4 ms·

Basically any group of organisms that have sex with each other...

by johnea 3y ago

hef19898 3y ago
And produce fertile offspring.
- kjkjadksj 3y ago
  Some humans would fail to meet that definition
  - borroka 3y ago
    You are, wrongly, scaling up from the potential of individuals to the potential of the group of individuals/species. Saying that "humans" are capable of locomotion or movement using their legs implicitly refers to an expectation, and nobody with that intends to say that individuals who are confined to a wheelchair are not humans. Saying that humans have 5 fingers on each hand, which is the expectation, does not imply that individuals born with a different number of fingers are not humans, but simply that is not the expectation.
    - Jensson 3y ago
      But when biologists finds an insect type with different number of something they will call it a new species. That we don't do that for humans has to do with politics more than anything else, some believe we would discriminate against such humans if we said they weren't really the same species.
      - borroka 3y ago
        > But when biologists finds an insect type with different number of something they will call it a new species. This comment cannot be answered properly without knowing who the "biologists" are, which insect types we are talking about, and what is going along with the different number of something. The fact that individuals with four or six fingers are considered to be of the same species has nothing to do with politics, but with the fact that people with "4 fingers" can reproduce (this is the expectation) with individuals with "5 fingers" and "6 fingers" and produce fertile offspring. Politics comes into play when it comes to, for example, species conservation. Populations of the same species that have remained isolated from each other for centuries, millennia or more may accumulate due to selection processes, genetic drift or founder effect, genetic and phenotypic characteristics that do not allow individuals from the two populations to reproduce successfully. Fertilization may not occur, the progeny may show morphological abnormalities, or the offspring may not be fertile. But the above may occur in, say, 20 percent, 50 percent or 90 percent of cases, and for any of these percentages the existence of a new species, variant or subspecies can be argued. Should the two populations be protected since they are (or are not) different species?
      - lo_zamoyski 3y ago
        Then defect is no longer intelligible. And yet, we can determine if a heart is defective, because we know the function of a heart, we know how that function composes into the telos of the organism (which is what transmits the function to organ, so to speak). Thus, any modification of the heart, certainly one that we see has ill effects for the organism, is a defect. It is clear that a human being who is sterile, or one who cannot move about, is in some sense a defective specimen, as these deficiencies impede the realization of human telos. (If you deny telos, then truly nothing is intelligible. Not only does the notion of defect no longer make sense, not only are biology and biological function impossible and anatomy made unintelligible, but even efficient causality is made unintelligible and science impossible, as the very fact that an effect follows from a cause, that is is not arbitrary, presupposes telos.)
  - Scarblac 3y ago
    I have had a vasectomy, I'm now on my own in my species :-(
    - Hucklederry 3y ago
      [dead]
camdenlock 3y ago
… and produce viable offspring. An important distinction, because without viable offspring, genetic transmission halts.
- gnatman 3y ago
  Y'all should read the article. It goes into more depth than these two comments! For example, two species can have sex, AND produce viable offspring, but NOT produce fertile offspring. Like a donkey and horse producing a typically infertile mule. Horses and donkeys are not the same species.
  - onychomys 3y ago
    And sometimes you can have two things that everybody agrees are different species but which happily hybridize (with fertile offspring) all the time! https://www.princeton.edu/news/2020/05/07/gene-flow-between-species-influences-evolution-darwins-finches https://www.princeton.edu/news/2020/05/07/gene-flow-between-...
  - eviks 3y ago
    Viable=fertile here
    - InitialLastName 3y ago
      Some mules are fertile: http://news.bbc.co.uk/2/hi/science/nature/2290491.stm http://news.bbc.co.uk/2/hi/science/nature/2290491.stm
      - eviks 3y ago
        Extremely rare exceptions like are not a challenge to classification
d35007 3y ago
The article tries to explain why your answer doesn’t tell the whole story. Did you read it?
- dang 3y ago
  "Please don't comment on whether someone read an article. "Did you even read the article? It mentions that" can be shortened to "The article mentions that."" https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html (your first sentence is good though!)
  - d35007 3y ago
