• ProbablyTrue
    192
    Speciation is the process where a population among a particular species becomes reproductively isolated and because of environmental pressures evolves to become a new and distinct species.
    Wiki Video Video

    Though there is consensus among scientists about evolution and much of how it operates, speciation is a topic that is continually brought up by proponents of intelligent design(ID) and creationism. I have seen many an ID'er or creationist say that speciation does not occur and therefore macro-evolution cannot occur. As far as I am aware, speciation in the animal kingdom has never been directly observed by scientists. The examples used in most videos and in all the literature I've read(admittedly not much) seem to show what I'd call 'preference speciation' or 'barrier speciation' and not a pure genetic speciation.

    For example, Western and Eastern Meadowlarks are considered separate species because they have different mating songs and therefore do not mate. While this is true, if one or the other of these species got the bird flu and managed to confuse a member of the other side to mate with it due to its raspy song, they could in fact produce offspring, and their offspring could produce offspring, and so forth.
    So it's easy to see how, with enough time and change, this could potentially lead to genetic speciation, but it will not strike the incredulous believer(ha) as convincing.

    So I ask you, do you believe speciation occurs? If yes, why? If no, why not?
    1. Do you believe speciation occurs? (11 votes)
        Yes
        100%
        No
          0%
        I'm not sure
          0%
  • StreetlightX
    3.8k
    Not only is speciation real, we can make it happen in the lab.
  • ProbablyTrue
    192

    Thanks for the link. Do scientists consider viruses to be 'living'? I thought there was some debate over that point. Also, viruses don't reproduce in the same way large multi-cellular organisms do, so does that not discount the finding?

    To be clear, I personally believe speciation occurs. I am trying to find interesting points on both sides of this so that I have more clarity and better explanations for myself and those I speak to about this subject.
  • ProbablyTrue
    192
    In that case, I am afraid that you'll have to tell them that they are right... :rofl:Agustino

    Care to take a position?
  • Baden
    8.2k


    Religionists of that level don't have anything useful to say about science nor are they worth trying to convince because their group identity is more important to them than being right. This has been studied extensively (see some of the podcasts I've linked to recently which give a good overview of the research ) and the results are as bleak as that. The best thing to do is to just leave them to their ignorance. Yes, speciation obviously happens otherwise there wouldn't be any different... species. And how it happens has been studied and described by scientists. It's not a mystery.
  • StreetlightX
    3.8k
    The 'living' status of viruses depends on one's definition of life (the issue being that viruses need to hijack the reproductive machinery of other organisms - in this case E. Coli - where most other living things have 'in-built' reproductive machinery), but it's not actually something that matters too much here, because the mechanism of reproduction isn't that important. To the degree that evolution is simply decent with modification, virus reproduction here exhibits just that, and in ways that also exhibit speciation. Whether the actual mechanism of reproduction is internal or external to the organism doesn't effect the results.
  • Ying
    223
    So I ask you, do you believe speciation occurs? If yes, why? If no, why not?ProbablyTrue

    What? No. Obviously not. And no, speciation isn't the problem to me, here. It's the "believe" part. I don't see how hypotheses and/or theories require belief. Then again, I'm one of those people who distinguishes between conjecture and dogmatism. So. To be perfectly clear: Do I think speciation is a thing? Sure. Am I willing to chuck the notion in light of counter evidence? Uh, yes. Do I think that such counter evidence is likely to surface? No.
  • Mariner
    367
    20 years ago I gave lessons on speciation.

    From memory, there are very obvious (and instantaneous) cases of speciation in plants, through chromosomes reconfiguration. It is probably the clearest example to provide to a recalcitrant non-speciacionist.

    (And if the claim that chromosome reconfiguration is not "true speciation" somehow, remind them that they are cheating, since the layman's idea of "a species" has nothing to do with genotypes; it is about morphology).
  • T Clark
    3.7k
    Religionists of that level don't have anything useful to say about science nor are they worth trying to convince because their group identity is more important to them than being right. .... The best thing to do is to just leave them to their ignorance.Baden

    Of course, the problem with that is that we have to live with these "ignorant" people. Govern our society together. Live next door to each other. There have been plenty of discussions on the forum about how a rigid reductionist "scientific" view of the world warps an understanding of how the world works.
  • charleton
    1.2k
    (And if the claim that chromosome reconfiguration is not "true speciation" somehow, remind them that they are cheating, since the layman's idea of "a species" has nothing to do with genotypes; it is about morphology).Mariner

    There is a body of knowledge which is relevant here. Groups of the same species that are separated geographically they can mate with groups near to them, but a sort of chain is formed in which the groups at the most extreme ends of the chain can no longer mate. There is a name for this, sadly I cannot recall what that is.
  • T Clark
    3.7k
    So I ask you, do you believe speciation occurs? If yes, why? If no, why not?ProbablyTrue

    So, what is the evidence for speciation? Not viruses, not unusual plant behavior, just regular organisms evolving from one species to another. 1) fossil record. 2) comparative genetic studies between organisms 3) experience with breeding 4) observations in nature 5) What else?
  • Baden
    8.2k


