Re: Date limit set on first Americans

Philip Deitiker <[EMAIL PROTECTED]> wrote:

> In sci.anthropology.paleo,          John Wilkins created a message ID
> news:[EMAIL PROTECTED]: 
> 
> > Philip Deitiker <[EMAIL PROTECTED]> wrote:
> 
> > I did distinguish between evolution and selection (that is, between
> > transmutation and common descent or the one hand and natural selection
> > and secondarily sexual selection on the other).
> 
> I think your looking at the history with Rose colored glasses, probably
> from a more anglo point of view. 

The theory did arise in an anglophonic environment, Phil. But note that
despite the objections of von Baer and others, Germany was a major locus
of evolutionary biology for the next fifty years, and even of an
obsession with selection. Nobody got thrown out for accepting it so far
as I can tell even in the ideal morphology departments.
>  
> > You appear to have garbled something here, Phil. Early in the 20thC,
> > Mendelian genetics was all triumphant - within about 6 years of the
> > initial "rediscovery", it was universally accepted - only a few
> > neo-Lamarckian holdouts existed. What people were opposing WRT Darwin
> > were two items: the efficacy of natural selection, and the idea that
> > use and disuse biases the transmission of traits, both of which were
> > peculiarly Darwinian.
> 
> Muellar caught hell for it (as with a few other things). Ended up in 
> USSR. 

Say what? HJ Müller or someone else? If you'll recall your Soviet
biology, Mendelism-Minchurism was a thought crime there, and Vavilov
died in a Gulag. Mendelism was opposed in post-revolutionary Russia and
most Russian geneticists such as I'urii Filipchecko (Dobzhansky's
teacher) left for Germany or the USA as soon as they could, including
Dobie who worked in Morgan's fly room.
> 
> > But common descent, descent with modification, and biogeographic
> > dsitribution were accepted within a decade of the Origin by all who
> > worked in the disciplines concerned. What was at issue c1900 was
> > Weismannism (sequestration of gametes) and Mendelism put that firmly
> > into lore.
> 
> Right, only after 40 years of complete ignorance by the scientific 
> community. Traces of mendelian inheritance can be traced back to biblical
> times, it was one of the most overlooked phenomena in human history. 
> Elsewhere, the Track record ain't that good. Yes there was a long of 
> foundational work done. 

It is arguable that Mendel was rediscovered or that people who developed
"Mendelian" genetics hooked on Mendel to avoid a priority dispute. In
fact Mendel's ratio had been independently discovered by Pierre
Maupertuis in the 1770s and forgotten.

As for Weismann's Barrier, the debate c 1900 was whether or not
information about the organism's experienced lifecycle was inherited or
not. Most (happily evolutionist) neo-Lamarckians thought that it was,
but this was also Darwin's opinion, so most of them thought they were
quite Darwinian in that respect. "Darwinian" did not equal "Weismannian"
until the 1920s or later, with the reconciliation of "Mendelian"
genetics and selection theory by Fisher and others.

It is my experience that scientists make the worst historians of
science, largely because they garble history into what they think
*should* have happened. Take care here.

The following is much more recent than the period we have been
discussing. You cannot leap from this to conclusions about things that
happened a century earlier.

>   Alot of people who did that work, for example, on cytochrome C and 
> Hemoglobin, are not given credit for finding genetic parsimony between
> pre-gene sequencing phenotypic analysis and the morphological/fossil 
> record. Ever heard of Gerald Braunitzer? 
> From a molecular point of view the mechanics of inheritance struggled
> from the time of Darwin until the 1960s, and some would argue 
> until Arthur Kornberg took his sabatacal and all hell broke out in
> his lab (lol). Alot of the reasoning for this is that people tinkered
> At 1960 you had 2 events converge.
> 1. The definition of DNA structure.
> 2. The codon usage table of tRNAses.
>  
> The reason this took so long is that everyone almost ignored DNA (in the
> cells they were studying) as the hereditary molecules. Though these 
> substances were identified, many considered it cellular junk, continuing
> to focus on protein as putative hereditary material. 
>   Therefore even inside the feild of people looking for the mechanism,
> there were still alot of questions. Many people felt something like 
> Darwinian evolution was occuring however the mechanisms they were 
> proposing were more lamarkian than darwinian, and that in some instances
> things evolved in Mendelian fashion, but it was not altogether clear that
> there was a systematic process controlling it until after the 1930s and
> really not confirmed in the minds of many people until late 1950s. Check
> the literature on this, you will find alot of arguments that would appear
> silly, almost religious, on the issue of hereditary mechanics. Many more
> arguments that are wholey laughable today than arguments that have stood
> the test of time. Mendel did not really theorize the importance of 
> mendelian inheritance, what is remarkable is that Darwin theorized based
> on a very chaotic data set with no experimentation and his summary is
> largely correct. If you compare Darwin's theory with other works of his
> time, randomly, Darwin
> work is so close to being right based on the weakest mechanistic 
> knowledge that his and Wallaces conclusions are almost prophetic. 

