|
Register | Sign In |
|
QuickSearch
Thread ▼ Details |
|
Thread Info
|
|
|
Author | Topic: How do you define the Theory of Evolution? | |||||||||||||||||||||||||||||||||||||||
Tangle Member Posts: 9510 From: UK Joined: Member Rating: 4.8
|
It's interesting watching the creationists wriggle. Their arguments have had to change (evolve) over time as discoveries in science made it impossible to support them. The age of the earth is one such seismic change but here we have another.
Until Darwin came along the predominent Christian belief was the fixity of species; they were said to be immutable, they could not change. They were put here by God as we see them now. Praise be! That idea had to change because we discovered more and more species and they all had to fit onto that mythological boat. Darwin came along just in time showing that species did actually change and now immutability of species has been totally abandoned by believers. It's even called unbiblical these days, despite being a firm Christian belief for centuries. But by allowing species to change they opened the gate to evolution. So now the great wriggle is to stop evolution at a convenient point - they have to allow change, but not so much change that it can harms creation itself. Hence 'kinds' - an undefinable idea allowing as much or as little change as is necessary for any particular organism just so long as they can be on that boat. This is tricky. The reason that CRR is being so pedantic about definitional issues of the ToE that no-one in science cares too much about is because he absolutely must find a definition which removes the logical conclusion of common descent. His job here is not to define the Theory of Evolution but to define OUT of the ToE common descent. He now needs to stop evolution at some convenient point for his beliefs to continue make some sort of sense to him despite the accumulation of evidence that they don't and they can't. Science has forced a change in how believers believe since the enlightenment. Prior to that, the priest stood at the front and told their congregation what to believe and they believed it. Now individuals have to reconcile facts discovered about our world with folk tales and the folk tales can't stand up to it. In American fundamentalism I think we're seeing Christianity's final struggle against rationality. Je suis Charlie. Je suis Ahmed. Je suis Juif. Je suis Parisien. I am Mancunian. I am Brum. I am London. "Life, don't talk to me about life" - Marvin the Paranoid Android "Science adjusts it's views based on what's observed.Faith is the denial of observation so that Belief can be preserved." - Tim Minchin, in his beat poem, Storm. |
|||||||||||||||||||||||||||||||||||||||
jar Member (Idle past 422 days) Posts: 34026 From: Texas!! Joined: |
Of course you are free to suggest absolutely silly, false, misleading and dishonest things like "The Theory of Evolution is the theory that all the living forms in the world have arisen from a single source which itself arose naturally from an inorganic form." but it is simply an example of the utter failure and worthlessness of the anti-evolution cult.
Now, had you suggested that "The evidence found in reality on Earth shows that all the living forms in the world have arisen from a single source which itself arose naturally from an inorganic form and that there is no evidence whatsoever of anything but natural origins." then you would be closer to being correct and would find many who agree with that statement.
|
|||||||||||||||||||||||||||||||||||||||
RAZD Member (Idle past 1433 days) Posts: 20714 From: the other end of the sidewalk Joined: |
That depends on your definition of species. There could be geographical, behavioral, or ecological reasons for maintaining separate varieties even though they could still interbreed. ... Curiously I don't care to much if the can or could interbreed, when we can force camels and llamas to produce offspring, reproductive incompatibility is a questionable metric. What matters is the natural normal behavior -- if the natural behavior is to mate with one group and not another then for all intents and purposes a division in genetic lineages has begun. And with ring species we see that total genetic isolation is not necessary for the two ends of the ring to normally decline mating with each other. In this regard isolation comes down to sexual selection. That is all that is necessary for evolution to develop more and more divergence between the populations as generations pass.
... This happens with cichlids where several varieties (species?) can live in the same lake but will interbreed if put in an aquarium. ie not their natural normal ecology, when the cichlids normally self segregate into different ecological niches, forcing them into a confined one changes their behavior.
Yes species IS hard to define and there are many "species" (and genera) today than can exchange genetic material. If I remember correctly Darwin doubted species as a valid taxonomic unit and thought of a species as a well defined variety. One problem of using "species" in the definition is that you then need to clearly define "species", especially where the meaning can vary. This is why I prefer cladistics to taxonomy -- taxonomy assumes a static classification (so 18th century), while cladistics only concerns itself with descent from common ancestors; it doesn't care what you call them, it cares what the behavior shows. We see anagenesis occurring all around us and we see instances of cladogenesis. We see the effects of a continuing changing distribution of traits within breeding populations from generation to generation, and we observe that this ongoing process also explains what we observe in the genetic record and the fossil record. The ToE explains the evidence. Enjoyby our ability to understand Rebel☮American☆Zen☯Deist ... to learn ... to think ... to live ... to laugh ... to share. Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)
|
|||||||||||||||||||||||||||||||||||||||
JonF Member (Idle past 196 days) Posts: 6174 Joined: |
If you read Darwin's "Origin of Species" you will find that common ancestry, from one or a few common ancestors, was a core part of his theory. I've read it and I disagree. Descent with modification is the core. Do you have any support for your claim? Edited by JonF, : No reason given.
