Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

How to defeat this anti-evolution argument?

  1. Sep 6, 2010 #1
    A creationist raised dog as an example, saying what we call dogs, are actually sub-species of grey wolf, thus they are also wolves, thus micro evolution is possible, but from a more macro angle, dog didn't evolve at all, how to counter this argument?

    He admits current taxonomy, so I would like to point out for him that grey wolf belongs to a even larger category which has coyote and other canis. Can coyote and dog cross-breed? Do you folks have any better idea than mine?
     
  2. jcsd
  3. Sep 6, 2010 #2

    Andy Resnick

    User Avatar
    Science Advisor
    Education Advisor
    2016 Award

    So this person agrees evolution occurs, except when it doesn't? That's definitely a new argument....
     
  4. Sep 6, 2010 #3

    Hurkyl

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Alex: "How to defeat"? Sounds like you are already absolutely confident beliefs are truth; so you should just counter with whatever reasons give you that confidence. :wink:

    The "argument" was a handful of words dressing up a flat assertion that macro-evolution doesn't happen.

    Question: is he trying to convince you? Then he has the burden of proof; just point out that he has said nothing to defend his assertion. Are you trying to convince him? Then you'll have to come up with something.




    Andy: I don't think it's particularly new at all. It's also what you would expect from statistical inference doing its job -- I believe that the empirical evidence supporting the occurrence of micro-evolution is stronger than that of macro-evolution. Additionally, I expect that the person has stronger priors against macro-evolution than he does micro-evolution. Thus, the conclusion should be greater confidence in micro-evolution than in macro-evolution.
     
  5. Sep 6, 2010 #4

    DavidSnider

    User Avatar
    Gold Member

    Ask him: If every animal was created as-is and only "microevolution" occurs amongst "kinds", then why don't we find modern life forms in the lower strata of the geological column? Why do we see a progression that would be exactly what you would expect if macroevolution occurred?
     
  6. Sep 6, 2010 #5
    Keep up the good work ppl, I wanna know how many genes do dogs (any kind of) and wild wolf share? Like Man share 96% with Chimps.
     
  7. Sep 7, 2010 #6
    Here's my logic,
    [Microevolution=A] [Macroevolution=B] [Wolves to dogs=C]

    If A then B
    A=C
    C
    Therefore, B, Evolution.
    KapowLOL
     
  8. Sep 7, 2010 #7
    But there Alex, lies the whole misunderstanding. As I heard it, the similarity of genes between humans and chimps is about 98%. But clearly our morphologies are not 98% similar. And further, the genes that differ between us aren’t even anything to do with morphology. Here’s an example: Amy1. It’s a gene that chimps have few copies of and humans have many copies of. Its function is in a process called ‘starch hydrolysis’. The result is, human beings are much better at processing starchy foods than are chimps, which leads to the differences in our diet. That in turn has other effects on the differences between the species, including that we are much better at fighting infections that cause diarrhoea than are chimps. As you can see, none of this has anything to do with morphology. In point of fact, human beings share many genes that do control morphology with fruit flies. The point is, it is not the content of the gene that controls morphology, it is how and when the gene is expressed during embryonic development that controls morphology. Wondering how two morphologically different species can share the same genes is like wondering how a plumber and a fitter have largely the same tools in their tool box.

    So, that modern domesticated dogs cannot breed with wolves, thus proving that they are a distinct species, is to do with misalignments of the chromosomes that mean a gamete of one species cannot fuse with a gamete of the other to make a viable zygote. Both species are still largely built by exactly the same genes.
     
  9. Sep 7, 2010 #8

    bobze

    User Avatar
    Science Advisor
    Gold Member

    Hey Alex,

    The problem that most creationists have with evolution is the one you are dealing with "micro vs macro". What they mostly fail to understand, is that biologists don't mechanistically (for the most part) distinguish the two. "Macroevolution" is the accumulation of microevolutionary processes over some subjective definition of time.

    Most creationists I've known, like to inject the "interbreeding" boundary of species. And then point out that dogs and wolfs can form a contiguous breeding population, which they then propose follows the "Creator creating the 'dog kind'"-line of logic they try and use.

    I'd point out that dogs are a sort of ring species, much like gulls or salamanders. Those distinct populations of dogs we call "breeds" could allow something like a chihuahua to breed with a great dane. Of course they can't directly breed because of obvious mechanical problems. But in theory, you should be able to breed chihuahuas with progressively larger dogs, until such a point their genes enter the gene pools of great danes'. And visa versa.


    However, suppose tomorrow some terrible K9 disease fell upon the world, wiping out all those in between breeds. Such that chihuahua and great dane gene pools would now be isolated from each other. Then, you would have two distinct species of dog. The chihuahua species and the great dane species.

    Now suppose some terrible disease arose which wiped out all people on earth. Such that the great dane and chihuahua species were once again "wild". Because of their morphological variation, they would have to occupy different ecological niches. Which means each would be subject to different environmental pressures and would "evolve away from each other". How divergent they become from each other (and their wolf ancestors) would be a function of the intensity of selective pressures and time since they diverged.

    If your friend doesn't believe you, you can point out that this same thing happens in nature as well. Probably my favorite example is with the salamanders in the genus Ensatina

    http://www.kqed.org/quest/files/ensatina.gif

    What you can see in this illustration is salamanders live in the mountainous regions surrounding the San Joaquin Valley, which is inhospitable to their livelihood.

    On the southern side of the circle, you find two species of salamander which look very different and don't interbreed. However, they are connected by populations extending north around the San Joaquin Valley and back down the sides, where interbreeding between subspecies occurs.

