wishful thinking of some “after-life”. As I say, it’s a personal choice and if your beliefs help you through the day, good for you.

    A godless universe is not changed in the slightest whether you exist or not. It does not even know you are here.

    Vanity! All is vanity! 🙂

    You can foolishly claim your life has meaning just as a self deluded fruit fly can claim to be the queen of england but that certainly does not make it so.

    As a point of fact, I doubt a fruitfly can do such a thing. Poor analogy!

  27. On the subject of poor analogies, perhaps the city vs species analogy could be improved by regarding the inhabitant population as the species and the city limits as the niche. The living population is the gene pool, quarters and districts could result in local populations becoming isolated enough to form subspecies. The founding of the city could be compared to a speciation event where a small group move from their old city and small groups could leave and find new sites to establish new cities. Over time, populations in different cities change enough, (language, culture, etc) to make moving back to the old city difficult enough to ensure separation. Modern Rome is very different from Ancient Rome but there’s a continuum.

  28. Alan,

    On the subject of poor analogies, perhaps the city vs species analogy could be improved by regarding the inhabitant population as the species and the city limits as the niche.

    No, because my point is not to analogize species with cities. I’ve simply provided New York City as a counterexample to fifth’s statement:

    I think “conventional” implies not real so I would not use that terminology either.

  29. John Harshman: The first ones I came across in google are Tragopogon mirus and Tragopogon miscellus

    Oh kay,

    But I was looking for examples from higher animals. The only one I’m aware of is Xenopus laevis but i don’t think it has the golden 50/50 ratio you threw out.

    John Harshman: Which is more reflective of Christian morality?

    I would say mine,

    I gave you the information you were requesting immediately after you asked and with context despite having already told you exactly where to find it and providing a link. The information I provided was also relevant to the topic we were discussing which was hybridization in species like the big cats and red wolves.

    peace

  30. keiths: The choice of the biological species concept, as a way of establishing species boundaries, is itself a human convention. But again, that doesn’t make it loose or arbitrary. It is a genuine attempt to carve nature at some plausible and meaningful joints.

    Fifth’s statement is clearly incorrect:

    I think “conventional” implies not real so I would not use that terminology either.

    Nope, sorry but you are the one who is incorrect here. Neil said species were human convention not species boundries

    That is why I asked you if you thought New York city was just a human convention.

    I have no problem with the idea that the boundaries we place on species being simply human convention.

    As Alan has pointed out I think the true boundaries are known to God

    peace

  31. keiths: No, because my point is not to analogize species with cities.

    but that is exactly what you did and now you are trying to act as if you did not

    peace

  32. fifthmonarchyman: I have no problem with the idea that the boundaries we place on species being simply human convention.As Alan has pointed out I think the true boundaries are known to God

    How does God reveal that there are true boundaries?

  33. fifthmonarchyman: But I was looking for examples from higher animals

    You didn’t say. What’s wrong with plants? What’s wrong with “lower” animals (whatever those are)?

  34. Erik,

    Yeah, islands are a conventional thing, because we can arbitrarily say that the border between water and land is here or there or wherever. Good point.

    Tide comes in, tide goes out. Static mean high water mark, perhaps, though sea level appears to be rising.

  35. John Harshman,

    Why do you end every post with “peace” when what comes before is so combative, not to say dickish?

    A keeper from some time back (to someone else):

    “Do you kiss Darwin with that mouth?

    peace”

  36. Corneel: You didn’t say. What’s wrong with plants? What’s wrong with “lower” animals (whatever those are)?

    Giraffes vs flounders.

  37. fifthmonarchyman,

    Again a introgression event is not the same thing as interbreeding. The 5% means that not only was interbreeding happening but the offspring of such unions were not evolutionary dead-ends but provided advantage of some kind over their more prudish and darwinianly “pure” neighbors.

    This seems to have gone unchallenged, even accepted, but I experienced a bit of a ‘youch’ moment. It is not necessary for genes to provide an advantage to become fixed.

  38. Two minor points worth stressing:

    1. To say of something that it is conventional is not to say that it is not real; it is to indicate what kind of reality something has. Buddhist metaphysics distinguishes between ‘conventional reality’ and ‘absolute reality’. A distinction like that seems quite helpful.

    2. Species can be perfectly real — “absolutely real”, if you like — even though our interests in biological explanation play a role in determining the exact spatial and temporal boundaries of a species.

  39. John Harshman: Why do you end every post with “peace” when what comes before is so combative, not to say dickish?

    FMM would hardly be a good example of a Christian if he weren’t condescending and passive-aggressive.

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