    It's no more rigid or reductionist to ignore the talking-snake crowd than it is to ignore the flat-earth crowd when it comes to science. They have zero to bring to the table and indulging them serves no purpose. And maybe you have to live next door to them, but most of us don't. In terms of developed countries, they're almost exclusively an American phenomenon. That being the case, you should know that what really warps an understanding of science, and can potentially destroy it, especially among the young, is giving these people a platform that leads to political influence, particularly over educational policy. They won't be given a similar platform here in the science category to spread pseudoscientific nonsense. Again, that has nothing to do with scientism or scientific reductionism. Philosophy and science itself are perfectly valid means to criticize the prevailing scientific orthodoxy.
  • T Clark
    3.7k
    They have zero to bring to the table and indulging them serves no purpose.Baden

    I think that shows your rigidity and lack of understanding rather than any fault in religious people. You can't separate science from the rest of society.

    you should know that what really warps an understanding of science, and can potentially destroy it, especially among the young, is giving these people a platform that leads to political influence, particularly over educational policy.Baden

    So, let's exclude a large portion of the electorate because we don't agree with their understanding of the world.

    They won't be given a similar platform here in the science category to spread pseudoscientific nonsense. Again, that has nothing to do with scientism or scientific reductionism. Philosophy and science itself are perfectly valid means to criticize the prevailing scientific orthodoxy.Baden

    Where did that come from? There is no discussion here about what should be allowed on the forum. @ProbablyTrue has expressed an interest in interacting with these troglodytes you have such disdain for. Maybe evolution denial is not welcome here, but how to talk to evolution deniers and how to understand what we think is true about evolution should be.
  • Baden
    8.2k
    I think that shows your rigidity and lack of understanding rather than any fault in religious people.T Clark

    I'm not talking about religious people in general, I'm talking about religious people who maintain that their religious beliefs have a scientific grounding or who try to enforce their religious views re science in the education system, which can only result in mass levels of ignorance, and is a form of abuse as far as I'm concerned.

    You can't separate science from the rest of society.T Clark

    I don't know exactly what you mean by this. On some level, it's trivially true, but science is the remit of scientists just like engineering is the remit of engineers. I'm not going to go tell an engineer how to build a bridge on the basis of my religious beliefs, or lack thereof, and if I did, he shouldn't listen to me, or we'd have a lot more cars in rivers.

    So, let's exclude a large portion of the electorate because we don't agree with their understanding of the world.T Clark

    It's not about agreement because there is no debate. The fact is that the Bible is not going to help in any way in understanding evolution. If you can't get that far, then you are not doing science to start with. You're still doing religion. So, yes, let's absolutely exclude them from this area because they have nothing of relevance to say. (In a conversation concerning morality, or theology or philosophy or even science if they are willing to keep religion out of it, that doesn't hold, of course).

    There is no discussion here about what should be allowed on the forum. ProbablyTrue has expressed an interest in interacting with these troglodytes you have such disdain for. Maybe evolution denial is not welcome here, but how to talk to evolution deniers and how to understand what we think is true about evolution should be.T Clark

    I'm just making it clear that we don't want pseudoscience (e.g. so called "ID" or creation science) in the science category. I'm not referring to anyone here, specifically, religious or otherwise. There are lots of ways to criticize evolutionary theory without going that route. We're not at the end of the road with evolution, we simply have a theory, which can and should be criticized, but not on the basis that it contradicts some group's holy book. That's just not the right way to go about things in this field.
  • Bitter Crank
    8.1k
    Speciation in progress:

    In the often-told evolutionary tale, the color shift in moths began as factories in Britain started to darken the skies with coal smoke during the Industrial Revolution in the 1800s. Victorian naturalists took note as a newly discovered, all-black carbonaria form of peppered moths (Biston betularia) blended into soot-covered backgrounds; the light-colored typica moths, which lacked the mutation, were easily picked off by birds. By 1970, nearly 99 percent of peppered moths were black in some localities. As air pollution decreased in the late 20th century, black moths became more visible to birds. As a result, carbonaria moths are now rare.Science News

    053116_ti_moth-butterfly_feat_free.jpg

    BLACK AND WHITE As soot settled onto trees in Britain during the Industrial Revolution, a black version of the peppered moth (right) started to overtake the mottled-wing form (left). Scientists have now found the mutation that caused the color shift in a gene called cortex.
  • T Clark
    3.7k
    Speciation in progress:Bitter Crank

    Is that really speciation? Can the different varieties interbreed? Do they? Are they present in the same populations, areas?

    All dogs are considered the same species, right? Even with very significant differences in form, size, and color.
  • Mariner
    367
    Once you accept that mutations can become stable in subpopulations of a species (as in the case of the moths), it becomes a case of special pleading (requiring justification) to argue that these mutations cannot establish interbreeding barriers. Why would that be the case?