    If some unfortunate chain of events led to the extinction of those "in between" subspecies, you'd be left with two distinct species incapable of gene flow and who are thus, reproductively isolated. Because each occupies a slight variation of ecological niche and each occupies a slight variation of environment, then each gene pool would accumulate changes which diverge the two populations farther and farther apart over time.

    Interestingly ring species are a geographical representation of what happens temporally in evolution.

    Stress to your friend this point. Its one that even most "advocates" of evolution don't understand. "Macroevolution" is only visible and possible because of the extinction of intermediary populations.

    If all the populations since the divergence of chimps and humans were still alive (like the ring salamanders) creationists would probably claim "God created one 'kind' of ape" and microevolutionary processes took it from there.

    We only look at chimps and humans as "distinct" isolated gene pools (populations) because the intermediary populations are now extinct.

    Of course that hellacious line of logic that creationist use to explain ring species (creating a "specific" kind) would fall apart if every intermediary population never went extinct. Creationists then would be forced to conclude that god created a "universal kind" from which "microevolutionary processes gave rise to all kinds", in essence macroevolution.



    Edit to add; Alex,

    Of course you must also consider that creationists are notoriously immune to reasoned and evidenced based arguments. You might consider that the time spent arguing with your friend, could be well spent on something else. I'm of the opinion if we teach evolution in our schools correctly, and only actively "attack" creationism when it rears its head and tries to gain entry into science classes; then in a generation or two's time, creationism (like those who currently hold the belief) will go the way of the dodo. I don't think its feasible to try and educate all current creationists, their http://www.talkorigins.org/origins/postmonth/feb02.html" [Broken] keep their beliefs unscathed besides for anything not tied to the front end of a Mac truck (and sometimes that's not enough!).
     
    Last edited by a moderator: May 4, 2017
  10. Sep 14, 2010 #9
  11. Sep 15, 2010 #10

    loseyourname

    User Avatar
    Staff Emeritus
    Gold Member

    There have been plenty of observed speciation events, but the most notable is probably the introduction in the 40s of new species of the goatsbeard plant in Pullman, WA, because that did not involve human interference with breeding patterns. Creationist arguments against macroevolution tend to ignore the existence of non-animal forms of life.

    Of course, my experience with these kinds of people says they'll just ignore observed speciation events and say "sure, but show me a turtle turn into a crow" or something stupid like that. They just fail to appreciate how incremental changes can add up over time.
     
  12. Sep 15, 2010 #11
    You make a valid point, however, I was just stating an argument. I wasn't "saying" evolution isn't real. I was just thinking of my theory and seeing if it would be well thought out and if it would work.
     
  13. Sep 17, 2010 #12

    bobze

    User Avatar
    Science Advisor
    Gold Member

    Dr Henegar,

    You've danced around with this "theory" of yours for some time now. If you have this "theory" why not make a topic and lay out your supporting science and idea? Why the dancing? That makes it look suspiciously like typical creationist tactics.....

    If you want some advice from someone who's practiced biology in both academia and the private sector, feel free to PM it to me. Or start a topic and open your "theory" up to scientific scrutiny. Just dancing around all night, waiting to make the move, is making you lose face fast.
     
  14. Sep 17, 2010 #13
    Macro *is* micro -- just for a longer period of time. They are the same thing. Ask him what happens if a wolf "micro-evolves" repeatedly until it looks like a walrus. Would he still call it a wolf?
     
    Last edited: Sep 17, 2010
  15. Sep 17, 2010 #14
    The argument, as I have heard it, admits that evolution is possible within a genus (micro-evolution) because the mutated offspring would still be able to reproduce with existing members of the genus. However one genus cannot evolve into a new genus or create an offshoot genus (macro-evolution) because the mutated offspring in the new genus would have no mates with whom to reproduce.
     
  16. Sep 17, 2010 #15

    alxm

    User Avatar
    Science Advisor

    A quite bizarre argument, for certain. Since AFAIK the way it goes down is that first two populations stop interbreeding and then they diverge genetically - eventually to the point where they can't interbreed.

    All that argument does is demonstrate that it can't happen in the reverse order of how it actually happens.
     
  17. Sep 17, 2010 #16

    loseyourname

    User Avatar
    Staff Emeritus
    Gold Member

    That's an argument against saltationism. Unfortunately, I think many creationists actually think Darwinian evolution requires saltationism.

    It's easy to see it doesn't hold up, though. Speciation has definitely been observed to occur. That is, two populations become reproductively isolated in one way or another and are eventually no longer able to mate at all. It's just a matter at that point of sufficient future divergence, incremental as it may be. Future mutations in either population will only be introduced into the one population and not the other. The change from one genus to another doesn't occur in a single generation.
     
  18. Sep 18, 2010 #17

    bobze

    User Avatar
    Science Advisor
    Gold Member


    This comes from a misunderstanding that evolution happens to individuals, thus "a boy and girl would need to evolve at the same time for evolution to happen".

    Of course as Looseyourname points out, that isn't true because individuals don't evolve, populations do.

    And since evolution is the change in allele frequency over time, then individuals within a breeding population will continue to breed with each other. However, you'd eventually find a "point" when representatives of some future population couldn't be interbreed with ancestral population.

    It seems apparently, incredibly hard for most humans to separate the notion of individuals and populations.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: How to defeat this anti-evolution argument?
  1. How did evolution begin? (Replies: 26)

  2. Defeating evolution (Replies: 16)

Loading...