    Got it, thanks boss.
    - simpletone 3y ago
      [flagged]
mcapodici 3y ago
Except - https://en.wikipedia.org/wiki/Asexual_reproduction https://en.wikipedia.org/wiki/Asexual_reproduction
- bjornsing 3y ago
  And also some individuals within a so called ring species: https://en.m.wikipedia.org/wiki/Ring_species https://en.m.wikipedia.org/wiki/Ring_species
  - antod 3y ago
    Thank you. Saved me posting it as a counter example. Basically nature will nearly always be able to defeat human efforts at putting things in neat boxes.
kjkjadksj 3y ago
Thats certainly a valid way to do it. It really doesn’t matter how you define species as long as you say how you’ve done the defining. Its just a human word like wall or chair. That being said depending on your research question, certain definitions of species might be better suited than others. For example if you just consider reproductive compatibility, then certain human couples with fertility issues would be considered different species because certain genetic incompatibilities mean they are unable to produce viable offspring.
- lo_zamoyski 3y ago
  > Thats certainly a valid way to do it. Well, then you have problems like how speciation occurs. If the ability to produce offspring is your definition, then interbreeding does not exist by definition. And then you're left with the question of how species come about. Let us suppose some member of species A produces an offspring of species B where B is not A. Then for the species B to survive, there must arise another member of that species B (i.e., one that can interbreed). So you have at least three low chance events: (1) two members of the same new species being born (2) at roughly the same time (3) meeting each other and (4?) breeding. You also could not say that A and B could interbreed, and it is only some species C arising form B that cannot interbreed with A, because you've already make interbreeding impossible; if you can breed, you are the same species. So if A and B can interbreed, and B and C can interbreed, then by transitive property, so can A and C. So interbreeding, full stop, cannot be criterion, certainly not the sole criterion. > Its just a human word like wall or chair. But this undermines the notion of species as objectively true. Artifacts of that sort differ from natural kinds in the sense that such artifacts have no inherent tendency to be what they are, whereas natural kinds do. A chair is not inherently to be something we sit on. That is merely a telos in the mind of the craftman, and this telos is what that determined the form he would give the artifact. The affordance and suitability of such an artifact for sitting is something that a user of that artifact may recognize in the chair and take advantage of. What qualifies as a chair is at least in part subject to convention for practical reasons. But a bird is not like that. It is not a matter of perspective that a bird is "birdy" and does birdy things and realizes objective ends in birdy ways that are not merely observer relative. Sure, we can categorize animals for practical purposes, and we may do so according to various ends for practical rather than theoretical reasons (like classifying beaver as a fish, and fish as not meat, for Lent), but that sort of practical classification is merely practical and secondary to the question of what something actually is. And we cannot avoid saying what a thing is as that is inherent to the notion that reality is intelligible. If you were to reduce "birdiness" to mere convention, then you would indeed be characterizing birds in the same manner as artifacts (this is called mechanism, and it has severe problems). But even a mechanist would still need to classify the things that go into making this object of merely conventional identity, at some level, or else be left to conclude that reality is unintelligible, though strangely conventions manage to magically escape this problem, as mental entities would remain intelligible. One who denies the intelligibility of the world would be left with the task of explaining how he can even make the distinction between his intelligible "mental world" and "the world out there" without some intelligibility in the first place. Ideas have consequences, consequences greater than many realize.
a_gnostic 3y ago
*Any group of organisms that can have sex to make viable offspring. (So bacteria don't have species?) Doesn't change the fact that there are 49 million kangaroos in Australia and 3.5 million people in Uruguay which means if the kangaroos were to invade Uruguay each person will have to fight 14 kangaroos.
mobilejdral 3y ago
There is the long standing joke around the Geeks and Jocks. The don't usually have sex with each other. Genetically they have even diverged with genetic attributes that you typically find in one and not the other. They are even more successful at having grandchildren if they mate their "own type" due to to certain genetic combinations that both parents will give to the kids. Are they two species?