|
|||||||||||||||||||||||||||||||||||||||
RAZD Member (Idle past 1433 days) Posts: 20714 From: the other end of the sidewalk Joined:
|
Here's a link on-line to link to the page(s) involved:
Darwin Online: On the Origin of Species I did a search of the text for "common ancestor" and all that came up was discussion of groups of animals having a common ancestor.
quote: The search also looked through papers and notebooks and his other books with similar results. Enjoy Edited by RAZD, : . Edited by RAZD, : ..by our ability to understand Rebel☮American☆Zen☯Deist ... to learn ... to think ... to live ... to laugh ... to share. Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)
|
|||||||||||||||||||||||||||||||||||||||
New Cat's Eye Inactive Member
|
According to you?
Yes. I'm not sure why I should care how you personally define the ToE. You don't get to determine how scientific theories are defined. The scientific community does that. Your definition differs from the accepted scientific one. So now what? We just share opinions and say cool story, bro?
After all the thread is "How do you define the Theory of Evolution?" Right, but remember the medium. These are three different question: "How do you define the Theory of Evolution?""How do you define the Theory of Evolution?" "How do you define the Theory of Evolution?" So, how do you define the theory of evolution? I don't. It is defined by scientific consensus, not us.
|
|||||||||||||||||||||||||||||||||||||||
Taq Member Posts: 10081 Joined: Member Rating: 5.1 |
CRR writes: Looking at domestic dogs we can see how new varieties have been produced over time within the existing species. The species has changed but there has not been a new species. Yes, the species has changed, and the theory of evolution explains why that happened. The theory deals with changes within a single species and it also deals with cases where populations split into two new populations that don't interbreed.
Your definition is quite consistent with Young Earth Creationism which theorizes that many modern species have been produced by speciation within the created kinds. Actually your definition doesn't even claim that much change. Perhaps I'm more of an evolutionist than you are. You would have to define "created kinds" in order for that statement to make sense.
|
|||||||||||||||||||||||||||||||||||||||
Taq Member Posts: 10081 Joined: Member Rating: 5.1
|
CRR writes: The Theory of Evolution is the theory that all the living forms in the world have arisen from a single source which itself arose naturally from an inorganic form. That is not the definition that scientists use. No theory of evolution I have seen requires abiogenesis. As to universal common descent, it is a finding that has come out of the theory, but isn't a requirement of the theory. If you want to use your own private definition for the theory of evolution then that is your prerogative. However, it seems to be a bit silly to beat on a strawman.
|
|||||||||||||||||||||||||||||||||||||||
Taq Member Posts: 10081 Joined: Member Rating: 5.1
|
CRR writes: Including or excluding abiogenesis is always a point of contention. Again I am following the example of more than one evolutionist. Who?
What good is a theory of origin of species that doesn't explain the origin of the first species? It is good for explaining how species changed after the emergence of the first life. If you reject every theory that does not explain the ultimate origin of the thing it studies then you will have to throw out most of science. The Germ Theory of Disease does not explain where the first germs came from. Do you reject that?
|
|||||||||||||||||||||||||||||||||||||||
Taq Member Posts: 10081 Joined: Member Rating: 5.1 |
CRR writes: Yes species IS hard to define and there are many "species" (and genera) today than can exchange genetic material. If I remember correctly Darwin doubted species as a valid taxonomic unit and thought of a species as a well defined variety. One problem of using "species" in the definition is that you then need to clearly define "species", especially where the meaning can vary. If evolution is true, then species should be hard to define. There should be a fuzzy line between populations during incipient speciation. There should be a continuum of morphological changes between generations as a species changes over time. The very fact that species are hard to define is strong evidence in favor of evolution.
That depends on your definition of species. There could be geographical, behavioral, or ecological reasons for maintaining separate varieties even though they could still interbreed. This happens with cichlids where several varieties (species?) can live in the same lake but will interbreed if put in an aquarium. You are looking at this completely backwards. What matters is what is going on in the genomes of those populations. It doesn't matter if two species can interbreed. What matters is do they interbreed, and to what extent. What matters is if their genomes are diverging. Species are defined by the effect of genome divergence. For cichlids, what matters is if they DO interbreed in the wild, and if they do so in great enough numbers so that the genomes of the two populations do not diverge.
|
|||||||||||||||||||||||||||||||||||||||
Taq Member Posts: 10081 Joined: Member Rating: 5.1 |
CRR writes: Yes. After all the thread is "How do you define the Theory of Evolution?"So, how do you define the theory of evolution? Why even bother asking others what the theory of evolution is when you will just use your own personal definition and attack that personal definition, otherwise known as a strawman.
|
|||||||||||||||||||||||||||||||||||||||
ringo Member (Idle past 439 days) Posts: 20940 From: frozen wasteland Joined: |
I would define the Theory of Evolution as, "the explanation of how evolution works."
