You seem to be claiming at some point "overwhelming evidence" accumulated. If you can't say what took the evidence over the line, then you are just drawing an arbitrary line and claiming I drew it in the wrong place. I think I supported my reasoning and I like my reasoning. The theory was only complete when we understood the how not just that it did occur. Some people may still argue the theory is not complete until we fill in the abiogenesis chapter. I see nothing in what you have posted that makes how I defined overwhelming evidence "wrong". We differ in how we view it is all.
I really don't think that I am being arbitrary. In the 30s and 40s the Modern Synthesis became the accepted consensus on evolution. To a large extent that Synthesis was not new, it just combined the pieces that lots of people had into a coherent picture. From that point to this there has been no serious scientific objection to Darwin's theory of evolution.
While it is always hard to point to a specific date at which a theory became definitively accepted (see my previous example of the Big Bang and Fred Hoyle), I think I'm on safe ground to say that Darwin's theory was solidly demonstrated by the time the Modern Synthesis came around and became accepted.
Overwhelming evidence also depends upon to whom you apply it. Evolution deniers repeat their arguments ad nauseum. But if we didn't have the mechanism of evolution precisely understood you cannot as decisively tell them, "it is no longer a theory, evolution is a fact". Even now if I put it in those terms there will be some scientists (and skeptics) who will object to using the word, fact.
The Modern Synthesis had a precise enough understanding of the mechanism to be able to make that assertion. And if you look at Gould's early essays (circa early 70s, which would be 40 years ago) you'll find clear and carefully reasoned assertions that evolution is a proven fact.
You mention Lamarckian theory as one competing theory. It hardly competes with Darwin's theory IMO since it merely offers a mechanism of inheritance. It is not my understanding that mechanism excludes Darwin's theory, it merely claims we can add to the genes in a way which the evidence when collected, did not support. But if you want to argue it offered a different version of inheritance as opposed to a different version of speciation, fine.
Hardly competes? A great many people would disagree with you, starting with one Charles Darwin. The key part of Darwin's theory is that the driver of change over time is that less successful individuals die rather than pass their traits on. Lamarck's theory provides a completely different mechanism which could drive change over time. If Lamarck's theory was true, then the importance of natural selection would play a distant second fiddle to teleologically driven change.
God has never been a scientific theory and I do not accept that claim at all. I'm not talking about beliefs. If you go that route, then Darwin certainly isn't 'overwhelmingly' accepted even today.
Then you're being a-historical.
If you read scientific papers from the 1800s, the possibility of Divine Intervention was seriously considered and discussed. This fact is acknowledged in the preface to
The Origin of the Species. (While Darwin gives a list of precursors to his theory, he acknowledges that "...the great majority of naturalists believed that species were immutable productions, and had been separately created." People of that time simply did not draw the line between religion and science as we now draw it, and to ignore this fact is to make it impossible to understand people of that day.
You refer two more times to competing theories, plural. You only note one alternate version of modified inheritance. You are exaggerating your case if you cannot present competing theories and you try to call god beliefs a theory.
I note Lamarck's theory because it was the main one. I am hardly an expert in this subject, and so would have to do research to be able to enumerate others. (Part of the difficulty in enumeration is that there were many people with vague and vaguely different notions of how change over time could happen, so dividing them into clear groups is very difficult.)
Secondly you continue to question calling god beliefs a theory,
but the fact is that it was! To say otherwise is to misrepresent the historical record. There were many prominent naturalists, whose contributions we respect to this day, who believed on variations of "God did it." I've already named the geologist John Phillips who corrected Darwin's miscalculation of the age of the Weald of Kent. A far better-known example is Louis Agassiz. Who to this day is recognized for his contributions to biology. You may read about him at
http://www.ucmp.berkeley.edu/history/agassiz.html. His accomplishments included gathering copious evidence that an Ice Age had happened, fundamental discoveries in embryology, the founding of Harvard's Museum of Comparative Zoology, and the discovery of significant parallels between ontogeny, paleontology and morphology.
If you wish to claim he was not a scientist, I will have to laugh. If you try to divide his religious beliefs from his scientific work, then you have guaranteed that you'll never understand his work.