Basically any group of organisms that have sex with each other...

by johnea 3y ago

Basically any group of organisms that have sex with each other...

hef19898 3y ago

And produce fertile offspring.

kjkjadksj 3y ago
Some humans would fail to meet that definition
- borroka 3y ago
  You are, wrongly, scaling up from the potential of individuals to the potential of the group of individuals/species. Saying that "humans" are capable of locomotion or movement using their legs implicitly refers to an expectation, and nobody with that intends to say that individuals who are confined to a wheelchair are not humans. Saying that humans have 5 fingers on each hand, which is the expectation, does not imply that individuals born with a different number of fingers are not humans, but simply that is not the expectation.
  - Jensson 3y ago
    But when biologists finds an insect type with different number of something they will call it a new species. That we don't do that for humans has to do with politics more than anything else, some believe we would discriminate against such humans if we said they weren't really the same species.
    - borroka 3y ago
      > But when biologists finds an insect type with different number of something they will call it a new species. This comment cannot be answered properly without knowing who the "biologists" are, which insect types we are talking about, and what is going along with the different number of something. The fact that individuals with four or six fingers are considered to be of the same species has nothing to do with politics, but with the fact that people with "4 fingers" can reproduce (this is the expectation) with individuals with "5 fingers" and "6 fingers" and produce fertile offspring. Politics comes into play when it comes to, for example, species conservation. Populations of the same species that have remained isolated from each other for centuries, millennia or more may accumulate due to selection processes, genetic drift or founder effect, genetic and phenotypic characteristics that do not allow individuals from the two populations to reproduce successfully. Fertilization may not occur, the progeny may show morphological abnormalities, or the offspring may not be fertile. But the above may occur in, say, 20 percent, 50 percent or 90 percent of cases, and for any of these percentages the existence of a new species, variant or subspecies can be argued. Should the two populations be protected since they are (or are not) different species?
    - lo_zamoyski 3y ago
      Then defect is no longer intelligible. And yet, we can determine if a heart is defective, because we know the function of a heart, we know how that function composes into the telos of the organism (which is what transmits the function to organ, so to speak). Thus, any modification of the heart, certainly one that we see has ill effects for the organism, is a defect. It is clear that a human being who is sterile, or one who cannot move about, is in some sense a defective specimen, as these deficiencies impede the realization of human telos. (If you deny telos, then truly nothing is intelligible. Not only does the notion of defect no longer make sense, not only are biology and biological function impossible and anatomy made unintelligible, but even efficient causality is made unintelligible and science impossible, as the very fact that an effect follows from a cause, that is is not arbitrary, presupposes telos.)
- Scarblac 3y ago
  I have had a vasectomy, I'm now on my own in my species :-(
  - Hucklederry 3y ago
    [dead]

camdenlock 3y ago

… and produce viable offspring. An important distinction, because without viable offspring, genetic transmission halts.

gnatman 3y ago
Y'all should read the article. It goes into more depth than these two comments! For example, two species can have sex, AND produce viable offspring, but NOT produce fertile offspring. Like a donkey and horse producing a typically infertile mule. Horses and donkeys are not the same species.
- onychomys 3y ago
  And sometimes you can have two things that everybody agrees are different species but which happily hybridize (with fertile offspring) all the time! https://www.princeton.edu/news/2020/05/07/gene-flow-between-species-influences-evolution-darwins-finches https://www.princeton.edu/news/2020/05/07/gene-flow-between-...
- eviks 3y ago
  Viable=fertile here
  - InitialLastName 3y ago
    Some mules are fertile: http://news.bbc.co.uk/2/hi/science/nature/2290491.stm http://news.bbc.co.uk/2/hi/science/nature/2290491.stm
    - eviks 3y ago
      Extremely rare exceptions like are not a challenge to classification

d35007 3y ago

The article tries to explain why your answer doesn’t tell the whole story. Did you read it?