What, about use and disuse affecting the frequency of a trait being
inherited? Or about particles from the body of unused energy being
gathered together in the blood (and later in the lymphatic tissues) and
affecting the pangenes? Come one. Darwin's theory had to be trimmed of
his pangenesis to fit Mendelian and later molecular genetics.

Don't misundertake me, as Cheech and Chong might say, Darwin was
amazingly correct on evolutionary matters, and even his selectionist
account of speciation is getting a show these days, but on heredity, the
best he could say and all of what he said that has survived is that it
happens and there are variants.

> I cannot think of a single scientific work out their that has stood the
> test of time and critique they way Darwin's work has. Even Einstein had
> lapses, like his rejection of uncertainty and other works, Einstein often
> tried to overstep the bounds of information he had with complex 
> mathematics. Had uncertainty and Plank's work been proven before Einstein
> began his studies his conclusions might have been different; however,
> without those basic elements would require some foresight, some 
> anticipation about the direction science was going
> For Darwinian thinking requires consideration of uncertainty theories
> before they existed, some sort of mendelian-like genetics scheme before
> it existed. Some sort of logical mechanistic construct (see below) before
> it existed. One had to have some sort of faith that such things were in
> play before any information on these existed. IOW Darwin took a mental
> snapshot of extrapolated chronology of the natural world and 
> recapitulated it into a theory and his snapshot was so robust that it has
> withstood the test of time. Intrinsically he must have understood that
> this process was backed up by some mechanics which would later be proven.

I don't disagree here, but I perfer more measured approaches like
Ghiselin's _Triumph of the Darwinian Method_. It doesn't pay to do
hagiography in science.

> 
> > Geneticists often misunderstand the ideas of evolution, I find,
> > particularly molecular geneticists, who are not taught either
> > phylogenetics or a proper appreciation of the nonlinearity of
> > population genetics over longer periods.
> 
>   But my point is that Kimura is a little like Mendel, his work has been
> out their for 50 years, and is still largely ignored by groups of 
> scientist supposedly experts, in the exact same way that many were not
> fully considering the impact of Mendels or Darwins work. Because of this
> fact many still vainly try to hold onto MREH. Its the same analogy, if
> scientist of postDarwinian/Mendelian accepted these as ultimate truths in
> biological systems, then they would have dropped Proteins and RNA as 
> heritable material and started looking for something that did not have
> the high cellular turn over. The basic problem is many molecular 
> biologist did not get themselves into the logic of what is required to be
> heritable material. 
> 
> 1. Longlived molecules (implicit)
> 2. Maintained          (implicit otherwise how would)  
> 3. Large linkage groups (much larger than proteins are long) 1910-1920s
> 4. Fidelity of replication. 
> 
> Its only when the N15 experiments were done that it was shown that DNA
> outlived the cell cycle, and many people started to flux into the 
> direction of DNA as the heritable material and lifelong stability of DNA.
> As long as protiens were in the picture, many felt that proteins some how
> imprinted themselves on the next generation of proteins, this is a 
> lamarkian idea, but many biochemist did follow this thinking. 
> 
> The point to people like Eric and Inger, Darwins are very rare even in
> his time, most of Darwins peers were shown to be wrong in most of their
> conclusions. In the scope of 21st century most will not survive long 
> enough to reach Darwin's capacity to create a 'composite' theory, and
> even so if you did this you would likely see that theory be proven wrong.
> It is better to take tiny proven steps than try to throw hail Mary 
> passes, and even so as you have stated Darwin had written previous 
> communications. In his day in age there was so many neglected connections
> that needed to be brought together after the data was collected and 
> presented that only a person who had this 'snapshot' of biology in his
> head could do. He worked in a feild that was smaller than a football 
> team.
>   But now we still have this lag effect within science, a molecular 
> geneticist knows that genetic drift may have an impact on the 
> interpretation of his results; however, that individual still does not go
> through all the logical implicits that need to be done.
> 
> I repeat. 
>  1. Is there an expection for MRCAs?
>  2. Is this expection affected by different ploidies.
>  3. Is there an expected distribution. 
> Answer if 1 yes, then 2 yes and 3 yes then
>  4. You have to derive a distribution
>  5. Compare your MRCA to that distribution
>  6. And compare it to others of same ploidy within that distribution.
>  7  Derive significance.
> 
> Many authors get 1, some get 2, with the exception Takahata none have
> extended their interpretations beyond 3.   

I have nothing to say about the foregoing. I wonder why, in this
context, you do.
-- 
John Wilkins - wilkins.id.au
[I]magine a puddle waking up one morning and thinking, "...interesting
hole I find myself in - fits me rather neatly, doesn't it? ...
must have been made to have me in it." Douglas Adams, Salmon of Doubt