If you think I have misrepresented selection pressures you need to reread my posts so I don't understand your complaint there.
I don't think you've misrepresented selection pressures. I think that you've missed the fact that alternatives to selection pressures as a mechanism of change are a direct challenge to Darwin's theory.
Ben Tilly said:
Remember that Darwin was not arguing against modern creationists. He was arguing against scientists of his time, who had their own opposing theories. It was not sufficient to argue that evolution happened. He had to argue that it happened in a specific way for a specific reason.
Like I said, so far you have only mentioned one.
See my above responses to this point. I've mentioned he main alternative. And your continuing refusal to not accept God as a competing theory notwithstanding, it
was a major competing theory within the scientific community.
Ben Tilly said:
Scroll back through this thread and looked for the phrase "punctuated equilibrium". See how many times I mention it, see who I say were the authors, and see what time frame that I said it happened in.
And you think I don't understand this? I posted the mechanism for it. I don't get your point, unless you have simply underestimated what I know about evolution.
Then perhaps I misunderstood the point of your reference to punctuated equilibrium. Back in your original post at
http://www.internationalskeptics.com/forums/showthread.php?postid=2478396#post2478396 you said that, "...the bulk of arguments evolution deniers put forth are based on 40 year old science." But I've seen those arguments, and the "40 year old science" that those arguments are based on are actually misrepresentations of the punctuated equilibrium debate. In fact that was the point which this side discussion started at, see
http://www.internationalskeptics.com/forums/showthread.php?postid=2502976#post2502976 for proof.
So when in
http://www.internationalskeptics.com/forums/showthread.php?postid=2505709#post2505709 you brought up advances in our understanding of speciation in the 60s and 70s, I thought that you were bringing it up to demonstrate that our evidence for evolution was weak at that time. Hence my response.
If I misunderstood your point in bringing that up, then I apologize.
Ben Tilly said:
I'm sorry, but back in the 1930s people knew very well what genes were and knew exactly how they were connected to chromosomes. They didn't understand how genes did what they did, nor could they measure them in detail, but they had more than a good enough understanding of them to understand evolutionary mechanisms. They didn't need to know the details of how chromosomes work to be able to explain, for instance, altruism.
You are stating that at the very beginning of our learning about the mechanisms of inheritance, the whole picture had emerged. Clearly it hadn't. So I'll have to disagree with you there. I posted dates and events. Genetic mechanisms were more fully understood by the 70s. On the one hand you say when Darwin proposed the theory it wasn't yet good enough and on the other hand you say when the material in the nucleus of the cell was proposed as the material which passed on the information, then it was good enough. It wasn't well understood as soon as it was discovered.
Excuse me?
"...the very beginning of our learning about the mechanisms of inheritance..."?
Let's see. Research was going on in how inheritance happened back around 1800. They didn't get very far, but they had lots of competing theories. You start to get real progress in the 1880s with Dalton's demonstration of regression to the mean. Mendel's work was rediscovered around 1900. Fisher managed to reconcile the two in 1918. And research continued from there. I do not know who demonstrated the connections betweeen genes and chromosomes, but when
http://en.wikipedia.org/wiki/Modern_evolutionary_synthesis claims that this connection was understood by the 30s and 40s, that fits with my understanding of what kind of research preceeded that (work on population genetics) and postdated it (Watson and Crick).
So in the 1930s they had been researching inheritance for over a century, and had been on the right general track for over 30 years. I would
not call this "the very beginning".
Then you go on to claim that I was saying, "...the whole picture had emerged." In fact I'd said no such thing, nor did I mean to imply it. I said that they had certain pieces of the picture, and those pieces are sufficient for evolutionary theory. This is true. But, for instance, some of Barbara McClintock's groundbreaking work on jumping genes was marginalized for many years because the theoretical framework that had been developed could not handle that concept.
(Incidentally if you read
http://en.wikipedia.org/wiki/Barbara_McClintock you'll find that in the 20s and 30s she not only knew about the connection between chromosomes and genes, but she was actually studying
where on the chromosome
specific genes were located! Yet further confirmation of the timeline that I gave above.)
Ben Tilly said:
Now you're falling prey to the "no true Scotsman" fallacy.