dang 3y ago
"Please don't comment on whether someone read an article. "Did you even read the article? It mentions that" can be shortened to "The article mentions that."" https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html (your first sentence is good though!)
- d35007 3y ago
  Got it, thanks boss.
  - simpletone 3y ago
    [flagged]

mcapodici 3y ago

Except - https://en.wikipedia.org/wiki/Asexual_reproduction https://en.wikipedia.org/wiki/Asexual_reproduction

bjornsing 3y ago
And also some individuals within a so called ring species: https://en.m.wikipedia.org/wiki/Ring_species https://en.m.wikipedia.org/wiki/Ring_species
- antod 3y ago
  Thank you. Saved me posting it as a counter example. Basically nature will nearly always be able to defeat human efforts at putting things in neat boxes.

kjkjadksj 3y ago

Thats certainly a valid way to do it. It really doesn’t matter how you define species as long as you say how you’ve done the defining. Its just a human word like wall or chair. That being said depending on your research question, certain definitions of species might be better suited than others. For example if you just consider reproductive compatibility, then certain human couples with fertility issues would be considered different species because certain genetic incompatibilities mean they are unable to produce viable offspring.

lo_zamoyski 3y ago
> Thats certainly a valid way to do it. Well, then you have problems like how speciation occurs. If the ability to produce offspring is your definition, then interbreeding does not exist by definition. And then you're left with the question of how species come about. Let us suppose some member of species A produces an offspring of species B where B is not A. Then for the species B to survive, there must arise another member of that species B (i.e., one that can interbreed). So you have at least three low chance events: (1) two members of the same new species being born (2) at roughly the same time (3) meeting each other and (4?) breeding. You also could not say that A and B could interbreed, and it is only some species C arising form B that cannot interbreed with A, because you've already make interbreeding impossible; if you can breed, you are the same species. So if A and B can interbreed, and B and C can interbreed, then by transitive property, so can A and C. So interbreeding, full stop, cannot be criterion, certainly not the sole criterion. > Its just a human word like wall or chair. But this undermines the notion of species as objectively true. Artifacts of that sort differ from natural kinds in the sense that such artifacts have no inherent tendency to be what they are, whereas natural kinds do. A chair is not inherently to be something we sit on. That is merely a telos in the mind of the craftman, and this telos is what that determined the form he would give the artifact. The affordance and suitability of such an artifact for sitting is something that a user of that artifact may recognize in the chair and take advantage of. What qualifies as a chair is at least in part subject to convention for practical reasons. But a bird is not like that. It is not a matter of perspective that a bird is "birdy" and does birdy things and realizes objective ends in birdy ways that are not merely observer relative. Sure, we can categorize animals for practical purposes, and we may do so according to various ends for practical rather than theoretical reasons (like classifying beaver as a fish, and fish as not meat, for Lent), but that sort of practical classification is merely practical and secondary to the question of what something actually is. And we cannot avoid saying what a thing is as that is inherent to the notion that reality is intelligible. If you were to reduce "birdiness" to mere convention, then you would indeed be characterizing birds in the same manner as artifacts (this is called mechanism, and it has severe problems). But even a mechanist would still need to classify the things that go into making this object of merely conventional identity, at some level, or else be left to conclude that reality is unintelligible, though strangely conventions manage to magically escape this problem, as mental entities would remain intelligible. One who denies the intelligibility of the world would be left with the task of explaining how he can even make the distinction between his intelligible "mental world" and "the world out there" without some intelligibility in the first place. Ideas have consequences, consequences greater than many realize.

a_gnostic 3y ago

*Any group of organisms that can have sex to make viable offspring. (So bacteria don't have species?) Doesn't change the fact that there are 49 million kangaroos in Australia and 3.5 million people in Uruguay which means if the kangaroos were to invade Uruguay each person will have to fight 14 kangaroos.

mobilejdral 3y ago

There is the long standing joke around the Geeks and Jocks. The don't usually have sex with each other. Genetically they have even diverged with genetic attributes that you typically find in one and not the other. They are even more successful at having grandchildren if they mate their "own type" due to to certain genetic combinations that both parents will give to the kids. Are they two species?