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Author | Topic: Where Is Macro-Evolution Occurring | |||||||||||||||||||||||||||||||||||||
bran_sept88 Inactive Member |
Crash,
You brought up that you or I have never seen an irreducibly complex organism created, but also i have never seen anything macro-evolve either, could you please direct me to were i can read up and find out what macro-evolutionary events I am missing out on. BRAN
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MrHambre Member (Idle past 1692 days) Posts: 1495 From: Framingham, MA, USA Joined: |
You're using the term macroevolution like it's something that 'happens' every day. What the term really means is the evolutionary heritage of diverse organisms can be traced to a common ancestor, through morphological and genetic examination. The family trees that are constructed this way contain branchings that constitute 'high-level' change, giving rise to very different lineages.
As for not being able to witness this first-hand, it's a process that typically spans hundreds of millions of years. The accumulation of small changes adds up to this high-level change. It's like saying we measure hot days with a thermometer, and heat waves are what we call a succession of hot days. The dark nursery of evolution is very dark indeed. Brad McFall
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crashfrog Member (Idle past 1766 days) Posts: 19762 From: Silver Spring, MD Joined: |
You brought up that you or I have never seen an irreducibly complex organism created, but also i have never seen anything macro-evolve either The mistake you're making is that there's no difference between macro- and micro-evolution. It's the same process over different lengths of time. Just as walking to the grocery store is micro-walking and walking to the next town over is macro-walking - but they're the same process. It's just that walking to the next town takes a little more time. So, the answer is, it's happening every day, all around you. You just mistakenly refer to it as "micro-evolution."
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sidelined Member (Idle past 6207 days) Posts: 3435 From: Edmonton Alberta Canada Joined: |
bran
You might check out this webpage Evolving Before Our Eyes / Songbirds and salamanders bolster Darwin's theory that change in habitat can create 2 species from oneIt deals with evidence of evolution in progress. 'Everyone is entitled to his own opinion but not his own facts.' (Daniel Patrick Moynihan)
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sidelined Member (Idle past 6207 days) Posts: 3435 From: Edmonton Alberta Canada Joined: |
Did-a-bump, did-a-bump,did-a-bump bump bump.
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Mespo Member (Idle past 3184 days) Posts: 158 From: Mesopotamia, Ohio, USA Joined: |
Hi Gang,
You might try googling on "London mosquito" In a nutshell, Culex pipines was the dominant mosquito species in London prior to the Tube (subway) being built at the end of the 19th century. With the completion of the Tube, the mosquitos followed their human hosts underground. Since the subway trains ran on regular schedules, there was no need for the mosquitoes to come up to find a meal. Not only did they stay underground, their diet was restricted mainly to humans, they bred in stagnant underground puddles and lived and died in artificial light. By the 1980s or so, this underground variety of mosquito was found to be completely sexually isolated from the above-ground stock from which it started. This is a rough summary mind you, so someone better versed in entomology might help fill in the blanks. Anyway, as I understand the definition of "macro evolution" as relating to the generation of new species, this one may qualify. (:raig
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truthlover Member (Idle past 4358 days) Posts: 1548 From: Selmer, TN Joined: |
You brought up that you or I have never seen an irreducibly complex organism created, but also i have never seen anything macro-evolve either People are answering your questions, but your point is not accurate logically. Those who support irreducible compexity use it as proof that irreducably complex organs could not have evolved. They are saying that these IC organs MUST have been produced in a single step. Therefore, it is appropriate to ask if this single step has ever been seen. Those who teach "macro-evolution" (I don't agree with the term, either, but I'm granting it for argument's sake) do not say that it disproves irreducibly complexity. Macro-evolution is not offered as a disproof of IC. Instead, it is a conclusion drawn from watching micro-evolution and from over a century of learning the mechanisms of micro-evolution. It follows, from the mechanisms we now understand and the micro-evolution we can see, that micro-evolution inevitably leads to macro-evolution. So, the request to show macro-evolution is not a legitimate request from ICers, and it's not offered to shoot down IC. The request to show IC as having happened is a legitimate request from science, because it is being presented as something that shoots down evolution. Gosh, that sounded much less clear than I thought it was going to sound. I hope someone understands what I said and that it really makes sense.