How about just using the definition of science, scientific evidence, supporting one's conclusions with evidence. You cannot tell me religious convictions are science. That is unsupportable. If God beliefs competed with Darwin's theory 175 years ago, then they still compete today. You can't have it both ways.
Let's apply your argument to a different example and see how well it holds up.
Back in the 1700s the theory of phlostigon was clearly science. It was an accepted part of chemistry and appeared in all of the textbooks. Then oxygen was discovered. Anyone who has been talking about phlostigon in, say, the last 200 years has not been doing science. Everyone can recognize that.
But by your theory, the fact that phlostigon was once part of serious scientific discourse means that it has to be considered part of serious scientific discourse forever. Clearly your theory isn't measuring up very well with the facts.
Now let's return to the God hypothesis. I've already quoted several examples of people who demonstrate that serious scientists, in serious scientific discourse, thought about and discussed the idea that God created species in various ways over various times. It is impossible to produce a coherent history of scientific thought that, for instance, includes the discussions that lead to the discovery of Ice Ages and excludes discussions of God. When I say that God was a part of serious scientific discourse at that time, there is a lot of history that backs me up.
But the practice of science has moved on. Today when you try to seriously advance the theory that God created different species, you're no more doing real science than you are if you're trying to measure phlostigon. But if you try to apply this standard back to scientists in the 1800s, you're being as a-historical as you are if you try to claim that Lavosier was not doing chemistry when he was trying to produce air without phlostigon.
The long and short of it is, of course, that our notion of science had to develop over time. Today you talk about a "definition of science". However the definitions that you'd use came about after the period that we're discussing. The standards that you'd apply developed in large part as a result of the debate over evolution. And therefore trying to apply your definitions and standards to people in the 1800s simply guarantees that you can't understand the historical debate that happened.
If you think I would use Behe's work as an argument for anything, you haven't read my pages and pages and pages of evolution posts. I have never been convinced by any argument supporting irreducible complexity. And if you can find a post where I said the mechanisms of evolution were only understood 10 years ago, I misspoke or you misread what I said. I believe I have consistently said, "a couple decades" since that is when the revolution in genetic research took place, and perhaps I should have said 3 decades. Time flies faster the older you get.
Well you'd said that we'd passed the point of overwhelming evidence "at least a decade ago". You're right that I'd misread that. I misread that as "about a decade ago". My apologies.
The cause of my misreading is that I was annoyed that you gave Creationists enough credit to say that their arguments are based on 40 year old science. They aren't. They are based on
misrepresentations of 40 year old science.
So you haven't made your case for what made the evidence overwhelming that contradicts what I have posted. If I understated the timing by a decade, I'll grant you that. I'll go with 3 decades and try to keep to that correction. I hadn't really ever looked up when the genetic science research began in earnest. The 70s sounds about right. Seems like only 2 decades ago.......
I haven't made a case that the evidence was overwhelming in the 30s and 40s? And here I thought I had.
When you're at the point of being able to identify where on specific chromosomes specific genes are encoded, you know enough about inheritance to give evolution theory solid underpinnings. Whether or not you know how chromosomes work or are able to directly read those genetic sequences off of the chromosomes. Barbara McClintock was getting us to that point back in the late 1920s. And evolutionary theorists realized, understood and accepted the consequences in the 30s and 40s.
When you're working at a detailed level, it is tempting to think that knowledge comes "bottom up". That is, you discover the mechanisms, figure out the consequences, and the move up the scale. But historically our knowledge of biology has proceeded "top down". Over time as techniques get better, we're able to examine biological processes on more and more detailed levels. But facts at higher levels that today one would present as being consequences of more detailed theories were historically discovered in the earlier order. Thus, for instance, we'd demonstrated what genes work, that they were encoded on chromosomes, and that the key substance was DNA before we had any idea what the structure of DNA was or how it could possibly do that encoding.
And, of course, evolution theory is a
very high level theory. Which is why it was able to be put on a very solid basis long before the advances in genetics that you cite as fundamental.
Regards,
Ben
was when we could look at the genome of widely different lifeforms and see that the genetic patterns confirm we are related without a doubt.