First, it is THE explanation. There is no other. Second, even creationists agree that evolution DOES work, so there's no need to argue that. They just have an unsupported claim that there's an unevidenced limit to how far evolution can go. Third, note that there is no mention of how many original ancestors, nor any need to mention it. The explanation works whether there is one or forty.
|
|||||||||||||||||||||||||||||||||||||||
Taq Member Posts: 10081 Joined: Member Rating: 5.1
|
ringo writes: I would define the Theory of Evolution as, "the explanation of how evolution works." Those explanations can also change depending on the context, as is true for all theories. Expecting a one paragraph definition of the theory to cover all possible contexts is a Fool's Errand because biology is a big, complicated, and divergent field. What may apply for eukaryotes may not apply for prokaryotes, with such things as horizontal genetic transfer and sexual reproduction causing different effects. How we define species will differ as it applies to asexual, sexual, living, or fossil species. Context is everything.
Third, note that there is no mention of how many original ancestors, nor any need to mention it. The explanation works whether there is one or forty. To use an analogy, gravity as an explanation for the orbit of planets works whether there are 8 planets or just 1.
|
|||||||||||||||||||||||||||||||||||||||
RAZD Member (Idle past 1433 days) Posts: 20714 From: the other end of the sidewalk Joined:
|
We've discussed the Pelycodus illustration before and as I have pointed out the resultant variation is less than in modern dogs which are all regarded as one species, ... So you would agree that these also show less variation and could all be one species, yes?
quote: Or these:
quote: ... so this does not necessarily show either anagenesis or cladogenesis since we can't say if a new species actually formed at any time. Actually the formation of a new species is not necessary for anagenesis, so we do necessarily see anagenesis in the Pelycodus fossils -- they change continuously from bottom to top. Likewise we do not need to know if Notharctus nunienus and Notharctus venticolus could interbreed to know that the fossil evidence shows that they didn't, and that each population went on to diversify further. So yes, in that regard new species were observed forming.
... less than in modern dogs which are all regarded as one species, ... In scientific circles that would make you a "lumper" compared to most people that would be "splitters".
quote: Anagenesis and cladogenesis explain the fossils above. Does your version of the ToE explain them?
quote: All I get from that is that all life could be one species ... the ultimate lumping. It doesn't explain the observed nested hierarchies that cladogenesis does, nor the observed change within species over multiple generations that anagenesis does. Enjoy Edited by RAZD, : .by our ability to understand Rebel☮American☆Zen☯Deist ... to learn ... to think ... to live ... to laugh ... to share. Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)
|
|||||||||||||||||||||||||||||||||||||||
dwise1 Member Posts: 5952 Joined: Member Rating: 5.2
|
The Theory of Evolution is the theory that all the living forms in the world have arisen from a single source which itself arose naturally from an inorganic form. Uh, no. Whatever would have made you think that? Except for typical creationist lies. To begin with, do you even have any idea what a theory is? Since you are a benighted creationist, I doubt that very much. Second, just what is the Theory of Evolution? A theory explains a phenomenon, so the theory of evolution explains evolution. Do you have any idea what that means?
The key elements of this are abiogenesis and ascent from a last universal common ancestor (LUCA); both of which I expect to be controversial. Uh, no. Complete failure on both points. Evolution is what life does. Sorry, but that's the plain facts. Once you have life, it quite naturally evolves. You cannot stop it regardless of your religious dogmata. Whether life arose through entirely naturalistic processes or by some supernaturalistic fiat, once that happened it proceeded to evolve. And for that matter, even if life arose from non-life through entirely naturalistic processes, why would any actual creationist ever want to claim that to disprove God?
The key elements of this are abiogenesis ... No, demonstratively false! Even if all life had come into being through means other that abiogenesis, the results would still be the same. All those specially created kinds would have immediately started to evolve from that point forward. Evolution happens despite abiogenesis or special creation. Therefore, evolution does not depend on abiogenesis. Your position is a lie.
... and ascent from a last universal common ancestor (LUCA); Also not part of the theory. Evolution handles multiple lines of descent just as well as one single one. It does not depend on a single "last universal common ancestor". Single universal common ancestor or multiple ones. No difference. Evolution works either way. So in typical creationist manner, you are lying to us about what evolution is. That makes your god the "God of Lies", which according to Christian doctrine would be Satan. Well done. Edited by dwise1, : Misspelling: life, not live
|
|
|
Do Nothing Button
Copyright 2001-2023 by EvC Forum, All Rights Reserved
Version 4.2
Innovative software from Qwixotic © 2024