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NosyNed Member Posts: 9012 From: Canada Joined: |
Anyway, as I understand the definition of "macro evolution" as relating to the generation of new species, this one may qualify. I have a couple of comments on this. (heck, I always seem to have a comment or 3 ) a) This iis/i "macro-evolution" by the original biological definition of the term. That is evolution is 'micro if belowp the species level. b)Creationists have decided to redefine the term (they tend to do that a fair bit). However, they haven't come to any agreement on what it does mean. Some do call this "macro" but others call macro the creation of new genera and still others waffle a bit and toss family in as well. You have to ask what someone means by the term. c)We have seen a number of posts with the arguement that 1+1=2 then 1+1+1+1 ... +1 = n to show that lots of micro produces macro. Note that this could be taken as not absolutely true. It is micro and geographic separation (of a sort) that allowed the evolution of the london mosquito. What isn't clear to me is whether this is a part of the orginial ideas of Darwin, neo-Darwinism or a further addition. Taking it in one extreme, if there are no cases where micro steps alone account for speciation, this means that darwinism (the orginal) or even neo-darwinism is wrong. It is, perhaps, wrong in exactly the same way the newtonian mechanics is wrong. That is, the base idea is intact but modifications are needed. Common sense isn't
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Brad McFall Member (Idle past 5332 days) Posts: 3428 From: Ithaca,NY, USA Joined: |
Dear Ned,
It is somewhat "un"clear to me too. I have been looking over Gould's "Species as Individuals in the Hierarchical Theory of Selection" in his THE STRUCTURE OF EVOLUTIONARY THEORY and given my own few or many quircks of interpretation I can not understand why Gould seperates for a "macro" perspective multiple issues which in these quick quircks I find only one process and only a meta or labeling scheme being proposed by him. It is nice that Gould "spaces" out his understanding of concepts for any one to read but I can not make out his idea into its "strong" form NO MATTER HOW HARD I TRY. I will explain this later and in bits relative to reading Faraday in terms of Galvani with some idea perhaps that DNA-RNA-Protein might indeed form a voltaic circuit and IF (the big if) microtubules are thought of as Faraday's "thermo" circuit then... but that I will reserve for a better, more relaxed Q&A. The point there will be that perhaps unlike Creswell this particular hook will be formed contrary to the notion of perpetualness in Volta but maybe not in "inventory". My problem is that I read Faraday's last paragraph in a "sarcastic" tone as to the notion of "perpetual" so I am not certain I have recieved the guy in his own voice.
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Loudmouth Inactive Member |
Hey, long time no reply Brad. Hope things are going well.
quote: I confess that I haven't read Gould's work (time to get a library card again) but it sounds like there may not be a concrete meaning. Perhaps micro and macro are more fluid and can never really illustrate differences, or even quantifiable degrees of evolution. I am shooting in the dark here, but I find this quite often in scientific literature and it may be the case here. Macro and micro seem subjective instead of objective.
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truthlover Member (Idle past 4358 days) Posts: 1548 From: Selmer, TN Joined: |
What isn't clear to me is whether this is a part of the orginial ideas of Darwin, neo-Darwinism or a further addition. I'm no scientist, but I did bother to read Origin of Species. He certainly discusses geologic separation as a pretty crucial part of the origin of a new species. I can't remember that he said it was essential or anything. He did discuss small changes getting lost in the population if there was no separation, and he devoted a whole chapter to the tendency of new species to revert to their old form unless they had been changed a very long time (he used doves of many breeds being born with rock pidgeon markings as an example of this, and various horse-like species being born with zebra-style stripes as another example). Anyway, it appears to me--from memory--that Darwin thought geologic separation was very important.
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Minnemooseus Member Posts: 3976 From: Duluth, Minnesota, U.S. (West end of Lake Superior) Joined: Member Rating: 6.0 |
I can't confirm what Darwin wrote (have a link to the book somewhere), but it sounds good to me. I'm sure you meant geographic separation, rather than geologic separation.
I believe that the geographic isolation of a small population is an important consideration in the punctuated equilbrium theory (punk eek). Moose
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NosyNed Member Posts: 9012 From: Canada Joined: |
Wow! I'm impressed. I did read the origin too but forgot that. That he recognized the need for that without knowing anything about genetics is very impressive.
Common sense isn't
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Wounded King Member (Idle past 332 days) Posts: 4149 From: Cincinnati, Ohio, USA Joined: |
That seems a wierd way to look at it Ned. Considering the nature of many of the best known examples Darwin studied, differing species on islands in a chain, it seems pretty obvious why he would consider geographic isolation to be a significant factor. To see how non-surprising it is you only have to notice the Alfred Russel Wallace reached the same conclusions after his studies in the Malay archipelago.
It is also worth noting that geographic isolation is not neccessarily required for evolution to occur. There is a PNAS review of an article on sympatric evolution in Drosophila which discusses the the differing possible mechanisms of speciation.
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Brad McFall Member (Idle past 5332 days) Posts: 3428 From: Ithaca,NY, USA Joined: |
They can with a lot of dough, content maganagemnet money and no future biotech beyond XML. My bet is that nanoecology will suffer a Marylin Manson type=public relations fall before this does not come to pass. Gould is relying as far as I see it on VRML not being able to out label his CONCEPT of SPANDREL but I can already see differences he would have had to shore up if he was still among the living. I have no guage of my generations' interest in his work but if Carl Zimmer is any indication I will be in just as much trouble on this line with what in my generation I can be clear about has I have not been with trying to not span two other generations of readings in biology. I now read back to 1800 not long ago it was 1900. In the 1980s I was only reading to biology of the 50s and I thought that would pass. It did not. by the 90s it was the 30s and the rest- well let me not get this far off a Buzz topic for I want to come back to the future as well.
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