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| Topic: Evolution: How much change is required to become a new speci | |
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Edited by
Bushidobillyclub
on
Mon 08/15/11 10:42 AM
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Maybe Carl just chose a poor term. Perhaps he should have simply said "Human selection" rather than "artificial selection". I understand what he meant. But technically he is basically implying that human activity is somehow 'artificial'.  Why shouldn't human activity be considered to be just as 'natural' as any other activity? This is just the terminology used by biologists, the meanings are clear even if you decide you dislike the natural/unnatural distinction that is used to denote the separation between human interaction and non-interaction. We could have a whole other conversation about that distinction, and I think we would tend to agree abra. I see nothing unnatural about how humans interact with the environment, even when it is very very destructive. |
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Evolution: How much change is required to become a new species? Answer: A species is defined currently (artificial definition, for an artificially conceptualized term) as a life form that can reproduce biologically reproductive offspring. ... How much change is required? By definition, exactly as much change as would make it impossible for a normal mating pair, one from the old species, one from the new, to bring about offspring that can't bring offsrping about, or one from the old, species, one from the new, whose consummation results in no offspring whatsoever. Great answers wux. It takes as much change as it takes, and that takes as long as it takes. |
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Evolution takes millions of years right? Who says? And what exactly did they mean by that? There are many different uses of the word evolution even when people speak specifically about biology and natural selection, and especially if we are asking 'how long does evolution take'. One definition is "change in the frequency of alleles in a population". This kind of evolution can happen within a few generations. Some people use the word 'evolution' as if it meant 'the development of new species', which is hugely different than simply a change in the frequency of alleles; given this enormous range of meaning, I think we should be careful and explicit about our criteria for what constitutes 'the occurrence of evolution' when we discuss 'how long it takes'. The overall process of 'the evolution of life on earth' would require the development of new species, but scientists often use the word evolution to simply mean the change in qualities of any species. HIV hit the scene in 1981 (some say before, but let's say 1981). We have a virus that for every year, it evolves 1 million years worth for a higher animal. So that's 30 million years worth of mutations for the HIV population, each population living in a different host. Why is HIV still a virus? Should we expect HIV to be anything other than a virus? Simply because a huge number of generations and mutations have occurred? It's a moving goal post. When Evolutionists want, they say Evolution is very fast (Punctuated Equilibria) or it's very slow, whichever argument works best at that moment. When you are arguing with irrational individuals who are attached to their beliefs who also happen to believe in evolution - sure, they abuse moving goal posts and all kinds of logical fallacies. But you speak as if all of the people who believe in some theory of evolution were one group of people, who ought to have only one set of beliefs on the topic; in reality there is a great deal of diversity of opinion on the topic. The fact that some people favor punctuated equilibria and that some don't doesn't indicate a moving goal post, it indicates a diversity of opinions. Also, the two ideas (as I understand them...) are not necessarily mutually exclusive, its possible that evolution is both fast and slow depending on the circumstances. I'm sure there are formulations of those ideas which are mutually exclusive, but that doesn't mean that all people who agree with a similar interpretation exactly adhere to that formulation. No rational person is going to argue against micro-evolution, the evidence is all around us. There just isn't any empirical evidence of macro evolution, it's long past time for Evolutionists to admit that. I believe that I am descended from non-human primates, and I admit that I am unaware of any definitive, immediate, strong, simple, clear and direct empirical evidence explicitly demonstrating the development of a new species. Also, I wouldn't expect there to be at this point. The Peppered Moth experiment has been debunked for years. Peppered Moths are nocturnal and sleep on the bottoms of leaves or branches, so color played no role in survival. It's also important to note that the experiment has never been duplicated and not for lack of trying. This claim reminds me of my favorite wikipedia page: http://en.wikipedia.org/wiki/List_of_common_misconceptions It honestly wouldn't surprise me if it were true that various commonly accepted claims surrounding pepper moths were simply false, given the wide range of completely false beliefs which have made their way into textbooks as 'facts'. Can you be a bit more explicit, though? Maybe there some part of this wikipedia page which you think is false? http://en.wikipedia.org/wiki/Peppered_moth_evolution |
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Evolution: How much change is required to become a new species? How much change do you think any species would have to go through to cross over from one species to another? Like fish to a lizard. I'm not an expert on the new (or even the old) theory. I can't see much hope for a fish turning into a lizard when it's so tough to get one species of a man to change to another. |
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isn't species defined through their genomes?
so until all of them are different wouldn't that qualify as new species? |
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Evolution: How much change is required to become a new species? Answer: A species is defined currently (artificial definition, for an artificially conceptualized term) as a life form that can reproduce biologically reproductive offspring. That's certainly not universally true. Take the genus Salix. The species readily interbreed and produce fertile offspring. And yet over time the intergrades tend to die away leaving only the original parent species. If the definition of species was to be rewritten to put it on a scientific footing rather than the gut instinct of zoologists and botanists, it ought to specify stability over time as a requirement. |
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Evolution: How much change is required to become a new species? Answer: A species is defined currently (artificial definition, for an artificially conceptualized term) as a life form that can reproduce biologically reproductive offspring. That's certainly not universally true. Take the genus Salix. The species readily interbreed and produce fertile offspring. And yet over time the intergrades tend to die away leaving only the original parent species. If the definition of species was to be rewritten to put it on a scientific footing rather than the gut instinct of zoologists and botanists, it ought to specify stability over time as a requirement. Dam those taxonomist! |
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Evolution: How much change is required to become a new species? How much change do you think any species would have to go through to cross over from one species to another? Like fish to a lizard. I'm not an expert on the new (or even the old) theory. I would say probably an eternity because I have yet to see a fruit fly evolve into so much as a flea. |
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Edited by
missyfissy
on
Tue 09/20/11 08:38 PM
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I totally agree with the concept there and how traits can indeed be controlled by natural selection. However, in that particular case, the crabs are still just crabs and the ones that have samurai makings on them can probably still breed with crabs of the same species that don't have those markings. So no "new species" was actually created due to that process. Not only that, but what happened to the ones that supposedly had those evolving shape-shifting abilities to start with? |
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Edited by
missyfissy
on
Tue 09/20/11 08:52 PM
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That's a man-made definition of what we mean by 'species'. We arbitrary used that distinction to define this term. So if you take a group of a single species and slit that group up on two isolated islands for a long enough period of time they will eventually diverge to the point where the two groups will no longer be able to procreate viable offspring. Then you are justified in stating that they are no longer the same species. Precisely how many generations that will take to achieve is something that a geneticist might be able to answer. Obviously you'll have far better luck using species that procreate quickly and die quickly. That way you can observe many generations over a short period of time. If you use elephants for your experiment you probably won't live long enough to see any change. I think a single generation for an elephant is longer than a human lifespan. So better off using fruit flies or something like that.  In fact, I think there have been biological experiments where this has actually been achieved. But arguments then arose concerning whether or not they had actually created a new "Species". Let's not forget that the very definition of "species" is a man made construct. We simply define "species" based upon an ability to procreate between the same creatures. That's a totally arbitrary definition and term created by man. If these fruit flies can no longer breed with those fruit flies does that really mean we have created a new "species"? They both still LOOK like Fruit flies to me! Just because they have sexual impotency problems doesn't mean they are a new species! That's the argument that is given against these kind of experiments. The whole notion of what it means to be a "species" comes into question. Especially when one species may simply have eliminated the fly and given birth instead to fruits. |
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