    The burden of proof is really upon those who dispute speciation. (And it becomes a really big burden when we consider that speciation has been observed in many different contexts; "X cannot happen" is a tough proposition to defend when X is all around you).
  • javra
    768
    Is that really speciation? Can the different varieties interbreed?T Clark

    It wouldn’t be yet. But given an environmental obstruction between the two variants, eventually further biological evolution would bring about two species that won’t interbreed, either for genetic or behavioral reasons. Two examples: Galapagos finches and new world finches (yes, there are more species than the just mentioned); chimps and bonobos.

    Edit: this being just one scenario in which specification [doubleedit for the typomister: otherwise known as speciation] would occur.
  • T Clark
    3.7k
    It wouldn’t be yet. But given an environmental obstruction between the two variants, eventually further biological evolution would bring about two species that won’t interbreed, either for genetic or behavioral reasons. Two examples: Galapagos finches and new world finches (yes, there are more species than the just mentioned); chimps and bonobos.javra

    I think I remember from somewhere that, for large mammals, there has to be 200,000 years of separation before populations will no longer be able to interbreed? Has anyone else heard that.

    Also - It is believed that homo sapiens interbred with both Neanderthals and Denisovans and that some of us share genetic material from them.
  • javra
    768
    Also - It is believed that homo sapiens interbred with both Neanderthals and Denisovans and that some of us share genetic material from them.T Clark

    Don't know about the first issue you bring up. But with this one ... one professor during my university days said that given our genetic similarity it is nearly indisputable that one can have a human-chimp offspring, only that whether or not this offspring would itself be able to reproduce is unknown .... think of mules here (and who in their right minds would even want to find out empirically) ... paraphrasing all this, obviously. Homo sapiens could have genetically interbred with Neanderthals; whether or not the two species (/variants?) interbred despite behavioral differences is in a good deal of dispute from what I know. New info on this is always of interest, though.
  • T Clark
    3.7k
    Homo sapiens could have genetically interbred with Neanderthals; whether or not the two species (/variants?) interbred despite behavioral differences is in a good deal of dispute from what I know.javra

    It has been reported that Neanderthal genetic material shows signs of homo sapien DNA and vise versa. At one point I guess that was controversial, but I think it has been resolved. Maybe someone can confirm or refute.
  • Baden
    8.2k
    one professor during my university days said that given our genetic similarity it is nearly indisputable that one can have a human-chimp offspring,javra

    No, it's been tried and it didn't work.

    https://en.wikipedia.org/wiki/Humanzee



    It does. E.g.:

    https://news.nationalgeographic.com/news/2010/05/100506-science-neanderthals-humans-mated-interbred-dna-gene/
  • T Clark
    3.7k
    It does. E.g.:Baden

    I had heard that there had been some alternative scenarios proposed for how the DNA got where it is e.g. Neanderthals and humans having a common African ancestor.
  • Baden
    8.2k


    The vast majority of the evidence seems to be on the side of interbreeding. E.g:

    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4947341/ (Full paper)

    https://www.nature.com/articles/nature12961 (Abstract)

    There is also this that mentions the other hypothesis but comes down on the side on intebreeding anyway:

    http://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1002947 (Full paper)
  • javra
    768
    No, it's been tried and it didn't work.

    https://en.wikipedia.org/wiki/Humanzee
    Baden

    from the article:

    In 1981, Ji Yongxiang, head of a hospital in Shengyang, was reported as claiming to have been part of a 1967 experiment in Shengyang in which a chimpanzee female had been impregnated with human sperm. According to this account, the experiment came to nothing because it was cut short by the Cultural Revolution, with the responsible scientists sent off to farm labour and the pregnant chimpanzee dying from neglect.wikipedia page

    1920's might not have been as advanced in artificial insemination as 1980's; I won't push the issue though. I'd like what you've said to be conclusive and this quoted account to have been a hoax. Still, in one way it makes my hairs stand up that humans have tried this, in another way nothing shocking ... given our capacities for amorality, to put it nicely (as thought the life that would've been birthed could then be dispensed away with after birth ... interesting)
  • Baden
    8.2k


    Unfortunately, scientists have historically carried out gruesome experiments on humans that make this kind of thing look relatively mild. I think it's safe to assume pretty much everything has been tried (and will continue to be though some of it covertly to be sure).
  • T Clark
    3.7k
    The vast majority of the evidence seems to be on the side of interbreeding. E.g:Baden

    Thanks.
  • Monique
    2
    Cichlid fish in Lakes Malawi may provide convincing evidence in favour of speciation: "Mate choice trials carried out in research aquaria showed that the Malawi and Chilingali forms preferred to mate with their own kind, showing that they were well on the way to evolving into distinct species."
  • javra
    768
    Unfortunately, scientists haveBaden

    To me, you're missing a crucial term here: some. To lump all scientist together like this is might be a disservice to scientists as a whole. Akin to: humans have historically .... you know what, I won't even mention examples. Linguistic gripe, that's all.
  • Baden
    8.2k


    Fair point.
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