Just watch a film of a giraffe drinking at a waterhole if this is not obvious to you.
What is your point supposed to be? That giraffe's splay their legs when they drink. I didn't notice any giraffe's failing to drink and dying of thirst. So in what way do longer necks 'force' a giraffe to eat off tree tops, are you saying that Giraffe's have no range of vertical motion in their necks? Giraffe's can eat grass so how can you possibly contend they are forced to eat from the tops of trees. Your knowledge of giraffe's seems as made up as your knowledge of genetics.
Secondly, genetic determinism says that a random genetic mutation does not simply 'influence' a long neck, but rather, as you yourself just finished saying, it _causes_ it. Unavoidably and directly/linearly.
And what is your evidence to the contrary? There is plenty of clear evidence of genetic mutations leading 'unavoidably and directly' to specific morphological changes, including changes in things like vertebra number and character, so why do you think it is unlikely to be directly determining a characteristic like vertebra size?
It may not be the only thing determining the exact adult size of the bone, other factors like diet will obviously influence those things, but genetic changes certainly can directly influence morphological characteristics, to think otherwise is to ignore everything we know of gentics sin Mendel.
'one gene, one trait'
This is by no means a tenet of modern genetics so perhaps your 'genetic determinism' is just one more in a string of strawmen. If you think modern genetics insists on 'one gene, one trait' you obviously haven't read any genetic research for the last 20 years or more. Genetics has moved on since Mendel just as evolution has moved on since Darwin.
All of the facts can be derived by web research, but the conclusions are derived by examining the logical inferences to be reasonably derived from those facts, and for that nobody needs a "source". Asking me to provide one is simply a demand that I use the fallacious, 'argument from authority'.
I think he was just asking you to make an argument rather than a random catalogue of things none of which support, and most of which contradict, your position. You seem to think that a simplistic strawman of how you think 'Genetic determinists' think genetics should operate is the same as a coherent argument against the massive importance of genetics in deteermining form., and it isn't.
To say that genes are merely 'correlated' to the same traits in different taxons is to severely abuse both the word correlated and the genetic literature. When you can show that knocking out or overexpressing the same gene in different species leads to the loss or ectopic development of the same structures then to not infer a causative role is to firmly plant ones head in the clouds.
That little gish Gallop contains much that is erroneous and some that is simply pure nonsense. Are you seriously claiming that there have been no master control genes identified? What about
Pax-6 in eye development?
Which fact takes genetic determinism, along with the RMNS darwinism that depends upon it, and shoots it down in flames.
Except it doesn't at all. The epigentic effects feed into exactly the same molecular pathways as the genes, and frequently only act by modifying the expression of genes. It doesn't matter if other factors modify an organisms morphology, the only ones which will contribute to evolution will be the heritable factors. There is some evidence for the inheritance of certain epigenetic trait
s but the extent to which this calls for a revision of the evolutionary view of the genome is not yet clear. So far epigenomics is more concerned with the determination of specific cell lineages in development rather than evolution.
But 'contributing' is miles away from 'determining', and reiterating [inheriting]is leagues away from generating novelty.
Just saying this rubbish doesn't make it true, and putting words in inverted commas doesn't make a substantial argument. There are hundreds of instances from the literature of specific genetic changes producing specific morphological effects, clear determination. Not being the sole contributing factor to a particular morphology does not stop genes determining that morphology to an unavoidable degree, and certainly not in the context of heritable morphologies.
As to novelty you haven't even begun to make any coherent point.
TTFN,
WK